As Supplement in the Diets of Rabbits Reared Under Deep Litter System

Anti-Endo Parasitic Effects of Garlic (Allium sativum) as Supplement in the Diets of Rabbits Reared under Deep Litter System

Bello, K.O.1*; Akanji, A.O.2; Irekhore, O.T.3 and Lala, A.O.1

1Institute of Food Security, Environmental Resources and Agricultural Research, Federal University of Agriculture, Abeokuta, Nigeria. 2Department of Animal Production and Health, Federal University of Agriculture, Abeokuta, Nigeria. 3Agricultural Medial Resources and Extension Centre, Federal University of Agriculture, Abeokuta, Nigeria. *Corresponding author: Email: [email protected]

ABSTRACT

This study was carried out to determine anti-endo parasitic effects of garlic (Allium sativum) in the diets of male (buck) and female (doe) weaner rabbits reared under deep litter system. Twenty-four cross bred weaner (8 weeks old) rabbits comprising twelve each of bucks and does were randomly allocated according to sex and feed supplement (conventional anticoccidia drug and garlic) in a 2x2 factorial arrangement. Data were collected on growth performance, faecal microbial population and carcass yield and analysed using ANOVA. Result showed that neither sex nor feed supplement had significant (P>0.05) effect on the growth performance of weaner rabbits. Coccidial load was progressively and completely eliminated in bucks and does from the baseline population of 1680epg and 600epg, respectively with rabbits fed diet supplemented with garlic. Also, does fed diet supplemented with commercial coccidiostat had complete coccidial load elimination from 5200epg at 8th week to the 16th week. Helminthic load (3800epg) recorded with bucks fed diet supplemented with garlic at the beginning of study were totally eliminated at the end of the study (56d). Helminthic load reduced from 6450epg at base line (0 week) to 950epg in the 4th week and was totally eliminated at 56d with bucks fed diet supplemented with the commercial coccidiostat. From the finding of this study, it could be concluded that sex, garlic or conventional anti-coccidiostat had no effect on growth performance and carcass yield of rabbits. However, garlic could be used as natural additive in rabbit production without adverse effects on growth and carcass yield where effective preventive measure for helminth and coccidiosis is paramount in deep litter housing type.

Keywords: coccidiosis; commercial coccidiostat; garlic; helminth,; rabbit

INTRODUCTION

Rabbits, beside their use as laboratory animals are equally reared for a variety of commercial purposes: for their meat and fur (wool). Rabbit meat production among other products has developed into an important industry that attracts high economic returns to the rabbit farmers (Samkol and Lukefahr, 2008; Fanatico and Green, 2012). Often times, the returns are affected by the outbreak of various diseases such as coccidiosis and helminths. Coccidiosis is mainly observed in animals that are managed under intensive production system (Amy, 2005). Coccidiosis is caused by Eimeria spp, and it results in tremendous economic losses in poultry industry worldwide. Currently, it is an emerging disease of increasing economic importance in commercial rabbit production (Licious et al., 1992; Kustos et al., 2003; Szendro et al., 2009).

Healthy rabbits often may be carriers of the organism (Eimeria) causing coccidiosis, but show no symptoms of the disease. The severity of the disease depends on the number of oocysts ingested by the rabbit. The entrance of Eimeria spores into the intestinal and liver cells of young rabbit scauses cells to malfunction and expand in size. Erosion and ulceration occur in the epithelial lining of the intestine, which result in poor absorption of nutrients, electrolyte imbalance, anemia and dehydration of the cells. Consequently, reduced appetite, depression, abdominal pain, retarded growth, diarrhea and pale mucous membranes ensue. Feaces may contain blood or mucous particularly in young rabbit (Amy, 2005). Similarly, helminths or worms are common parasites in the digestive tract of livestock including poultry and rabbit and result in high economic loss or marginal profit (Besier et al., 2003).

Studies have shown that the continuous and indiscriminate use of drugs have caused a growing problem of parasite resistance to conventional commercial treatments (Devendra et al., 2006). However, plant essential oils (and/or active components) can be used as alternatives to conventional commercial anti-hel¬minth and anti-coccidial drugs. Garlic has been used to treat animals that suffer from gastrointestinal parasitism (Guarrera, 1999). There are numerous reports indicating the efficacy of garlic in the prevention and treatment of a variety of diseases and for validating its traditional uses. For instance, garlic has been described to exhibit antimicrobial activity (Chowdhury et al., 1991; Yoshida et al., 1998; Fleischauer et al., 2000), antitumor activity (Sundaram and Milner, 1996; Karasaki et al., 2001), as well as antithrombotic, antiarthritic, hypolipidemic, and hypoglycemic activities (Duraka et al., 2002; Kumar et al., 2003). Moreover, garlic has been reported to be effective against diverse parasites such as Amoeba (Peyghan et al., 2008). However, there is dearth of information on use of garlic supplement in the prevention and control of coccidiosis and worms in male and female weaner rabbits. This is therefore the focus of this study.

MATERIALS AND METHODS

Study location

The study was carried out at the Rabbit Unit of the Directorate of University Farms (DUFARMS), Federal University of Agriculture Abeokuta, Ogun state, Nigeria. The site is located in the rain forest vegetation zone of south-western Nigeria on latitude7˚ 13ʼ 49.46ˮ N, longitude 3˚ 26ʼ 11.98ˮ E and at an altitude of 76m above sea level. The climate is humid with a mean annual rainfall of 1037mm and mean temperature and humidity of 27˚C and 83%, respectively (Obot et al., 2011). This housing was a typical movable, raised floor deep litter type. It has a dwarf wall with the sides covered with chicken net. The size was 1.2m x 3m x 1.7m in breadth, length and height respectively. The experimental pen was divided into 12 cells. It had individual internal cell dimension of 45cm x 60cm that ran both the length of the cage to the left and to the right sides to accommodate 24 rabbits comprising of 12 males (Bucks) and 12 females (Does) at 2 animals per cell; 2 Bucks, 2 females Does, respectively.

Animal Treatment

Twenty-four 8 weeks old cross-bred rabbits comprising 12 bucks and 12 does were used for the study. The animals’ weight ranged between 621.67g and 939.00g. They were divided into four treatment groups according to their sexes and anti-endo parasite feed additives and balanced for weight. Treatment 1 (male rabbits fed with commercial coccidiostat); treatment 2 (male rabbits fed with garlic supplement); treatment 3 (female rabbits fed with commercial anticocciodia preparation); and treatment 4 (female rabbits fed with garlic supplement). There were 6 replicates in all and each animal served as replicate. The rabbits were sourced from a reputable farm within Abeokuta metropolis. The hutch was washed and disinfected and wood shavings were spread as bedding materials. The animals were fed with grower diet that contain crude protein of 18% and Metabolizable Energy (ME) of 11.0MJ/KG and water ad-libitum.

Provide appropriate headings for the methodologies

Rabbits on garlic supplement were fed with grower diet that contained 1.25g of garlic per kilogram of the animal diet (Ari et al., 2012). The treatment groups on convectional anticoccidia diets were administered according to manufacturer recommendation (0.6g per kilogramme feed). Feacal samples were collected from each animal per treatment and replicate. The samples were collected through the rectum using swab stick. The swab stick was inserted into the rectum and rolled round the internal lining of the rectum to gather sample. The clogged was thereafter transferred into the sterile casing for analysis in the laboratory. Samples were collected at the beginning (base line) of the study, mid-stream (4th week = 28d) and at the end (8th week = 56d) of the study.

At the 56th day, 6 bucks and 6 does comprising 50% of the population were sacrificed for carcass evaluation. The live weight of the animal per treatment was taken before slaughtering. The animals were slaughtered through neck decapitation. The fur was removed by singeing, washed and eviscerated. The eviscerated weight was taken and then hot carcass was stored in a refrigerator at about 0˚C - 4˚C for 24hrs. Carcass was prepared according to the norms of the World Rabbit Science Association (Blasco and Ouhayoun, 1996). Then the cooled carcass was weighed and expressed in percentage relative to live weight as described by Lukefahr et al., (1982). Record of cut parts (fore-limbs, hind limbs, loin, head), organs (heart, liver, kidney, lungs) was taken.

Statistical analysis Data generated were subjected to analysis of variance (ANOVA) in 2x2 factorial (randomized complete block design) using SAS (2000). Significant mean at 5% was separated using Duncan's multiple range test (Duncan 1955) as contained in SAS.

RESULTS AND DISCUSSION

Table 1 shows effect of sex and anti-coccidia type on growth performance of the weaner rabbits. Male rabbits (bucks) had the least final weight (859.17g) while the females (does) had the highest (1122.50g). Though bucks recorded higher numeric daily weight gain (4.24g) compared with females (3.92g), final weight which ranged from 859.17g-1122.50g and daily weight gain were not significantly different (P>0.05) among rabbits of different sexes. This observation was consistent with the findings of Ortiz and Rubio (2001) and Bello et al. (2015) who reported that no significant difference in weight gain and final weight of rabbits of different sexes. Also, feed intake and feed conversion ratio were not significant (P>0.05) with sex of rabbits.

Furthermore, the result revealed that all growth parameters measured were neither significant (P>0.05) with convectional commercial anticocciodia nor with garlic inclusion in the diet. These findings were at variance with earlier result of Onu and Aja (2011) on weaned rabbits who reported that herbs controlled and limited the growth and colonization of numerous pathogenic and non-pathogenic species of bacteria in the gut leading to improved translation of feed to meat. Though wide range of herbs are available and used as alternative natural growth promoters (Samkol and Lukefahr, 2008) in animal agriculture, no particular mention was made of the particular herbs as reported by Onu and Aja (2011) therefore the findings could not be compared with garlic.

Ramakrishna et al. (2003) suggested that garlic supplementation enhances the activity of pancreatic enzymes and provides the environment for better absorption of nutrients. Also, Pourali et al. (2010) suggested that allicin in garlic promotes the performance of the intestinal flora thereby improving digestion and enhancing the utilization of energy, leading to improved growth. The variations obtained in this result could also be as a result of mode of administration and the experimental animal species. Feeding garlic in powder and through infusion, resulted in a significant difference (P<0.05) in the final body weight, and feed conversion ratio (Oleforuh-Okoleh et al., 2014) while digestive morphology of rabbit and poultry are not necessarily the same. Demir et al. (2003); Ademola et al. (2005); Javendel et al. (2008) reported significant increase in daily body weight gain and final body weight of birds fed ginger and garlic as growth promoters in broiler diets and observed a pronounced improvement in their body weight gain and feed conversion ratio.

Table 1: Effects of sex and anti-coccidial supplements on growth performance of weaner rabbits reared under deep litter system Sex Feed supplement Parameter Conventional Male Female Garlic Anticoccidial Initial weight (g) 621.67±39.92 939.00±97.48 771.67±103.02 759.00±47.46 Final weight (g) 859.17±37.41 1122.50±90.63 1027.08±86.82 921.00±52.27 Total weight gain (g) 237.50±40.09 219.40±40.09 255.50±44.98 198.00±40.27 Weight gain (g/day) 4.24 ±0.71 3.92 ±0.88 4.56 ±0.80 3.54 ±0.71 Feed intake (g/day) 58.69 ±2.15 60.23 ±0.29 61.04 ±1.08 57.40 ±2.12 FCR 13.84 ±3.64 15.36 ±4.11 13.39 ±3.22 16.21 ±4.12

Table 2 shows the effects of sex and anticoccidia supplementation on carcass yield of rabbit. Eviscerated percentage was 49.45% for buck and 50.17% for doe while it was 50.62% and 48.99% with rabbits fed diets supplemented with commercial anti-coccidiostat and garlic, respectively. However, there was no significant (P>0.05) difference in the carcass yield of rabbits fed with garlic and those fed with conventional commercial coccidiostat. This result was consistent with that of Singh (1997) who reported no significant (P>0.05) difference in carcass quality among different breeds and sex of rabbits. And this gave credence to the result obtained. The result also showed that sex of rabbits had no significant (P>0.05) effect on the relative weights of different cuts. This result was in agreement with the findings of Salroo et al (1989), Farghaly and El-Mahdy (1999), and Sen and Bhagwan (1999) who reported no significance in the carcass traits of rabbits of different breeds.

The result of the organ weights of the two sexes of rabbits is shown in Table 2. There were no significant (P>0.05) differences in organ weights. Table 2 also shows effect of anticoccidial supplementation on carcass performance of rabbit reared under deep litter system. There were no significant (P>0.05) differences in all the parameters of killing out, cut-parts and organs of the experimental animals. These results were similar to that of Sen and Bhagwan (1999) who reported non- significant effect of sex on carcass performance except (P<0.05) alimentary canal and its contents in does. However, the value of the alimentary canal reported by Sen and Bhagwan (1999) was higher than that of others Rao et al. (1978) and Nofal et al. (1995). Equally, the result of this study was consistent with that of Farghaly and El-Mahdy (1999) who reported non-significant effect of sex on different organ weights except liver which was significantly more (P<0.01) in females than males. Furthermore, this result was consistent with the finding of Hossian et al. (2015) who reported no significant (P>0.05) differences in the carcass weight and dressing percentage among the rabbit groups treated with either 0%, 0.25% and 0.5% mixture of garlic powder.

Table 2: Effects of sex and anticoccidial supplementation on carcass Performance of weaner rabbits reared under deep litter system

Sex Anti-endo parasite feed supplement Parameter Commercial Male Female Garlic Drug Killing out

Live weight(g) 1652.08±228.05 1598.50±169.74 1724.08±134.32 1526.50±243.22 Bled weight (%) 72.45±3.26 76.38±1.68 72.08±2.01 76.75±2.95 Plucked (%) 69.10±2.53 70.17±1.45 69.33±1.20 69.95±2.67 Eviscerated weight (%) 49.45±1.06 50.17±0.40 50.62±0.16 48.99±1.02 Cut-Part (%)

Head 7.29±0.52 7.48±0.28 7.32±0.25 7.45±0.53 Fore limb 6.97±0.31 7.22±0.16 7.29±0.26 6.89±0.19 Hind limb 10.99±0.52 10.93±0.40 11.24±0.52 10.69±0.37 Loin 5.10±0.31 5.53±0.39 5.27±0.41 5.37±0.32 Organ (%)

Liver 1.94±0.14 2.25±0.20 2.13±0.23 2.07±0.12 Heart 0.18±0.01 0.17±0.01 0.18±0.00 0.18±0.01 Kidney 0.43±0.02 0.48±0.04 0.48±0.04 0.43±0.03 Lungs 0.49±0.08 0.45±0.05 0.44±0.05 0.50±0.07

Table 3 shows the type of coccidial and helminth organisms present in weaner rabbits fed diet supplemented with commercial anti-endo parasitic preparation and garlic. Eimeria spp was present in bucks fed with both commercial anticoccidial drug and Garlic. Eimeria spp incidence was also recorded in does fed with convectional anticoccidial drug while it was absent in does fed with garlic. This result was consistent with the finding of Piyush et al. (2013) who reported that a number of plants of the local flora are used for curing various ailments and diseases. Garlic was probably responsible for the elimination of Eimeria spp in female rabbits. In addition, the result revealed incidence of Ascaridia galli in bucks fed with garlic but absent among bucks fed with diet supplemented with commercial anticoccidial drug. However, the result revealed incidence of Ascaridia galli (helminth organism) in does fed diet supplemented with either garlic or commercial anti-parasitic preparation. This result was similar to the finding of Sadzikowski et al. (2008), who reported presence of Eimeria species in rabbits from south-eastern Poland. Protozoon from genus Eimeria was recognized in 94.80% of the experimental rabbits’ population. Therefore, Eimeria spp could be the commonest coccidiosis causing organism in rabbit production. Wide range of Eimeria spp probably suggested the reason for occurrence of coccidiosis in rabbits (Amy, 2005).

Table 3: Coccidial and Helminthic types present in weaner rabbits fed conventional anti-microbial drug and garlic supplement

Males (Bucks) Females (Does)

Parameter Commercial anti-endo Commercial anti-endo Garlic Garlic parasitic drug parasitic drug Eimeria spp + + + - Ascaridia galli - + + + + = Present; - = Absent; Eimera spp = Coccidiosis causal organism; Ascaridia galli = Helminthic causal organism

Figure 1 shows population of coccidial organisms (Eimeria spp.) present in bucks and does fed with conventional anticoccidia drug and garlic. The result showed that bucks and does fed with garlic supplement had reduced coccidial load from 1650epg and 600epg, respectively at the beginning of the study to no incidence at the 4th week (progressive load) and 8th week (final load) of the study. This trend therefore revealed the effect of garlic as an anticoccidial that could be used as herbal supplement instead of convectional anticoccidial drug. This finding was consistent with that of Toulah and Al-Rawi (2007) who reported the efficacy of garlic on coccidia infections in rabbits.

The result on the does fed with convectional anticoccidial drug revealed a decline in coccidial population from 5500epg at the beginning to zero (0epg) at the 4th week (progressive load) to 8th week (final load) of the study. Though commercially available antibiotics with proven efficacy had been reported to engender growth and treat sick animals (WHO 2001), they

Figure 1: Coccidial Load of Weaner Rabbits Fed Diet Supplemented with Conventional Anti-microbial Drug and Garlic.

Where MGB.L- Male Rabbits (Bucks) fed diet supplemented with Garlic = 1650epg base-line, MGPRG - Male Rabbits (Bucks) fed diet supplemented with Garlic = 0epg progressive, MGF.L - Male Rabbits (Bucks) fed diet supplemented with Garlic = 0epg final load, MAB.L - Male Rabbits (Bucks) fed diet supplemented with Conventional Anti-Coccidial Drug = 0epg base-line, MAPRG – Male Rabbits (Bucks) fed diet supplemented with Conventional Anti-Coccidial Drug = 0epg progressive, MAF.L – Male Rabbits (Bucks) fed diet supplemented with Conventional Anti-Coccidial Drug = 0epg final load, FGB.L- Female Rabbits (Does) fed diet supplemented with Garlic = 600epg base-line, FGPRG - Female Rabbits (Does) fed diet supplemented with Garlic = 0epg progressive, FGF.L - Female Rabbits (Does) fed diet supplemented with Garlic = 0epg final load, FAB.L - Female Rabbits (Does) fed diet supplemented with Conventional Anti-Coccidial Drug = 5500epg base-line, FAPRG – Female Rabbits (Does) fed diet supplemented with Conventional Anti-Coccidial Drug = 0epg progressive , FAF.L – Female Rabbits (Does) fed diet supplemented with Conventional Anti-Coccidial Drug = 0epg final load, BL – Base-line Load of Helminth organism, PRG – Progressive Load of Helminth organisms, FNL – Final Load of Helminth organisms, EPG - Egg-count Per Gram had also been reported to result in resistance as use increased in both animals and humans while concerns about this have generated many international reports and recommendations (WHO 2000; WHO 2001). Therefore, herbal supplement instead of conventional anticcocidial drug could be explored in rabbit production for prevention and control of coccidiosis. Figure 2 shows population of helminth organism present in the rabbits (bucks and does) fed with conventional anticoccidial drug. The result showed that buck fed with garlic supplement had reduced helminth population. The helminth load of 1650epg at the beginning of the study faced-out at the 4th and 8th week. This could be an indication of the efficacy of garlic to reduce helminth population in rabbit production. This opinion was supported by the findings of Orr (1998) who reported that garlic has an anti-helminthic property. Erol et al. (2008) also reported that garlic has anti-helminthic effect in mice.

The result of female rabbits (does) fed with conventional anti-coccidial drug and garlic was also showed in Figure 1. Both supplements were able to reduce helminth population in does from baseline values of 550epg (garlic supplementation) and 5500epg (commercial drug supplementation). It was also further revealed that does on garlic supplement recorded no helminth population at the 4th and 8th week of the study while those on conventional anti-coccidial drug recorded no helminth population at the 8th week.

CONCLUSION From the findings of this study it could be concluded that sex of rabbits, Commercial anticoccidial drug (coccidiostat) and garlic supplements in diets had no effect on growth performance and carcass traits of rabbit. However, Garlic had potential to reduce coccidial and helminth populations in rabbits without any detrimental effect on performance and carcass and therefore could be utilized as an effective preventive measure in deep litter rabbit rearing production system.

Figure 2: Helminthic Load of Weaner Rabbits Fed Diets Supplemented with Conventional Anti-coccidial Drug and Garlic.

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Chemical Composition and Sensory Evaluation of Cookies Baked from the Blends from the Blends of Soya Bean and Maize Flours

Atobatele, O.B. and Afolabi, M.O.*

Department of Food Science and Technology, Bowen University Iwo, Osun State *Corresponding author: Email: [email protected], [email protected]

ABSTRACT

Cookies were produced from the blends of maize flour (MF) and soya bean flour (SF). The functional properties of the MF and SF were determined using standard methods. Proximate composition, mineral analysis and sensory evaluation of the baked cookies from the flour blends were carried out .The SF possessed good water and oil absorption capacities (310%; 160%) than the MF (169%; 120%); the bulk density of SF (0.52%) was significantly lower than that of the MF (0.80%). The protein content of the cookies increased from 4.5% in 100% maize cookies to 7.00% for cookies with 30% soya bean flour. Substitution of soy-flour also significantly increased the ash (1.00%-1.8%), fibre (0.24%-0.94%) and fat (16.10%- 18.13%) contents of the cookies. However, the moisture and carbohydrate contents decreased with addition of soy-flour while the mineral contents of the cookies samples increased with increase in soy-flour inclusion. Sensory evaluation showed that the cookies samples were not significantly different (p>0.05) in terms of colour, aroma, crunchiness, sweetness, flavour and general acceptability. Cookies produced from the blends of 70% MF+30% SF were the most acceptable of all the samples.

Keywords: cookies; functional properties; maize flour; nutrients contents; soy-flour

INTRODUCTION

Cookie is conventionally a wheat flour-based food product that has become a major component of human snacks in most part of the world. Most other English-speaking countries would call it a biscuit. In North American English a biscuit is a kind of quick bread similar to a scone. Cookies are small, flat dessert treats, commonly formed into a circular shape. They constitute an important component of the diet (Mishra et al., 2012). Cookies are convenient snacks product dried to a very low moisture content taken among young people and adults (Okaka, 1997).

Wheat flour constitutes the basic ingredient for biscuit production because of its gluten proteins, which are not present in flours of other cereals (Kent, 1975). Gluten protein forms elastic dough during baking and gives high organoleptic quality to the finished products (Ihekoronye and Ngoddy, 1985). Unfortunately wheat production is low in Nigeria due to the climatic condition which is unfavourable to the crop leading to the importation of wheat. Nigeria is endowed with many legume crops like soybean (Glycine max) which is cheap and used mostly in the production of milk in most homes. The use of soybean is increasing because of its functional properties and being an economic source of dietary protein and important bio-active components such as isoflavones.

Soy-based foods may provide additional benefits for consumer due to their hypolipidemic and anticholesterolemic properties with reduced allergenicity (Sipos, 1988). Soybeans are considered an inexpensive source of high-quality protein (38%-55%) that are abundantly rich in lysine and essential amino-acid that are deficient in most cereal grains (Dhingra and Jood 2004; Shorgren et al., 2006) but low in sulphur amino-acids, lutein and xanthenes. On the other hand, maize is rich in methionine but deficient in lysine and tryptophan (Mishra, 2012) and low in calcium. Therefore, on the basis of complementary, the combination of maize and soybean flours in food formulations could potentially provide most of the nutrients needed by sub-Saharan Africans. This has stimulated the research into the determination of the chemical composition and sensory properties of cookies baked from maize fortified with soy-bean flour. The objective of this study is to develop soy-maize cookies that will be acceptable to the consumers.

MATERIALS AND METHODS

Materials Dry maize (Zea mays), Soybean (Glycine max) seeds, cooking margarine, Sodium bicarbonate, Sugar,Salt, skimmed milk powder, Condensed milk flavour and Aluminium foil paper were purchased from ‘okesa’ market in Ado-Ekiti, Ekiti state, Nigeria. Master Chef electric toaster oven (Model MC-1957k, people’s republic of china) was used for baking.

Maize flour preparation Maize flour was produced according to the procedure described by Okoruwa (1995). Dried maize kernels was sorted to remove dirt’s and impurities, thereafter it was milled using hammer mill and packaged into high density polyethylene film.

Preparation of soybean flour Soybean flour was produced using the procedure of Smith and Circle (1972). The soy bean seeds were roasted for 2 hours and dehulled. It was dried, milled and sieved and the soybean flour was packed into polyethylene films till used.

Preparation of maize-soy cookies batter 200g of the maize flour was mixed into 150ml of water to produce the maize gel. The paste was mixed thoroughly and heated to 700C for about 3minutes until the gel was formed. The maize gel was added to the remaining200g maize flour and mixed with other ingredients as shown in Table 1.

Table 1: Maize-soy biscuit recipe

Ingredients Quantity Flour (composite) 400g Sugar 120g Margarine 200g Baking powder 5g Milk 5g Egg 80g Maize gel ½ g of maize flour Maize-soy flour blends used for cookies production were as follows: 100% maize flour; 95% maize flour + 5% soy-flour; 90% maize flour + 10% soy-flour; 85% maize flour + 15% soy-flour; 80% maize flour + 20% soy-flour; 70% maize flour + 30% soy-flour

Maize gel formation

Addition of flour

Mixing (Sugar and Margarine)

Addition of other ingredients

Mixing

Shaping/placing on tray

Baking at 120oC for 20 min

Cooling for 15 min

Packaging in polythene bags

Maize-Soy Cookies

Figure 1: Flowchart for the production of maize-soy fortified cookies

Production of maize-soy cookies The ingredients were added to the gel formed and mixed thoroughly into a batter. The batter was rolled on a flat rolling with a rolled on a floured board using pin to a thickness of 0.2-0.3cm. The rolled batter was cut into shapes and arranged on a greased tray and baked at 1500c for 20 minutes (colour changes indicate the cookies are done. The cookies were brought out, cooled and packaged in high density polyethylene bag until used.

Chemical composition of the samples The biscuits and flours were analyzed for moisture contents, crude proteins, Total lipids, Total ashes, Crude fibres, calcium and zinc using AOAC (2005) methods. The carbohydrate contents were determined by difference

Functional properties of the flour The flour (maize and soy bean) was analyzed for bulk density, water absorption capacity and oil absorption capacity using the methods of Okaka et al. (1979) and Lin et al. (1974)

Sensory evaluation The sensory evaluation of the cookies was conducted using 20 member-untrained panellists from different age groups. A 9 point Hedonic scale was used with 1 corresponding to dislike extremely and 9 corresponding to like extremely.

Statistical Analysis Means of triplicate determinations were analyzed using the one way ANOVA with α=0.05 (SPSS 20.0 for windows, USA) to determine statistically differences between the quality attributes of samples with Duncan’s multiple range test.

RESULTS AND DISCUSSION

Functional properties of the maize flour (MF) soy bean flour (SF) The bulk density, water absorption and oil absorption capacities of the biscuit samples are shown in Table 2. These parameters are essential to the industrial application of the basic recipes of MF and SF in cookies production. The bulk density of the MF (0.80g/ml) and SF (0.52g/ml) are significantly different from each other. The bulk density of the SF is relatively higher than the value (0.43g/ml) reported by Apotiola et al. (2013) and in agreement with the value (0.58g/ml) recorded by Akubor et al. (2003). While that of maize is higher compared to value (0.47g/ml) recorded by Edema et al. (2005). The bulk density of the sample describes the degree of compactness of the matrices, an important factor in mixing of ingredients.

The values of the water absorption capacity of the SF (310%) was very high compared to WAC value of maize (170%).The polar groups of proteins, especially ones of amino acids are chiefly responsible for the binding of water and other ingredients (Ihekoronye and Ngoddy,1985). Water absorption capacity is an important pointer to whether the blends can be incorporated into aqueous foods products. WAC is the maximum amount of water that a food material can take up and retain under formulation condition which is related to the dryness and porosity of material (Oyelade et al., 2002) The OAC of MF is (120%) while that of SF is 160% which is similar to values (168.28%) recorded by Edema et al. (2005). SF had higher value of OAC which makes it excellent flour for baked products. The samples were significantly different at 5% significance level (p<0.05). Good oil absorption capacity of flour in baking improves handling characteristics of products (Akubor, et al., 1999). Absorption of oil by baked food products improve the mouth-feel and retain flavour.

TABLE 2: Functional Properties of Maize flour and Soy flour Sample Bulk Density (g/ml) WAC (%) OAC (%) Maize Flour 0.80±0.30 169.33±1.15 120.0±0.00 Soy Flour 0.52±0.10 310.00±10.0 160.0±20.00 Where, WAC: Water Absorption Capacity, OAC: Oil Absorption Capacity Values are Mean±SE (n=3).

Proximate compositions of cookies from maize flour and soy flour Table 3 shows the proximate composition of cookies produced from composite flour (maize and soy-flour). The carbohydrates, proteins, moistures, ashes, crude fibres and total fats of the cookies were significantly different at 5% level of significance. The highest moisture and carbohydrate contents were recorded in sample with 100% maize flour while the highest value for proteins, fats, ash, fibre was recorded in sample containing 70% maize flour and 30% soy-flour. This was due to the high level of protein and fibre in the soy-flour. The high protein content in the soy-bean supplemented cookies would be of nutritional importance in most developing countries like Nigeria where many people can hardly afford high proteinous foods because of their high cost. (Falola, et al., 2011)

Table 2: Proximate composition (%) of soy-maize fortified cookies

Sample Protein Crude Fat Ash Crude Fibre Carbohydrate Moisture Content d d d e a a M100S0 4.59+0.48 16.10±1.00 1.00±0.35 0.24±0.11 71.17±0.30 6.87±0.95 c c c d b b M95S5 5.34+0.00 17.30+1.00 1.30±0.32 0.45±0.15 69.57±0.10 6.02±0.22 b b b c c b M90S10 5.99+0.12 17.60±0.11 1.55±0.50 0.50±0.23 68.41±0.11 5.87±0.19 b b a b d c M85S15 6.39+0.90 17.76±0.57 1.80±0.00 0.85±0.00 67.79±0.66 5.39±0.70 a a a a e c M70S30 7.00+0.85 18.13±0.57 1.86±0.17 0.94±0.37 66.64±0.02 5.45±0.25 Where: M100S0: 100% maize flour, M95S5: 95% maize flour +5% soy-flour, M90S10 : 90% maize flour +10% soy flour, M85S15: 85% maize flour +15% soy flour, M70S30: 70% maize flour + 30% soy flour. Values are means of triplicate determination ± SD. Means within a column with the same superscript are not significantly different at 5% level of significance.

Moisture contents of cookies samples The moisture content of the sample ranged from 5.45% to 6.87% as shown in table 4.. There was significance difference (p<0.05) in the moisture content of the cookies. The result shows that the addition of soy-flour caused a reduction in the moisture content of the cookies with 100% maize cookies having the highest value (6.87%) and 70%maize+30%soy-flour cookies having the lowest value (5.45%). This is similar to the work carried out by Edema et al. (2005) and Rita et al. (2010) in soy and wheat flour composite cake, where there was a decrease in moisture content with increase in soy-flour addition. Smith (1972) reported that the total moisture content of cookies samples should not exceed 14% and 5% was observed the best. The moisture content of these cookies falls within the acceptable moisture level which extends the shelf- life of the product due to low water activity.

Carbohydrate contents of cookies sample The carbohydrate contents of the cookies are shown in table 4 and it ranges from 66.64 to 71.17% with the highest value in 100% maize cookies. This value is similar to 72.1% reported by Adeyeye et al. (2014) in maize-potato flour cookies. This confirms that maize is a major source of carbohydrate and starch. In various energy based snacks and cookies that requires carbohydrate as their based ingredients, maize can be used. The result showed that the lowest value (66.64%) was recorded in cookies made from the flour blends with 30% soy-flour.

Total fat contents of the cookies The total fat contents of the cookies samples (Table 4) baked from the flour blends were significantly different (p<0.05). The values ranged from 16.10-18.13%. The lowest value was observed in 100% maize cookies (16.10%) and this is relatively high compared to the values (9.9%) obtained by Adeyeye et al. (2014) in maize cookies supplemented with sweet potato flour. The highest value was observed in cookies samples with 30% soy-flour and this is due to the high fat content of the soy-flour. The soy-flour used in this research work was not defatted and expected to add cholesterol free high grade lipid in the cookies sample.

Total Ash contents of the cookies The ash contents of the cookies samples ranges from 1.0 to 1.86%. The samples were different at 5% level of significance (p<0.05). Cookies samples from 30%soy-flour had the highest value (1.86%) while 100% maize flour had the lowest (1.0%).Higher ash contents indicated that the mineral content is higher in the soy-flour than in the maize flour. Adeyeye and Akingbala (2014) reported 1.3% for 100% maize cookies. It was observed that there was an increase in the ash contests of the cookies with increasing level of soy-flour in the flour blends.

Fibre contents of the cookies There was a significant difference between the samples at 5% level of significance (p<0.05). The fibre contents of the cookies ranges from 0.24 to 0.94%. The highest fibre value was recorded in the cookies from the flour blends containing 30%soy-flour and the lowest value in the ones baked from 100% maize flour. This was due to the high content of fibre in the soy-flour compared to that of maize flour. Fibre is good for the body as it increases the stool bulk by acting as a vehicle for faecal water. The fibre content consists of hemicelluloses, cellulose and lignin. It contributes to the health of the gastrointestinal system and metabolic system in man.

Protein contents of the cookies The protein content of the cookies ranged between 4.59 and 7.0% with the lowest in 100% maize cookies and the highest (7.0%) in the flour blend with 30%soy-flour. There were significant differences (P<0.05) among the entire samples except for M90S10 and M85S15 which were not significantly different. The increase in protein content was due to the high content of protein in the soy-flour. Therefore, soy-flour served a complementary purpose in increasing the protein content of products based with maize-flour and also helps in providing the limiting protein (lysine and tryptophan) in maize. The increase in protein content agrees with the findings of Olaoye et al.( 2006) and Rita et al.( 2010) but the value is lower than that reported by Mishra (2010) in development and compositional analysis of protein-rich cookies. The soy-fortified cookies will help to alleviate diseases like kwashiorkor that result from higher carbohydrate intake

Mineral contents of the Cookies The zinc contents (table 4) of the samples were significantly different at 5% (p<0.05) significance level. The highest value (5.39mg/kg) observed in sample formulated with 30% soy-flour. The inclusion of soy-bean increases the zinc content at different levels of addition. The lowest value was observed in 100% maize flour (2.40mg/kg). Zinc is important in the body for wound healing. The calcium levels of the cookies samples were significantly different from each other (p<0.05). The highest value (0.40mg/kg) was observed in the sample with 70%maize flour while the lowest value (0.24mg/kg) was recorded in 100% maize. This is because soy-bean is rich in calcium which is very good and necessary for the formation and development of bones.

TABLE 4: Mineral contents of soy-maize fortified cookies. Sample Zinc (mg/kg) Calcium (mg/kg) c c M100S0 2.40±0.10 0.24±0.10 b c M95S5 3.25±0.25 0.24±0.10 a b M90S10 5.28±0.30 0.32±0.10 a b M85S15 5.30±0.15 0.33±0.10 a a M70S30 5.35±0.15 0.40±0.10 Where: M100S0: 100% maize flour, M95S5: 95% maize flour +5% soy-flour, M90S10 : 90% maize flour +10% soy flour, M85S15: 85% maize flour +15% soy flour, M70S30: 70% maize flour + 30% soy flour. Values are means of triplicate determination ± SD. Means within a column with the same superscript are not significantly different at 5% level of significance.

Sensory properties of soy-fortified maize cookies Table 4 shows the mean sensory scores of soy-fortified maize cookies. Cookies sample with 100% maize have the lowest rating for crunchiness while the sample containing 100% wheat flour has the highest rating. The colour of the cookies samples were not significantly different at (p<0.05). The highest colour rating was recorded for the samples baked with 100% wheat flour followed by samples from 70% MF while the lowest rating was observed in samples from 85%MF. Addition of soy-flour improved the yellow colour of the MF to give a more attractive colour. The scores for texture of the samples were not significantly different from each other, but the sample with 70%MF had the next highest rating to the sample from100% wheat flour. The lowest sample rating was observed in sample formulated with 90%MF. Addition of soy-flour improved the texture of the sample up to 30% inclusion level and this may be due to the fact that SF is higher in fat and fats have been associated with crispiness of baked foods which impacted flavour and tenderness to the cookies (Akubor et al., 2003). The aroma of the samples was not significantly different from each-other. The highest score was found in cookies from wheat flour while the lowest rating was found in 100%Maize flour. In terms of general acceptability the cookies formulated from 70%MF and 30%SF has the next highest score to the cookies sample from the wheat flour . The lowest rating was observed in sample formulated with 100%MF.

Table 5: Sensory scores of soy- maize fortified cookies. General Samples Aroma Texture Crunchiness Colour Sweetness appearance b b b a ab b M100S0 5.70±1.71 6.00±1.70 5.20±1.78 5.80±1.87 6.65±1.94 5.70±2.03 b ab b a ab ab M95S5 6.25±1.25 6.50±1.29 6.45±1.00 5.90±2.45 7.05±1.55 6.65±1.41 b b b a ab b M90S10 6.10±1.00 5.55±1.55 6.50±1.20 6.15±2.26 6.70±1.00 5.95±2.11 b b b a b b M85S15 6.46±1.55 5.80±1.84 6.10±1.64 6.00±2.38 5.90±1.46 5.60±2.97 b b b a ab b M70S30 6.35±1.74 6.20±1.93 6.15±2.09 6.30±1.87 6.95±1.03 6.50±1.85 a a a a a a W100 8.00±1.05 7.90±1.66 8.70±1.00 8.00±2.49 7.80±1.22 8.40±1.07 Where: W100: 100% wheat flour; M100S0: 100% maize flour, M95S5: 95% maize flour +5% soy-flour, M90S10 : 90% maize flour +10% soy flour, M85S15: 85% maize flour +15% soy flour, M70S30: 70% maize flour + 30% soy flour. Values are means of triplicate determination ± SD. Means within a column with the same superscript are not significantly different at 5% level of significance.

CONCLUSION Substitution of maize-flour with soy-bean flour has been found to increase the protein, crude fibre, ash, fat and mineral contents of cookies from maize. Cookies with high nutritional content can be produced from different combination of composite flours to alleviate the problems of malnutrition due to low protein intake and also improve the nutritional status of Nigerians.

REFERENCES Adeyeye, S.A. and Akingbala, J.O. (2014). Evaluation of Nutritional and Sensory Properties of Cookies from maize-potato flour blends. African Journal of Food and Nutrition. 6 (9): 61-70 Akubor, P.I. and Ukwuru, M.U. (2003). Functional properties and biscuit making potential of soybean and cassava flour blends’ Plant Foods for Human Nutrition 58: 1-12 Akubor, P.I., Chukwu, J.K. (1999). Proximate composition and selected functional properties of fermented and unfermented Africa oil bean (Pentaclethra macrophylla) seed flour blends. Plant Foods for Human Nutrition. 54: 227-238 AOAC (2005). Official Methods of Analysis 18th Edition, Washington, D.C: Association of Official Analytical Chemist. Dhingra, S. and Jood, S. (2004). Effect of flour blending on functional, baking and organoleptic characteristics of bread. Intl. Journal of Food Science Technology 39 (2): 213-222 Edema, M.O., Sanni, L.O. and Sanni, A.I. (2005). Evaluation of maize-soybean flour blends for sour maize bread production in Nigeria. African Journal of Biotechnology. 4 (9) 911-918 Ihekoronye, A.I. and Ngoddy, P.O. (1985). Integrated food science and technology for tropics. Macmillan Publishers, London, PP 104-105 Kent, N.L. 1975 Technology of cereals with reference to wheat. 2nd ed, Pergamon press, Oxford, pp 194-211 Lin, M.J., Humbert, E.S. and Sosuiki, F.W. 1974. Functional properties of sunflower products. Journal of Food Science 39:368-371 Liu, K. (1997). Soybeans: chemistry, Technology, and Utilization Gaithersburg, MD: Aspen Publishers. pp. 69. Mishra, V., Puranik V., Akhatar N. and Rai G.K. (2012). Development and compositional analysis of protein rich soy- maize flour blended cookies. Journal of Food Processing and Technology 3:182 Okaka, J.C. (1997). Cereals and legumes: Storage and Processing Technology. Data and micro system publishers, Enugu, Nigeria pp. 11-124 Okaka, J.C. and Potter, N.N. (1979). Physiochemical and functional property of cowpea processed to reduce beany flavor. Journal of Food Science 44; 1235-1240 Okoruwa E.A. 1995. Utilization and processing of maize. IITA research guide. 35. p. 29. Olaoye, O.A., Onilude A.A. and O.A. Idowu, (2006). Quality characteristics of bread produced from composite flours of wheat, plantain and soybeans. Africa Journal of Biotechnology. 5:1102-1106. Oyelade, O.J., Sunny I., Otunola E.T. and Ayorinde, A. 2002. Effect of tempeh addition on selected physico-chemical and sensory attributes of the re-constituted cassava flour. Pakistan Journal of Nutrition. 9 (6): 535-538. Rita, E. S., Adiza, S. and Sophia D. 2010. Nutritional and sensory analysis of soya bean and wheat flour composite cake’. Pakistan Journal of Nutrition 9 (8): 794-796 Shorgen, R.L., Hareland, G.A. and Wu YU. (2006). Sensory evaluation and composition of spaghetti fortified with soy flour. Journal of Food Science 71: 428-432 Sipos, E.F. 1988. Edible uses of soybean protein. Presented at Soybean Utilization Alternatives Symposium. Uni. of Minnesota, Feb. 16-18, Minneapolis, MN. Smith, A.K. and Circle, S.J. (1972). Soybeans: Chemistry and Technology. AVI Publishing Company, page 442 Smith, W.H. 1972 Wire-cut cookies. In: Smith, W.H (Ed.). Biscuits, crackers and cookies: Technology, Production and Management. Applied Science publishers, London, pp: 737

Chemical, Anti-Nutritional and Sensory Attributes of Melon Enriched Gari

Abiodun, O.A.1*, Adepeju, A.B.2, Odedeji, J.O.3 and Amanyunose, A.A.3

1Department of Home Economics and Food Science, University of Ilorin, Kwara State, Nigeria. 2Department of Food Science and Technology, Joseph Ayo Babalola University, PMB 5006 Ikeji Arakeji Osun State. 3Department of Food Science and Technology, Osun State Polytechnic, Iree, Osun State, Nigeria. *Corresponding author: Email: [email protected]

ABSTRACT

This study was carried out to determine the chemical, anti-nutritional and sensory quality attributes of melon enriched gari. Freshly harvested cassava was peeled, washed and grated into pulp. Cassava pulp and melon flour were mixed together in ratio 90:10 and 80:20 respectively. The fermented mixture was packaged in a sack and fermented for five days. The fermented mixture was dewatered and samples taken each day, pulverized and toasted. Proximate, mineral, anti- nutritional factors and sensory quality attributes of the gari were determined. Protein content ranged from 0.83-8.86 % in the gari with 20% melon. Fat and crude fibre increased with melon substitution. Carbohydrate contents of the control were higher than melon substituted gari. The pH ranged from 5.5 in control day 5 to 6.6 in enriched gari at 20 % level. Higher potassium and sodium were observed in the control gari while the melon substituted gari had higher values in the calcium, magnesium and phosphorus. Oxalate, tannin and hydrogen cyanide contents ranged from 0.27-1.35 mg/g, 0.24-0.69 mg/g and 0.05-0.18 mg/g respectively in the gari. Sensory evaluation conducted showed no significant differences (p<0.05) in the texture of the control gari from day one to five but there were significant differences (p>0.05) in the texture, aroma and appearance of melon fortified gari. The longer the fermentation of gari fortified with melon, the better it becomes in term of the sensory quality attributes. Enrichment of gari with 10 % melon in day 3 to 5 was more acceptable in terms of texture, appearance and overall acceptability. The protein contents of gari increased with increase in the level of melon flour addition.

Keywords: Cassava, gari, melon, mineral, proximate

INTRODUCTION

Cassava is the chief source of dietary food energy for the majority of the people living in the lowland tropics, and much of the sub-humid tropics of West and Central Africa (Echebiri and Edaba, 2008). The major constraint in the utilization of cassava is the perishability of the roots which results in post-harvest physiological deterioration (Isamah, 2004). According to Nwabueze and Odunsi (2007), cassava plays important role in alleviating African food crisis. Processing of cassava improved palatability, product quality, shelf life and reduce the hydro-cyanide contents of the products (Chijindu and Boateng, 2008). Cassava are processed into chips, pellets, flour, adhesives, alcohol, and starch, which are vital raw materials in the livestock feed, alcohol/ethanol, textile, confectionery, wood, food and soft drinks industries (Knipscheer et al., 2007).

Gari is a fermented dry product from cassava. It is a cheap and popular meal consumed by mixing with boiling water to form paste and eaten with soup in many rural areas of Nigeria especially among the low income earners (Makanjuola et al., 2012). Arisa et al. (2011) reported the use of gari as snack. It could be soaked with cold water and eaten with groundnut, fried fish and coconut with addition of sugar. Gari is a staple food and therefore consists of majorly carbohydrate. The protein content of cassava is low and of poor quality (Oluwamukomi and Jolayemi, 2012), due to this a lot of studies had been conducted to improve the nutritional value of gari using soybean, melon, groundnut and sesame seed flour (Osho, 2003; Oluwamukomi et al., 2005; Oluwamukomi and Jolayemi, 2012; Arisa et al. 2011; Oluwamukomi, 2015). Melon is a cucurbit crop that belongs to the Cucurbitaceae family with protein content ranging from 33.80-39.96% (Abiodun and Adeleke, 2010).

There is limited work on the enrichment of gari with melon seed flour despite its high protein content. However, Oluwamukomi and Jolayemi (2012) enriched gari with combination of soybean and melon seed flour and improvement in the protein contents were reported. Studying the effect of fermentation on gari enriched with melon seed flour could give an in-depth knowledge of possible reactions and contents of the product. Enrichment of gari with high proteineous crop such as melon could improve the nutritional contents of the product. Therefore, objective of this paper was to determine the chemical, anti-nutritional and sensory attributes of gari enriched with gari.

MATERIALS AND METHODS

Materials

Cassava was obtained in a farm at Ada, Osun State, Nigeria while the melon seeds were purchased at a market at Osogbo, Osun State.

Methods

Modified method of Oluwamukomi and Jolayemi (2012) was used for the gari production. The Cassava tubers were peeled manually with a sharp knife, washed and grated in a locally fabricated mechanical grater. The grated wet mash were then packed into sack and allowed to ferment for 1-5 days after which they were pressed and dewatered with a mechanical press. Melon seeds were sorted, cleaned, dried and milled into flour. The cassava and melon were mixed together in ratio 90:10 and 80:20 % respectively. The enriched cassava pulp was dewatered each day and toasted for a period of 5 days. The gari was processed according to the method in Fig. 1.

Cassava

Peeling

Washing

Grating

Mixing (Addition of melon)

Fermentation (1-5 days)

Dewatering

Cake disintegration

Sifting

Toasting

Cooling (at ambient temperature)

Melon enriched gari

Fig. 1: Production of gari enriched with melon flour

Analyses

Proximate, pH, mineral and anti-nutritional contents of the gari was determined using standard methods (AOAC, 1990). Temperature data of the experimental periods (17-21 November 2014) were obtained at Meteorological Agency in Osogbo, Osun State, Nigeria. Eba, a reconstituted paste was prepared by reconstituting it with hot water in ratios 1:2.2 (w/v) after which it was mixed thoroughly with spoon to form stiff dough (Oluwamukomi et al., 2005). The sensory evaluation was determined using untrained 20 panelists. The panelists were requested to examine the dough and score according to their degree of likeness using a 9-point Hedonic scale ranging from 1 (dislike extremely) to 9 (like extremely) (Larmond, 1977). The parameters evaluated were the texture, aroma, appearance and overall acceptability. Statistical analysis

The data were subjected to one way Analysis of Variance (ANOVA) and a difference was considered to be significant at p≤0.05. Means were separated using Tukey’s tests through SPSS software (version16.0) (Abiodun and Akinoso, 2014). RESULTS

The proximate composition of gari enriched with melon is shown in Table 1. Ash contents of gari ranged from 2.20 % in gari enriched 20% melon at day 5 to 2.99% in gari enriched 20% melon at day 3 while moisture contents ranged from 1.07% in day 4 control to 4.89% in day 1 control. Fat contents of gari with 20% melon at day 1 and 2 were not significantly different (p>0.05) from each other but significantly different (p<0.05) from the control and 10 % melon substitution. Crude fibre contents of 10 % (day 5) and 20 % (day 1 and 2) melon substituted gari were significantly different (p<0.05) from other gari samples. Protein contents ranged from 0.83-8.86 % with higher values in 20 % melon fortified gari. Gari with 20 % melon (day 1) was significantly different (p<0.05) from control and other samples.

Table 1: Proximate composition (%) and pH of gari enriched with melon flour.

Crude Sample Day Crude ash Moisture Fat Crude fibre Carbohydrate pH protein 1 2.65±0.03c 4.89±0.07a 0.92±0.04f 2.21±0.02g 0.83±0.02g 88.50±013b 5.9 2 2.89±0.06b 1.33±0.02h 0.94±0.08f 2.86±0.10d 1.07±0.02g 90.91±0.09b 5.9 Control 3 2.34±0.12e 1.10±0.06i 0.89±0.02f 2.80±0.10d 1.04±0.04g 91.83±0.23a 5.8 4 2.34±0.07e 1.07±0.02i 0.90±0.14f 2.46±0.30f 1.73±0.10f 91.50±0.17a 5.6 5 2.60±0.01cd 2.16±0.03f 0.94±0.10f 2.20±0.05g 1.45±0.02f 90.65±0.09b 5.5 1 2.58±0.07d 2.10±0.09f 8.25±0.11e 2.53±0.03e 3.06±0.06e 81.48±0.28c 6.2 2 2.50±0.09d 2.30±0.10e 8.93±0.05d 2.67±0.06e 3.51±0.20e 80.09±0.06c 6.0 10 % melon 3 2.65±0.01c 1.90±0.04g 8.78±0.07d 2.94±0.03c 3.60±0.10de 80.13±0.16c 5.9 4 2.99±0.05a 2.66±0.07c 8.10±0.16e 2.55±0.12e 4.32±0.07d 79.38±0.08c 5.9 5 2.35±0.05e 2.80±0.02b 8.62±0.08d 3.68±0.08a 3.87±0.03d 78.68±0.07c 5.8 1 2.85±0.11b 1.10±0.13i 15.67±0.03a 3.78±0.03a 8.86±0.21a 67.74±0.13d 6.6 2 2.70±0.09c 2.20±0.09e 15.43±0.04a 3.76±0.01a 8.00±0.05b 67.91±0.18d 6.5 20 % melon 3 2.99±0.16a 2.50±0.01d 14.47±0.04b 3.50±0.01b 7.66±0.06c 68.88±0.06d 6.2 4 2.85±0.01b 2.23±0.03e 14.54±0.02b 3.60±0.08b 7.82±0.04c 68.96±0.15d 6.0 5 2.20±0.07f 2.79±0.02b 12.74±0.07c 3.44±0.04b 7.83±0.03c 71.00±0.11d 6.0 Value with the same letter down the column are not significantly (p<0.05) different.

Table 2: Temperature data for the experimental periods.

Temperature (oC) Day Maximum Minimum 1 32.0 23.7 2 31.5 24.2 3 31.0 23.4 4 32.8 21.0 5 33.0 20.0 Source: Metereological agency, Osogbo, Osun State

Carbohydrate contents of the controls at day 3 (91.83 %) and day 4 (91.50 %) were significantly different (p>0.05) from the melon fortified gari. pH values ranged from 5.5 in control at day 5 to 6.6 in gari enriched with 20 % melon in day 1. pH value decreased slightly from day 1 to 5 in the control and gari enriched with melon. Table 3 showed the mineral composition of melon fortified gari. Highest sodium value (59.48 %) was in gari enriched with 20 % melon at day 2 while the least sodium content (20.20 mg/kg) was observed in day 5 of gari substituted with 20 % melon. Potassium contents of gari ranged from 30.00 to 175.00 mg/kg with highest value in control sample at day 2.

Anti-nutritional compositions of gari are shown in Table 4. The gari had low oxalate, tannin and hydrogen cyanide. Likewise, gari enriched with melon had higher phytic acid when compared to the control. The values ranged from 1.17 to 3.54 mg/g. Table 5 showed the sensory properties of melon fortified eba (gari dough).

Table 3: Mineral composition (mg/kg) of gari enriched with melon flour Sample Day Sodium Potassium Calcium Magnesium Phosphorous 1 52.20±0.01b 158.00±0.03b 36.00±0.03d 14.40±0.01de 32.00±0.01c 2 52.40±0.02b 175.00±0.03a 20.00±0.03e 13.20±0.02e 30.00±0.03c Control 3 49.78±0.01c 106.00±0.02c 22.00±0.03e 9.60±0.01ef 24.00±0.02cd 4 50.08±0.03c 102.00±0.01c 28.00±0.05c 11.60±0.02e 16.00±0.10d 5 51.56±0.01b 93.00±0.02c 22.10±0.05e 12.00±0.04e 20.28±0.02d 1 40.89±0.02d 76.20±0.01d 48.02±0.04de 16.00±0.01d 21.60±0.04d 2 47.17±0.01cd 75.90±0.01d 42.17±0.05c 18.00±0.02d 24.15±0.05cd 10% 3 50.40±0.01c 64.80±0.02d 66.00±0.03ab 17.20±0.01d 27.20±0.01c melon 4 47.95±0.02cd 62.00±0.01d 61.09±0.04b 24.56±0.01c 28.00±0.03c 5 49.48±0.01c 51.00±0.04e 54.00±0.02b 25.20±0.02c 22.40±0.03d 1 50.47±0.03c 45.00±0.02e 56.18±0.02b 32.10±0.01a 54.00±0.05a 2 59.48±0.02a 38.96±0.01f 70.10±0.04a 36.00±0.02a 40.10±0.02b 20% 3 51.88±0.02b 40.70±0.01ef 60.00±0.03b 27.60±0.01b 44.40±0.02b melon 4 52.80±0.01b 30.00±0.02f 60.10±0.05b 28.00±0.01b 40.00±0.03b 5 20.20±0.01e 30.78±0.02f 68.00±0.03a 28.80±0.03b 32.00±0.01c Value with the same letter down the column are not significantly (p<0.05) different

Table 4: Anti-nutritional composition (mg/g) gari enriched with melon flour. Sample Day Oxalate Tannin HCN Phytic acid Control 1 0.45±0.10e 0.33±0.14c 0.18±0.13a 1.42±0.16d 2 0.47±0.21e 0.31±0.12c 0.15±0.20b 1.18±0.17d 3 0.33±0.13g 0.24±0.10cd 0.09±0.18c 1.17±0.12d 4 0.54±0.11e 0.29±0.11c 0.08±0.15c 1.99±0.17d 5 0.62±0.12d 0.33±0.13c 0.07±0.16cd 1.76±0.12d 10 % 1 0.63±0.20d 0.43±0.14b 0.08±0.10c 3.14±0.10a g b c melon 2 0.36±0.15 0.39±0.11 0.10±0.11 2.61±0.13c 3 0.35±0.21g 0.44±0.10b 0.08±0.10c 2.01±0.17c 4 0.45±0.19f 0.30±0.18c 0.06±0.11d 2.26±0.12c 5 0.35±0.15g 0.43±0.19b 0.05±0.16d 2.71±0.17b 20 % 1 1.35±0.11a 0.63±0.20a 0.08±0.12c 3.54±0.12a melon 2 0.94±0.10b 0.69±0.11a 0.06±0.09d 2.45±0.10c 3 0.72±0.09c 0.41±0.12b 0.06±0.23d 2.28±0.22c 4 0.63±0.08d 0.35±0.15c 0.05±0.16d 2.26±0.09c 5 0.73±0.09c 0.45±0.16b 0.05±0.12d 2.21±0.19c Value with the same letter down the column are not significantly (p<0.05) different

Table 5: Sensory quality characteristics of eba from gari enriched with melon flour Sample Day Texture Aroma Appearance Overall acceptability Control 1 4.36d 6.22b 7.93a 7.89b 2 4.82d 6.94a 7.86a 7.85b 3 7.67a 6.87a 7.88a 8.16a 4 7.65a 6.95a 7.73b 8.14a 5 7.63a 7.01a 7.62b 8.14a 10 % 1 2.30f 5.32c 2.34f 2.33f melon 2 2.55f 5.12d 3.21e 3.46e 3 6.79b 5.63c 4.50d 6.17c 4 6.86b 5.77c 5.17c 6.26c 5 7.12b 5.73c 5.02c 6.29c 20 % 1 1.90i 4.58e 2.10f 2.10f melon 2 1.95i 4.34e 2.00f 2.18f 3 3.23e 4.39e 3.25e 4.65d 4 5.77c 4.11e 3.67e 5.16d 5 5.87c 4.14e 3.62e 5.19d Value with the same letter down the column are not significantly (p<0.05) different

DISCUSSION There were significant differences (p<0.05) in the ash contents of the control and the melon fortified gari. Ash contents of gari fortified with 10% melon at day 4 and 20 % melon at day 3 were higher than other samples. Control gari was significantly different (p<0.05) from other samples in moisture contents. Moisture contents of control gari and gari enriched with melon were low and within the Codex standard for gari (12 %) (Codex, 2013). Low moisture content is desirable in gari as this reduces the activity of microorganisms in the product. Therefore, low moisture contents of gari signified high stability of the products. Control samples had low fat contents than the melon substituted gari. Fat contents increased with increase in melon substitution. Increase in fat contents may reduce the shelf life of the gari due to its susceptibility to oxidative rancidity (Ihekoronye and Ngoddy, 1985). Addition of 20 % melon increased the crude fibre contents of the fortified gari. Crude fibre contents of gari substituted with 20 % melon flour were higher than the maximum level (3 %) recommended for gari (Ibe, 1981). Values obtained for ash, crude fibre and fat were higher than the values reported for gari by Makanjuola et al. (2012). Mokanjuola et al. (2012) recorded 0.69-0.78% for ash, 0.33-0.44% for fat and 0.48-0.66 % for crude fibre contents of gari. This may be due to the cassava cultivar and melon seed flour used. Protein contents increased with melon substitution but these decreased with days of fermentation in 20 % melon substitution. Protein contents of gari enriched with 10 % melon increased from day 1 to day 4 and there was reduction in the protein value at the 5th day. In the control, the protein contents increased with fermentation days. Increase in protein contents in the control with duration of fermentation was in line with the study of Irtwange and Achimba (2009). Decrease in protein contents with fermentation periods in gari enriched with melon may be due to leaching of the nutrients especially the water soluble protein during dewatering process. Protein content is very important and is one of the reasons for enriching gari with melon so as to alleviate the problem of malnutrition. Carbohydrate contents decreased with increase in melon substitution. This may be due to increase in fat and protein contents of the melon fortified gari. The pH of the gari was slightly decreased from day 1 to 5 in control and gari enriched with melon. The pH of gari enriched with melon was higher than the control samples. The control at day 5 had the lowest pH which indicates higher acidity in the control than the gari enriched with melon. The pH values observed in this study were higher than the values (4.3-4.5) reported for gari by Makanjuola et al. (2012). This might be as a result of low temperature as shown in Table 2. The fermentation temperature for gari reported by Ogueke et al. (2013) was 35-40 oC. However, the temperatures during the experimental periods were lower than these values. Lower temperature may hinder the activities of the fermentating microorganism. The experiment was carried out during harmattan period and invariably affected the rate of fermentation process as this resulted in higher pH values in the gari. This also led to reduced breakdown and utilization of the chemical components of the control and gari enriched with melon. Gari with 20 % melon at day 2 was significantly different (p<0.05) from other samples in sodium content. There were slight increases in sodium contents of melon fortified gari. Potassium contents of the control samples were higher than melon fortified gari and substitution with melon reduced the potassium contents. This showed that the cassava tubers used for the gari product have high potassium contents. Magnesium, calcium and phosphorus contents were higher in melon fortified gari than the control samples. Mineral contents depend on the soil, location, species and cultural practices adopted during planting (Steven et al., 1985). Oxalate and tannin contents of control and gari enriched with melon values decreased with melon substitution and days of fermentation. Hydrogen cyanide (HCN) contents in the control and melon fortified gari were low when compared to the report (4.31-4.77 mg/kg) of Ogueke et al. (2013) and maximum limit (10 mg/kg) recommended for gari (Codex, 2013). Low HCN may be as a result of the cultivar of cassava used for the experiment. Reduction in HCN might be due to the processing methods employed which include peeling, grating, fermenting, dewatering/pressing and toasting. Phytic acid values also decreased with fermentation periods. Slight increase in melon fortified gari samples may be as results of melon added to the grated cassava pulp. Reduction in anti-nutritional contents may be as a result of leaching of the anti-nutrients into the medium during fermentation and dewatering process. As shown in Table 5, texture of the control was not acceptable to the panelists at day 1 to 2 of fermentation due to the high starch contents. But at day 3 to 5 of fermentation, the texture were acceptable with no significant difference (p>0.05) among the control samples. Fortified gari (10 and 20 %) were not acceptable at day 1 to 2 due to the texture of the eba but the textural qualities were improved from day 3 to 5. Aroma of eba from the control were acceptable than the fortified gari. Increase in melon substitution up to 20 % level imparted undesirable aroma on the eba. These may be due to high fat contents in the fortified gari. The appearances of the control eba were acceptable but the appearances became darker with increase in fermentation days. Among the fortified gari dough, appearances of eba from 10 % melon fortified gari at day 3 to 5 were acceptable and significantly different (p<0.05) from 20 % melon fortified gari. Overall acceptability revealed the control sample from day 3 to 5 as the most acceptable followed by enriched gari at day 3 to 5 at 10 % level.

CONCLUSION The objective of this work was to improve the nutritional values of gari with melon flour. Addition of melon to gari increased the protein, fat and crude fibre contents of the gari at both 10 and 20 % levels. The pH of the enriched gari was higher than the control samples and fermentation rate was affected by low temperatures during this experimental periods. Lower anti-nutrients were observed in the control and fortified gari. The reductions in these anti-nutrients were observed with increase in number of days of fermentation. The dough made from gari with 10 % melon at day 3 to 5 were more acceptable to the panelist than the eba made from gari with 20 % melon in terms of texture, flavor and appearance.

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Effect of Sucrose Concentration and Immersion Time on Weight Loss and Shelf Life of Poultry Eggs

Olatunde, G.O*., Akinbomi, V.B. and Adebowale, A.A.

Department of Food Science and Technology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria. *Corresponding author: Email: [email protected], [email protected]

ABSTRACT

Egg preservation is a serious problem in Nigeria, due to challenges of high ambient temperatures, expensive refrigeration facilities and erratic power supply. Osmotic preservation has been successfully used for fruits and vegetables. In this study, osmotic preservation was applied to poultry eggs; the effect of four (4) concentrations of sugar solutions (0.5-2.0 M) and four (4) immersion times (1-4 hour), on weight loss and shelf life of the eggs were investigated. The shelf-life at room temperature (28±2 °C) was determined using the candling method. Data obtained was subjected to two-way analysis of variance to determine significant (P<0.5) difference among the egg samples with respect to weight loss and shelf life. There were significant (P<0.05) differences in weight loss and shelf life of the eggs. Sucrose concentration and immersion time, as well as the interaction between the two factors had significant (P<0.001) effect on shelf life of the eggs. The lowest weight loss of 10% was observed with eggs immersed in sucrose solutions of 0.5 M for 4 hours and 1.0-2.0 M for 1 hour. The control eggs had a shelf life of 28 days while eggs immersed in sucrose solutions of 0.5 M for 2 hours, 1.0 M for 3 hours and 1.5 M for 1 hour had the highest shelf life of 61 days each. This study suggests that osmotic preservation could be an effective method for extending the shelf life of poultry eggs.

Keywords: osmotic preservation; shelf life; shell eggs; weight loss

INTRODUCTION

Eggs are one of the most nutritionally complete foods due to the excellent balance between fats, carbohydrates, minerals, vitamins and especially protein (Watkins, 2007). They are considered the second best source of protein available for human consumption, preceded only by maternal milk (Theron et al., 2003). In recent times, eggs are widely recognized not only as a source of nutrients, they are reported to possess biologically active components and functional properties which can be exploited by pharmaceutical, food processing and cosmetic industries (Mine and Kovacs-Nolan, 2004; Hartmann and Wilhemson, 2001). However, eggs are highly perishable and can lose their quality rapidly (Theron et al., 2003). From the moment of posture to the marketing of egg, quality loss occurs through gaseous exchange and moisture loss with the external environment, through the pores of the shell (Giampietro-Ganeco et al., 2015). The porous shell of the egg allows escape of carbon dioxide and moisture resulting in weight loss. Weight of the egg is one of the quality factors that are important particularly to the producer. There are several categories of quality factors important to the producer, the consumer, as well as the processing industry (Giampietro-Ganeco et al., 2015). Weight of egg has been associated with internal and external quality traits (Alkan et al., 2013). Hence there is need to monitor egg weight vis-à-vis preservation of egg quality.

Several methods have been used for egg preservation; these include one or a combination of means such as refrigeration, sandblasting, water wash with or without an added bactericidal component, coating the shell of eggs with a sterile mineral oil, and the application of heat (Collier and McConnell, 1959). Each of these methods was reported to have one or more disadvantages. Refrigeration was expensive, while sandblasting removed only superficial or gross impurities but does not remove microorganisms effectively. Water wash may carry microorganisms from the exterior to the interior portions of eggs shells while mineral oil is not effective against microorganisms except it is applied hot. Meanwhile, use of heat whether it is applied in the form of a hot mineral oil or otherwise, have the tendency to coagulate the albumen in eggs (Collier and McConnell, 1959). A process was invented by Collier and McConnell (1959) which involved the use of epoxide-water vapour to sterilize the egg shells without spreading infection while killing microorganisms. The process was reported to achieve this at a time and temperature which do not cause coagulation of albumen. Obanu and Mperi (1984) studied the efficacy of three dietary vegetable oils in preserving the internal quality of shell eggs under ambient tropical conditions (25-32 °C). The authors reported that groundnut oil, cottonseed oil and coconut oil significantly (P<0.01) limited diurnal weight losses among other quality parameters of the over 36 days storage period. The preservative effects of the vegetable oils were attributed to their fatty acid component. Al-Hajo et al. (2012) also reported that coating of eggs reduces weight loss and gas (oxygen and carbon dioxide) transport as well as maintenance of albumen and yolk measurements, however, Al-Obaidi et al. (2011) argued that although oiling of eggs is very effective in slowing down reduction in albumen and yolk quality, it does not replace the need for cool storage. Giampietro-Ganeco et al. (2015) assessed the quality of eggs packed under modified atmosphere, they reported that vacuum packaging with oxygen gas and carbon dioxide gas generator were more efficient in maintenance of egg quality based on the values of Haugh’s unit and yolk index.

Preserved egg also known as pidan or century egg is a popular egg product consumed in China and some other South East Asian Countries such as Thailand and Malaysia. Fresh eggs from duck, chicken and quail can become preserved for 4 to 5 weeks after preserving in mixture of alkali, salt, black tea, and metal ions at room temperature (Su and Lin, 1993; Wang and Fung, 1996). Zhao et al. (2014) reported that pickling with alkali and other additives can significantly produce preserved egg with characteristics of rich elements, brown colour, high springiness but low vitamin.

Application of osmotic preservation to shell eggs is limited in literature. Osmotic preservation is a pretreatment method which involves product immersion in a hypertonic aqueous solution leading to a loss of water through the cell membranes of the product and subsequent flow along the inter-cellular space before diffusion in the solution (Sereno et al., 2001). The advantages of osmotic dehydration as a minimal processing technique includes retention of organoleptic qualities of treated food, prevention of loss of flavour compounds, prevention of cell damage that may be caused by excessive heat, retention of colour and nutritional characteristics of raw food items (Moazzam, 2012). Osmotic dehydration has been applied successfully to preservation of fruits and vegetables such as onion and strawberry (Ferrando and Spiess, 2003) and apple (Nieto et al., 2004). It has been used for the improvement of processed fruit quality characteristics such as texture, pigment, vitamin and aroma (Torreggiani and Bertolo, 2001). Akerman (2014) applied a mixture of an edible acid and an osmotic agent to peeled hard-boiled as well as fried eggs, the product was reported to have acceptable aroma and taste. Duduyemi et al. (2015) applied osmotic dehydration to poultry eggs and reported that treated eggs had a shelf life of over 66 days. Application of osmotic preservation to shell eggs appears to be a relatively new area of research, hence the dearth of comprehensive information. Therefore, the objective of this study was to determine the weight loss and shelf-life of poultry eggs using different sucrose concentrations and immersion times.

MATERIAL AND METHODS

Chicken eggs Freshly laid poultry eggs were obtained from MAITO Farms Nig. Ltd., Camp in Abeokuta. Sixteen eggs were used in all and the experiment was conducted in duplicate making a total of 32 eggs.

Sucrose solutions Sucrose solution was used as the osmotic agent. Four concentrations (0.5, 1.0, 1.5, and 2.0 M) of sucrose solution were prepared. For each concentration, four different immersion times (1, 2, 3 and 4 hours) were employed; therefore, each of the four different sucrose solutions was further divided into four parts in 250 ml beakers to make a total of sixteen solutions.

Weight loss of eggs Each egg was weighed separately using a weighing balance and the weight recorded against it. An egg was placed in each of the sucrose solutions. Each egg was withdrawn from each of the sucrose solutions after the appropriate immersion time. The egg was allowed to dry, re-weighed and the value obtained was recorded against the initial weight. The egg that was not immersed in the sucrose solution served as a control. Weight loss was calculated as Weight loss (%) =Wf – Wi x 100 Wi where Wf – final weight of egg, Wi – initial weight of egg

Shelf life of the eggs The eggs were stacked in egg crates and closely monitored to observe any changes in the internal egg quality using the candling method (Kekeocha, 1985) as described below. Candling is a method of testing eggs for internal and external quality, without breaking the shell. It consists of inspecting an egg with a beam of light that makes the interior quality visible. The judgment of internal quality is based mainly on the visibility, ease of movement and shape of yolk. The quality of egg white is judged by the degree of movement of the yolk and by the definition of its outline (Kekeocha, 1985).

A very simple form of candling is placing a candle in a dark room and positioning an egg in front of the flame and looking at the interior quality. In the present study, a light bulb was used because electricity was available. The light bulb was placed in an enclosed box to serve as a candling box. A hole of about 3 cm in diameter was made in the box, sufficient to hold egg sizes ranging from 40 to 70 g. The egg was placed near the candling box hole with the large end of the egg held against the light and with the axis at a 45° angle so that the egg has light shining through it. The egg was twirled so as to observe defects which otherwise might not be observed. The main interior quality points of the eggs were observed as described by (Kekeocha, 1985) and the egg quality was recorded as good (G) or bad (B) against each day. The total number of good days was recorded as the shelf life of the eggs.

Statistical analysis The experiment was conducted in duplicate. Data obtained were subjected to two-way analysis of variance to determine significant (P<0.5) difference among the egg samples with respect to weight loss and shelf life. Multivariate General Linear Model was used to determine the individual and interactive effect of the treatments on the weight loss and shelf life of the eggs. Significant effect was accepted at P< 0.001.

RESULTS AND DISCUSSION

Sucrose concentration, immersion time, as well as the interactive effect of both had a significant (P<0.001) effect on weight loss and shelf life of the eggs. The weight loss of the eggs as influenced by sucrose concentration and immersion time is shown in Figure 1. The weight loss ranged between 10% and 40%. The lowest weight loss of 10% was observed with eggs immersed in sucrose solutions of 0.5 M for 4 h and 1.0-2.0 M for 1 h. The highest weight loss of 40% was observed with sucrose solutions of 1.0 M for 3 h, 1.5 M for 4 h and 2.0 M for 4 h. A steady increase in weight loss with an increase in immersion time was observed with eggs immersed in 1.5 M and 2.0 M sucrose solutions. This suggests that at concentrations higher than 0.5 M, the osmotic gradient favours movement of water from the albumen at a faster rate which also increases with an increase in immersion time, consequently leading to weight loss of the egg. This means that a combination of lower concentration and longer immersion time or higher concentration and lower immersion time is required to reduce weight loss of eggs.

Figure 1: Weight loss of poultry eggs as influenced by sucrose concentration and immersion time.

The consideration of cost involved in using either higher sucrose concentration or longer immersion time will be an important economic factor that will influence the decision of the end user for commercial adoption of this technology. Duduyemi et al. (2015) reported that at lower sugar concentrations (16 and 32 °Brix), weight loss was pronounced than at higher concentrations (43 and 54 °Brix).

It was observed that the eggs tend to float with an increase in sucrose concentration. This is in support of the observation by Duduyemi et al. (2015) that the eggs tend to float as the sucrose concentration increased particularly at 54 °Brix. The floating of the eggs even at low immersion times may be attributed to increase in density of the sucrose solutions with increase in concentration. The floating of the eggs may pose a challenge unless a device is developed to keep the eggs immersed in the solution for the required time.

Figure 2: Shelf life of poultry eggs as influenced by sucrose concentration and immersion time

The control eggs had a shelf life of 28 days while the eggs immersed in sucrose solutions had a shelf life of between 21 and 61 days (Figure 2). Duduyemi et al. (2015) reported that eggs immersed in sucrose solution of 42 °Brix for 30 min had a shelf life of over 60 days. In the present study, the eggs that had the highest shelf life of 61 days were those immersed in sucrose solutions of 0.5 M for 2 h, 1.0 M for 3 h and 1.5 M for 1 h. The shelf life of eggs immersed in 0.5 M sucrose solution were generally low (28-33 days) except for 2 h immersion time which achieved 61 days. At 1.0 M sucrose concentration the shelf life of the eggs was 39-61 days with 4 h and 3 h immersion time having the lowest and highest shelf life respectively. At 1.5 M, the shelf life of the immersed eggs was generally high (50-61 days) except for immersion time of 3 h which gave the lowest shelf life of 23 days. A shelf life of between 43 and 49 days was observed for sucrose concentration of 2.0 M except for immersion time of 3 h which resulted in a shelf life of 21 days. The results show that generally, concentrations higher than 0.5 M favour longer shelf life even though, as stated earlier, sucrose concentration of 0.5 M for 2 h gave the highest shelf life of 61 days among other combinations. It appears from this study that the combination of sucrose concentration and immersion time have an inverse effect on the weight loss and shelf life of poultry shell eggs. This suggests that the higher the weight loss, the longer the shelf life. Furthermore, it suggests that the presence of more water in the egg contributes to spoilage over time, particularly if not properly stored, while reduced water in the egg as indicated by weight loss favour an increased shelf life.

CONCLUSION

Weight loss and shelf life of poultry eggs were significantly affected by the combined effect of both sucrose concentration and immersion time. A combination of lower concentration and longer immersion time or higher concentration and lower immersion time reduced weight loss of eggs. The consideration of cost involved in using either higher sucrose concentration or longer immersion time will be an important economic factor that will influence the decision of the end user for commercial adoption of this technology. The combination of sucrose concentration and immersion time have an inverse effect on the weight loss and shelf life of poultry eggs, suggesting that the higher the weight loss, the longer the shelf life. Osmotic preservation using sucrose solution has potentials for extending the shelf life of poultry eggs.

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Influence of Roasting Techniques on Chemical Composition and Physico-chemical Properties of Sesame (Sesamum indicum) Seed Flour and Oil

Makinde, F.M.1*, Adetutu, A.O.2 and Olorunyomi, G.O.2

Department of Food Science and Technology, Bowen University, Iwo, Osun State, Nigeria. *Corresponding author: Email: [email protected]

ABSTRACT

The most common form of utilization of sesame seed is its roasting, which supplies nutrients to the diet. The objective of this study was to determine the effect of different roasting techniques (using open pan and microwave) on the chemical composition of sesame seed flour and physico-chemical properties of its oil. The raw sesame flour (RSF), open pan roasted sesame flour (ORSF) and microwave roasted sesame flour (MRSF) were analysed for proximate composition, minerals, vitamins, anti-nutritional factors and colour, and the seed oils were analyzed for peroxide and iodine values. The ranges of proximate composition of the flours were: protein 24.3-27.5 g/100g, fat 52.4-59.0 g/100g, crude fiber 3.86- 6.13 g/100g, ash 2.88-3.67 g/100g, carbohydrate 5.4-13.2 g/100g and energy value 552.5 -576.6 kcal/100g. Crude fat, ash, fiber and energy values were significantly higher in MRSF and ORSF compared to RSF. However, protein and carbohydrate values were significantly lower in roasted seeds compared to RSF. Calcium, potassium, phosphorus and magnesium ranged from 439.25-445.02, 342.14-346.77, 427.81-434.77 and 357.38- 364.03 mg/100g respectively with the RSF having the least value. Whereas micro elements such as iron, manganese and zinc ranged from 3.06-6.42, 0.76-1.50 and 2.78-3.62 mg/100g. Thiamine values for RSF, ORSF and MRSF were 40.23, 20.56 and 4.52 mg/Kg respectively; riboflavin values were 21.08, 15.33 and 2.60 mg/Kg respectively while niacin values were and 28.28, 17.30, 2.01 mg/Kg respectively. Roasting in open pan caused significant reduction in phytate and oxalate contents in sesame than roasting in microwave oven. Colour values (L*) of seed flour significantly decreased, whereas a* and b* values increased (P ≤0.05) in ORSF and MRSF compared to RSF. The peroxide values of RSF, ORSF and MRSF were 1.43, 11.21 and 10.02 mEq O2/kg oil respectively while the iodine values were 118.65, 106.44 and 109.71 g I/100g oil for RSF, ORSF and MRSF respectively. The effect of roasting techniques with regard to loss and retention of the nutrients differed significantly (P ≤ 0.05).

Keywords: chemical composition; microwave irradiation; open pan roasting

INTRODUCTION

There has been immense expansion in oil seeds production as a result of increasing demand for food applications. Sesame seeds are small, the size, form and colour vary with the thousands of varieties known (Oplinger et al., 1990). Sesame seeds occur in many colours depending on the cultivar (Langham, 2008). The most traded variety of sesame is off-white coloured. Other common colours are buff, tan, gold, brown, reddish, gray, and black. Through the ages, sesame seeds have been a source of food and oil. Sesame is also grown for its leaves that are used in stews, and the dried stems may be burnt as fuel with the ash used for local soap making, but such uses are entirely subordinate to seed production. Sesame seeds contain 47-50% fat, 25-27% protein, 10-12% carbohydrate, 3.7-6.4% fiber and 3.7-4.6% ash (Makinde and Akinoso, 2013). The seeds are rich in mono-unsaturated fatty acid (oleic acid) and equally rich sources of many minerals such as calcium, phosphorus, manganese, zinc, magnesium and potassium which play vital roles in the body (Makinde and Akinoso, 2014). The seeds also contain B complex vitamins such as niacin, folic acid, thiamine, riboflavin and pyridoxine with some health benefiting compounds such as sesamol, sesamolin and sesamin (Nakai et al., 2003). Phillips et al. (2005) however reported that the seeds contain phytic and oxalic acids, which are anti- nutrients.

The effects of various processing methods in the preparation of oilseeds for human consumption are of utmost importance. Roasting is the most important practice for sesame seed processing in Nigeria and is commonly carried out in open pan over fire with continuous stirring, however, such roasting process takes about 20 min or more, which may adversely affect sesame constituents such as lipids, protein, vitamins and other essential nutrients. Meanwhile, social changes and rapid lifestyle make the working women search for a rapid method for preparing food with microwave oven especially those needed a long time for cooking or roasting. Microwave operation have been applied with increasing success in oil extraction, pasteurization, sterilization, baking, blanching, roasting, cooking, drying, and thawing of different food products (Tan et al., 2001; Mariod et al., 2013) and it is accomplished by means of electromagnetic waves, which penetrate deeply and heat rapidly (Schlegel, 1992). Electromagnetic waves are of electrical and magnetic energy moving together through space. They include gamma rays, x-rays, ultraviolet radiation, visible light, infrared radiation, microwaves and the less energetic radio waves. Although there is no formal definition of the frequency range for microwave radiation, these electromagnetic waves occur in the 300MHz - 300GHz region. Nevertheless, and in accordance with the industrial, scientific and medical (ISM) frequency bands for non- communication purposes, only 915 MHz and 2.45MHz are used for food applications, especially the second due to its worldwide availability (Malheiro et al., 2011). Numerous advantages boosted the use of microwave heating making it in many cases a technique preferred in the processing of food. These advantages include precise timing, rapidity, and energy saving. Moreover, it has been found to be safe; there was no toxicity or adverse effects on microwave treated foods (Miller et al., 1989).

Many researchers have been concerned with the evaluation of the effect of roasting on sesame seeds; these include: anti oxidative activity of roasted sesame seed oil and the effect of using the oil for frying (Fukuda et al., 1986), influence of seed roasting process on the changes in composition and quality of sesame oil (Yen, 1990), oxidative stability of sesame oil prepared from sesame seed with different roasting temperatures (Yen and Shyu, 1989) and microwave roasting effects on the composition and oxidative stability of sesame oil (Yoshida and Kajimoto,1994). However, there is paucity of information on the effect of roasting techniques on chemical composition of sesame seeds. This study was designed to determine the effect of open pan and microwave roasting on the chemical composition of sesame flour and physicochemical properties of its oil.

MATERIALS AND METHOD

Sample materials White sesame seeds (Sesamum indicum L.) were purchased from a local market in Oyo state, Nigeria and transported to the laboratory in airtight polythene bags and stored under cool dry storage (4°C) condition until needed. All the chemicals and reagents used in the study were of analytical grade.

Sample preparation Figure 1 shows the flow diagram for the preparation of the raw and roasted sesame seeds. The seeds were first cleaned by removing extraneous materials such as chaff and stone, after which the unwholesome grains were removed by sorting.

Raw Sesame Flour (RSF) Whole sesame seeds were dehulled by soaking in water (1: 5 w/v) for 4 h at 29 ± 2°C according to the method reported by Mohamed et al. (2007). The ruptured seed coats were then removed by rubbing with palms and washed with water. The dehulled seeds were spread on trays and sundried for 4 h. The dried seeds were milled (Wiley mill, 30 mesh) to obtain raw sesame flour (RSF) and stored in glass container.

Open pan Roasted Sesame Flour (ORSF) The dried dehulled sesame seeds (200g) were roasted in an open iron pan at a temperature of 75 – 85oC with continuous stirring for 20 min until the seeds turned golden brown. After roasting, the seeds were allowed to cool to ambient temperature, milled (Wiley mill, 30 mesh) to obtain open pan roasted sesame flour (ORSF) and stored in glass container.

Microwave Roasted Sesame Flour (MRSF) The dried seeds (200g) were spread on the glass plate of a domestic-size Beko microwave oven (BKMD 1550) capable of generating 1330 watt powers at 2450 MHz. The microwave oven used operates at a frequency of 2450 MHz, with 1330, 931, 665 and 399 watts of output with power levels of high, medium high, medium and defrost, respectively. Samples were microwave treated at medium power level (665W) for 10 min. Each time the plate of the microwave oven contained 200 grams of seeds with a depth of 1 cm. After roasting, the seeds were allowed to cool to ambient temperature, milled (Wiley mill, 30 mesh) to obtain microwave roasted sesame flour (MRSF) and stored in glass container.

Chemical Analysis

Proximate Analysis Proximate analysis was determined following the standard methods of the Association of Official Analytical Chemists (AOAC, 2005). Different samples were analysed in triplicate and the results were reported as means. Total carbohydrate content was calculated from the difference. The energy value was estimated (kcal/100g) following the method as described by Ekanayake et al. (1999). Sesame seeds

Cleaning and Sorting

Soaking (6hr)

Dehulling

Sun drying

Milling Raw sesame flour (RSF)

Roasting in Microwave (10min) Roasting in Open pan (20min)

Cooling Cooling

Milling Milling

Microwave roasted sesame flour (MRSF) Open pan roasted flour (ORSF)

Figure 1. Flow diagram for preparation of raw and roasted sesame flour

Determination of mineral contents

Analysis of potassium content of the samples was carried out using flame photometry, while phosphorus was determined by the phosphovanado-molybdate (yellow) method (AOAC, 2005). The other elements (Ca, Mg, Fe, Zn and Mn) were determined, after wet digestion of sample ash with an Atomic Absorption Spectrophotometer (AAS, Hitachi Z6100, Tokyo, Japan). All the determinations were carried out in triplicates.

Determination of vitamin content Thiamine (vitamin B1) and riboflavin (vitamin B2) were determined by using spectrophotometric method (AOAC, 2005). Niacin content was determined by high performance liquid chromatography (HPLC) according to the method of Ward and Trenerry (1997).

Determination of anti-nutritional compounds Phytate content of each sample was determined according to the method described by Maga (1982). The titration method was used to determine the oxalate content according to Day and Underwood (1986).

Colour value measurement The colour of raw and roasted sesame flour was measured using the Konica Minolta Spectrophotometer (CR- 410, Japan). The flour samples (30g) were placed in the sample holder and the surface colour was measured at three different positions. The colour readings were displayed as L* a* b* values where L (100 = white; 0 = black) is an indication of lightness; a* measures chromaticity, with positive values indicating redness and negative values indicating greenness; while b* also measures chromaticity, with positive values indicating yellowness and negative values indicating blueness. Each sample was analyzed in triplicate.

Determination of seed oil characteristics The seed oils of the samples were extracted using Soxhlet apparatus and the rancidity indices (peroxide value and iodine value) were determined according to Official American Oil Chemist’s Society methods (AOCS, 1985). The peroxide values were expressed as milliequivalents of peroxide oxygen per kg of sample (mEqO2/kg oil) while iodine values were expressed in g I2/100 g oil.

Statistical analysis Determinations were carried out in triplicates and the error reported as standard deviation from the mean. Analysis of Variance (ANOVA) was performed and the least significant differences were calculated with the SPSS software for window release 16.00; SPSS Inc., Chicago IL, USA. Significance was accepted at p ≤ 0.05 levels.

RESULTS AND DISCUSSION

Effect of roasting on chemical composition The proximate compositions of raw and roasted sesame (Sesamum indicum L.) flours are presented in Table 1. Crude fat content increased from 52.37g/100g in RSF to 58.9g /100g in ORSF which is about 13% increase, however in MRSF about 11% increase was observed. The crude fibre also increased by 80% and 59% in ORSF and MRSF respectively compared to RSF. The increase in fat and fiber content in roasted sesame flour is the direct result of the concentration of the constituents during roasting brought about by loss of moisture. Dietary fiber has a number of beneficial effects related to its non- digestibility in the digestive tract (Asp, 1996). Also, fat is important in diets because it promotes fat soluble vitamin absorption and as such sesame seed can be considered as a potential source of vegetable oil for domestic and industrial purposes. The increase in fat content was in good agreement with those indicated by different authors (Damame et al., 1990; El-Badrawy et al., 2007) on roasted peanut.

Table 1: Chemical composition of sesame seeds flour (g/ 100g dry weight) Parameter RSF ORSF MVRF Ash 2.88±0.03 a 3.11±0.04 b 3.67±0.03 c Protein 27.53±0.02 c 24.35±0.06 a 26.31±0.04 b Fat 52.37 ±0.04a 58.97±0.06 b 58.54±0.02 b Crude fiber 3.86 ±0.05a 6.94 ±0.03 c 6.13±0.03 b Carbohydrate 13.18±0.02c 6.61±0.04b 5.38 ±0.05 a Energy (kcal/100g) 552.51a 576.61c 573.40b Values are means ± standard deviation of triplicate determinations. Means within a row not followed by the same superscript are significantly different (p ≤ 0.05). RSF- Raw sesame flour; ORSF- Open pan roasted sesame flour; MRSF- Microwave roasted sesame flour.

Similarly the ash content increased from 2.88 g/100g in RSF to 3.11 g/100g and 3.67 g/100g in ORSF and MRSF respectively. Statistical results indicated that the protein of sesame is in the order of RSF > MRSF> ORSF. The roasting process accelerates the Maillard reactions and subsequently making the protein and its amino acids significantly unavailable for digestion which explains the observed decrease in the protein content of roasted flours (Makinde and Akinoso, 2014). The raw sample is higher in protein than reported values in the literature for other oilseeds, e.g. cashew nuts (22.8%) and cottonseed (21.9%), and that of animal proteins (16.0-18.0%) such as lamb, fish, and beef (Ajayi et al., 2006). Likewise, the protein content of 23.6 g/100g in sesame seed suggests that it can contribute to the recommended daily protein need of adults (Ajayi et al., 2006). This protein value also falls within the recommended daily allowance for children (23.0- 36.0g/100g) as provided by NRC (1989).

The carbohydrate values of MRSF and ORSF were significantly lower than RSF. The loss in carbohydrate due to roasting may be attributed to the role of sugar as a precursor in the production of roasted sesame flavour, where it provide a source of carbon for the production of flavour compounds as a result of Maillard reaction (Koehler et al., 1969). The significant differences recorded in calculated energy values of raw and roasted flours reflect differences in the observed values of other proximate composition as discussed above. The energy values of 552.5, 576.6 and 573.4 kcal/100g for RSF, ORSF and MRSF indicate that 497.7g, 476.9g and 479.6g of these samples would, respectively, provide 2750 kilocalories – an energy value which falls within the range of the daily calorie requirement of 2500 to 3000 kilocalories for adults (Onyeike and Oguike, 2003).

The differences in the mineral composition between raw and roasted sesame samples are presented in Table 2. The predominant mineral was calcium followed by phosphorus, magnesium and potassium. Concentrations of major elements such as calcium, magnesium and potassium in RSF (439.25, 357.38, 342.14 mg/100g) were significantly (P≤ 0.05) lower than ORSF (445.02, 365.95 and 345.98 mg/100g) and MRSF (442.27, 364.03 and 346.77mg/100g). Digestibility of nuts and oilseed are reported to increase by roasting, this might be responsible for the release and increment in some mineral content (Mohini and Eram, 2005). In contrast, roasting affected the iron and manganese contents of the sesame seeds in varying proportions.

Table 2. Mineral composition of sesame seeds flour samples (mg/ 100g dry weight) Sample RSF ORSF MRSF Ca 439.25±1.00a 445.02±0.58c 442.27±0.43b Mg 357.38±0.54 a 365.95±0.51c 364.03±0.63b K 342.14±0.69 a 345.98±0.47b 346.77±0.52c P 434.77±0.97 c 428.46±0.64b 427.81±0.72a Fe 6.42±0.02c 4.98±0.04b 3.06±0.03a Mn 1.50±0.02c 0.87±0.03b 0.76±0.01a Zn 2.79±0.04a 3.07±0.04b 3.62±0.05c Ca/P 1.01a 1.04a 1.03a K/(Ca+Mg) 0.43a 0.43a 0.43a Values are means ± standard deviation of triplicate determinations. Means within a row not followed by the same superscript are significantly different (p ≤ 0.05). RSF- Raw sesame flour; ORSF- Open pan roasted sesame flour; MRSF- Microwave roasted sesame flour

The results also showed that iron content of RSF was 6.42 mg/100g while it reduced to 4.98 and 3.06 mg/100g in ORSF and MRSF respectively. Similarly, the manganese content of RSF was 1.50 mg/100g while 0.87 and 0.76 mg/100g were recorded for ORSF and MRSF respectively. The ratio of Ca/P of the flour samples range between 1.01 for RSF, 1.04 for ORSF and 1.03 for MRSF respectively. The ratio of Ca/P indicated that raw and roasted sesame were good sources of these essential mineral elements as food products containing Ca/P ratio of greater than 1.0 is rated good, while less than 0.5 is rated poor (Nieman et al., 1992). The same value (0.43) was recorded for [K/ (Ca+Mg)] ratio of RSF, ORSF and MRSF. The ratio is of great concern for the prevention of disease known as hypomagnesaemia. The milliequivalent of [K/ (Ca+Mg)] of less than 2.2 is recommended in food sample (Marten et al., 1987); hence consumption of raw and roasted sesame flour may not lead to hypomagnesaemia.

There was significant reduction in vitamin content of sesame when subjected to roasting as presented in Table 3. Riboflavin level decreased by almost 25.40%, thiamine by 47.60% and niacin by 42.4% respectively in ORSF compared to RSF. Similarly, 15.86% riboflavin, 29.70% thiamine and 31.42% niacin were lost in MRSF. Results showed that roasting significantly affected vitamin content of sesame seed. Nutritional substances, such as vitamins and amino acids, may be destroyed or they can be blocked by reactions with other ingredients during roasting.

Table 3. Vitamin content of sesame seed flours (mg/Kg dry weight) Sample RSF ORSF MRSF Thiamine 40.23±0.18c 21.08±0.15a 28.28±0.20b Riboflavin 20.56±0.24c 15.33±0.07a 17.30±0.12b Niacin 4.52±0.03c 2.60±0.01a 3.10±0.02b Values are means ± standard deviation of triplicate determinations Means within a row not followed by the same superscript are significantly different (p ≤ 0.05). RSF- Raw sesame flour; ORSF- Open pan roasted sesame flour; MRSF- Microwave roasted sesame flour

The anti-nutritional factors of raw and roasted sesame flours are presented in Table 4. The values of oxalate were 63.70, 15.16 and 17.50mg/100g for RSF, ORSF and MRSF respectively. Microwave roasting reduced the oxalate content by 72.5% with open pan roasting causing further decrease (76.30%) in the activity of this anti nutrient. The significant loss of oxalate in ORSF and MRSF could be attributed to the destruction of the oxalate at high temperature as oxalates were heat labile. Similar to oxalate reduction activity, roasting process caused significant decrease in phytate level. It was reduced up to 80.23% in ORSF and 68.72% in MRSF. The reduction of phytate concentration is an indication of chemical degradation of phytate to lower inositol phosphates and inositol or cleavage of the phytate ring itself during roasting (Chen and Betty, 2003). The reduction in phytate and oxalate levels could be interpreted as the main reason for the observed increase in the concentrations of some of the minerals during roasting.

Table 4. Anti-nutrient concentration of sesame seed flour (mg/ 100g dry weight) Sample RSF ORSF MRSF Phytate 25.64±0.42c 5.07±0.03a 8.02±0.04b Oxalate 63.70±0.11c 15.16±0.03a 17.50±0.05b Values are means ± standard deviation of triplicate determinations Means within a row not followed by the same superscript are significantly different (p ≤ 0.05). RSF- Raw sesame flour; ORSF- Open pan roasted sesame flour; MRSF- Microwave roasted sesame flour

Effect of roasting on colour Roasting had a significant effect on colour values of sesame flour as presented in Table 5. The colour of sesame flour showed a significant decrease (p≤0.05) in L values of ORSF and MRSF while there was significant increase in a (redness) and b (yellowness) values compared to RSF. This is an indication that the colour of the roasted flour is darker and less saturated than that of the unroasted flour. Colour development depends on the creation of brownish-colored polymeric compound known as melanoidins. Melanoidins are water-insoluble, high molecular weight compounds formed through Maillard browning products that correspond directly to colour development in foods.

Table 5. Colour values of sesame seed flour Samples Attribute RSF ORSF MRSF L* 70.40±0.19c 57.22±0.16a 60.18±0.12b a* -1.13±0.01a 9.20±0.03c 7.86±0.08b b* 12.91±0.07a 28.38±0.15c 26.20+0.05b Values are means ± standard deviation of triplicate determinations Means within a row not followed by the same superscript are significantly different (p ≤ 0.05). RSF- Raw sesame flour; ORSF- Open pan roasted sesame flour; MRSF- Microwave roasted sesame flour

Effect of roasting on oil constants The peroxide and iodine values of raw and roasted sesame seed oil are presented in Table 6. The chemical properties of oil are amongst the most important properties that measures of oil quality. The lowest peroxide value was the characteristics of oil extracted from RSF (1.43 mEqO2/kg oil) while 10.05 and 11.40 mEqO2/kg oil were recorded for the MRSF and ORSF respectively. The peroxide value is a measure of the content of hydroperoxides, which are primary oxidation products. They are extremely unstable and decompose via fission, dehydration, and formation of free radicals to yield a variety of chemical products, such as alcohols, aldehydes, ketones, acids, dimmers, trimers, polymers, and cyclic compound (Tan et al., 2001) including the volatile compounds responsible for off-flavours in seed oils and olive oils. The oxidation of oil seeds accelerates during microwave heating, which leads to the formation of reactive radicals which account for the higher peroxide value compared to RSF. This is an indication of decreased stability and increased rancidity of the oil during microwave heating. Yoshida et al. (1990) have also reported an increased peroxide value during microwave treatment of linseed, soybean, corn, olive and palm oil. Meanwhile the only condition for obtaining the highest peroxide value for ORSF was as a result of roasting the seeds in air with higher humidity. The properties of fat may depend on the moisture content contained in it. Increased water content in the material subjected then to thermal treatment contributes to the formation of smaller quantities of bronze substances, which significantly influence the nature of oxidative changes in fat (Yoshida et al., 1995). Fresh oils have values less than 10 mEq O2/kg oil, however, it has been shown that oils become rancid when the peroxide value ranges from 20.0 to 40.0 mEq O2/kg oil (Ajayi et al., 2006).

Table 6: Characteristics of oil extracted from sesame seed. Samples Parameters RSF ORSF MRSF Iodine value (g I/100g oil) 118.65±0.48c 106.44±0.15a 109.71±0.16b Peroxide value (mEqO2/Kg oil) 1.43±0.03a 11.21±0.04c 10.02±0.03b Values are means ± standard deviation of triplicate determinations Means within a row not followed by the same superscript are significantly different (p ≤ 0.05). RSF- Raw sesame flour; ORSF- Open pan roasted sesame flour; MRSF- Microwave roasted sesame flour

Iodine value of RSF was 118.65 g I/100 g oil while 106.44 and 109.71 g I/100 g oil were recorded for the ORSF and MRSF respectively. The iodine number of oil is the number in grams of iodine which can be absorbed by 100g of the oil, and it measures the amount of unsaturated fatty acids occurring in the oil. Iodine does not react readily with the double bonds of oil/fat molecule and the quantity of iodine absorbed by oil is an index of its degree of unsaturation. The RSF oil had the highest iodine value indicating a high degree of unsaturation. This loss of the unsaturation degree in ORSF and MRSF as a result of roasting due could be due to the degradation of the natural antioxidants (tocopherol, sesamin and sesamol) of sesame oil. Moreover, it has been reported that the oxidative degradation of the oil during microwave heating depends on its natural antioxidant content (Dostalova et al., 2005). However, it is imperative to note that the quality of oil depended on power, time and temperature of microwave treatment as longer microwave heating times, temperatures and high-power setting resulted in a greater degree of oil deterioration (Tan et al., 2001).

CONCLUSIONS

This work has shown that significant improvement in the nutritional value of Sesamum indicum can be attained through roasting of the seeds prior to conversion into flour. However, open pan roasting offers greater reduction of inherent anti nutrients (phytate and oxalate), over its microwave counterpart. Extracted oil from open pan and microwave roasted seeds showed similar characteristics but significantly different from that of raw sesame oil, indicating that quality of oil is affected by roasting treatment. The present study indicates that microwave roasting can be used as a desirable energy - saving alternative to open pan roasting technique of sesame seeds; however, further study is needed to evaluate the cost of this process, as well as the technical feasibility of setting up an industrial process.

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Qualitative Analysis. 5th Ed. New Delhi, India: Prentice Hall Publications. 701. Dostálová, J., Hanzlík, P., Réblová, Z. and Pokorný, J. 2005. Oxidative changes of vegetable oils during microwave heating. Czech Journal of Food Sciences 23:230–239. Ekanayake, S., Jansz, E.R. and Nair B.M. (1999). Proximate composition, mineral and amino acid content of mature Canavalia gladiata seeds. Food Chemistry 66: 115-119. El-Badrawy, E.E.Y., El-Zainy, A.R.M., Shalaby, A.O. and El-Sayed, N.Y. (2007). Effect of microwave roasting on chemical composition of peanut seeds and comparing it with the ordinary roasting process. Proceeding of Annual Conference Credit and Accreditation, Faculty of Specific Education, Mansoura University, Egypt, 938-957. Fukuda, Y., Nagata, M., Osawa, T. and Namika, M., (1986). Chemical aspects of the antioxidative activity of roasted sesame seed oil, and the effect of using the oil for frying. Agricultural and Biological Chemistry 50(4): 857-862. Koehlar, P., Mason, M. 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Knowledge, Attitude and Practice of Mothers Regarding Iodized Salt in Selected Communities in Ibadan, Oyo State

Esan Olukorede T.1 and Fadupin Grace T.2

1Home Economics and Food Science Department, University of Ilorin, Ilorin. Nigeria 2Human Nutrition Department, University of Ibadan, Ibadan. Nigeria *Corresponding author: Email: [email protected]

ABSTRACT

Iodine deficiency disorder (IDD) is a public health problem in developing countries such as Nigeria and universal salt iodization has been chosen to be the basic measure for sustainable elimination of IDD. This study evaluated the knowledge, attitude and practice of mothers regarding iodized salt in selected communities in Ibadan. The study was carried out among 250 purposively selected mothers of under-5 children in three randomly selected local government area of Ibadan, Oyo state. Nigeria. A structured interview schedule was used to obtain relevant information from the respondents. Data were analyzed using Statistical Package for Social Sciences version 15. Level of significance was 5%. Chi square test was used to test for the relationship between variables. Less than a third (22.1%) had less than secondary education. About52%were either full housewives or petty traders. Seventy nine percent have heard about iodized salt but only 48.4% know the main sources of iodine was iodized salt while 51.6% had inadequate knowledge about the sources of iodized salt. Most of the mother (58.0%) had positive attitude towards iodized salt. More than half of the mothers (53.2%) had poor practices regarding iodized salt. Knowledge about iodized salt was found to be significantly associated with usage of iodized. There was association between the attitude and consumption of iodized. The study showed that most mothers with children under 5 years in Ibadan had positive attitude towards iodized salt, however, their knowledge and practices were inadequate.

Keywords: attitude; iodized salt; knowledge; mothers of under-5; practice

INTRODUCTION

Iodine is required during the synthesis of thyroid hormones, which plays a determining role in the process of the early growth and development of most organs, especially the brain, in human subjects during fetal and early post natal life (Sebotsa et al., 2009). Iodine deficiency disorders (IDD) has been adopted to describe the spectrum of effects of iodine deficiency that include goiter, endemic cretinism, psychomotor delay and increased pre- and post-natal mortality (Takele et al., 2003). The consequences of iodine deficiency can be found at all stages of life, but mostly in vulnerable groups such as children, adolescents and pregnant women (Dragan et al., 2006)

Globally, Iodine deficiency disorders (IDDs) are associated with many thyroid related diseases including hypothyroidism, hyperthyroidism, goiter and cretinism and also inherit real risk of coronary artery diseases, autoimmune disorders, psychiatric disorders, cognitive impairment and cancer. (Patrick, 2008, Verheesen and Schweitzer, 2008, Simone, 2010). Iodine deficiency disorders remain a significant public health problem in many countries. Recent studies have shown that over 200 million people in the world are affected by the most visible symptom of iodine deficiency disorder (Takele et al., 2003). Globally, 30% of the world’s population is affected by iodine deficiency disorders and more than 150 million people are affected in Africa alone. (Takele et al.,2003). According to World Health Organisation estimates, goiter is present in 28.3% of the African population and approximately 25% of the global burden of iodine deficiency as measured by disability-adjusted life years (DALYS) occurs in Africa (Okosieme, 2006). Lar et al (2007) reported that goiter rate in Nigeria was between 15% and 59% which still makes it a public health problem. The prevalence of iodine deficiency disorders was established by measurement of total goiter rate and the total goiter rate for Nigeria was put at 20%, thereby generating public health concern (Egbuta et al., 2002).

The most effective preventive measures against iodine deficiency disorder is universal salt iodization recommended by the International Iodine Deficiency Disorders Elimination Program (Okosieme, 2006). All food-grade salt, used in household and food processing should be fortified with iodine as a safe and effective strategy for the prevention and control of iodine deficiency disorders in populations living in stable and emergency settings. (WHO, 2014).This study is therefore necessary to provide information on the knowledge, attitude and practice of mothers regarding iodized salt in Ibadan, Oyo state.

MATERIALS AND METHODS

Provide sub-heading for this section The descriptive study was carried out in three randomly selected local governments’ areas (LGA) which include: Ibadan North Local Government, Ido Local Government and Ibadan South-East Local Government. A community was selected from each of the selected LGA using simple random sampling technique. A systematic purposive sampling technique was used to select households consisting of mothers with children under 5 years of age. The sampling unit was household and after selection of first household by lottery method, every 4th household that have mothers with under 5 (U-5) children was selected for the assessment of knowledge attitude and practice of mothers regarding iodized salt and iodine deficiency disorders. Eighty three percent of people who are familiar with iodized was used as prevalence and 95% confidence interval was used to get minimums sample size. Using formula according to the Food and Agricultural Organization (1995) a sample size of 216 subjects was gotten which was rounded up to 250 subjects that were included in the study. A pretested and validated structured, interview schedule was used to collect information on the socio-demographic characteristics, knowledge, attitude and practice of mothers on iodized salt and iodine deficiency disorders. Knowledge was assessed using ten questions relating to iodine deficiency disorder and iodized salt, every right answer was scored 10 marks and every wrong answer was scored zero. Knowledge score was calculated for each respondent, a score of 50th percentile or less were categorized as inadequate knowledge while knowledge score above 50th percentile were categorized adequate knowledge. To assess respondents attitude towards iodized salt, 5-point likert scale was constructed by asking respondents series of positive and negative statements to reflect underlying attitude in a variety of ways. Attitude statements had five possible responses; strongly agree, agree, uncertain, strongly disagree, and disagree. For positive statements, response including strongly agree and agree were categorized as positive attitude while strongly disagree, disagree and uncertain were categorized as negative attitude and vice versa. Every right answer was scored twelve and half and every wrong answer was scored zero. Marking the total attitude score summed up to hundred, those with score greater than 50th percentile were rated to have positive attitude and those with score of 50th percentile and below were rated to have negative attitude. Practices were assessed by asking questions about the cooking practices and habit of purchase of iodized salt. Every good practice was scored 7.7 marks and wrong/ bad practice was scored zero. The practice score was calculated for each respondent out of a hundred. Practice score above 50th percentile were labeled good practice while practice score of 50th percentile and below were labeled poor practice.

Statistical analysis Data obtained were analyzed using SPSS windows version 15. The level of significance was set at 5%. Descriptive statistics was used to summarize the continuous variables while Chi square test was used to evaluate the relationship between variables.

RESULTS

Table 1 shows the socio demographic status of the respondents. The mean age of respondents was 28years, most of the mothers were petty traders, 11% of the respondents had no formal or primary education and a high percentage (71.7%) of the respondents earned less than #15,000 monthly.

Knowledge of respondents on iodized salt and iodine deficiency disorder Table 2 shows the knowledge of respondent. Majority (51.8%) of the respondents lacked knowledge of what iodine is; only 48.4% indicated that iodine is a mineral and knew that iodized salt is the main source of iodine in their foods, Also, 79.4% of the respondents indicated that they have heard about iodized salt and 48.5% of the respondents identified iodized salt through labeling, 28.7% identified iodized salt through the taste, 17.8% identified through texture while 5.0% identified it through colour.

Attitude of Respondents Regarding Iodized Salt Table 3 shows the attitude of the mothers. Some (48.4%) usually buy iodized salt and less than half of the respondents (47.6%) disagreed that iodized salt incure more cost,42.4% of the respondents .disagreed that food cooked with iodized salt is less delicious,48.0% agreed to giving children iodized salt. More than half of the respondents (57.8%) agreed to using iodized salt exclusively.

Table 1: Socio-demographic characteristics of the respondents.

Group Number Frequency Percentage Age

16-25years 97 38.7 26-30years 107 42.8 Above 35 years 46 18.5 Place of Residence

Urban 84 33.6 Sub-Urban 82 32.8 Rural 84 33.6 Religion

Islam 77 30.6 Christianity 167 66.9 Traditional 6 2.5 Highest Level of Education

No Formal Education 28 11.1 Primary School 40 16 Secondary School 78 31.1 Tertiary Education 104 41.6 Employment Status

Full Housewife 37 14.6 Petty Trader 121 48.6 Employed 92 36.9 Household Income Per Month

Less than N5,000 73 29.2 N5,000-N10,000 69 27.5 N11,000-N15,000 37 15 N16,000-N20,000 23 9.2 Above N20,000 48 19.2 Type of Housing

Brick 30 12 Concrete 220 88 Total 250 100

Practice regarding iodized salt Table 4 shows that less than average of the respondents (48.4%) indicated they usually read the label of the packaging during purchase of salt and more than average (79.9%) of the respondents obtained their salt from local shops. Table 5 shows that more than half (51.6%)of the respondents had inadequate knowledge about iodine and iodized salt,58% of the respondents had positive attitude regarding iodized salt,53.2% of the respondents had poor practice towards iodized salt.

Table 2: Percentage Distribution of respondents on knowledge regarding iodized salt and iodine deficiency disorders Parameter Frequency Percentage What is Iodine?

Mineral 121 48.4 Main source of iodine in your foods Iodized salt 121 48.4 Have you heard about iodized salt? Yes 199 79.4 No 51 20.6 How do you identify iodized salt? Labeling 121 48.5 Taste 71 28.7 Texture 45 17.8 Colour 13 5 Effects of iodized salt?

At least one 95 38.1 Two or more 41 16.2 No idea 114 45.7 Do you know that iodized salt prevents IDD? Yes 138 55 No 103 41.3 No Response 9 3.7 Have you ever seen iodized salt? Yes 208 83.2 No 42 16.8 Is iodized salt sold in your locality? Yes 189 75.6 No 61 24.4 Is iodized salt important for children? Yes 201 80.6 No 49 19.4 Is iodized salt important for everybody? Yes 193 77.3 No 57 22.7 Total 250 100 IDD: Iodine deficiency disorder

Table 3: Attitude of Respondents Regarding Iodized Salt Variables Agree Uncertain Disagree Do you buy iodized salt? 121 (48.4$) - 129 (51.6%)

Iodized salt incure more 21(8.4%) 110(44.0%) 119(47.6%) cost than its benefits

Food prepared with iodized salt taste less delicious than 87(34.8%) 57(22.8%) 106(42.4%) non-iodized salt does

Giving iodized salt to 120(48.0%) 50(20.0%) 80(32.0%) children is good for them

Iodized salt should be 171()68.4% 66(26.4%) 13(5.2%) handled and stored properly

Iodized salt needs greater 152(65.0%) 71(30.3%) 11(4.7%) care to store

Using iodized salt 144(57.8%) 77(30.6%) 29(11.6%) exclusively

Every member of my family should use iodized salt 141(56.5%) 80(31.9%) 29(11.6%) exclusively

Iodine should be added to table salt for preparing 205(82.0%) 23(9.2%) 22(8.8%) meals

DISCUSSION

The results of this study showed that more than average (51.6%) of the respondents had inadequate knowledge of iodine and iodized salt but more than half of the respondents were aware that iodized salt is important for children and pregnant women and most of the respondents were aware of its health benefits. A similar result was reported by Dragan et al (2006) who found that the participants were not well informed about the importance of using iodized salt in prevention of iodine deficiency disorders. It was reported that only half of the participants in Dragan’s study (49.1%) knew of iodine deficiency disorders. Most of them were familiar with goiter (70.2%) while only 14.5% are able to single out stillbirth as a consequence of iodine deficiency disorders Similar result was also reported by Gul Nawaz Khan et al, (2012) that the respondents were not well informed about the advantages of using iodised salt in prevention of IDDs. Most of them were familiar with goiter, while 17.1% of the respondents in Sindh and 42.2 % in Punjab mentioned that use of iodised salt helped to prevent goiter. With regard to the factors that influence the use of iodized salt and iodine consumption, the results showed that literacy status and thorough awareness of IDD influence positively the usage of iodized salt (Okosieme, 2006).. The result was contrary to the survey conducted by Palafox et al (2002)among school children, mothers/caregivers (of 1-5 years old children), pregnant and lactating women in selected Philippine, all the three groups of respondents were more knowledgeable on the sources of the micronutrients than on the deficiency diseases arising from lack of a particular nutrient The study further revealed that more than half (58.0%)of the mothers had positive attitude towards iodized salt and agreed that iodized salt does not incure more cost than its benefits and it has no negative effect on the taste of food. Regardless of the fact that not all the respondents are aware of iodine and its deficiencies, 82.3% of the respondents agreed to iodine being added to table salt and this finding is similar to the study of Takele et al(2003) conducted among the food caterers and shopkeepers which showed that half of the caterers (50.0%) and 80.0% of the shopkeepers had favorable attitude towards iodized salt. Study on patients with hyperthyroidism in Free State of South Africa indicated that the patients agreed to iodine being added to salt (Sebotsa et al., 2009). The results of this survey indicates that despite the inadequate knowledge and positive attitude of the respondents toward iodized salt, 53.2% of the respondents had poor practices towards iodized salt and this is similar to the study conducted by Takele etal (2003) who reported that higher education level was significantly associated with good practices (no habit of sunlight exposure of salt) (P = 0.002), better education may influence good practices therefore, the poor practice recorded in this study may be linked to the inadequate knowledge of the mothers and this may suggest the need for more awareness and better education on iodine, iodized salt and the right practices in iodized salt usage because 80% of the respondents in this study generally add salt to food at the early beginning and in the middle of cooking their foods, more than half (54.0%) of the respondents stored their salt in the plastic bags in

Table 4: Practice of Respondents Regarding Iodized Salt Parameters Frequency Percentage What Brand name of salt do you use?

Anapuna Salt (Iodized salt) 88 35.2 Dangote Salt (Iodized salt) 77 30.8 Mr Chef (Iodized salt) 40 16 Puno Salt (Non iodized salt) 45 18 Why do you choose the brand?

Taste 91 36.3 Cost 31 12.5 Availability 80 32.1 None 48 19.2 Salt brand iodized salt

Yes 121 48.4 No 129 51.6 Reading product label

Yes 121 48.4 No 91 36.4 Cannot read 38 15.2 Source of salt

Shops 200 80 Street vendors/hawkers 48 19.2 Salt producers 2 0.8 Frequency of purchase

Every week 84 33.6 Every month 105 42 Every 2 months 32 12.8 Every 3 months 20 8 Once in 6 months 9 3.6 Quantity purchased

Small bag 131 52.4 Big bag 26 10.4 Tins/other household measures 93 37.2 Time of adding salt to food

Late end of cooking 48 19.2 In the early beginning 75 30 In the middle of cooking 127 50.8 Expose of salt to sunlight

Yes 25 10 No 225 90 Types of storage

Open container 55 22 Container with hole at that op 31 12.4 Glass container with lid 33 13.2 Plastic bag in which the salt was bought 131 52.4 Type of container

Moist container 12 4.8 Dry container 238 95.2 Reasons for buying iodized salt

They are the type salt available in the locality 129 51.6 Doctor’s recommendation 70 28 Shop assistant’s recommendation 51 20.4 Total 250 100

TABLE 5: Knowledge, attitude and practice of respondents in each community. Abadina Oranyan Apete Total Knowledge

0 -50% 34(40.5%) 53(63.9%) 42(50.6%) 129(51.6%) (Inadequate) Above 50% 50(59.5%) 30(36.1%) 41(49.4%) 121(48.4%) (Adequate) Total 84(100.0%) 83(100.0%) 83(100.0%) 250(100%) Attitude

0-50% 33(39.3%) 26(31.3%) 46(55.4%) 105(42.0%) (Negative) Above 50% 51(60.7%) 57(68.7%) 37(44.6%) 145(58.0%) (Positive) Total 84(100.0%) 83(100.0%) 83(100.0%) 250(100%) Practice

0-50% (Poor) 48(57.1%) 29(34.9%) 56(67.5%) 133(53.2%) Above 50% 36(42.9%) 54(65.1%) 27(32.5%) 117(46.8%) (Good) Total 84(100.0%) 83(100.0%) 83(100.0%) 250(100%) which the salt was bought which indicates a poor practice among the respondents because iodine is a volatile substance which is lost when salts are not properly stored. There was a significant relationship between knowledge of mothers and iodized salt usage, there was also a relationship between some socio demographic characteristics (level of education, household income)of respondent and usage of iodized salt and this agreed with the study conducted by Van et al(2000) that with regards to the influencing factors on usage of iodized salt and intake of iodine, literacy status and thorough awareness on iodine deficiency disorders of the respondents influences positively the usage of iodized salt.

CONCLUSION

The result of the survey showed that most mothers with children under 5 years in Ibadan had positive attitude towards iodized salt, however, their knowledge and practices were inadequate and this might be the characteristics of women in other parts of Nigeria. This indicates the need for continuous and intensive public enlightenment campaign and effective monitoring regarding proper use and storage of iodized salt and the consequence of its deficiency to health.

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Dragan, N., Cemerlic Kulic, A., Kurspahie-mujcic, A., Bajnaktareuic, S. and Haris N. .(2006)Iodized salt for allFacta univesitatis ,medicine and biology.13.(1): 49-53. Egbuta, J., Onyezili, F. and Vanormelingen, K. (2002) Impact evaluation of efforts to eliminate iodine deficiency disorders in Nigeria. Public Health Nutrition. 6(2):169-173. Food and Agricultural Organisation. FAO (1995) Technical consultation on food fortification: Teehnology and Quality Control, Rome. Gul Nawaz Khan, Imtiaz Hussain, Sajid Bashir Soofi, Arjumand Rizvi and Zulfiqar A. Bhutta (2012) A Study on the Household Use of Iodised Salt in Sindh and Punjab Provinces, Pakistan: Implications for Policy Makers. Journal of Pharmacy and Nutrition Sciences, 2012, 2, 148-154 Lar. U.A. and Tejan, A.B. (2007) Highlight of some environmental problems of geomedical significance in Nigeria. J. Environmental Geochemistry and Health 30(4):383-389. Okosieme, O.E.(2006). Impact of iodization on thyroid pathology in Africa. J. Royal Soc. of Medicine. 99: 396-401. Palafox, E.F., Villavieja, G.M., Nones, C.A., Juguan, J.A. and Cerdena, C. M. (2002). Knowledge, Attitude and Practices on Food and Nutrition among Children, Mothers (Caregivers of 1-5 year old children), Pregnant and Lactating Women in selected Philippine Barangays. Science and Technology project. Patrick L. (2008) Iodine deficiency and therapeutic considerations. Altern Med Rev 13(2): 116-27. Sebotsa M.D., Dannhauser A., Mollentze W.F., Oosthuizen G.M., Mahomed F.A., Jooste P.L. (2009). Knowledge, Attitude and Practices regarding iodine among patients with hyperthyroidism in the Free State, South Africa. S Afr. J. Clin. Nutr. 22(1):18-21. Simone Caramel. (2010) Coronary artery disease and CAD inherited real risk, http://www.sisbq.org/uploads/5/6/8/7/5687930/ cad_caramel.pdf Takele L., Belachew T. and Bekele T. (2003). Iodine concentration in salt at household and retail shop levels in Shebe town, South west Ethiopia. East African Med. J. 80:532-539. Van Binh T., Kim Uoc H. and Quang Toan L.(2000) Report on IDD control activities. UNICEF evaluation database. Verheesen RH, Schweitzer CM. (2008) Iodine deficiency, more than cretinism and goiter. Med Hypotheses 71(5): 645-8. World Health Organisation (2014). Fortification of food-grade salt with iodine for the prevention and control of iodine deficiency disorders

Nutritional Qualities of Weaning Foods from Protein-Rich Food Mixtures Using Bioassay Method

Adepeju, A.B.,1 Abiodun, A.O.2 and Esan, Y.O.1 1Department of Food Science and Technology, Joseph Ayo Babalola University, PMB 5006, Ikeji Arakeji, Osun State, Nigeria. 2Department of Food Science and Technology, Osun State Polytechnic, P.M.B 301 Iree, Osun State, Nigeria. *Corresponding author: Email: [email protected] or [email protected]

ABSTRACT

The study evaluated the effect of crayfish and soybean protein enrichment on the quality of formulated weaning foods. The evaluation was done using both in vitro and in vivo (animal models) methods. The nutrient composition results showed that the protein and fat contents of then crayfish-ogi, soy-ogi and control diets of all the diets were 17.66, 14.16, 16 and 12.6, 18 and 9 g/100 g, respectively. The ash content of the experimental diets ranged from 2.14 to 4.85 g/100g. These values were in the FAO standard ranges recommended for infant weaning diet. The bioassay analysis showed that crayfish- ogi diet had higher protein efficiency ratio (PER) and net protein ratio (NPR) than soy –ogi diet. The animals fed with crayfish- ogi diet showed increased in weight when compared with others. The organs (tissues, liver and kidney) of animals in the crayfish-ogi group weighed higher and contained total protein level than those of the control diet group.

Keywords: carbohydrate; crayfish; protein; soybeans; weaning food

INTRODUCTION

The nutrition in the first two years of life has long-term consequences on the health and productivity of such newborns. At this stage of rapid development, infants require higher energy and protein in their diets so as to meet the increasing demand for metabolism (FMOH, 2005). Infants in developing countries generally show satisfactory growth during the first six months of life when they are almost exclusively breastfed (Pelto et al., 2003).Therefore inappropriate complementary food to breast milk has been identified as a contributing factor to the high incidence of malnutrition in developing countries (WHO/UNICEF,1998).Over these formative years, the insufficient quantities and inadequate quality of weaning foods, poor child-feeding practices and high rates of infections have posed a detrimental impact on health and growth of the infants. Even with optimal breastfeeding, children become stunted if they do not receive sufficient quantities of quality complementary foods from six months of age (FMOH, 2005).Past study recommended prevention of an estimated six percent or six hundred thousand under-five deaths through thorough optimal complementary feeding (Davis, 2001).Among many approaches needed to improve child survival and growth in developing countries therefore, is the provision of safe and nutritious infant foods (Peltro et al., 2003). Infant mortality rate in Nigeria has increased from 86 in 2000 to 111in 2005 (UNFPA, 2005; Ojofeitimi, 2008). Also, among the under-five children, the rate of stunting, wasting and underweight were reportedly exceeded 40%, 9%, and approximately 25% respectively (Wardlaw, 2000).Meanwhile, most of the other factors (diarrhea, measles and malaria) responsible for infant mortality can be controlled if infants are adequately fed with foods that meet all the nutritional requirements (FMOH, 2005).

Traditionally, infant porridges in developing countries are usually made from local staples and the resulting gruels may have low nutritional value in terms of micronutrients and macronutrients (Dewey and Brown, 2003). In most developing countries, like Nigeria, the traditional complementary foods that are commonly introduced to infants are based on some local staples which are usually cereals such as maize, sorghum, millet, wheat, oat and barley made into gruels. The nutrient contents of this product, however is far below the recommended values for infant and cannot meet the nutritional “demands” of an infant (Brown et al., 1998). Although a number of commercial infant foods exist but, most families in the low and middle income-earning groups cannot afford them. It is therefore expedient to formulate foods from local staples that are nutritious, fit into the traditional culinary and child feeding practices of the region and are very affordable (Dewey and Brown, 2003).This research work, those aimed at producing and evaluating formulated weaning foods from fermented corn, crayfish and soybean flours.

MATERIALS AND METHODS Sweet corn, and soybean were purchased at the Ife Central Market, fresh crayfish was obtained from Eko-ende in Ikirun, Nigeria while Nutrend (control diet) was purchased from Infinity grace supermarket, Obafemi Awolowo University in Ife. The vitamin and mineral mix used were from Pfizer Nigeria Plc. Twenty- five male and female albino rats (Wister strain) were obtained from the Department of Pharmacy, Obafemi Awolowo University, Ile Ife, Nigeria.

Preparation of fermented corn flour The grains were cleaned and steeped for 48 h to encourage fermentation. The fermented corn was then washed dried, milled, sieved and packaged in a polythene bag and stored in the refrigerator for later use.

Preparation of soybean flour The soybean seeds were sorted, cleaned and boiled for 30 mins. They were dehulled and thoroughly washed and dried in the cabinet dryer (Gallenhamp SM 905, England) at 45 oC for 24 h. The dried soybean seed were cleaned by winnowing, milled, sieved, packaged and stored in the refrigerator.

Preparation of crayfish flour The crayfish was sorted and cleaned in water and unwanted materials were removed. It was dried at 45 oC for12 hrs. It was milled, packaged and stored in the refrigerator.

Mineral and vitamin mixtures The mineral mixture in gram per kilogram of the corn flour contain 5.40g calcium, 4.30g phophorus, 0.01g iron, 1.60g sodium, 6.60g potassium, 0.035g zinc. All these were mixed for 10 min using kenwood mixer (Kenwood, A200, Britain). The vitamin mixture in milligrams per 50 g of corn flour contained 3.0mg vitamin A, 0.60mg vitamin D, 300mg vitamin E, 350mg vitamin C, 0.25 mg folic acid, 8.0mg thiamine, 3.0mg riboflavin, 40mg niacin, 3.0mg vitamin B6, 0.075 mg vitamin B12, 2.5mg biotin, 15.0mg pantothenate and starch to make up to 50g. They were all mixed for 10 min using kenwood mixer (Kenwood, A200, Britain).

Preparation of the experimental diets The fermented corn flour was mixed in a Kenwood mixer (Kenwood, A200, Britain) for 10 min with sugar, vegetable oil, cod liver oil, mineral and vitamin mix, to obtain the basal diet. Similar processing method was followed for the other diets (Table 1).

Experimental animal The 25 male and female albino rats were weighed and divided into five groups randomly until each group had approximately same average weight. One group of five animals served as the control for the experimental group and was sacrificed. Tissue from the liver, kidney and plantaris muscle of the hind-leg were removed, weighed and frozen till nitrogen efficiency was determined. The remaining animals were placed on experimental diet fed ad libitum over a period of 28days.

Analyses of the formulated diet and experimental animal Proximate analyses of commercial (control) and experimental diet were carried out using AOAC (2005) methods. The dietary intake and weight of the experimental animals were studied and the organs such as the muscle, liver and kidney were collected and examined. The Net Protein Ratio (NPR) and Protein Efficiency Ratio (PER) were calculated.

RESULTS AND DISCUSSION

The nutrient composition of control and experimental diets were shown in Table 2. The result showed that the protein contents of, the crayfish-ogi (17.66 g/100 g) and soy-ogi (14.16 g/100 g) diets compared well with the 16 g/100 g of control diet. The protein contents of the experimental diets obtained in this study (14-18 g/100 g) meet the normal requirement standards (12-20 g / 100 g) set for infant diet (FAO/WHO, 1992).it is noteworthy that both crayfish and soybean flours increased the protein contents of Ogi by four and five times respectively, since Ogi was reported (Adepeju and Abiodun, 2011) to contain 3.40g/100 g protein .Meanwhile, the fat content of the crayfish-enriched diet (12.60 g / 100 g) is lower than 18 g/100 g obtained for soybean-enriched diet. The difference may be due to the fact that soybean seeds are well known as a good source of vegetable oil production. The fat content also meets the standard requirement (9-10 g/100 g) for infant diet. The ash content of the experimental diets ranged from 2.14 to 4.85 g/100g. The value for crayfish-ogi was higher when compared with that of the control diet (2.00 g/100g) while soy-ogi had a similar value with the control diet (2.00 g/100 g). The moisture contents of all the diets (7.54-7.88 g/100 g) were higher than that of the control diet (4.00 g/100 g). However, these values still fall within the expected range for weaning diet which must not exceed 10%. The carbohydrate content of the diets compared well with the control diet (64.00 g/100 g). The most favourable protein efficiency ratio (PER) and net protein ratio (NPR) were apparent in all the groups. The values of PER in crayfish-ogi exceeded the recommended value which is 2.1 (PAG, 1982) while soy-ogi and control diet fall below the recommended requirement. The result of this work agreed with the report of Ahenkora et al., 1994).

Animal Feeding Experiment

During the 28 days experimental period the adaptation of the animals fed on each dietary sample and utilization of each diet were studied and the result presented in Fig. I. The animals that depend on the basal diet for survival were found to become leaner and weaker each passing day of the experiment. The physical changes were observed on the skin as well as in their consumption rate. For instance, loss of weight was dramatic from average weight of 67.60 g at day one to 54.22 g at day twenty eight (even animal loss was recorded in this group). On the other hand, the animals fed with other diets increased in weight especially in the crayfish-ogi diet group followed by the control diet group (Fig.1) and this might be due to the fact that crayfish is very nutritious as compared to other sources of protein. Meanwhile, the lower rates results recorded for soy- ogi diet as compared to the control diet, might be due to the presence of antinutrients (such as oligosaccharides and protease inhibitors) in soybean, which might rendered it bio-unavailable for metabolism. Past works had also reported the decrease in weight of the animal fed on basal diet over a set period of time (Fashakin et al.,1991; Adepeju and Abiodun, 2011) . The weight gained was largely influenced by the quality of protein constituents of the diet. Protein is required among other things for growth, healthy living and maintenance and production of tissues and cells of the body (FMOH, 2005). The current results supported the fact that ogi has a protein content of poor biological value which did not support growth in rats. The results of the rate of diet consumption by the rats were presented in Table III. The rate at which crayfish-ogi, soy- ogi and the control diets were consumed by the animals was low when compared with the basal diet, but highest in the control diet towards the middle and to the end of the experiment than those of the animals from other experimental groups. The tissues of animals fed on basal diet were smaller than those of animals from other experimental groups as shown in Table IV. The livers, kidney and muscle of animals in the crayfish-ogi were found to have the highest total protein level when compared to the control and soy-ogi diet groups (Table V).This work compared well with the work of Murray et al., (1993) who reported higher body weight and high kidney value for rat fed a high protein diet.

Table 1: Composition of experimental diet

Crayfish Soybean Constituents Basal diet Ogi diet Ogi diet Crayfish flour (g) - 200 - Corn flour (g) 809 609 609 Soybean flour (g) - - 200 Vitamin premix (mg) 10 10 10 Mineral Premix (g) 16 16 16 Vegetable oil (g) 100 100 100 Cod liver oil (g) 5 5 5 Sugar (g) 60 60 60

Table 2: Chemical composition and energy values of experimental diets in g/100g of diet Parameter Crayfish-Ogi Soybean-Ogi Control diet Protein 17.66±0.88 14.16±0.40 16.00±0.20 Fat 12.60± 0.33 18.00 ±0.20 9.00 ±0.50 Moisture 7.88± 0.35 7.54 ±0.40 4.00 ±0.35 Values are Mean±SD

Fig.1. Average weight changes over the experimental period

Table 3: Food composition (g) over experimental period

Experimental Diets Period (days) Basal Crayfish ogi Soy-ogi Control 7 33.2 32.44 32.74 31.62 14 74.78 70.62 66 73.34 21 114.7 109.7 110.19 119.88 28 155.54 149.34 148.39 165.54

Table 4: Weight of various tissues of Experimental animals

Zero day Crayfish- Tissues Basal Diet Soy-ogi Control Animal ogi Liver 2.42±0.11 1.33±0.12 3.60±0.10 2.62±0.12 2.70±0.45 Kidney 0.24±0.33 0.16±0.33 0.34±0.30 0.27±0.46 0.29±0.18 Muscle 0.62±0.42 0.26±0.19 0.72±0.12 0.65±0.24 0.68±0.12 The zero day animals (control) are the animals sacrificed on the first day of the experiment. The tissues collected from these animals served as the initial level for the other animal’s tissues at the end of the experiment

Table 5: Total protein level (mg/N) in various tissues of experimental animals

Zero day Crayfish- Basal Diet Soy-ogi Control Tissues Animal ogi Liver 80.47±0.24 37.43±0.12 192.60±0.20 125.11±0.20 132.98±0.20 Kidney 7.28±0.33 3.77±0.40 15.24±0.30 11.40±0.43 12.57±0.15 Muscle 18.31±0.42 6.50±0.20 35.45±0.10 27.94±0.18 31.79±0.20 The zero day animals (control) are the animals sacrificed on the first day of the experiment. The tissues collected from these animals served as the initial level for the other animal’s tissues at the end of the experiment CONCLUSION

Based on the findings of the investigation, it may be concluded that locally available protein-rich food resources have great potentials in the formulation and preparation of infant weaning foods. The potential, viability, cheaper sources and readily accessibility of crayfish-ogi and soy-ogi diets as the infant weaning diet formulations were fully exploited in this study. Moreso, this will go a long way in ameliorating the usual symptoms (stunted growth, wasting of muscles, low height for age) associated with protein energy malnutrition (PEM) that are commonly prevalent in the developing country.

REFERENCES

Adepeju, A.B. and Abiodun, O.A., (2011). Effect of protein rich foods mixtures on the quality of formulated weaning food diet. International Research Journal of Biochemistry and Bioinformatics. 1 (5):114-118 Ahenkora, K.S., Iwumasi-Afriyie, W. Hagg and Dzah, B.D., (1994). Ghananian kenkey from normal and quality protein maize comparative chemical composition and fat growth trials. Cereal Research communication. 23(3):299-304. AOAC, (1990). Official Methods of Analysis. 15th Edn. Association Official Analytical Chemists. Washington D.C Brown, K.H., Dewey, K.G. and Allen, L.H., (1998). Complementary feeding of young children in developing countries: a review of current scientific knowledge. Geneva: WHO/NUT/98. Davis, M.K., (2001). Breastfeeding and chronic disease in childhood and adolescence. Ped. Clin. Amer.48:125-142. Dewey, K.G and Brown, K.H., (2003). Update in Technical Issues concerning complementary feeding of young children in development countries and implications for intervention programs. Food Nutr. Bulletin. 24:5-28. FAO/WHO, (1992). International conference on Nutrition and Development- A Global Assessement, Rome. FAO. Fashakin, J.B, Ilori M.O., Olanrewaju I.,(1991). Cost and quality optimization of a weaning diet from plant protein and corn flour using a computer aided linear programming model. Nig. Food J. 9:123-127. FMOH, (2005). Infant and Young Child Feeding in Nigeria- Guidelines. Federal Ministry of Health, Abuja. Ojofeitimi, E.O., (2008). A Healthy Life: Your Birth right. An inaugural lecture series 2209. OAU press Ltd. OAU, Ile- Ife. 8th January, 2008. PAG, (1982). Protein rich mixture for use as weaning foods. Protein Auditory Guidelines. No. 8. Food and Agriculture Organisation of the United Nations Children’s funds.1-7. Peltro, G.H, Levitt, E., and Thairu, L., (2003). Improving Feeding Practices. Current Patterns Common constraints and Design of Intervention. Food and Nutrition Bulletin. 24:24-82. UNFPA, (2005). Country profiles for population and reproductive health. Policy development and indicators 2005. Population Reference Bureau. 1-9. Wardlaw, G.M., (2000). Contemporary Nutrition Issues and Insights. 4th ed. McGraw- Hill Higher Education, USA:450- 475. WHO/UNICEF., (1998). Complementary feeding of young children in developing countries: a review of current scientific knowledge, WHO/NUT/98.1.

Physico-chemical, Nutritional and Sensory Characteristics of Chin-Chin made from Trifolate Yam (Dioscorea dumentorum) Flour Enriched with Pumpkin Seeds (Telfaria occidentalis) Flour

Adelekan, A.O.*, Arisa, N.U. and Ogunseye, F.R.

Department of Food Technology and Nutrition, Bells University of Technology, P.M.B 1015, Ota, Ogun State, Nigeria. *Corresponding author: Email: [email protected]

ABSTRACT

Trifoliate yam flour (Dioscorea dumentorum) was produced and enriched with pumpkin (Telfaria occidentalis) seed flour at three substitution levels (10%, 15% and 20%) and processed into chin-chin, the quality of this product was compared with the chin-chin made from Irish potato (Solanum tuberosum) flour. The flour was analysed for physico-chemical, mineral, vitamins and anti-nutritional factors using standard procedures. The product made from the flour (Chin-chin) was analyzed for proximate composition and sensory evaluation to determine its acceptability. Results showed that enrichment of trifoliate yam flour with pumpkin seed flour increased the pH of the flour from 5.95 at 10% substitution to 6.03 at 15% substitution level, while the protein content also increased from 14.23% (10% substitution) to 16.53% (20% substitution). There was also an increase in fat content at the same substitution level. Potassium and Phosphorous also showed an increase in their contents after enrichment. Tannin decreased from 5.34% at 10% substitution level to 3.86% at 15% substitution. The overall acceptability showed that 10% substitution level had the highest rating and there was no significant difference in the chin-chin made from the enriched flour (P>0.05).

Keywords: acceptability; enrichment; pumpkin seed flour; trifoliate yam flour

INTRODUCTION

The importance of yam in general has been communicated by various researchers. Manuel et al., (2005) reported yam to be one of the principal foods in Nigeria, also an economically, socially and traditionally valuable crop in many tropical countries predominantly in West African, South Asian and Caribbean continents. Yam has been reported to be rich in carbohydrate with many of its varieties widespread throughout the humid tropics. The most economically important species grown are: White yam (Dioscorea rotundata), Yellow yam (Dioscorea cayenensis), Water yam (Dioscorea alata), Chinese yam (Dioscorea esculenta), Aerial yam (Dioscorea bulbifera) and Trifoliate yam (Dioscorea dumentorum) (Ike and Inoni, 2006) but only a few species of yams are cultivated as food crops. To some extent, processing of yam has not reached a significant level commercially.

Predominantly, the use of yam has been limited to the preparation of local dishes such as pounded yam (yam dough) and porridges (Amani et al., 2002). The production of instant yam flour, yam flakes and starch has been explored but industrial scale production has been limited due to various constraints including high fresh market price (Onayemi and Potter, 1974; FAO, 2005). In other words, some yam varieties are widely known and overexploited for food while others are known and exploited as food only in a few rural communities in Nigeria and as a result underutilized. Over dependence on the common yam varieties for food and industrial use account for the high market price of yams and this incidentally limits industrial exploitation.

Trifoliate yam is a species of yam in which limited work has been done in terms of its production and utilization though it is high yielding compared to other yam species. In Nigeria, its local names include; Esuru (in Yoruba language), Ona (in Ibo language) and Kosanrogo (in Hausa language). Some of its other common names are three-leaved yam, bitter yam and cluster yam. It has starch grains that are smaller, more soluble and more digestible than those of other yam species (Treche and Guion, 1980). The proteins also, are more balanced than those of white yam (Mbome and Treche, 1994) and it is rich in vitamins and minerals. The consumption of trifoliate yam is restricted due to its bitter taste, inability to keep for longer time after harvesting and poor binding capacity of its flour (Martin et al.,1983;Mbome and Treche, 1994; Sefa-dedeh and Afoakwa, 2001). Some works have been done on ways of minimizing the post-harvest problem associated with trifoliate yam but no solution has been suggested yet but processing the yam tuber into a shelf –stable product offers an alternative to fresh storage. Pumpkin seeds used for the enrichment of the trifoliate yam are valuable both as oilseeds (54%) and also as protein source (27%) with a fairly well balanced amino acid composition (Akwaowo et al., 2000; Hamed et al., 2008). Unfortunately, 78 to 91% of the fruits are wasted annually (Fagbemi et al., 2005). It has also been reported by Jun et al. (2006) that pumpkin is a good source of carotene, pectin, mineral salts, vitamins and other substances that are beneficial to health. These facts lead to the processing of pumpkin into various food products. In the quest for industrial progress, a contribution was made through this research using trifoliate yam, an underutilized yam species as a case study. The trifoliate yam was enriched with pumpkin seed another underutilized food crop and compared with Irish potato a commonly known and utilized food crop which served as the control sample. This research was carried out to determine the effect of enriching trifoliate yam flour with pumpkin seeds (in three substitution levels) on the physico-chemical, nutritional and sensory qualities of its product (Chin chin).

MATERIALS AND METHODS

Source of materials

Fresh Trifoliate yam tubers and the fluted pumpkin fruit containing viable seeds were obtained from Lusada market, Ogun state. The raw Irish Potato tubers were obtained from Sango Ota market, Ogun State.

Raw Materials Preparation

Production of Trifoliate Yam Flour: The tubers were washed with clean water, peeled with sharp kitchen knives and sliced to a thickness of between 2mm to 3mm and oven-dried at a temperature of 65oC for duration of 11 hours. The dried yam slices were milled into flour using a hammer milling machine and sieved through a standard laboratory sieve of 500 micron meter aperture to produce uniform particle size flour as described by Eke Ejiofor and Kiin-Kabari, (2010).

Production of Irish Potato Flour: The fresh raw Irish potatoes were washed, peeled, and sliced to a thickness of about 2 to 3 mm and treated to stop enzymatic browning by soaking in a 0.3% salt water solution for 10 minutes. The treated potatoes were thereafter drained and oven-dried at a temperature of 65oCfor duration of 9 hours. The dried potato chips were thereafter hammer-milled into flour and sieved through a standard laboratory sieve of 500 micron meter essentially as described by Chukwuonso et al.,(2010).

Production of Pumpkin Seeds Flour: The fresh seeds were removed from the gourds, washed and sun dried to reduce sliminess, and thereafter broken out of shells, size-reduced by chopping with a kitchen knife and oven-dried at a temperature of 60oC for duration of 30 hours and thereafter milled into flour using first, a laboratory dry miller and secondly, a small size hammer mill as described by Eke Ejiofor and Kiin-Kabari, (2010).

Enrichment Formulation: The dried pumpkin seeds flour was added directly into the plain trifoliate yam flour in different proportions of 10% (to 90% trifoliate yam flour), 15% (to 75% trifoliate yam flour and 20% (to 80% trifoliate yam flour) and made to pass through a 500 micron meter aperture standard laboratory sieve to obtain the enriched trifoliate yam flour.

Production of Chin-Chin: The flour sample (250 g) was sifted and margarine (25g) was rubbed in with 1 and half eggs added. This was followed by the addition of sugar (80g) and nutmeg (10g). All these were mixed into fairly stiff dough, turned into a floured board, rolled out thinly and cut into strips which were then squared. The squares of dough were fried (King’s vegetable oil) in small batches and frequently turned until brown. These were thereafter drained, allowed to cool and packaged in an air-tight freezer bag.

Physico-chemical analysis

Determination of pH of flour samples The pH meter was switched on and allowed to warm up for about 5 minutes and then standardized with pH buffer solutions to ensure the sensitivity and accuracy of the meter. This was done by dipping the electrode of the meter into each buffer solution with thorough rinsing with distilled water. The pH values of samples (initially prepared by dissolving 10 grams of dry sample into 10mls of distilled water) were taken individually by dipping the pH meter electrode into the samples followed by thorough rinsing with distilled water after each dip. The pH values were consequently read out from the display unit of the meter.

Chemical Properties The moisture, protein, crude fat, crude fiber, and ash contents of the “Trifoliate yam flour ”were determined using the methods of AOAC (2000). Carbohydrate was determined by difference according to James (1995).

Mineral Content determination The dry ashing procedure was used for mineral content determination. Five (5) grams of each of the samples were accurately weighed into porcelain crucibles and pre-ashed until the sample was completely charred on a hot plate. The pre- ashed samples were thereafter ashed in the muffle furnace at 500oC till the ash was white for about 2 hours. After ashing, the crucibles were transferred into the desiccator to cool and the reweighed. Each sample was quantitatively transferred into volumetric flasks by carefully washing the crucibles with 1ml nitric acid, then with portions of dilute nitric acid. All washings were transferred to individual volumetric flasks, repeating the washing procedure twice. The solutions were diluted to volume with deionized water and were used for individual mineral determination using the appropriate standards and blank. The content of the minerals; Calcium, Magnesium, Potassium, Sodium, Manganese, Iron, Copper and Zinc were determined with the Atomic Absorption Spectrophotometer (Buck Scientific, Model 210). Calculation: Mineral Element concentration (%) = Ppm / 1000 Where Parts per million (Ppm) of any element = Meter reading x Slope x Dilution factor

Phosphorus Content: Phosphorus was determined using the Spectrophotometric method described by Ceirwyn (1998). The dry ash of each sample obtained was digested by adding 5mls of 2Molar Hydrochloric acid to the ash in the crucible and heated to dryness on a heating mantle. 5mls of the 2Molar Hydrochloric acid was added again, heated to boil and filtered through a Whatman No.1 filter paper into a 100ml volumetric flask. 10ml of the filtrate solution was pipetted into 50ml standard volumetric flask and 10ml of Vanadate – molybdate yellow was added and the flask was made up to mark with distilled water, stoppered and left for 10 minutes for full yellow development. The concentration of phosphorus was obtained by taking the absorbance of the solution on a Spectronic 21D (Milton Roy Model) Spectrophotometer at a wave length of 470nm. Calculation: Phosphorus (%) = (Absorbance x Slope x Dilution Factor) / 10000

Vitamin Content Determination Vitamin A: Each sample was weighed (2g) into a flat bottom reflux flask and 10ml of distilled water was added followed by careful shaking to form a paste. This was followed by the addition of 25mls of alcoholic Potassium Hydroxide solution and the attachment of a reflux condenser. The mixture was then heated in boiling water bath for 1 hour with frequent shaking and rapidly cooled with 30mls of distilled water added. The hydrolysate obtained was transferred into a separating funnel and the solution was extracted three times with 250ml quantities of chloroform. Two grams of Anhydrous Sodium tetraoxosulphate (Na2SO4) was thereafter added to the extract to remove any traces of water. The mixture was then filtered into a 100ml volumetric flask and made up to mark with chloroform. Standard solutions (within the range of 0 to 50 micron gram/ml) prepared were determined with reference to their absorbance from which average gradients were taken to calculate Vitamin A (Beta- Carotene in micron gram/100 gram). Absorbance of each sample and standards was read on the Spectrophotometer (Spectronic 21D, Milton Roy Model) at a wavelength of 328nm. Calculation: Vitamin A (micron gram / 100g) = [(Absorbance x Dilution Factor) / (Weight of sample)] x100/1 Vitamin C: Equal weights of each of the samples and 3% metaphosphoric acid were individually mechanically blended and each portion mixed to obtain homogenous slurry. Five (5) grams of individual slurry was transferred using a pipette into a 100ml volumetric flask and made up to mark with 3% metaphosphoric acid. Each mixture was filtered, discarding the first portion of the filtrate and 10ml of the aliquot was pipetted into a 50ml volumetric flask and titrated immediately with the standard dye solution of 2, 6 – dichlorophenolindophenol to a faint pink colour which persisted for 15 seconds. Calculation: Vitamin C (mg/100g) = [(W1 + W2) / (W1 x W3)] x [V1/V2] x [100 (V x F)] Where: W1 = Weight of sample (grams), W2 = Weight of extracting acid (grams), W3 = Weight of slurry removed for analysis, V1 = Volume to which slurry sample in diluted (ml), V2 = Volume of filtrate taken for titration (ml), V= Volume of dye solution used for titration, F = Ascorbic acid Equivalent of dye in milligrams/milliliters.

Determination of Anti-nutritional Composition Determination of Tannins: One (1) gram of each sample was weighed into a beaker and individually soaked with a solvent mixture (made up of 80mls of acetone and 20mls of glacial acetic acid) for five hours to extract the tannin. Samples were thereafter filtered through a double layer filter paper to obtain filtrate. This was followed by the preparation of a set of standard Tannic acid solution ranging from 10ppm to 50ppm. The absorbance of the standard solution and that of the filtrates were read at 500nm on a Spectronic 21D (Milton Roy Model) Spectrophotometer. Calculation: Tannin (%) = (Absorbance x Average gradient x Dilution factor) / 10,000

Determination of Oxalate: One (1) gram of each sample was weighed into 250mls conical flask and soaked with 100mls of distilled water to extract the oxalates. Soaked samples were allowed to stand for three (3) hours and each was filtered through a double layer of filter paper. 10ppm, 20ppm, 30ppm, 40ppm and 50ppm standard solution of oxalic acid were prepared and the absorbance of standard solution and that of the filtrates from each sample was read using a Spectronic 21D (Milton Roy Model) Spectrophotometer at 420nm. Calculation: Oxalate (%) = (Sample Absorbance x Average gradient from the Standard’s curve x Dilution factor) / 10,000

Determination of Phytates: The method described by Inuwa et al., (2011) was used for phytate determination. Sample (2g) was weighed into 250mls conical flask. 100mls of 2% concentrated hydrochloric acid was used to soak each of the samples in conical flasks for 3 hours and then filtered through a double layer filter paper. Each of the sample filtrates (50mls) was placed in 250ml beakers and 107mls of distilled water was added to each of the samples to improve proper acidity. 10mls of 0.3% Ammonium Thiocyanate solution was added to each sample solution as indicator and titrated with standard iron (III) chloride solution which contained 0.00195 g iron per ml. The end point was signified by brownish-yellow coloration that persisted for 5 minutes. Calculation: Phytic acid (%) = [(Titre value x0.00195) x 1.19 x100] / 2

Determination of Saponin: Two (2) grams of each of the samples were weighed into 250ml beakers and 100ml of isobutyl alcohol (octanol) was added to each sample and left for 5 hours on a UDY shaker for uniform mixing so as to obtain a uniform solution .The mixtures were then filtered through a No 1 Whatman filter paper. The filterate was transferred to another 10ml beaker and saturated with magnesium carbonate solution. The mixture thereafter obtained was then filtered to obtain a clear colourless solution. Standard saponin solutions (0 ppm to 10ppm) were prepared from 1000ppm saponin stock standard solution and saturated with magnesium carbonate as done above followed by filtration. The absorbances of the saponin standard solution (0 to 10ppm) were read at 380nm to obtain the gradient of the plotted curve. Calculation: Saponin (%) = [(Abs. Standard – Abs. Sample) / Weight of Sample] x [(Dilution factor x Average gradient) / 10,000]

Determination of Trypsin Inhibitor: Samples (0.2g) were weighed into screw cap centrifuge tubes. Thereafter 10mls of 0.1 Molar phosphate buffers were added into each and contents were shaken at room temperature for 1hour on a UDY shaker. The suspension obtained was thereafter centrifuged at 500rpm for 5 minutes and filtered through Whatman No 42 filter paper. The volumes of each were adjusted to 2mls with phosphate buffer and the test tubes were placed in water bath maintained at 37degrees Celsius. 6mls of 5% TCA Solution was added to an empty tube to serve as the blank. 2mls of casein solution was added to each of the tubes initially placed in the water bath followed by incubation for 20 minutes. TCA solution (6mls) was added into the sample tubes 20 minutes after (so as to stop the reaction) and shaken. The reaction was allowed to proceed for 1 hour at room temperature and the mixture was filtered through Whatman No 42 filter paper. The absorbance of sample filtrates and trypsin standard solutions were then read at 280nm. Calculation: Trypsin Inhibitor (mg/100 g) = [(Abs. Standard – Abs. sample) / 0.19 x Sample weight in grams] x [(Dilution factor) / 1000 x Sample size]

Determination of cyanogenic glycoside: Five (5) grams of each sample was weighed into 250ml conical flasks and incubated for 16 hours at a temperature of 38°C. Extraction of the cyanogenic glycoside was followed by filtration using double layer of hardened filter paper. Distillation was done using Markham distillation apparatus and each extracted sample was transferred into two-necked 500ml flasks connected to a steam generator. The steam was distilled with saturated sodium bicarbonate solution contained in a 50ml conical flask for 60 minutes. 1ml of starch indicator was added to 20mls of each distillate and titrated with 0.2N of Iodine solution. Calculation: Hydrogen cyanide (%) = (Titre x 10 x 0.27 x 100) / (1000 x Weight of Sample)

Sensory evaluation Quality parameters such as the crust color, crumb color, crispiness, taste, flavor, aroma, texture and overall acceptability of the chin-chin made from the various flour samples were evaluated with a Scoring difference test. A 9-point hedonic scale was used to determine the overall acceptability of flour products. A twenty-man (untrained) panel was used for the sensory test using a questionnaire that was provided, for scoring. All quality parameters were evaluated as: Like extremely = 9. Like very much = 8, Like moderately = 7, Like slightly = 6, Neither like nor dislike = 5, Dislike slightly = 4, Dislike moderately = 3, Dislike very much = 2 Dislike Extremely = 1 Data obtained were subjected to Analysis of Variance (ANOVA).

RESULTS AND DISCUSSION

Effect of enrichment on proximate composition of Trifoliate yam flour Table 1 shows the proximate composition of the flour samples. The moisture content determines the shelf life of the product. The range of moisture content for all the flour samples was between 5.38% and 7.31% which is at the minimum limit of moisture content for flour (Adeleke and Odedeji, 2010). The moisture content of the chin-chin made from all flour samples ranged from 2.81% to 4.9%. Proteins are made up of amino acids which perform different functions in the body such as growth and repair of body cells and tissues, synthesis of hormones and antibodies (Anne and Allison, 2006). The flour with the highest protein content was the 20% enriched trifoliate yam flour (16.53%) followed by the 15% enriched trifoliate yam flour (15.32%). The 100% plain trifoliate yam flour had 10.84%. The protein content of all flour samples reduced after frying into chin-chin. Fats provide the most concentrated source of chemical energy and heat. They support certain body organs and help with the transportation and storage of fat-soluble vitamins A, D, E, and K (Anne and Allison, 2006). The control flour sample (Irish potato) had the lowest fat content of 2.84% followed by the plain trifoliate yam flour (3.71), the fat content values increased with increase in level of enrichment On the other hand, frying significantly increased the fat content of chin-chin made from all the flour samples. This suggests that for health related purposes, the flour could be processed into a baked product rather than being made into a fried product. Alternatively, low cholesterol oil such as olive oil may be used in frying in place of ground nut oil. Above all, vegetable fats are essentially unsaturated which makes them more health-friendly than animal fat (Anne and Allison, 2006). Crude fiber helps with the peristaltic movement of food substances during digestion. The Irish potato had the lowest crude fiber content (1.61%). The fibre content of the flour increased with increase in enrichment levels. The plain trifoliate yam flour had 2.43%. Ash content increased with increase in enrichment in flour samples. The enrichment decreased the carbohydrate content of the flours gradually.

Table 1: Effect of enrichment on proximate composition (%) of Trifoliate yam flour Crude Samples Moisture Protein Fat Carbohydrate Ash Fiber IRP. Flour 7.30e 15.11c 2.87a 70.43d 4.29c 1.61a 100% TRIF.Y Flour 6.30d 10.84a 3.70b 76.77e 2.36a 2.43b 90% TRIF.Y+ 10% PPK Flour 6.12c 14.23b 9.55c 67.71c 2.40b 2.44b 85% TRIF.Y+ 15% PPK Flour 5.60b 15.32c 10.70d 65.97b 2.42b 3.20c 80% TRIF.Y+ 20% PPK Flour 5.38a 16.53d 12.44e 63.18a 2.47b 3.83d Values within the same column with different superscript letters are significantly different from each other IRP. Flour = Irish Potato flour (Control) 100% TRIF.Y FLOUR = 100% Trifoliate Yam Flour 90% TRIF.Y+10% PPK FLOUR = 90% Trifoliate Yam Flour Enriched with 10% Pumpkin seeds 85% TRIF.Y+15% PPK FLOUR= 85% Trifoliate Yam Flour Enriched with 15% Pumpkin seeds 80% TRIF.Y+20% PPK FLOUR= 80% Trifoliate Yam Flour Enriched with 20% Pumpkin seeds

Effect of enrichment on the vitamin composition of the Trifoliate yam flour Table 2 shows the vitamin A and C composition of the flour samples. Vitamins are organic compounds necessary for good health and vitality. Vitamin A is a fat soluble vitamin essential for the building and growth of all cells and for maintenance of normal vision in dim light. Vitamin C is a water soluble vitamin which acts as an anti-oxidant. Although vitamins are required in minute quantities, the resulting vitamins after enrichment in this study were insignificantly different (at P ≤ 0.05 significance level). A loss in vitamin composition could have been as a result of the heat treatments.

Table 2: Effect of enrichment on the vitamin composition of the Trifoliate yam flour Vitamin A Vitamin C Samples (%) (%) IRP. Flour 0.03c 0.71c 100% TRIF.Y FLOUR 0.02b 0.59a 90% TRIF.Y+ 10% PPK FLOUR 0.02b 0.75c 85% TRIF.Y+ 15% PPK FLOUR 0.01a 0.81d 80% TRIF.Y+ 20% PPK FLOUR 0.02b 0.65b Values within the same column with different superscript letters are significantly different from each other IRP. Flour = Irish Potato flour (Control) 100% TRIF.Y FLOUR = 100% Trifoliate Yam Flour 90% TRIF.Y+10% PPK FLOUR = 90% Trifoliate Yam Flour Enriched with 10% Pumpkin seeds 85% TRIF.Y+15% PPK FLOUR= 85% Trifoliate Yam Flour Enriched with 15% Pumpkin seeds 80% TRIF.Y+20% PPK FLOUR= 80% Trifoliate Yam Flour Enriched with 20% Pumpkin seeds

Effect of enrichment on the mineral composition of Trifoliate yam flour Table 3 shows the mineral composition of flour samples. Minerals are inorganic substances necessary for maintaining good health. Water balance, regulation of fluids and the acid base balance in the body depend to a great extent on certain mineral balance in the body. Phosphorus plays an important role in the calcification of bones and plays an essential part in carbohydrate metabolism (Raheena, 2007). Magnesium plays an important role in normal calcium and phosphorus metabolism in man. Iron forms a constituent of haemoglobin which takes part in the transportation of oxygen from the lungs to the tissues. Copper stimulates the absorption of iron and it is a constituent of the elastic connective tissue protein elastin. Potassium is an important constituent of cells and it helps with muscular function (Raheena, 2007). Manganese functions in many enzyme and it activates certain enzymes which take part in the digestion and metabolism of carbohydrates, proteins and lipids. Calcium is necessary for the ossification of bones and for normal nerve impulse transmission. Sodium is essential for normal functioning of the body and it also plays a role in the regulation of acid base balance and water metabolism in the body. Zinc plays an essential role in enzymatic action and aids in the healing of burns and wounds (Raheena, 2007). Majority of the trifoliate yam flour samples had mineral composition higher than that of the Irish potato flour. Phosphorus and Potassium were highest in the 20% enriched trifoliate yam flour. Magnesium, Iron, Copper, Manganese, Calcium and Zinc were highest in the 10% enriched trifoliate yam flour while sodium was highest in the Irish potato flour.

Table 3: Effect of enrichment on the mineral composition of Trifoliate yam flour Samples P Mg Fe Cu K Mn Ca Na Zn IRP. Flour 2.50a 93.48d 2.90b 0.44a 325.35a 0.73d 3.20a 372.15e 1.26a 100% TRIF.Y Flour 3.00c 83.10a 3.45c 0.54b 827.62b 0.48a 9.98c 366.82d 1.72b 90% TRIF.Y+ 10% PPK Flour 3.13c 100.38e 4.53e 0.82d 781.38c 1.08e 10.75d 41.88b 2.46d 85% TRIF.Y+ 15% PPK Flour 2.75b 86.93b 2.75a 0.80d 827.92d 0.63c 8.92b 86.93c 2.06c 80% TRIF.Y+ 20% PPK Flour 3.22c 88.88c 3.98d 0.60c 845.40e 0.58b 8.50b 40.25a 2.24d Values within the same column with different superscript letters are significantly different from each other IRP. Flour = Irish Potato flour (Control) 100% TRIF.Y FLOUR = 100% Trifoliate Yam Flour 90% TRIF.Y+10% PPK FLOUR = 90% Trifoliate Yam Flour Enriched with 10% Pumpkin seeds 85% TRIF.Y+15% PPK FLOUR= 85% Trifoliate Yam Flour Enriched with 15% Pumpkin seeds 80% TRIF.Y+20% PPK FLOUR= 80% Trifoliate Yam Flour Enriched with 20% Pumpkin seeds

Effect of enrichment on the anti-nutritional composition of Trifoliate yam flour Table 4 shows the anti-nutritional composition of the flour samples. Tannins cause decreased feed consumption in animals, bind dietary protein and digestive enzymes to form complexes that are not readily digestible (Aletor, 1993).Tannins can also interact with dietary iron by preventing its absorption and they have the capability of decreasing the digestibility and palatability of proteins because they form insoluble complexes with proteins (Osagie et al., 1996). Irish potato flour had the highest Tannin content. Too much of soluble oxalates in the body prevent the absorption of soluble calcium ions as the oxalate binds the calcium ions to form insoluble calcium oxalate complexes. As a result of this, people with the tendency to form kidney stones are advised to avoid oxalate-rich foods (Adeniyi et al., 2009). The bioavailability of the essential nutrients in plant foods could be reduced by the presence of anti-nutritional factors such as oxalates (Akindahunsi and Salawu, 2005).The 20% enriched trifoliate yam flour had the highest oxalate content.

Table 4: Effect of enrichment on the anti-nutritional composition of Trifoliate yam flour Cyanogenic Tannins Oxalates Phytic Saponins Trypsin Samples glycoside (%) (%) Acid (%) (%) Inhibitors (%) (%) IRP. Flour 5.89d 1.98a 6.15a 2.51a 1.31d 0.17a 100% TRIF.Y Flour 4.75b 3.05c 8.25c 2.95b 1.14c 0.85b 90% TRIF.Y+ 10% PPK Flour 5.34c 3.14c 8.25c 3.88c 0.95a 0.87b 85% TRIF.Y+ 15% PPK Flour 3.86a 2.08b 7.14b 4.31d 1.02b 0.95c 80% TRIF.Y+ 20% PPK Flour 4.15b 3.66d 8.39d 4.26d 0.88a 0.92c Values within the same column with different superscript letters are significantly different from each other IRP. Flour = Irish Potato flour (Control) 100% TRIF.Y FLOUR = 100% Trifoliate Yam Flour 90% TRIF.Y+10% PPK FLOUR = 90% Trifoliate Yam Flour Enriched with 10% Pumpkin seeds 85% TRIF.Y+15% PPK FLOUR= 85% Trifoliate Yam Flour Enriched with 15% Pumpkin seeds 80% TRIF.Y+20% PPK FLOUR= 80% Trifoliate Yam Flour Enriched with 20% Pumpkin seeds

Phytates have twelve replaceable hydrogen atoms and therefore could form insoluble salts with many metals like calcium, iron, zinc, magnesium and phosphorus thereby preventing the proper utilization of these minerals and making them unavailable (Jack et al., 1985). The 20% enriched trifoliate yam flour also had the highest phytic acid content. Saponins characterized by their bitter taste bind cholesterol, making it unavailable for absorption and they also cause haemolysis of red blood cells and are toxic to rats (Johnson et al., 1986). Humans generally, do not suffer severe poisoning from saponins. Some types of saponins are health friendly. They inhibit growth of cancer cells and help to lower blood cholesterol hence useful in the treatment of cardiovascular diseases and other health problems (Del-Rio et al., 1997). The 15% and 20% enriched flours had the highest saponin contents. These are anti-nutrients for monogastric animals but they do not exert adverse effects in ruminants because they are degraded in the rumen (Cheeke and Shull, 1985). Trypsin (protease inhibitor) causes pancreatic enlargement and growth depression (Aletor and Fetuga, 1987). The Irish potato flour had the highest content of trypsin inhibitors. Cyanogenic glycosides on hydrolysis yield toxic hydrocyanic acid (HCN). The cyanide ions inhibit several enzyme systems; depress growth through interference with certain essential amino acids and utilization of associated nutrients (Akindahunsi and Salawu, 2005). They also cause acute toxicity, neuropathy and death (Fernando, 1987). The cyanogenic glycoside content was highest in the 15% and 20% enriched flour samples.

Effect of frying on the proximate composition of trifoliate yam flour dough Table 5 shows the proximate composition of the Chin-chin. The chin- chin samples generally had a decrease in most of their proximate composition compared to that of the flour samples they were made from. Although, the fat content increased because oil was used in producing the Chin-chin.

Table 5: Effect of frying on the proximate composition (%) of trifoliate yam flour dough Crude Samples Moisture Crude Fat Carbohydrate Ash Crude Fiber Protein IRP. Flour 3.18c 9.96a 23.58d 60.99a 2.30c 1.37c 100% TRIF.Y Flour 3.09c 10.73b 20.93b 63.37c 1.89a 1.23b 90% TRIF.Y+ 10% PPK Flour 2.81b 11.71c 19.92a 63.66c 1.91a 1.52d 85% TRIF.Y+ 15% PPK Flour 2.67a 11.71c 22.79c 60.99a 1.84a 1.69e 80% TRIF.Y+ 20% PPK Flour 4.90d 9.96a 20.81b 61.95b 2.38d 0.75a Values within the same column with different superscript letters are significantly different from each other IRP. Flour = Irish Potato flour (Control) 100% TRIF.Y FLOUR = 100% Trifoliate Yam Flour 90% TRIF.Y+10% PPK FLOUR = 90% Trifoliate Yam Flour Enriched with 10% Pumpkin seeds 85% TRIF.Y+15% PPK FLOUR= 85% Trifoliate Yam Flour Enriched with 15% Pumpkin seeds 80% TRIF.Y+20% PPK FLOUR= 80% Trifoliate Yam Flour Enriched with 20% Pumpkin seeds Effect of enrichment on the acceptability of trifoliate yam flour chin-chin Sensory quality is considered a key factor in food acceptance because consumers look out for food with specific sensory characteristics. The acceptance of a food will depend on whether it responds to consumer needs, and on the degree of satisfaction that it is able to provide (Heldman, 2004). Irish potato chin-chin had the highest score of 6.95 for crust color while the 10% enriched trifoliate yam chin-chin had the highest score of 6.85 for crumb color (Table 6). Irish potato chin- chin had the highest score of 6.90 for texture. Irish potato also had the highest score of 6.5 for flavor. The sample with the highest score (6.45) for aroma was the 15% enriched trifoliate yam while for taste Irish potato chin-chin had the highest (6.65). For overall acceptability, the Irish potato chin-chin was the most acceptable (6.80), followed by the 10% enriched trifoliate yam chin-chin (6.20), the 15% enriched trifoliate yam chin-chin (5.90), and lastly the 20% enriched trifoliate yam chin-chin and the plain trifoliate yam chin-chin which both had the same score of 5.70. These values, being above average on a 9 point hedonic scale, indicate to some extent that all samples were moderately acceptable to consumers.

Table 6: Effect of enrichment on the acceptability of Trifoliate yam flour chin-chin Crust Crumb Overall Samples Texture Flavor Aroma Taste Color Color Acceptability IRP. Flour 6.95d 6.50b 6.90e 6.50e 6.30b 6.65d 6.80d 100% TRIF.Y Flour 6.25b 6.60c 6.35a 5.30a 6.15a 5.55b 5.70a 90% TRIF.Y+ 10% PPK Flour 6.70c 6.85d 6.75d 5.60c 6.40c 6.00c 6.20c 85% TRIF.Y+ 15% PPK Flour 6.75c 6.80d 6.60c 5.85d 6.45d 5.55b 5.90b 80% TRIF.Y+ 20% PPK Flour 6.15a 6.25a 6.55b 5.55b 6.35b 5.30a 5.70a Values within the same column with different superscript letters are significantly different from each other IRP. Flour = Irish Potato flour (Control) 100% TRIF.Y FLOUR = 100% Trifoliate Yam Flour 90% TRIF.Y+10% PPK FLOUR = 90% Trifoliate Yam Flour Enriched with 10% Pumpkin seeds 85% TRIF.Y+15% PPK FLOUR= 85% Trifoliate Yam Flour Enriched with 15% Pumpkin seeds 80% TRIF.Y+20% PPK FLOUR= 80% Trifoliate Yam Flour Enriched with 20% Pumpkin seeds

CONCLUSION

It can be concluded that pumpkin seeds can be used to improve the nutritional composition (especially the protein content) of foods high in carbohydrate and low in other nutrients. Pumpkin seed can be used as a substitute for soya bean and other protein rich seeds. The enriched Trifoliate yam flour can be used as an industrial flour or made into dough (like ‘Amala’) because of its bitter taste, which makes it not too acceptable as chin-chin. The trifoliate yam flour should undergo a heating process before consumption so as to reduce the intake of anti-nutrients.

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Physico-chemical and Functional Properties of Sweet Potato-Soybean Flour Blends

Omoniyi, S.A.1*; Awonorin, S.O.2; Idowu, M.A.2 and Adeola, A.A.3

1Department of Home Science and Management, Federal University, Gashua, Yobe State, Nigeria 2Department of Food Science and Technology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria 3Institute of Food Security, Environmental Resources and Agricultural Research, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria. *Corresponding author: Email: [email protected]

ABSTRACT

The study investigated the physicochemical and functional properties of sweet potato-soybean flour blends. Defatted soybean and sweet potato flours were blended in the ratios of 10:90, 25:75, 30:70 and 40:60, respectively, while 100% sweet potato flour was used as a control. The moisture, crude protein, crude fat, ash, crude fibre and carbohydrate contents of the flour blends were significantly different (p<0.05)with the values ranging between 7.28-7.32, 7.05-12.4, 2.62-3.22, 1.87-2.62, 3.76-4.55 and 68.10-76.63%, respectively. The bulk density, degree of starch damage, water absorption index, swelling power, amylose content and water solubility index of the flour blends were also significantly different (p < 0.05) with values ranging between 0.59-0.68 g/cm3, 0.74-1.17%, 2.34-2.81%, 1.46-1.56g/g, 12.62-12.91%, and 1.12-1.41% respectively. The results revealed that the increase in percentage of defatted soybean led to increase in moisture, protein, ash, crude fat, bulk density, degree of starch damage, water absorption index, swelling power and water solubility index of the flour blends but decrease in carbohydrate, crude fibre and amylose content of the flour blends. The study showed that the flour blends from defatted soybean and sweet potato had higher protein content and better physico-chemical properties making it a potential ingredient in baking products, extruded snacks and complementary/weaning foods formulations.

Keywords: defatted soybean flour; physico-chemical properties; proximate composition; sweet potato flour

INTRODUCTION

Sweet potato (Ipomoea batatas), a dicotyledonous plant belongs to the family convolvulaceae (Douglas, 1987). It is an important food crop of the tropics with potential to alleviate food insecurity, improve nutrition and economy of many African countries including Nigeria (Hurton, 1998; Saeed et al., 2012). It is an important alternative source of carbohydrates and attains fourth place after rice, corn and cassava (Saeed et al., 2012).West African sweet potato production is about 2.516 million tonnes per annum with Nigeria being one of the largest producers (FAO, 2006). The crop is reported to be of low income value but with a significant social importance due to its high potential food source for most developing nations with limited resources as a result of its short maturity time, ability to grow under diverse climatic condition on less fertile soil (Saeed et. al., 2012). Sweet potato flour has been reported as a source of energy and carbohydrates, beta carotene (pro Vitamin A), Vitamin C, Vitamin B6, minerals (calcium, phosphorus, iron, manganese and potassium) and dietary fibre, which can add natural sweetness, colour and flavour to processed food products (Ulm, 1998; Woolfe, 1992; Onabanjo and Ighere, 2014). The underutilization of this crop, despite the industrial applications of its flour, has been reported (Putri et al., 2014; Mohd-Hanim et al., 2014). For instance, the flour could be used in production of cakes, muffins, cookies and noodles, extruded snacks, chiffons even as cereal flour supplements in bakery products such as pancakes and pudding (Zainun et al., 2005; Jennifer, 1992).

Soybean (Glycine max), a grain legume cultivated in many areas of the world, belongs to the family leguminosae and sub- family papillionnideae (Sanful and Darko, 2010). It is an excellent source of protein (40-45%) and the seeds are the richest in food value of all plant food consumed in the world (Egunlety and Aworh, 1990). Igbabul et al., (2013) reported that soybean contributes protein, fat, vitamins, and minerals in the diet of people in developing countries. Soybean contains some anti-nutritional factors, which inhibit the availability of the desirable elements such as protein, minerals and vitamins. However, several studies have been reported that most of these anti-nutritional factors can be destroyed through processing (Enwere, 1998; Osho and Dashiell, 1998). However, many studies had reported the improvement of protein quality of cereals and tuber crops, for instance, in production of soy-‘ogi’ (Adeyemi and Beckley, 1986), yam-soy flour (Akingbala et al., 1995), and soy-‘agidi’(Akpapunam et al., 1997).

However, it should be noted that sweet potato has high carbohydrate content but low in protein content and many studies have reported this, for instance Mais (2008) reported that sweet potato tubers are regarded as being relatively high in starch and dietary fibre but low in protein. Since, sweet potato tuber is low in protein content, there is therefore, a need to supplement its flour with high protein content sources, such as legume flour, which could increase the nutritional qualities of the flour. In view of the increasing utilization of sweet potato in composite flours for various food formulations, its physico-chemical and functional properties are of greater significance (Mohd-Hanim et al., 2014; Mais, 2008). This study is thus, aimed at determining the physico-chemical properties of the flour blends from defatted soybean and sweet potato flours.

MATERIALS AND METHODS

Materials

Fresh sweet potato tubers (white variety) were purchased at Mile 12 market, Lagos state while soybean (variety – TGX 1485 – ID) was obtained at Kuto market, Abeokuta, Ogun state.

Preparation of flour samples The methods described by Omoniyi (2003) were used for the preparation of sweet potato flour and defatted soybean flour. The sweet potato tubers were sorted, washed, peeled under water, cut into thin chips (1.5–2.0mm), washed again and dried in cabinet dryer (60⁰C for 18h). The dried chips were then milled and sieved (250μm) to obtain flour. The soybean seeds were sorted, heated in the cabinet dryer at temperature of 60⁰Cfor 1 h and soaked in clean water for 18 h. It was then washed with clean water and dehulled. After dehulling, it was autoclaved for 30 mins and then dried at a temperature of 65⁰C for 24 h. The dried soybean seeds were then milled using hammer mill (Glen Crescent Ltd., Germany). The soybean flour was defatted using soxhlet extraction method (using n-hexane as solvent) for a period of 6 h. Thereafter, the defatted soybean was dried at temperature of 65⁰C for 2 h, cooled, milled and packaged in sealed polyethylene bag.

Blending of sweet potato-soybean flour samples Soybean and sweet potato flour samples were blended in ratios of 10:90, 25:75, 30:70, 40:60, respectively while 100% sweet potato flour was used as control sample (Table I).

Table 1: Composition of sweet potato-soybean flour blends Soybean Sweet potato Samples (%) (%) SPF 0 100 SS1 10 90 SS2 25 75 SS3 30 70 SS4 40 60 Where SPF–100% Sweet potato flour; SS1– 90% Sweet potato flour:10% Soybean flour; SS2–75% Sweet potato flour:25% Soybean flour; SS3–70% Sweet potato flour:30% Soybean flour; SS4-60% Sweet potato flour:40% Soybean flour

Analyses

Determination of proximate composition The moisture content, protein content, crude fat, crude fibre and ash were determined according to AOAC (2000) while the carbohydrate content was obtained by difference.

Determination of physico-chemical properties The bulk density, degree of starch damage and swelling power were determined according to method described by Onabanjo and Ighere, (2014), Williams and Fegol (1969), and Adeleke, and Odedeji, (2010) respectively. Amylose content was determined using the method described by Hoover and Ratnayake (2001), while water absorption and water solubility indexes were determined according to a prescribed method (Ruales et. al.,1993).

Statistical analysis All data were obtained in triplicate; while analysis of variance (ANOVA) of the data was carried out using SPSS (21.0) and means separated using Duncan’s multiple range test (DMRT).

RESULTS AND DISCUSSION

Table 2 shows the proximate composition of sweet potato-soybean flour blends. The proximate composition of the blends were significantly different (p<0.05) with the values ranging from 7.28 to 8.19 %, 2.21 to 12.42 %, 1.02 to 3.22 %, 1.73 to 2.62 %, 3.76 to 4.62 % and 69.38 to 84.22 % for moisture, crude protein, crude fat, ash, crude fibre and carbohydrate contents, respectively. Table 3 shows the physicochemical properties of sweet potato-soybean flour blends. The physicochemical properties of the blends were also significantly different (p<0.05) with values ranging from 0.59 to 0.68g/cm3, 0.56 to 1.17%, 2.35 to 2.81%, 1.21 to 1.56g/g, 12.62 to 12.94%, and 1.12 to 1.41% for bulk density, degree of starch damage, water absorption index, swelling power, amylose content and water solubility index, respectively.

Table 2: Proximate composition (%) of Sweet potato-soybean flour blends.

Moisture Crude Crude Samples Crude fat Ash Carbohydrate content protein fibre SPF 8.19a 2.21e 1.02e 1.73e 4.62a 83.14a SS1 7.28c 7.05d 2.62d 1.87d 4.55b 76.63b SS2 7.29bc 9.55c 2.67c 2.02c 4.27c 72.90c SS3 7.30bc 11.54b 3.04b 2.42b 3.89d 69.61d SS4 7.32b 12.42a 3.22a 2.62a 3.76e 68.10e Means with different superscripts in a column are signiﬁcantly different (p < 0.05) Where SPF–100% Sweet potato flour; SS1– 90% Sweet potato flour:10% Soybean flour; SS2–75% Sweet potato flour:25% Soybean flour; SS3–70% Sweet potato flour:30% Soybean flour; SS4-60% Sweet potato flour:40% Soybean flour

Table 3: Physico-chemical properties of Sweet potato-soybean flour blends

Bulk Degree of Water Swelling Amylose Water Samples density starch damage absorption power content solubility (Unit) (%) index (%) (g/g) (%) index (%) SPF 0.66b 0.56d 2.35d 1.42d 12.94a 0.98e SS1 0.59d 0.74c 2.34d 1.46c 12.91b 1.12d SS2 0.62c 0.84b 2.58c 1.47c 12.87c 1.25c SS3 0.65b 1.14a 2.71b 1.51b 12.81d 1.29b SS4 0.68a 1.17a 2.81a 1.56a 12.62e 1.41a Means with different superscripts in a column are signiﬁcantly different (p < 0.05) Where SPF–100% Sweet potato flour; SS1– 90% Sweet potato flour:10% Soybean flour; SS2–75% Sweet potato flour:25% Soybean flour; SS3–70% Sweet potato flour:30% Soybean flour; SS4-60% Sweet potato flour:40% Soybean flour

The increase in percentage of defatted soybean led to increase in moisture, protein, crude fat and ash contents of the flour blends samples. Though an increment was recorded for the moisture contents of flour blends at increased percentage defatted soybean, but the values are lower than the13% maximum moisture content recommended for flour by Christensen and Kaumann (1973). Thus, the low moisture content is expected to lead to longer shelf life of the flour blends. The increase in protein content of sweet potato-soybean flour blends may be attributed to the high quantity of protein in defatted soybean flour (up to 40%) and this could improve the nutritional value of the flour blends. The same observation was reported for wheat-soy–plantain (Olaoye et al., 2006), fermented soybean-sweet potato (Abayomi et al., 2013) and soy- plantain (Abioye et al., 2011) flour blends. Similar observation on the increase in ash and crude fat contents of sweet potato-soybean flour blends was also reported for soy-plantain and fermented soybean-sweet potato flour blends (Abioye et. al.,2011; Abayomi et. al., 2013). The increase in ash contents of the flour blends showed that the blends might be very rich in macronutrients. The decrease in carbohydrate contents recorded for the flour blends when the percentage defatted soybean flour increases, is supported the observations of Oyewole and Aibor (1992) on increase in protein and decreased carbohydrate contents of soy-fortified fufu. The increase in defatted soybean substitution led to increase in bulk density, degree of starch damage, water absorption index, swelling power and water solubility index of the flour blends but with decreased amylose content of the flour blends. The high bulk density value recorded for the flour blends might likely aid its industrial applications, according to a past study (Oladebeye et al., 2009) that suggested the suitability of high bulk density- sweet potato as drug binder and disintegrant in pharmaceuticals industries. It should be noted that as the degree of starch damage in the flour blends increases, there was increase in water absorption index of the blends as well. This observation is in support of the findings of Adeyemi and Beckley (1986) that reported a direct relationship between the water absorption indexes and higher damaged starch of the flour. The increase in water absorption index might be due to the increase in protein and carbohydrate contents reported for the flour blends. This correlates with the study of Afoakwa (1996) that reported the importance of protein and starch (cellulose) in water uptake of flour at room temperature.

CONCLUSION

The study showed that the flour blends from defatted soybean and sweet potato had high protein content and better physicochemical properties which could make it a potential and functional ingredient in the production of baking and complementary/weaning food products.

REFERENCES

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Proximate Composition, Microbial Quality and Consumer Acceptability of Gruel from Fermented Maize and Soybean

Balogun, M.A.*; Kolawole, F.L.; Karim, O.R. and Fasakin, T.B.

Department of Home Economics & Food Science, University of Ilorin, Ilorin, Nigeria. *Corresponding author: Email: [email protected]; [email protected]

ABSTRACT

Gruel is an acid-fermented cereal food product mostly made from maize and wrapped in banana leaves. This study was aimed at producing an enriched gruel from maize by incorporating soybean. Maize and soybeans pastes were mixed in ratios of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 to produce maize-soy gruel. Proximate, sensory and microbial analyses were carried out on the samples using standard methods. The proximate result shows that moisture content decreased from 35.22% in 100:0 to 25.97% in 50:50 maize-soy gruels. Protein content increased from 6.56% in 100:0 to 14.84% and 16.75% in 60:40 and 50:50 maize-soy ratio respectively. The carbohydrate content decreased from 55.01% in 100:0 to 47.92% in 60:40 maize-soy ratios while the ash content, fat content and crude fiber content increased from 100:0 maize to 50:50 maize and soybeans with values of 1.21% to 3.77%, 1.25% to 4.88% and 0.74% to 2.71% respectively. The maize-soy of 100:0 and 80:20 were highly acceptable by the sensory evaluators whereas addition of soybeans up to levels above 20% affected the colour of the samples. The microbial load of the samples stored at room temperature increased with increasing soybeans composition with values ranging between 3.0 x 105 to 26.0 x 105 cfu/g for bacterial count and 4.0 x 105 to 24.0 x 105 cfu/g for mould count. This work has shown that maize-soy gruel will make a balanced meal that is affordable and acceptable to the consumers..

Keywords: acceptability; gruel; maize; proximate; soybeans

INTRODUCTION

Gruel is a white thin or cream coloured traditionally prepared fermented food product made majorly from cereals especially maize which can be consumed as a whole or using stew or other food products (Abdulrahaman and Kolawole, 2006). It is commonly consumed in West Africa mostly in Nigeria. The organisms responsible for its fermentation are lactic acid bacteria, Lactobacillus plantarum; the aerobic bacteria, Corynebacterium and Aerobacter, the yeasts Candida mycodema and Saccharomyces cerevisiae. (Odunfa and Oyewole, 1998). It is a good source of carbohydrate which is mostly packaged in banana leaves (Musa spp) but majority use the leaf Thaumatocococcus daniella normally used to wrap moinmoin (depending on your locality) to obtain a characteristic doomed shape. It has recently been wrapped in polythene bags.

In Nigeria, maize is known and called by different vernacular names ‘masara’ (Hausa); ‘agbado’ (Yoruba); ‘oka’ (Ibo); ‘apaapa’ (Ibira); ‘oka’ (Bini and Isha); ‘ibokpot’ (Efik) and ‘igumapa’ (Yala). Reports showed that maize contains 80% carbohydrate, 10 % protein (although deficient in lysine and tryptophan, but has fair amounts of sulphur-containing amino acids), 3.5% fiber (soluble and insoluble) and 2% mineral. Iron and Vitamin B are also present in maize. Maize is high in both soluble and insoluble fiber. Maize protein is deficient in lysine and tryptophan, but has fair amounts of sulphur- containing amino acids (IITA 2001).

Maize is most popularly consumed as fermented gruel ‘ogi’ (Aminigo and Akingbala, 2004) but which has low nutritional value as they are not adequate sources of micro and macro nutrients (Fasasi et al., 2006). Substantial nutrient losses occur during the various steps of ogi processing. The situation is even made worse by the method of its processing which involves wet milling, wet sieving and several washings which deplete it of even the little nutrients contained and therefore incapable of supporting growth and good health of the people (Otunola et al., 2007). Much of the protein in cereal grains is located in the testa and germ which are usually sifted off during processing (Aminigo and Akingbala, 2004).

Soybean (US) or soya bean (UK) (Glycine max) assumed to be a source of complete protein, is a species of legume native to Southeast Asia, widely grown for its edible bean which has numerous uses such as a substitute for expensive meat and meat products. (Adelakun et al., 2013). In addition to its high food value, it is one of the least expensive sources of protein when compared to eggs, milk, beef and cowpea. They contain proteins which provide all the essential amino acids in the amounts needed for human health. Most of the essential amino acid present in soybean is available in an amount that is close to those required by animals and humans (Adelakun et al., 2013).

Efforts have been made to modify the processing of foods with a view of enhancing their nutritive value, shelf life and possible therapeutic qualities. Such effort include s but not limited to fortification of foods with legumes in enrichment processes (Osundahunsi and Aworh, 2003). Soybeans has been used to fortify foods such as kunun zaki (Ayo and Gaffa, 2002); tapioca flour (Samuel et al., 2006); tortilla (maize product) (Obatolu et al., 2007); Hausa koko (Owusu-Kwarteng et al., 2010); tapioca meal (Balogun et al., 2012) and gari (Ogunlakin et al., 2015; Karim et al, 2015).

The production of gruel from maize and soybeans is a way of increasing the utilization of soybeans at the household level and providing a complete meal for consumers. Therefore, this work is designed to produce gruel from different maize-soy ratios and determine the proximate and microbiological compositions as well as assessing the consumer acceptability of the samples.

MATERIALS AND METHODS

Materials The white maize (Zea mays), soybeans (Glycine max) and banana leaves (for packaging) were purchased from a local market in Ilorin, Kwara State, Nigeria.

Methods The maize-soy gruel was prepared in the Home Economics and Food Science kitchen of the Department of Home Economics and Food Science, University of Ilorin in a hygienic manner according to the method of Omemu, (2011). The maize was soaked for 72h in clean water at room temperature (27 ± 20C) to initiate fermentation. The steep water was decanted while the fermented maize grains were washed with clean water and then wet-milled using a fabricated attrition mill (Sanzid Nig Ltd) to obtain a white coloured maize paste. The maize paste was then mixed with water and wet- sieved using muslin cloth to remove the shaft or bran. The sievate was left to settle beneath the mixture for another 48h during which fermentation proceeds in the process known as souring. The soybeans were sorted by handpicking to remove unwanted materials such as stones, threads, pebbles, broken beans, spoilt beans etc. while the soy-paste was prepared according to the method of Nwosu et al. (2014) with slight modifications. The sorted beans were boiled for 45min to reduce the antinutrional factors in them and to facilitate easy dehulling. The soybeans were then dehulled and wet milled to obtain soybeans paste. The maize-soy gruel was thereafter prepared according to the method of Adesokan et al. (2011) with slight modification. The maize and soy pastes were mixed together at different proportions (100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 respectively). The mixture was poured in boiled water, stirred to obtain a custard-like semi-solid product. Water was then added at the sides of the gruel and left for 10min to mix properly with the water. After stirring, the gruel obtained was packaged in banana leaves and left to cool in order to obtain the doomed shape. Proximate Analysis Proximate analysis (crude protein, crude fat, ash, moisture, crude fiber) was determined as described by AOAC (2000) methods while carbohydrate content was obtained by difference.

Microbial Analysis

Agar Preparation Nutrient agar (NA) and Potato Dextrose Agar (PDA) were prepared according to manufacturer’s instruction. 28g of NA and 40g of PDA were weighed into separate beakers and each dissolved in 1L of distilled water, the mixture was thoroughly mixed and sterilized using the autoclave at 121°C for 15 min.

Microbial Examination of Samples One gram of the gruel sample was added to 10ml of sterile water in sterile test tube and was shaken properly. 1 ml from the first test tube was transferred to 9 ml of sterile water and shaken properly to achieve solution of 10-1 dilution. 1 ml from the 10-1 solution was then transferred to 9 ml sterile water in another sterile test tube to achieve 10-2 and the procedure was repeated until 10-5 solution for both bacterial and fungal analysis. The microbial examination was performed according to method described by Barnett et al., (2000) with slight modification. The pour plate technique was used. 1 ml each from 10- 3 and 10-5 were dispensed into sterile petri dishes using sterile pipettes. Cooled, molten sterile NA and PDA were poured separately to cover the mixture in the petri dishes and swirled. The petri dishes were left for some minutes to solidify. After solidifying, the plates for bacterial examination were inverted and incubated at temperature of 360C for 24 h while those for fungi were incubated at ambient temperature (27 ± 20C) for 72 h. The colonies were counted after incubation using the colony counter.

Sensory Evaluation Sensory evaluation of maize-soy gruel was carried out by a fifteen-man panel comprising people who are familiar with the product. The parameters evaluated were colour, aroma, taste, texture and overall acceptability using a 7-point hedonic scale. The rating of samples ranged from 1(like extremely) to 7(dislike extremely).

Statistical Analysis Proximate composition data were obtained in triplicates and expressed as mean ± standard deviation. All data obtained were analyzed using one way Analysis of Variance (ANOVA) and the means separated using Duncan Multiple Range Test.

RESULTS AND DISCUSSION

The result of the proximate analysis carried out on the gruel samples are reported in Table 1. The moisture content in maize-soy gruel are as follows; 35.22%, 33.69% , 31.10%, 29.85% , 27.96% and 25.97% for 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 maize- soybean respectively. Soybean has been reported to have a high water absorption capacity (Ribotta et al., 2005; Samuel et al., 2006). However, the values of the moisture content obtained in the present study are higher than 8.8-8.9% reported by past study (Ijarotimi and Famurewa, 2006) for soy-maize flour.

Table 1: Proximate composition (%) of maize-soybean gruel.

Crude Crude Sample Moisture Ash Crude fat Carbohydrate protein fibre M 35.22±0.01a 6.56± 0.01f 0.74± 0.01f 1.21± 0.01e 1.25± 0.0f 55.01 ± 0.04f MSA 33.69± 0.01b 8.72± 0.01b 1.18± 0.01e 1.86± 0.01d 2.29± 0.01e 52.26± 0.01e MSB 31.10± 0.01c 10.83± 0.01d 1.50± 0.01d 2.13 ± 0.01c 3.58± 0.02d 50.86±0.02d MSC 29.85± 0.02d 12.78± 0.02c 1.79± 0.02c 2.44± 0.01b 3.95± 0.01c 48.87 ±0.04c MSD 27.96± 0.02e 14.84± 0.02b 2.15± 0.03b 2.95± 0.01a 4.32 ± 0.02b 47.92±0.04b MSE 25.97± 0.01f 16.75± 0.01a 2.71± 0.01a 3.77± 0.01a 4.88± 0.01a 46.51±0.04a Values represent means of triplicate determinations. Means within a column with different superscripts are significantly different at P < 0.05. where M- 100% maize; MSA- 90% maize and 10% soybeans; MSB- 80% maize and 20% soybeans; MSC- 70% maize and 30% soybeans; MSD- 60% maize and 40% soybeans; MSE- 50% maize and %50% soybeans

Soybeans addition undoubtedly increases protein content of any food product of its inclusion. For 6.56% protein content was recorded for 100%:0 while 90:10, 80:20, 70:30, 60:40 and 50:50 maize-soybean had 8.72, 10.83, 12.78, 14.84 and 16.75% respectively. A similar increase of values ranging from 10.85 to 20.48% has been reported for soy–maize snacks (Lasekan and Akintola, 2002), soy fortified kunun zaki (Ayo and Gaffa, 2002; Ijarotimi and Famurewa, 2006) and soy- fortified custard (Okoye and Mazi, 2011). This is a desirable attribute especially for a developing country like Nigeria where other sources of protein are relatively expensive.

There was increase in fat content on addition of soybeans in the gruel samples 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 maize-soybean having 1.25, 2.29, 3.58, 3.95, 4.32 and 4.88% respectively. The present result is in correlation with fat content (0.97 to 4.52%) reported for tapioca-soybean fortified flour (Samuel et al., 2006). The ash content of maize-soy gruel (p < 0.05) significantly increased from 1.21% in 100:0 to 3.77% in 50:50 maize-soybean samples. This is due to the fact that soybeans are rich in minerals. Okoye and Mazi, (2011) reported similar findings in the production of soy fortified custard with values ranging from 3.45 to 6.02%. However the crude fiber content varies considerably with increasing soybean inclusions. This ranges from 0.74% in 100:0, 1.18% in 90:10, 1.50% in 80:20, 1.79% in 70:30, 2.15% in 60:40 and 2.71% in 50:50 maize-soybean. This same variation has been previously observed in past research work (Ijarotimi and Famurewa, (2006).

Meanwhile the carbohydrate content of the 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 maize-soybean are 55.01, 52.26, 50.86, 48.87, 47.92 and 46.51% respectively. This is showing a decreasing trend in the gruel sample as proportion of soybean flour increases. The present result is lower than those (64.73 - 73.86%) by previous works consistent with previous works (Lasekan et al., 2004; Samuel et al., 2006; Okoye and Mazi, 2011).

The sensory evaluation result of the gruel samples are presented in Table 2. The result showed no significant difference in the colour between samples M and MSA and samples MSB and MSC whereas significant difference was observed between samples MSB and MSD as well as samples MSD and MSE. Samples MSD and MSE were the least preferred in terms of colour with a mean value of 3.06 and 3.33 respectively while samples MSB and M were most preferred with mean values of 1.73 and 2.00 respectively. Similar low sensory scores for colour of soy-fortified kunun zaki and soy-warankashi have been reported (Aworh et al., 1987; Ayo and Gaffa, 2002).

Table 2: Sensory evaluation of maize-soybean gruel. Overall Sample Colour Taste Aroma Texture acceptability M 2.00bc 1.93c 2.67b 2.07b 2.13b MSA 2.13bc 2.40c 2.87ab 2.53ab 2.47b MSB 1.73c 1.87bc 2.27b 2.00b 2.13b MSC 2.60abc 2.20bc 2.27b 2.27b 2.27b MSD 3.06b 3.31ab 2.94ab 3.87a 3.12ab MSE 3.33a 4.00a 4.00a 3.38b 3.93a Values represent means of triplicate determinations. Means within a column with different superscripts are significantly different at P < 0.05. where M- 100% maize; MSA- 90% maize and 10% soybeans; MSB- 80% maize and 20% soybeans; MSC- 70% maize and 30% soybeans; MSD- 60% maize and 40% soybeans; MSE- 50% maize and %50% soybeans

This low preference could be as a result of the off-colour effects of soybeans on the final food products. The result showed no significant difference between the taste of samples M and MSA, samples MSB and MSC and between samples MSD and MSE. Samples M and MSB were mostly preferred in terms of taste with mean values 1.93 and 1.87 respectively while sample MSE was the least preferred with mean value of 3.31. This may be as a result of the increase in soybeans incorporated to the gruel samples. Past study (Ijarotimi and Famurewa, 2006) has also noted the same observation. Samples MSB and MSC were mostly preferred while sample MSE was the least preferred in terms of aroma with mean values of 2.27, 2.27 and 2.94 respectively. This could be due to carry-over of the beany aroma which could be attributed to the presence of soybean fats as that possess the flavoring compounds (Owusu-Kwarteng et al., 2010). The texture of sample MSB is the most preferred while the least preferred sample is sample MSE with mean values of 2.00 and 3.38 respectively. The overall acceptability of the products shows that sample MSB was mostly preferred while sample MSE was least preferred of all the samples as also observed in the report past study (Ijarotimi and Famurewa, 2006).

Table 3: Total viable count of mesophilic bacteria on sample (cfu/g x 105) Storage period (days) Sample 1 2 3 4 M 3 9 21 31 MSA 7 12 25 36 MSB 10 17 32 44 MSC 15 23 38 52 MSD 19 28 46 58 MSE 26 35 52 66 where M- 100% maize; MSA- 90% maize and 10% soybeans; MSB- 80% maize and 20% soybeans; MSC- 70% maize and 30% soybeans; MSD- 60% maize and 40% soybeans; MSE- 50% maize and %50% soybeans

Table 4: Total mould count on sample (cfu/g x 105) or spore forming? Storage period (days) Sample 1 2 3 4 M 4 9 19 25 MSA 6 12 28 41 MSB 9 19 35 52 MSC 11 25 46 55 MSD 16 33 57 64 MSE 24 47 65 74 where M- 100% maize; MSA- 90% maize and 10% soybeans; MSB- 80% maize and 20% soybeans; MSC- 70% maize and 30% soybeans; MSD- 60% maize and 40% soybeans; MSE- 50% maize and %50% soybeans Tables 3 and 4 shows the total viable counts of mesophilic bacteria and mould counts for the samples during storage at room temperature. There was increase in the number of microorganisms as the storage days increased. Increase in growth rate of these microorganisms may be attributed to nutrient availability for the microorganisms, which are enormous in the gruel samples due to its composition. For instance soybean has been as a rich medium containing proteins, vitamins and importantly fermentable sugars such as sucrose and the oligosaccharides raffinose and stachytose that could aid microbial growth (Adesokan et al., 2011).

CONCLUSION

Consumption of maize-soy gruel should be encouraged as it is of good nutritional value and a complete meal. The sample with 80% maize and 20%soybeans was the most preferred according to the sensory evaluation (final consumer perception), therefore, maize-soy gruels of acceptable quality may be prepared with up to 20% soybean paste

REFERENCES

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Marketing Perspective of Smoked Catfish by Consumers in South-West Nigeria

Adeola, A.A.1*; Ayegbokiki, A.O.2; Akerele, D.3; Adeniyi, B.T.4 and Bamidele, N.A.4

1Food and Nutrition Research Programme, Institute of Food Security, Environmental Resources and Agricultural Research, Federal University of Agriculture, Abeokuta, Nigeria 2Food Security and Socio-Economic Research Programme, Institute of Food Security, Environmental Resources and Agricultural Research, Federal University of Agriculture, Abeokuta, Nigeria 3Department of Agricultural Economics and Farm Management, Federal University of Agriculture, Abeokuta, Nigeria 4Fishery Research Programme, Institute of Food Security, Environmental Resources and Agricultural Research, Federal University of Agriculture, Abeokuta, Nigeria. *Corresponding author: [email protected]

ABSTRACT

Catfish consumption is increasingly becoming popular among Nigerians. With the rate of growth in population, demand is likely to be on the increase in the future. This paper determined the marketing perspective of smoked catfish (Clarias gariepinus) by consumers in South West Nigeria. A Multistage sampling procedure was used for data collection. Three States in South West were randomly selected for the study. A total of 300 respondents were sampled. Descriptive statistics and Tobit model were the statistical tools used for the analysis. The result revealed that there was a high level of smoked catfish acceptance (92.6%) and consumption (88.3%) in the study area. Considering the factors that actually influenced the quantity of smoked catfish consumed, the result showed that consumers’ income (0.0018671) and household size (0.2691329) had positive and statistically significant influence (at 5%, respectively) on the quantity of smoked catfish consumed. There was a negative relationship between higher educational level and fish consumption (-0.3855556), which was significant at 10%. Since household size, level of income and male headed household (0.5373099), which was significant at 1%, all influenced consumption of smoked catfish, it is therefore expected that smoked catfish will be a lucrative business in south west Nigeria..

Keywords: catfish; consumers; consumption; marketing; perception; quality

INTRODUCTION

Fish is an essential source of food and relatively cheap source of animal protein to many people across developing nations, especially Nigeria. People in some communities in various regions and states in Nigeria derived their livelihood from fishing and related activities as a result of their closeness to oceans and seas. Fish is an important part of the diets of people in these regions. It has been reported that fish consumption accounts for about 35% of animal protein consumption in Nigeria and this could mean that fish farming is a vibrant and dynamic commercial sector in Nigeria, ripe with investment and employment opportunities (USAID, 2014).

Data shows that Nigeria produced about 968,283 metric tons of fish in 2012 (Shehu, 2014). Despite this high level of fish production in Nigeria, the demand for fish is still higher than what the supply in the market could meet up with. According to USAID (2014), consumer demand in Nigeria was reported to be 2.66 million metric tons which was met only in part by imports of about 740,000 metric tons that same year. Fish ranked second to wheat in the total food imported into Nigeria between years 2006-2010 with an average annual value of N113.63 billion (Vaughan et al., 2014). This shows how thousands of the Nigerian populace derive their livelihood directly from activities related to fish procurement, distribution or consumption.

Furthermore, the average fish consumption in Nigeria is placed at 9.8 kg/caput (USAID, 2010); this is still far from meeting the World Health Organisation (WHO) recommendation of 15 kg/caput fish consumption. With the rate of population growth in Nigeria, demand is likely to be on the increase for the consumption of fish in the future. The reasons for particular food choices are complex and diverse and food consumption, like any other complex human behaviour, is influenced by many interrelating factors. According to Furst et al. (1996) and Olsen (2001) such factors include food quality aspects (such as flavour, texture, odour) and characteristics of the individual (such as personality, preferences, attitudes, perceptions, knowledge). Consumers’ preferences and interests are always of the foremost importance to aquaculturists, leading to an improvement of aquacultural techniques and producing food, which is considered by the consumer as attractive and acceptable. In this view, the fish consumer constitutes a major link between the supply and demand. The knowledge of consumers’ preferences might increasingly contribute in the improvement of the terms of production, fish distribution and the quality of their processed products (Garnier et al., 2003).

Different types of fish are consumed in Nigeria, among which include: Senegal jack (Caranx senegalllus), Marine catfish (Arius mercatoris), Alexandria’s pompano (Alectis alexandrines), Mud catfish (Clarias gariepinus), Bonga fish (Ethmalosa fimbriata) and Baraccudas (Sphyraena afria). Mud cat fish consumption is increasingly becoming popular among Nigerians. It can be consumed in different ways. Due to its perishability, many preservative methods are employed to extend its shelf life in Nigeria. Such methods include freezing, drying, smoking, etc. However, smoking is the most common and practicable method of preservation (Eyo, 1992). This is due to the fact that it is affordable and improves the organoleptic properties of the final product. Smoking is practised by rural and urban dwellers. In preserving fish by smoking, water activity is lowered to the point where the activity of spoilage microorganisms is inhibited (Okonta et al., 2005; Akinola, 2006).

Processors of smoked fish adopt different handling methods which have effect on the quality of the final product. According to Eyabi-Eyabi (2000) and Omojowo et al (2008) salting, addition of vinegar as well as the type of wood used for the smoking fire have significant contribution to the quality of smoked fish. Other methods that may contribute to the quality of smoked fish include method of harvesting and killing the fish, duration of holding the fish before smoking, type of oven. It is therefore important to obtain information on consumers’ perspective of fish quality as this would assist processors to meet their demand.

In view of the above, this paper therefore seeks to answer the following questions: i. What are the socio-economic characteristics of smoked catfish consumers? ii. What is the level of smoked catfish consumption among the respondents? iii. What is the perception of people towards smoked catfish? iv. What are the criteria considered before buying smoked catfish? v. What are the factors that determine the consumption of smoked cat fish?

The broad objective of the study is to determine marketing perspective of smoked catfish (Clarias gariepinus) by consumers in south west Nigeria. Specifically, the study sought to: i. determine the socio-economic characteristics of smoked catfish consumers; ii. determine the consumption pattern of catfish among the respondents; iii. determine the perception of people about smoked catfish; iv. examine the criteria being considered by the respondents before purchasing smoked catfish; and v. determine the factors that contribute to consumption of smoked cat fish..

METHODOLOGY

Study Area The study was conducted in South West Nigeria, made up of six states, namely: Ekiti, Lagos, Ogun, Ondo, Osun and Oyo states. The region has a land mass of 76,852 square kilometers and a population of about 27.7 million (Nigeria Bureau of Statistics, 2010). The south-west region is dominated majorly by Yoruba tribe. The weather conditions vary between the two distinct seasons in Nigeria; the rainy season (which usually starts in March and ends around November) and the dry season (usually between November-February). During the dry season, the region experiences harmattan which is associated with dust, cold, dry winds from the northern deserts. Male and female, both old and young are involved in fishing activities in the region. Although, women are more involved in processing and marketing of the product; while men are into the production and harvesting of fish. Traditionally, men paddle canoe (mostly in the coastline) to harvest fish. Lately, production of cat fish through culture system is becoming popular in the region.

Sampling procedures Multistage sampling procedure was used for data collection. Three (3) South West states, namely: Ogun, Ondo and Osun were selected using random sampling method for the study. Then, there was purposive selection among communities where catfish was regularly smoked and marketed in order to get adequate respondents. A total of 100 respondents were randomly sampled across the selected communities in each of the state. 300 questionnaires were administered in all the three states, out of which 19 questionnaires were found not useful for analysis due to missing data. The questionnaire was partitioned into three basic sections: socio-economic characteristics; their smoked catfish consumption pattern as well as the factors considered in purchasing the product. Analytical technique Descriptive statistics was employed to measure the socio-economic characteristics, consumption and perception of smoked catfish by the respondents, while Tobit model was used to determine the factors that contributed to smoked catfish consumption by the respondents. Some of the variables such as sex (male = 1, female = 0), age, marital status, secondary occupation, consumption, etc. were coded as dummy variables (1, and 0 if otherwise). The respondents whose smoked catfish consumption is insignificant, that is, those that consumed smoked catfish once-in-a-blue-moon were censored to 0. Shazam statistical package, version 9, was used to run the data to generate results.

Tobit model is specified as: Yi* = Xiβ + ei where; ei = N (0, ϭ2). Y* = latent variable that is observed for values greater than 0 and censored otherwise. The observed Y is defined by the following measurement equation: Yi ={█(y* if &y* >0 @0 if &y* ≤0)┤ Yi= Yi* Traditionally, if we parameterize μ as Xiβ, this will give us the likelihood function for the Tobit model as: L = ∏_i^n▒ 1/σ ϕ ((yi-Xiβ)¦σ) di 1- 흓 (Xiβ¦σ) 1 - di where; Yi = observable choice or outcome Xi = independent variable (X1, X2... Xn) Β = coefficient of independent variables d = dummy indicator variable that equals 1 if y > 0 흈 = variance of the of estimate Φ= standard normal probability distribution function

RESULT AND DISCUSSION

Socio-economic characteristics of the respondents Table 1 below shows the socio-economic information of the respondents. Majority of the respondents (35.2 %) belonged to the age range of 26-35 years, followed by the people in the age range of 36-45 years (24.6 %) while those who were less than 18 years were in the minority. This age distribution reflects that a good percentage of the sampled population are smoked catfish consumers and this could contribute significantly to improving health status among the larger percentage of working group in the society. The result also shows that 54.8 % of the respondents were male while about 45 % were female. This could mean that a good percentage of household heads are more interested in consuming smoked catfish and this could positively influence the entire family members into consuming smoked catfish. Parents, especially the household heads, are more influential in modifying the diet of children in the family and thus, this may have influence in encouraging the children in the family to consume smoked catfish (Jennifer et al., 2007; EUFIC, 2016) The marital status distribution of the respondents’ shows that majority (62.6 %) of the respondents were married; about 35 % were single while 2.2 % were either divorced or widowed. About 53.4 % of the respondents had household size range of 4-6; with 34.2% and 12.5% possessing 1-3 and above 6 household sizes, respectively. It could therefore be deduced that smoked catfish is more popular among the married people and who could possibly have an average household size of 4-6 in the study area.

Considering the educational background of the respondents, majority of them (69.4 %) had tertiary education; 14.2 % had secondary education and 4.6% of the respondents had no formal education. The educational background might be an indication that the people of south-western Nigeria are well educated. This view is also supported by Huang (1994) and Madu (2013) as Leonard Madu concluded that the people of the south west Nigeria are very significant in Nigeria’s business and commerce, politics and also predominate the media and legal professions in Nigeria. More than 74 % of the respondents were Christians, about 22 % practised Islam while 3.2 % practise other forms of religions. This may indicate that consumption of smoked fish is most rampant among Christians than other religions. It may also mean that food taboo has the most impact among traditional worshippers. The socio-economic distribution of the respondents further shows that about 43 % of them were public/civil servants; about 22 % were either traders/artisans or render some other form of services in business world while about 35 % were students. This distribution could be an indication that all classes of the society are interested in the consumption of smoked catfish in the southwest region of Nigeria.

Table 1: Socio-economic characteristics of the respondents. Socio-Economic Frequency Percentage Characteristics Age distribution

<18 2 0.7 18-25 60 21.4 26-35 99 35.2 36-45 69 24.6 46-55 36 12.8 56-65 15 5.3 Total 281 100 Sex distribution

Male 154 54.8 Female 127 45.2 Total 281 100 Marital status distribution

Single 99 35.2 Married 176 62.6 Divorced 3 1.1 Widowed 3 1.1 Total 281 100 Household size distribution

01-Mar 96 34.2 04-Jun 150 53.4 Above 6 35 12.4 Total 281 100 Education background distribution

No formal education 13 4.6 Primary education 20 7.1 Secondary education 40 14.2 Tertiary education 195 69.4 Adult education 13 4.7 Total 281 100 Religion distribution

Christianity 209 74.4 Islam 63 22.4 Traditional 5 1.8 Others 4 1.4 Total 281 100 Primary occupation distribution

Public/Civil servants 121 43.1 Trading/Business/ Artisan 62 22.1 Students and others 98 34.8 Total 281 100 Income distribution(N)

<10,000 39 13.9 10,000-30,000 75 26.7 30,001-60,000 72 25.6 60,001-90,000 33 11.7 90,001-120,000 27 9.6 120,001-150,000 8 2.8 150,001-180,000 17 6 180,001-250,000 8 2.8 >250,000 2 0.7 Total 281 100

Table 2: Consumption/perception of catfish by respondents. Consumption/Perception Frequency Percentage Consumed smoked catfish

Yes 248 88.3 No 33 11.7 Total 281 100 Preferred form of consumption

Boiled 62 22.1 Pepper soup 102 36.3 Smoked 91 32.4 Fried 21 7.5 Indifferent 5 1.8 Total 281 100 Acceptability by household

Yes 260 92.6 No 21 7.5 Total 281 100 Present smoked catfish as gift

Yes 211 75.1 No 70 24.9 Total 281 100 Attraction to smoked catfish

Sweet aroma 80 28.5 Rich source of nutrient 59 21 More delicious 81 28.8 Storage quality 39 13.9 Indifferent 22 7.8 Total 281 100 Smoked catfish is more Nutritious Strongly agreed 90 32 Agreed 70 24.9 Strongly disagree 25 8.9 Disagreed 47 16.7 I do not know 49 17.4 Total 281 100 Preferred processing method

Oven drying 102 36.3 Smoking Kiln 109 38.8 Charcoal pot 38 13.5 Sun Drying 26 9.3 Indifferent 6 2.1 Total 281 100 Average quantity purchased in a month (kg) <1 98 34.9 01-Mar 108 38.4 04-Jun 36 12.8 07-Oct 12 4.3 >10 12 4.3 Never purchased 15 5.3 Total 281 100

The income distribution of the respondents shows that about 14 % of the respondents earned less than N10,000:00k per month. Majority of the respondents (about 53 %) earned between N10,000.00k and N60,000.00k, while very few (8.8 %) earned between N150,001.00k and N250,000.00k. It was observed that income did not vary evenly along with educational background of respondents.

Respondents’ perception and consumption of smoked catfish Table 2 below shows the respondents’ perception and consumption of smoked catfish in the study area. About 88.3 % of the respondents consumed smoked catfish in the study area while 12% did not. Thus, there was a high level of smoked catfish acceptance and consumption in the study area. The mode of consumption differed as most of the respondents who consumed catfish (36.3 %) preferred it in pepper soup form while 32.4 % of the respondents preferred to consume it in the smoked form while 1.8 % of the respondents were indifferent. Majority of the respondents (92.6 %) revealed that smoked catfish was acceptable to the members of their household. Smoked catfish consumers constitute an important link between supply and demand. The knowledge of the consumer preferences might therefore play important role in the production and distribution of smoked catfish.

About 75 % of the respondents accepted they had either purchased or could purchase smoked catfish as a gift to either friends or families. This again indicates a good acceptability of smoked catfish in the south west Nigeria. Major factors that attracted consumers to purchasing smoked catfish were found to be the ‘sweet aroma that exudes from smoked catfish’(28.5 %), ‘rich source of nutrient’(21 %), ‘good delicious taste that comes with smoked fish’ (28.8 %) and ‘better storage quality’ (13.9 %) . Only 7.8 % of the respondents were indifferent to the attractive factors associated with smoked catfish.

When considering the perception of the nutritional value of the smoked fish, a good number (32 %) of the respondents ‘Strongly agreed’ while some (24.9 %) others ‘Only agreed’ that smoked catfish is better in nutritional quality than the fresh catfish. This high level of knowledge could be associated with the educational status of the respondents in the study area. The result further showed that about 25.6 % of the respondents ‘totally disagreed’ that smoked catfish was of better nutritional quality than fresh catfish while a few others (17.4 %) of the respondents did not actually know any information about the nutritional quality of smoked catfish.

Table 2 further shows that 38.8 % of the respondents preferred smoking kiln as a means of processing catfish while about 36 % actually liked it oven dried, and only 2.1 % were indifferent about how catfish was being processed. Those indifferent only desired to eat smoked catfish. An average of 1-3 kg and 4-6 kg of smoked catfish were purchased and consumed monthly by most of the respondents who represented 38.4 % and 12.8 %, respectively. This shows an indication that smoked catfish will be a huge success if it can be taken as a business as there is potential good market for the product. About 35 % of the respondents consumed less than 1 kg per month while only few respondents (5.3 %) had never purchased smoked catfish as some claimed that they do not like how it tasted. A similar research carried out in the United States indicated that 13 % of the survey respondents decreased their consumption of sea foods during the previous two years, because of the change in lifestyle and taste (Wessells et al., 1996). Also, in a research conducted by Kreider et al. (1993) in Delaware-US, taste was the most frequent reason given by respondents (42.3 %) who did not consume fish and sea foods. Thus, 5.3 % of the respondents who did not consume smoked catfish would not have any major impact on the marketability of the product in the study area like it would have caused if the percentage was as high as the similar study in Delaware, US.

Criteria being considered by the respondents before purchasing smoked The extent to which certain attributes of catfish influenced respondents’ decision to purchase is shown in Table 3. Attributes such as aroma (56.2 %), skin condition (59.4 %), level of dryness (84.7 %), and packaging (51.2 %) were desirable factors that most respondents considered during purchase of smoked catfish. Hence, it is advisable that the potential producers and/or marketers of smoked catfish take cognizance of these factors in order to obtain high acceptability of their products by the consumers. On the other hand, majority of the respondents were not really interested in considering factors such as skin colour of the smoked fish (55.6 %), body rigidity (61.2 %), body consistency of the smoked fish (63 %) and the fish belly puffiness (74.7 %). Also, majority of the consumers were neither interested in the source of the smoked catfish nor cared about the National Foods Drugs Administration and Control (NAFDAC) registration number before they placed their order of smoked fish. Again, all these can be considered a great advantage for any potential investor in smoked catfish as they have less to worry about to attain consumers’ satisfaction.

Factors influencing the quantity of smoked catfish consumed by the respondents Considering the factors that actually influenced the quantity of smoked catfish consumed by the respondents per month, the results in Table 4 shows that consumers’ income (0.0018671) and household size (0.2691329) had positive and statistically significant influence (at 5%, respectively) on the quantity of smoked catfish consumed, suggesting that improved income and increases in household size could substantially raise consumption of smoked catfish in south-west Nigeria. This study is in line with Amao and Ayantoye (2014); Mafimisebi (2012); Musaba and Namukwambi (2011); Amao et al (2006) and Delgado et al. (2003) who found positive influence of increase in household size and income on fish consumption in their respective studies as well as Dalhatu and Ala (2010) who established positive relationship between household fish consumption and household size. Ali-ud-din Khan and Ahmad (2014) in their study on income and consumption generally concluded that the level of income and household size both had positive influence on level of consumption and this study is in concordance with that. The findings of this study contradicts Cengiz Sayin et al. (2010) who established negative/insignificant relationship between income and household size on the level of fish consumption. Table 4 further shows that there was a negative relationship between higher educational level and fish consumption (-0.3855556), which contradicts Ali-ud-din Khan and Ahmad (2014) findings that increase in level of education had a positive influence on consumption. This suggests that higher formal educational attainment may induce negative incentive towards smoked catfish consumption in southwest Nigeria. This finding is contrary to our expectation; this is because appreciation of the nutritive values of foods has been shown to be positively related with higher educational attainment.

Table 3: Attributes of smoked catfish affecting purchase Attributes Frequency Percentage Aroma Yes 158 56.2 No 123 43.8 Total 281 100 Skin condition

Yes 167 59.4 No 114 40.6 Total 281 100 Level of dryness

Yes 238 84.7 No 43 15.3 Total 281 100 Packaging

Yes 144 51.2 No 137 48.8 Total 281 100 Skin colour

Yes 125 44.5 No 156 55.6 Total 281 100 Body rigidity

Yes 109 38.8 No 172 61.2 Total 281 100 Body consistency

Yes 104 37 No 177 63 Total 281 100 Belly puffiness

Yes 71 25.3 No 210 74.7 Total 281 100 Source of catfish

Yes 109 38.8 No 172 61.3 Total 281 100 NAFDAC registration number Yes 41 14.7 No 240 85.4 Total 281 100 Source: Field Survey, 2014

Table 4: Tobit regression on factors influencing the quantity of smoked catfish consumed by the respondents per month Robust Variable Coefficient Std. T-Ratio P>|t| [95% Conf. Interval] Error Household size 0.2691329 0.11959 2.25** 0.025 0.0336738; 0.504592 Income (N) 0.0018671 0.00094 1.99** 0.048 0.0000167; 0.0037174 Secondary Education dummy -0.2316601 0.28301 -0.82 0.414 -0.7888785; 0.3255583 Tertiary Education dummy -0.3855556 0.23125 -1.67* 0.097 -0.8408659; 0.0697548 Age range 31 to 45 -0.2828767 0.20062 -1.41 0.16 -0.6778657; 0.1121123 Age ≥45 0.0274807 0.26539 0.1 0.918 -0.4950361; 0.5499976 Sex (Male) dummy 0.5373099 0.15264 3.52*** 0.001 0.2367742; 0.8378456 Marital status (single) dummy 0.2486610 0.19600 1.27 0.206 -0.1372448; 0.6345667 Religion 0.0418194 0.17145 0.24 0.807 -0.2957432; 0.379382 Occupation (civil servant) dummy 0.1442914 0.17674 0.82 0.415 -0.2036912; 0.4922739 Ogun state (dummy) -0.3123081 0.25835 -1.21 0.228 -0.8209718; 0.1963555 Osun state (dummy) -0.2562524 0.26782 -0.96 0.34 -0.7835576; 0.2710529 Ondo state (dummy) -0.0299263 0.27835 -0.11 0.914 -0.5779726; 0.5181201 Constant 1.106266 0.41003 2.7 0.007 0.2989603; 1.913571 Sigma 1.213596 0.06722 1.081248; 1.345943 Source: Computed from Field survey, 2014 Note: *** = Significant at 1%, ** = Significant at 5% and * = Significant at 10%

The position of this paper is not to marginalize or downplay the significant role of education in improving food (fish) consumption. It might be thinkable that with higher level of education beyond the secondary school, nutritional knowledge may drive food (animal protein) consumption away towards consumption of other types of fish or animal protein sources. Some of the studies that have found positive relationship between level of education and fish consumption include Dalhatu and Ala (2010) and Amao et al. (2006) and those that have established insignificant/negative relationship include Gebrezgabher et al. (2015) and Mafimisebi (2012), among others. None of the coefficients of state-level dummies is statistically significant; suggesting that the qualitative (spatial) differences in the consumers place of residence is unlikely to substantially influence consumption of smoked catfish among the consumers. The study also revealed that the gender (male) specificity of the consumer would have little influence on smoked catfish consumption.

CONCLUSION

It could be drawn from this study that smoked catfish is highly popular among the people of south-west Nigeria as good percentage of respondents preferred smoked catfish to any other form of processing due to its high nutritive value. The level of dryness of the smoked catfish and the packaging strategies of the smoked catfish by the farmers/marketers also played significant roles in the sales of smoked catfish in the study areas. The significance of packaging is in consonance with Adebo and Toluwase (2014) which recommended that there is need for research focus on packaging of smoked catfish for value addition in order to improve the marketability of the product. Since household size, level of income and male headed household all influenced the consumption of smoked catfish, it is therefore expected that smoked catfish will be a lucrative business in the south-western Nigeria. It is necessary to encourage those in the business through micro-credit scheme to improve on packaging technology which could enhance the marketability of the product and relevant law enforcement agents should ensure strict Good Manufacturing Practice among smoked catfish processors since majority of consumers never care about the endorsement of the product by government agency such as NAFDAC before consumption.

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Seafood Safety Perceptions and their Effects on Anticipated Consumption under Varying Information Treatments. Agricultural and Resource Economics Review, 25: 12–21. Effects of Agricultural Sector Reforms on the Performance of some Quoted Agric-Based Companies on Nigerian Stock Exchange

Ayegbokiki, A.O.1*; Arigbede, H.O.2; Okuneye, P.A.3; Ayinde, I.A.3 and Adeoye, S.O.3

1Institute of Food Security, Environmental Resources and Agricultural Research (IFSERAR), Federal University of Agriculture, Abeokuta, Nigeria 2Department of Agricultural Economics, University of Ibadan, Ibadan, Nigeria 3Department of Agricultural Economics and Farm Management, Federal University of Agriculture, Abeokuta, Nigeria *Corresponding author: [email protected]

ABSTRACT

The study was focused on the effects of Agricultural sector reforms on the performance of some quoted Agric-based companies on the Nigerian Stock Exchange (1993-2007). The variables of the study were measured and analyzed statistically using financial ratios such as Return on Equity (ROE), Average Price/Stock Price per Share, Earnings Yield, Dividend Yield, Price-Earnings Ratio, etc. These helped to ascertain the financial conditions of the firms and regression analysis was used to capture the performance of the Agric-based companies with regards to the reforms in the Agricultural Sector in Nigeria. Cobb-Douglas explicit functional model was selected as the lead equation based on econometric, economics and statistical criteria. The results showed the significance of price earnings ratio, net assets per share, dividend yields as well as the dummy variables for Okomu Oil Palm Plc and the results further reflected that the reforms during the periods under review has significantly stimulated the market and operational performance of Okomu Oil Palm Plc and Nestle Nigeria Plc. Based on some indicators; it was shown that these companies has made considerable progress over time.

Keywords: Agric-Based; Nigerian government; Policy; Reform; Stock exchange

INTRODUCTION

Olomola (2007) opined that the neglect of the Agricultural sector upon the advent of oil has confirmed to take its toll on the Nigerian economy. Government’s low budget provision at every fiscal year has made it more worrisome. Hence, Agriculture which used to be the mainstay of the Nigerian Economy has been relegated to the backstage. Agriculture is Nigeria’s second-largest source of national wealth, after oil. Despite the dominant role of the petroleum sector as the major foreign exchange earner, agriculture remains the mainstay of the economy. In addition to contributing the largest share of Gross Domestic Product (GDP), it is the largest non-oil export sector earner, the largest employer of labour, and a key contributor to wealth creation and poverty alleviation, as a large percentage of the population derives its income from agriculture and related activities. Agricultural sector, one of the sources of economic growth, is looked unto to pave the way for economic development since it has the potentials of generating employment opportunities, alleviating food insecurity, encouraging agro-industrialization and improving entrepreneurship through capacity building. The realization of this fact led Nigerian government to embark on several agricultural development programmes, many of which, unfortunately, failed (Manyong et al, 2005 and Ogungbile, 2008). However, over the years, the rate of growth in agricultural production has stagnated, and failed to keep pace with the needs of a rapid growing population, resulting in a progressive rise in import bills for food and industrial raw materials. The potentials of the agri-business sector as a major employer of the growing labour force and earner of foreign exchange have also been undermined.

Given the dominant role of agriculture in the economy, prospects for food security, supply of industrial raw materials and overall economic growth are critically dependent on what happens in this sector. Jacques (2004) quoted the Greek philosopher - Xenophon who said: “Agriculture is the mother of all arts. When it is well conducted all other arts prosper. When it is neglected, all other arts decline. “Also, quoting Jawaharlal Nehru-India’s first post-colonial Prime Minister who remarked as follows: “Everything else can wait but not agriculture.” The role of agricultural sector contributing to economic development depends not only in creating a conducive financial environment for the farming community alone but also an attempt must be extended to develop conditions that will enhance the growth of the Agro-industrial sector as well as food and beverages sector which takes on the excess that is not immediately consumed. The growth of these depends to a large extent on access to finance which can be derived from a variety of sources, especially, from the equity share sold on the Stock Exchange (Yazdani, 2008).

The role of the Nigerian government in agriculture is predicted on the prevailing socio-economic conditions of the Nigerian Society, particularly at independence. The conditions generally made state intervention inevitable. For instance, agriculture provided nearly two-thirds of government’s revenue and foreign exchange earnings in the 1960s (Haggblade, 2005). Also, about 70 percent of the population lived on agriculture for household income and employment. However, the agricultural sector was characterized by little growth of output per capita, low productivity, pervasive illiteracy, static and poorly developed institutions, restrictive markets and unprogressive policy stance or policy inconsistency. The government was unable to ignore these challenges and saw agriculture as the fulcrum ground which the entire national socio-economic development should revolve. Consequently, agriculture was perceived as having a significant role to play in the development process and government intervention was seen as desirable (Haggblade, 2005).

Bello (2007) examined the agricultural sector and its constraints, actions taken to address these constraints, key policy thrusts and directions, strategies adopted to implement the policy actions; ongoing programmes, successes recorded so far, observed gaps in strategy and programmes, and the prospects for the future and the way forward. It must be noted that current achievements recorded in the agricultural sector must be assessed from the perspective of regaining lost ground, especially when viewed from the role agriculture played in the Nigerian society economy in the 1960s to late 1970s. This perhaps underscored the need to go beyond sustaining current achievements to breaking new grounds and positioning agriculture as the mainstay of the Nigerian economy through gainful employment, agro-industrial development and growth, raw material production for industry, enhanced foreign exchange earnings, food security and poverty reduction (Akande and Olomola, 2007). The ongoing effort of the federal government to reposition Nigeria among respected and economically stable nations is challenging. The Obasanjo Administration did therefore, undertake very wide and penetrating reforms in the Nigerian economy such as the National Economic Empowerment and Development Strategy (NEEDS), the liberalization of the economy in order to reduce the opportunities of rent-taking officials, fiscal discipline, free market and privatization among others over the period of his two-term tenure from 1999-2007 (John, 2011 and Augustine, 2007). These reforms were inevitable if the economy was to achieve the desired level of growth and if poverty is to be reduced to its barest minimum by reducing unemployment rate and avoiding the vulnerability to fluctuations in oil prices and thereby improve the average income per capita of the citizens. Reforms in the Agricultural Sector Agriculture has not been spared the strokes of the now pervasive reforms process. Right from the onset of the civilian dispensation, it was considered an advantageous policy to fuse agriculture and rural development into a single government ministry. In 2001, the National policy and strategy for Integrated Rural Development was launched and adopted as a replacement for that enacted as far back as 1989. The key leaning of the new policy were said to be, among others: the creation of a conducive macro-economic environment to stimulate greater private sector investment in agriculture; the rationalization of the roles of the different tiers of government; reorganization of the industrial framework for government interventions in the sector; actualizing and implementing integrated rural development; increased budgeting allocation to enhance production and productivity; increasing fiscal incentives to agriculture and reviewing trade regulations; promoting increased use of machinery and input through favourable tariff policy.

For most sub-Sahara African countries including Nigeria, agricultural development is considered to hold the key to economic development. In view of this, development Economists insist that, if there is to be a structural transformation in output and labour force in the long-run, there must first be in the short-run some successful policies of agricultural development to facilitate this transformation (Ayodele, 2000). According to Essien (2005), most countries of the world have undertaken one form of economic reform or another at a time in their history. The goals of these reforms may differ from country to country: nevertheless, they are all closely aligned towards putting their economies on a path of sustainable growth and development. Consolidating on the policies made to reform agriculture in Nigeria, the National Economic Empowerment and Development Strategy (NEEDS) sets the following targets to restore agriculture to its former status as a leading sector in the economy. a. Achieve minimum annual growth rate of 6 percent in agriculture b. Raise agricultural exports to $3billion in 2007. c. Drastically reduce food imports from 14.5% of total imports to 5% by 2007 d. Protect all prime agricultural lands for continued agricultural Production e. Develop and implement a scheme of land preparation services to increase cultivable arable land by 10% a year and forest private sector participation through incentive schemes.

The Nigerian Stock Exchange is the major stock exchange of Nigeria. It is headquartered in Lagos and was established on September 15, 1960 and then known as Lagos Stock Exchange (LSE) In December 1977, it came to be called “The Nigerian Stock Exchange and it currently consists of nine trading floors located at Lagos, Kaduna, Kano, Onitsha, Ibadan, Yola, Abuja, Port Harcourt and Benin-city. As of March 9, 2007, it has 283 listed companies with a total market capitalization of N15 trillion ($125billion). All listings are included in the only index, the NSE All Share Index. The Exchange has an Automated Trading System (ATS). Data on listed companies’ performance are published daily, weekly, monthly, quarterly and annually. Ambe (1998) wrote that the Nigerian capital market performs a lot of roles in the development of the economy. The roles include providing: a. opportunities for companies to borrow funds for investment purposes b. an avenue for marketing of shares and other securities to the investing public in order to raise fresh funds for expansion of operations of companies. c. opportunities for governments to finance their projects, including infrastructure for socio-economic development. d. needed SEED money for venture capital and encouraging good corporate governance by ensuring transparency, good accounting and management practices. Agro-Allied Sub-Sector Stock Market Guide (2005) forecasted that the Agric-sector is promising in terms of prospects for rapid growth over the few years. This is strongly indicated by the impressive annual growth of about 7.0 percent recorded in 2003-one of the highest sectoral growth records obtained in the year. Improvement in capacity plus emerging opportunities for exports should raise new hopes and expectations for investors. The low import content of agricultural output is expected to preserve profit margin. The operator has a firm control of their market in terms of customers, prices and margins. This put them in a position to achieve some of the highest growth rates in sales and profit in the stock market. In 2003, listed agric. companies came among the top equities that recorded the highest price appreciation. At the NSE, seven companies are quoted under the Agricultural/Agro-allied sub-sector. However, only about two to three companies have been operating as a going concern; Okomu Oil Palm Plc and Presco Plc., located in Benin City. The companies have continued to compete favourably even as they design strategies to expand their share of the market. ( NSMA (2005) ) however, wrote that the two companies have constantly appreciated the contribution of their shareholder’s towards their continued growth. For instance, Okomu Oil paid a dividend of 45k per 50k share in 2007; this probably explained the rise in price of Okomu to N18.45 as at August 2004.

From a global perspective, the state of the capital market gives an idea of the state of health of the national economy. It also measures the stability of the economy with regards to the extent to which economic activities can rely on it. -Essentially the level of national economic development and the extent to which most economic activities can effectively rely on the safety of the capital market are major indicators of a healthy balance between a sound financial system and macro-economic stability. Having briefly considered the reforms in the agricultural sector, it is therefore imperative to examine its effects on the market and operational performance on agri-business in Nigeria. The agricultural sector, prior to the inception of the Obasanjo Administration in 1999 was characterized by decaying infrastructure, poor research facilities, low yield of crops, high post-harvest losses, poor institutional linkages and partnerships, inconsistent macro-economic policies, lack of appropriate technology and modern inputs, weak extension services, ineffective control of pests and diseases and poor data base or policy formulation. The reform measures to tackle these problems commenced with the updating of the existing agricultural policy and approval of a new policy in 2001. What then are the effects of these reforms on the performance of listed based companies on the NSE? The dismal performance of Nigerian agriculture in the last two decades raises a number of critical questions in relation to the perceived roles of agriculture in the process of economic development: First, to what extent has Nigerian agriculture been able to perform its roles? Second, how have different policies failure had significant effects on the agricultural sector and consequently on the growth of quoted agric-based companies on the NSE? Third, what implications do these have for Nigeria’s agricultural, private and public sector development in the future? These and other pertinent issues are the focus of this study.

The broad objective of this study is to critically examine the effects of Agricultural sector reforms on the performance of some quoted Agric-based companies on the Nigerian Stock Exchange (1993-2007). Specifically, the study aims at achieving the following objectives: i. identify the different economic reforms in the Agricultural Sector in Nigeria from 1999-2007 ii. access the impacts and shared values of the companies under consideration on the Nigerian economy. iii. evaluate the trend in some financial ratios of these companies. iv. evaluate the performance of the Agric-based companies with regards to the reforms in the Agricultural Sector in Nigeria..

RESEARCH METHODOLOGY

Focus of Study This study focuses on the agric-based companies of the Nigerian Stock Exchange: Okomu oil palm plc from the Agriculture sub-sector as well as Nestle Nigeria Plc from Food/Beverages Sub-sector. The former uses oil palm (Elaeis guineensis) as its major raw material and the latter uses cocoa (Theobroma cacao).

Data Collection Procedure Literatures on the Agricultural sector reforms in Nigeria from 1999 to 2007 were sourced from secondary sources – such as journals, conference monographs, and occasional papers, as well as magazines and workshop proceedings. Data for the performance indicators of the Agric-based companies are extracted from verifiable, published sources - Central Bank’s statistical bulletin, official daily lists and fact-books of the Nigerian Stock Exchange for various years and Annual Reports of the companies in question filled at the NSE in accordance with the provision of the companies and Allied Act (CAMA, 1990). For the purpose of establishing their real performance before the recent crash of the stock market (caused by world economic recession), a cut-off period is established: 1993-2007. Any report with an accounting year-end earlier or later than this cut-off period are left out of the assessment; this will facilitate the understanding of the probable effects of changing policies of the government and that of the reforms. A time series analysis was used and the data that were not directly available in all these sources were estimated indirectly by using simple arithmetic manipulation, interpolation and by ratio analysis used in Financial Management. Ratio analysis is a process of identifying the financial strengths and weaknesses of the firm. This may be accomplished either through a trend analysis if the firm’s ratios over a period of time or through a comparison of the firm’s ratios with its nearest competitors and with the industry averages.

Analytical Framework The variable of the study were measured and analyzed statistically. Financial ratios such as : Return on Equity - (ROE), Average Price/Stock Price per Share, Earnings Yield, Dividend Yield, Price-Earnings Ratio – (PER), Profit Margin Ratio – (PMR), Net Asset per Share – (NAPS) were employed. These helped to ascertain the financial conditions of the firms and regression analysis was used to capture the fourth objective. The multiple regression equation models are as follows: Implicit Functional Model: Y = f(X1, X2, X3, X4, X5, X6, X7, µ) ………………………………………………………..(i) Explicit Functional Models: a. Linear Function Y = bo + b1X1 + b2X2 + b3X3 + b4X4 + b5X5 + b6X6 + b7X7 + µ ……………………(ii) b. Semi-Log Function Y = bo + b1lnX, + b2lnX2 + b3lnX3 + b4lnX4 + b5lnX5 + b6lnX6 + b7lnX7 + µ ……...(iii) c. Double-log function/Cobb-Douglas Model: LnY = bo + b1lnX, + b2lnX2 + b3lnX3 + b4lnX4 + b5lnX5 + b6lnX6 + b7lnX7 + µ …...(iv) Where: Y = Profit after Tax (in Naira), X1 = Return on Equity (in per cent), X2 = Earnings Yield (in per cent), X3 = Dividend Yield (in per cent), X4 = Price- Earnings Ratio (in per cent), X5 = Profit Margin Ratio (in per cent), X6 = Net Assets per Share (in Kobo), X7 = Dummy variable (0 = before the reforms, 1999; 1 = during the reforms, 2000-2007), µ = Random Error Term, Number of years considered = 15 years (1993 – 2007). One of the above explicit functions was therefore chosen as the Lead equation base on the function that has the highest R2, highest F-value, function that has more significant ß (coefficient) and the function that has more ß (coefficient) with correct expected sign. The a priori Expectation is expressed as: b1›0, b2›0, b3‹0, b4›0, b5›0, b6›0, b7›0. It is therefore expected that X1, X2, X4, X5, X6 and X7 would have positive relationships on the Profit after Tax. This implies that if the variables increase, ceteris paribus, the PAT would also increase and vice versa. Only the X3 is expected to have a negative relationship with the PAT. That is, if X3 increases, the PAT would decrease, all things being equal, and vice versa.

RESULTS AND DISCUSSION

Okomu Oil Palm Plc The equation was significant at 1% and 5% levels. The coefficient of multiple determination (R2) of the lead equation was 0.91 which implies that 91% of the total variation in the PAT was explained by the modeled explanatory variables included in the regression model while the remaining 9% was explained by the error term. Also, the F-value 58.603 is significant at 1% which showed that the model used was fit and appropriate for the data. The explicit form of the equation is as shown below: In Y = 14.196 + 0.126X1 – 0.007X2 – 1.178X3** – 1.670X4*–0.088X5 + 1.497X6* + 1.089X7* (5.758) (0.509) (-0.263) (-2.548) (-2.591) (-0.227) (4.913) (4.435) R2 = 90.8% Adj. R2 = 89.1% F – value = 58.603 The values in the parenthesis are standard T-values.

Out of the seven explanatory variables captured in the model, X4, X6 and X7 were significant at 1% while X3 was also found to be significant at 5%. This implies that these four variables exerted significant effect on the profit after Tax. Dividend Yield (X3) showed a negative relationship with the PAT, which is in conformity with the a priori expectation. It connotes that for every 1% decrease in the DY, the PAT is decreased by 1.178%. Price–Earnings Ratio (X4) showed a negative relationship with the PAT, which is not in conformity with the a priori expectation. It indicates that for every 1% increase in PER, the PAT is decreased by 1.670%. Net Asset per Share(X6) showed a positive relationship with the PAT, which is in conformity with the a priori expectation. This also implies that for every 1% increase in NAPS, the PAT would increase by 1.497%. Dummy variable (X7) showed a positive relationship with the PAT, which implies that Agricultural sector reforms between 2000 and 2007 with the value of 1, have significant effect at 0.007 (that is, 1%) on the PAT of Okomu Oil Palm Plc., used as a proxy for the profitability and performance of the company.

Nestle Nig Plc The equation is significant at 1% and 10%. The coefficient of multiple determinations (R2) is 0.895 which implies that 89.5% of the total variation in the PAT was accounted for by the set of the explanatory variables captured in the model. It could also be said that 10.5% of the total variation in the PAT was accounted for by other predictors not included in the regression model. Also, the F-value is 181.982 and it is significant at 1%. Out of the seven predictors captured in this study, X1, and X6 were found to be significant at 1%, while only X5 was significant at 10%. This implies that only three variables were found significant to influence PAT. The explicit form of the equation Nestle Nig Plc is as shown below: In Y =10.427 + 0.742X1* – 0.316X2 – 0.159X3 – 0.003X4 – 0.513X5*** + 1.071X6* + 0.099X7 (8.687) (5.395) (-0.931) (0.799) (-0.184) (1.654) (12.134) (-0.604) R2 = 89.5% Adj. R2 = 88.9% F – value = 181.982 Return on Equity (X1) showed a positive relationship with the PAT, which is in conformity with a priori expectation. It implies that for every 1% increase in ROE, the PAT would increase by 0.742%. Profit Margin Ratio (X5) showed a negative relationship with PAT, which is not in conformity with the a priori expectation. It implies that for every 1% increase in PMR, the PAT is decreased by 0.513%. Net Asset per Share (X6) showed a positive relationship with the PAT, which is in conformity with the a priori expectation. It implies that for every 1% increase in NAPS, the PAT would increase by 1.871%.

Table 1: Multiple Regression Result on the Determinants of PAT Price- Profit Adjusted Functional Return on Earnings Dividend Net Asset Dummy Constant b0 Earnings Margin R-square R-square F – Value form Equity b1 Yield b2 Yield b3 Per Share b6 Variable b7 -2 Ratio 44 Ratio b5 R Okomu Oil Palm Plc Linear -5.1×108** -1.05×106 -2.51×107*** 81.00% 66.70% 5.684

(T-value) (-2.323) (-0.689) 1.99×107** (-1.740) -64623.97 -39461* 691162.6*

-2.401 (-0.046) (-3.952) -4.226 1.64×108 -1.211 Semi-log -3.97×108 -7.12×106 -1.4×102 -1.52×108 -3.88×108 -1×108 1.7×108 4.39×108* 83.60% 81.20% 11.187 (T-value) -0.399 -0.07 (-1.427) (-0.795) (-1.370) -0.712 -1.529 -3.936

Double log 14.196 0.126 -0.007 -1.178** -1.670* -0.088 1.497* 1.089* 90.80% 89.10% 58.603 (t – value) -5.758 -0.509 (-0.263) (-2.548) (-2.591) (-0.227) -4.913 -4.435

Nestle

Nigeria Plc Linear -1.756×109

(t-value) 5.23×106 -8.50×107 3.217×107 74.90% 73.30% 67.687

(-1.353) 5.×107 2.8×107* 4.58×106* 2.31×106

-1.114 (-0.138) -1.162 -9.814

-1.171 -4.06 -0.605 -6.94×108(- Semi-log -1.27×1010 -1.95×109*** 2.544 1.54×109 2.4×107 2.11×109* -4.7×109 86% 83.70% 23.508 1.089) (-2.022) -0.158 -1.549 -1.555 -4.688 -0.567

(t – value) -3.165

Double log 10.427 0.742* -0.316 -0.159 -0.003 0.513*** 1.071* -0.099 89.50% 88.90% 181.982 (t – value) -5.758 -5.395 (-0.931) (-0.799) (-0.184) (-1.654) -12.134 (-0.604)

Table 2 below clearly showed that the average profit after tax of Okomu Oil Palm Plc rose from 27.3% before the reform to 72.7% during the reform (that is, 62.4% increase). Likewise, the average net asset per share rose from 32.6% before the reform to 67.4% during the reform (that is, 51.7% increase). Also at Nestle Nigeria Plc, the average PAT rose rapidly from 15.5% before the reform to 84.5% during the reform (that is, 81.6% increase). Likewise, the net asset per share rose rapidly from 18.1% before the reform to 81.9% during the reform (that is, 77.8% increase).

Table 2: Average PAT and Average NAPS of the Companies. Average Profit After Tax Average Net Asset Per Share

Companies During the Before the Reform Before During Reform Okomu Oil N134,433,341.4 N357,389,875 472.24 kobo 977.68 kobo Palm Plc Nestle Nigeria N720, 928,000 N3,919,457,625 164.14 kobo 740.50 kobo Plc Values were calculated from interpolated data

CONCLUSION AND POLICY RECOMMENDATION

This study is motivated primarily by the need to enhance the performance of two named Agric-based companies on the Nigerian Stock Exchange through the Agricultural sector reforms. In this regard, this exercise has demonstrated that there is a positive relationship between the two. These reforms have been observed to be capable of stimulating the market and operational performance of Okomu Oil Palm Plc and Nestle Nigeria Plc. Based on some financial indicators; it was shown that these companies had made considerable progress over time, as their models were also significant at one per cent, each. Although, the reform process appeared not to have much significant influence on Nestle Nigeria Plc as much as it does on Okomu Oil Palm Plc. The positive effect of the reform on Nestle Nigeria Plc was only shown by its profit after tax on net asset per share computed and the return on equity.

In absolute terms, the reforms in the Agricultural sector have had significant effects on the performance of the two quoted Agric-based companies on the Nigeria Stock Exchange. The effects have been shown through the increasing trend in the profit after tax of the companies as a true measure of their performance. Agricultural sector at large that has a growth rate of 2.8 per cent in the 1990s has now been growing at 7 per cent since 2003 (Soludo, 2006). The message is that the Nigeria economy is changing its fundamental ways and the rest of the world is taking notice. From a perception of Nigeria as a hopeless case for investment, the growing view now is that Nigeria is a preferred investment destination. It is against this background that this question should be asked: will the Obasanjo-initiated reforms be sustained? The answer to this question would determine the rate of investment in the Agricultural sector by Nigerians at home, in the Diaspora and by Foreign Direct Investment (FDI); as agriculture, in the near future, holds the key to growth, employment and poverty reduction. The outcomes of the reforms have been impressive. Evidently, the first thing to do is to keep doing the right things we are doing now, continue with the reforms under the NEEDS framework. Build upon the current momentum of reforms, sustain them and even take them to the next higher levels. In the next few years, the name of the game will continue to be REFORMS, REFORMS!

Policy Recommendations The Federal Government should vigorously pursue the ongoing reform efforts in the Agricultural sector and ensure that they are completed – and not abandoned – a task to which this government is fully committed; through appropriate funding of the reform process. It is also important to make critical evaluation of the successes and failures as well as entrench learning in the process while making necessary adjustments. There is equally the need to formulate deliberate policies to make the Nigerian Stock Market more attractive to investors through tax incentives, improved settlement procedure, and considerable reduction in transaction costs. The quoted companies should be encouraged to raise funds for their firm’s expansion from the Nigerian Capital Market. The Government should intensify growth in the Agricultural sector of the economy which will consequently strengthen people’s confidence in the Stock Market investments.

A basic limitation of this study is the unavailability of some relevant data on performance indicators such as Market value of share, number of ordinary share, number of deals recorded during the year etc. for the companies under considerations. Also, the limitation of inability to map out, possibly on one-to-one basis, the relationship between economic reforms in the Agricultural sector in Nigeria and Stock market indicator since most of these variables are inter-related. However, the limitations had been attempted to be resolved by considering the average profit after tax and net asset per share before and during the reform; 1993 – 1999 and 2000 – 2007 respectively.

REFERENCES

Akande, S. O and A. S. Olomola (2007). Consolidating and Sustaining the Gains of Reforms in Nigeria. Workshop Proceedings, 43-57 pp. Nigeria Institute of Social Economic Research (NISER), Ibadan. Ambe, J. (1998). An Analysis of the Performance of Selected Agricultural Sub-Sector in the Nigeria Stock Exchange. (Unpublished B. Agric Thesis) Department of Agricultural Economics and Farm Management, University of Agriculture, Abeokuta, Nigeria. Augustine N. G. (2007). The Nigerian economy and current economic reforms. Is this a book? If yes please state the name and publisher 323pp. Ayodele, A. (2000). The State in the Nigerian Agricultural Development. NISER Review of Nigerian Development, 192- 213 pp. NISER, Ibadan. Bello, D. (2007). Consolidating and Sustaining the Gains of Reforms in Nigeria. Workshop Proceedings, 43-57pp. NISER, Ibadan. Chukwuma, C. Soludo (2006). ‘‘Can Nigeria be the China of Africa?’’ Lecture Proceeding at the Founders’ Day, University of Benin, Benin City, Nigeria. 17-33 pp. Chukwuma, C. Soludo (2006). ‘‘Law, Institution and Nigeria’s Quest to join the First World Economy’’ Lecture Proceeding at O. A. U. Ile-Ife, Nigeria. 4-15 pp. Essien, A. E. (2005). Agricultural Sector under the National Economic Empowerment and Development Strategy (NEEDS). Central Bank of Nigeria Statistical Bulletin, Vol.29. No. 4 Esosa, B. O. (2007). Capital Markets (African and Global). The Book house Company. 333-401pp. Haggblade, S. (2005). From Roller Coaster to Rocket ships: the Role of Technology in African Agricultural Successes. The African Food Crisis Lessons from the Asian Green Revolution. Ikhide, S. I. (1997). ‘‘Financial Sector Reforms and Growth of Capital Market in Nigeria’’ Institute of Developing Economies. V. R. F. Series, No. 291 February, Tokyo, Japan. Jacques, D. (2007). Millennium Agricultural Revolution. Lecture Proceedings at the International Association of Research Scholars and Fellows, IITA, Ibadan. John, I. (2011). Obasanjo, Nigeria and the World. James Currey Publishers, Woodbridge, Suffolk, UK. 213Pp. NEEDS (2004). National Economic Empwerment and Development Strategy. Published by the National Planning Commission. Nestle Nigeria Plc, Annual Reports (Various issues) The years should be indicated Okomu Oil Palm Plc, Annual Reports (Various issues) The years should be indicated Omole, D. A. 1999. Financial Deepening and Stock Market Development in Nigeria. NISER Monogragh Series No. 15. NISER, Ibadan. Pandey, I. M. (2005). Financial Management. Indian Institute of Management Ahmedabad. Pp 531-533. Olawuyi, S. A and I. O. Famojuro (1998). Essential of Research Methodology. Published by Grapheal Printing and Publishing Company. The Stock Market Guide, (2008). Published by Datatrust Stock Trading Guide.Vol. 4 No.7. The Nigerian Stock Market Annuals, NSMA.2005 & 2008 Edition The Nigerian Stock Exchange, Annual report and Acounts (1993-2007). Published by the Authority of the Council of the Exchange. The Nigerian Stock Exchange, Daily Official List (January 1993 - December 2007). Published by the Authority of the Council of the Exchange. The Nigerian Stock Exchange, Factbooks (1993-2007). Published by the Authority of the Council of the Exchange. Yazdani, S. (2008). Financial market development and Agricultural Economic Growth in Iran, American-Eurosian Journal of Sustainable Agriculture, 2 (3), 338-343pp.

Haematological and Biochemical Parameters of Broiler Chicken Supplemented with Humic Acid in the Drinking Water

Lala, A.O.1*; Okwelum, N.1; Irekhore, O.T.2; Ogunlade, B.A.3; Adigun, A.A.3; Elegbede, L.A.3 and Oyedeji, M.M.3

1Institute of Food Security, Environmental Resources and Agriculture Research, Federal University of Agriculture, Abeokuta Ogun State, Nigeria. 2Agricultural Media Resources and Extension Centre, Federal University of Agriculture, Abeokuta Ogun State, Nigeria. 3Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta Ogun State, Nigeria. *Corresponding author: [email protected]

ABSTRACT

This study was conducted to evaluate the effects of supplementing humic acid in the drinking water on some haematological and biochemical parameters of broiler chickens. One hundred and twenty (120), day-old Arbor Acre broiler chicks were randomly divided into three treatments in a completely randomized design. Each treatment of forty birds was replicated 4 times with 10 chicks per replicate and the experiment lasted for 56 days. Treatment I served as the control without humic acid in the drinking water while, treatment II was supplemented with 1 mL/L humic acid and treatment III was supplemented with 2 mL/L of humic acid. Results obtained showed that supplementation with humic acids had no significant effect (P > 0.05) on haematological indices of the broiler chickens. Significant (P<0.05) reduction in serum level of uric acid was achieved as the level of supplementation of humic acid increased while, serum phosphorus and calcium concentrations were significantly (P<0.05) increased with humic acid. Liver function enzymes were not significantly (P>0.05) affected because the activity of serum alanine transaminase and aspartate transaminase were similar among all treatments. The results indicated that humic acid supplementation had a beneficial effect on mineral absorption and detoxification as revealed through uric acid concentration of broiler chickens.

Keywords: blood biochemistry; blood minerals; drinking water; haematology; humic acid

INTRODUCTION

Antibiotics had been used widely world-wide in poultry industry in order to prevent poultry disease and improve production. However, with the unavoidable spread of bacterial resistance and cross resistance the use of antibiotics has been considered hazardous (Andremont, 2000). Several additives have been tested as growth promoters to avoid the excessive use of antibiotics or at least reduce or substitute their inclusion in feeds, while maintaining an efficient animal production to obtain safe edible products (Islam et al., 2005; Gomez et al., 2012). Among these additives are humic substances which have been tested in domestic animals in several studies around the world with promising results. The humic substances are very common in nature as they originate from the decomposition of organic matter, and are normally present in the drinking water and soil (Islam et al., 2005).

Humic acids are naturally occurring decomposed organic constituents of soil and lignite that are complex mixtures of polyaromatic and heterocyclic chemicals with multiple carboxylic acid side chains (MacCarthy, 2001). Farmers utilize humic substances to accelerate seed germination and improve rhizome growth. These materials stimulate oxygen transport, accelerate respiration, and promote the efficient utilization of nutrients by the plant (Visser, 1987). These observations have prompted scientists to assess the specific properties of humates and their possible benefits in the improvement of health and wellbeing in animals (Wang et al., 2008). The use of humic acid to replace antibiotics in poultry has gained widespread interest (Mutus et al., 2006). Beneficial effects of humic acid are described concerning stress management (Enviromate, 2002) immune system (Hooge, 2004; Loddi et al., 2002), anti-inflammatory activity (Yang, 1996), antiviral properties (Huck et al., 1991). It has been observed that humic acid included in the feed and water of poultry promote growth (Kocabagli et al., 2002; Mirnawati and Marlida, 2013). It has also been proposed that humic acid plays an effective role on some blood parameters (Banaszkiewicz and Drobnik, 1994; Rath et al., 2006) and have been used to minimize health problems and potential losses (Yoruk et al., 2004; Kucukersan et al., 2005; Trckova et al., 2006).

Humic acids have been reported to improved immune responses and electrolyte balance in turkeys (Parks et al., 1998). It is considered as safe to be used as the feed additives in animal production (Celik et al., 2008). This study was conducted to evaluate the effect of supplementing humic acid in the drinking water of broiler chickens on the haematological and serum biochemistry parameters.

MATERIALS AND METHODS

The commercial humic acid used is a product of Dynapharmlab Associate SDN. BHD. It contains chelated micronutrients, nitrogen 2.35%, phosphorus 4.44%, potassium 1.75%, magnesium 0.36%, iron 867ppm, manganese 223ppm, copper 144ppm, zinc 153ppm, boron 0.011%, molybdenum 0.002% and humic acid 0.68%. Experimental birds: A total of one hundred and twenty (120) day-old Abor Acre broiler chicks were randomly allocated into three (3) treatments. Treatment I (control) with no humic acid supplementation, treatment II supplementation with 1mL/L humic acid and treatment III with 2mL/L humic acid supplementation in drinking water. Each treatment was replicated four (4) times with ten (10) chicks per replicate. The duration of the experiment was eight (8) weeks; broiler starter mash was fed for the first four (4) weeks while broiler finisher mash was given at the last four weeks. The gross composition of the diets are presented in Table 1. Fresh water was given on daily basis.

Table 1: Percentage composition of broiler chickens basal diets Ingredient Starter (0-4 weeks) Finisher (4-8 weeks) Maize 53.9 60 Fish meal 2.5 0 Soya bean meal 35.6 28 Wheat offal 4 7.7 Bone meal 1.3 1.8 Oyster shell 1.8 1.5 Premix 0.3 0.3 Salt (NaCl) 0.3 0.3 L-lysine 0.1 0.1 L-methionine 0.2 0.3 Total 100 100 Analyzed values

Crude protein (%) 23.64 19.91 Ether extract (%) 3.61 3.51 Crude fibre (%) 3.22 3.27 Calculated values

Calcium (%) 1.08 1.09 Phosphorus (%) 0.43 0.39 Metabolizable energy 11.98 12 (MJ/kg) Starter premix provided: Vitamin A-10,000,000iu, Vitamin D3-2,000iu, Vitamin E-40,000mg, Vitamin K-2,000mg, Vitamin B1-1,500mg, Vitamin B2-4,000mg, Vitamin B6-40,000mg, Vitamin B12-20mg, Niacin-40,00mg, Pantothenic-10,000mg, Folic-1,000mg, Biotin-100mg, Choline-300,000mg, Manganese-80,000mg, Zinc-60,000mg, Iron-40,000mg, Copper-80,000mg, Iodine-800mg, Selenium-200mg, Cobalt-300mg, Antioxidant-100,000mg.

Blood parameters measurements: At the end of the 56 days of the trial, blood samples (5mL/bird) were obtained from 2 chickens per replicate by puncturing the brachial vein. Blood samples were collected into vials containing ethylene diamine tetra-acetate for the determination of haematological indices and the remaining into universal bottles without anticoagulant for serum analysis. Haemoglobin concentration (Hb) was estimated using the cyanmethaemoglobin method (Cannan, 1958). Packed cell volume (PCV), red blood cell (RBC), and white blood cell count (WBC) were determined with Wintrobe haematocrit tube according to the method of Schalm et al. (1975). Differential leucocyte counts (heterophils, lymphocytes, eosinophils, basophils and monocytes) were carried out on blood smears stained with May-Grunwald–Giemsa stain. Sera were harvested from blood by centrifugation and kept inside the freezer until needed for biochemical analysis. Total serum protein and albumin were determined using bromocresol purple method (Varley et al., 1980). Serum uric acid concentration was estimated according to standard procedures of Wootton (1964). Serum creatinine level was determined using the method described by Tietz (1986). Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase were determined by standard methods using Randox test kits (Randox_ Laboratories, Antrim, UK). Calcium and phosphorus were determined using the methods of Gindler and King (1972) and Goodwin (1970) respectively. Statistical analysis: Data generated were subjected to analysis of variance using the general linear model procedure of the SAS (2000). A probability of (P<0.05) was considered to be statistically significant using Duncan Multiple Range Test of the same package. Polynomial contrast (linear and quadratic) was used to determine the effect of varying dosage of humic acid.

RESULTS AND DISCUSSION

The haematological data presented in Table 2 indicated that supplementation of humic acid did not show any significant (P>0.05) effect on packed cell volume, red blood cell, haemoglobin, white blood cell and white blood differential count. Table 3 showed (P<0.05) reduced uric acid concentration in birds supplemented with humic acid when compared to those in the control treatment. Higher (P<0.05) blood Calcium (Ca) and Phosphorus (P) concentrations were obtained in the treatments supplemented with humic acid than control. Serum Ca and P (P<0.05) increased as the level of humic acid supplementation increased. Total protein, albumin, globulin and the liver enzymes (aspartate aminotransferase, alkaline aminotransferase and alkaline phosphatise) showed no significant difference among the treatments. However, haemoglobin and serum globulin were numerically higher in birds supplemented with humic acid than birds in the control group. While creatinine and the liver enzymes were reduced in birds supplemented with humic acid.

Table 2: Haematological parameters of broiler chickens supplemented with humic acid. Humic acid supplemented P-value Parameter level (mL/L) SEM 0 1 2 Linear Quadratic Packed cell volume 31.67 32.33 30.33 1.04 0.634 0.922 (%) Red blood cell 3.18 3.10 2.94 0.21 0.189 0.451 (x106/µL) Haemoglobin (g/dL) 10.60 11.33 11.90 0.39 0.073 0.202 White blood cell 8.83 6.13 5.07 0.87 0.456 0.666 (x109/L) Lymphocytes (%) 66.33 66.67 64.00 1.18 0.92 0.982 Heterophil (%) 29.67 29.00 29.33 1.22 0.056 0.187 Monocyte (%) 2.00 3.00 4.00 0.44 0.381 0.171 Eosinophil (%) 1.67 1.00 2.33 0.28 0.244 0.422 Basophil (%) 0.33 0.00 0.00 0.11 0.067 0.12 SEM= standard error of mean

Table 3: Biochemical parameters of broiler chickens supplemented with humic acid Humic acid supplemented level P-value Parameter (mL/L) SEM 0 1 2 Linear Quadratic Total protein (g/dL) 3.30 3.30 3.80 0.26 0.467 0.72 Albumin (g/dL) 1.83 1.47 1.63 0.14 0.593 0.627 Globulin (g/dL) 1.80 1.83 2.13 0.22 0.57 0.835 Uric acid (mg/dL) 4.53 3.50 3.63 0.18 0.031 0.009 Creatinine (mg/dL) 0.83 0.63 0.60 0.06 0.141 0.3 Aspartate 58.00 51.33 48.67 2.29 0.096 0.254 aminotransferase (U/dL) Alanine aminotransferase 33.67 31.67 25.00 1.90 0.053 0.143 (U/dL) Alkaline phosphatase 30.00 28.67 25.00 1.54 0.203 0.447 (U/dL) Calcium (mg/dL) 5.42 6.4 6.80 0.21 0 0 Phosphorus (mg/dL) 2.58 3.21 3.45 0.13 0 0 SEM= standard error of mean

Similar haematological values obtained from broiler chickens supplemented with humic acid with those in the control group is indicative of tolerance of the humic acid used and the quantity supplemented in the drinking water to the chickens. According to Rath et al. (2006) RBC, WBC and PCV values in broilers were not affected by humic acid supplementation. Similarly, Cetin et al. (2006) reported that supplementation of humic acid to laying hens had no effects on WBC and PCV, but affected, RBC and Hb. However, Banaszkiewicz and Drobnik (1994) reported that Hb, PCV and RBC were observed to increase in rats treated with humic acid. The inconsistency of results obtained in the various studies might be attributed to the composition and quantity of the humic acid used. The increase of Ca and P levels in blood serum produced by humic acid may be attributed to the lowering of gastrointestinal tract pH by using this acid, which increases the absorption of the minerals from the gut into the blood stream. Improvement in the utilization of calcium and phosphorus by organic acids supplementation was revealed by Boling et al. (2001). Also, Abdo and Zeinb (2004) observed an increase in blood calcium of broiler chicks fed on dietary acidifier. Furthermore, (Kishi et al., 1999) reported that dietary acetic acid prevented osteoporosis, through the reduction in bone turnover, as it enhanced intestinal Ca absorption by improving Ca solubility in ovariectomized rats. After humate feeding, increased levels of some essential minerals (such as Ca, Al and Fe) in serum, liver and muscles were recorded by Stepchenko et al. (1991). Whereas, Klocking (1994) reported a reduction in the serum concentrations of Ca and P at 2.5 % level of humic acid, which may be due to its metal chelating effects caused by large number of carboxylic acid side chains. Reduced uric acid concentrations with humic acid could be as a result of better utilization of protein and amino acid digestibility. As uric acid is the major end product of protein metabolism. The present results coincide with the findings of Abdo and Zeinb (2004) who obtained lower uric acid in broiler chicks due to citric acid and acetic acid inclusion. Sturkie (1986) also revealed that dietary addition of organic acid slightly reduced serum concentration of uric acid. Supplementation of humic acid showed no deleterious effects on liver functions enzymes as the values were similar (P>0.05) among the treatments. The result of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase means that broiler chickens could tolerate the addition of up to 2 mL/L of the humic acid without any deleterious effects on liver functions. Abdel-Azeem et al. (2000) showed that level of aspartate aminotransferase was reduced, although alanine aminotransferase was not significantly affected when citric acid was supplemented in the diets of rabbits.

CONCLUSION

The result showed that broiler chickens could tolerate the addition of humic acids in the drinking water up to 2 mL/L without any deleterious effect on the health status.

REFERENCES

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Chemical and Sensory Qualities of Stored Gari Fortified with Soybean and Groundnut Flour

Ajani, A.O.1; Alade, O.A.1; Olagbaju, A.R.1; Fasoyiro, S.B.2; Arowora, K.A.3 and Oyelakin, M.O.1

ABSTRACT

Gari, a creamy white granular food product from cassava roots is a major staple consumed in both urban and rural areas due to its convenience. Gari was fortified with soybeans or groundnut at 10%, 20% and 30% respectively to produce “soy- gari” and groundnut-gari. The samples were analyzed at the initial stage of production and after eight months of storage. The proximate composition showed that moisture content, protein, fat, ash, crude fibre and carbohydrate were in range of 7.97 – 8.93%, 1.17 – 1.57%, 1.33 – 1.47%, 1.67 – 1.73%, 1.67 – 1.63% and 86.20% - 84.83 respectively at the initial production while results at eight months of storage ranged between 8.93 – 9.23%, 1.40 – 3.80%, 1.57– 3.73%, 1.20 – 2.50%, 2.80 – 1.90% and 79.50 – 84.10% respectively for soy-gari. Groundnut fortification increased the protein content from 1.17% to a range of 1.77% - 4.47%, the fat increased from 1.33% to 1.37% - 4.17%; while the carbohydrate content reduced from 86.20% to 84.33% - 78.45%. Sensory evaluation of flour and gari meal (Eba) was conducted. The result showed that gari fortified with 30% soybeans and groundnut preferred most in term of appearance, aroma, texture and mouth feel. The sensory evaluation for the soy and groundnut gari meal (Eba) showed that control samples were the most acceptable followed by the 10% of each legume. However, the increase in protein and other essential nutrients indicate that fortified gari have better nutritional qualities than control gari, therefore if globally accepted, it can prevent protein energy malnutrition.

Keywords: fortification; groundnut-gari; sensory qualities; soy-gari; storage

INTRODUCTION

Cassava (Manihot esculenta crantz) is an important vegetable crop that is grown throughout the tropics and sub-tropics, where it contributes a considerable proportion of the total caloric intake and ranks fourth after rice, wheat and corn on food energy production basis as a source of complex carbohydrates (Beleia et al.,2006). Cassava occupies a prominent position in foreign exchange earning following the Presidential Cassava Initiative of the federal government of Nigeria (FGN, 2006).

Gari (fried, fermented cassava flour) is the most popular cassava products consumed in West Africa and the most important component in the diet of millions of Nigerians providing about 11.835 kJ/person/day (Osho, 2003). However, cassava and its products are low in protein, deficient in essential amino acids and therefore have poor quantitative and qualitative protein content (Obatolu and Osho, 1992). Due to high cost of animal protein and ignorance about the importance of protein in diets, there is need to search for cheaper but good quality protein sources that are readily available for the fortification of “gari” and as this will increase the amount of protein in the diet of the consuming population (Oluwamukomi, 2008). Soybean is an excellent source of dietary protein for human food providing complete human requirement of almost all the amino acids (Liu, 1997). It is also an excellent source of minerals and vitamins (Aworh et al., 1987; Igyor et al., 2006). Recently, many functions of soybeans have been in the spotlight, for example, reducing the risk of heart disease, cancer and so on (Messina et al., 1994). Soybean is the concentrated source of vegetable protein with about 40% protein and 20% oil. Groundnut (Arachis hypogaea L.) is the 6th most important oil seed crop in the world. It contains 48-50% oil, 26-28% protein and 11-27 % carbohydrate, minerals and vitamin (Mukhtar, 2009). Groundnut is grown on 26.4 million hectare worldwide, with a total production of 37.1 million metric tons and an average productivity of 1.4 metric tons /ha. Developing countries constitute 97% of the global area and 94% of the global production of this crop (FAO, 2011).

In tropical and sub-tropical areas of the world, feeding of the fast growing population has continued to pose a serious problem. These areas are also characterized by a shortage of animal protein and incidences of protein energy malnutrition are higher because they are rich in starchy tubers, such as yam, cocoyam and cassava (Hernandez et al., 1996). Hence, continuous dependence on gari without fortification with protein-rich sources would result in protein deficiency. Soybean and groundnut are protein-rich legumes with good essential amino acids profiles are potentially useful for this purpose. This study aims to determine the chemical and sensory qualities of gari fortified with soybean and groundnut flour.

MATERIALS AND METHODS

Freshly harvested improved cassava cultivar (TMS 30572) sourced from IITA, Ibadan, Nigeria. Soybean seed (TGx536- 02D) was obtained from the seed store of IAR&T, Ibadan. Groundnut and other ingredients were purchased from Bodija market in Ibadan, Oyo State, Nigeria.

Methods Production of gari supplemented with soybean or groundnut Freshly harvested non-infected cassava roots was washed using potable water and peeled using kitchen knives. The peeled roots was washed and grated in a cassava grater. Grated cassava was fermented for 3 days and the liquor squeezed out using hydraulic press. Drained grated cassava was sifted to remove fibre and roasted. Soybeans of white variety were cleaned by removing stones, sticks and damaged beans and washed using potable water. The soybeans seeds de-hulled by soaking in potable water for 12 hours, follow by hand –rubbing (within two palms) to remove the hulls. The floated hulls were removed by decanting until no hull was present. De-hulled soybean seeds were milled in slurry form (wet mill) and mixed with fermented cassava roots the second day. Matured and wholesome grains of groundnut were slightly roasted, de-coated and winnowed. This was washed with potable water and wet milled. The slurry was incorporated into the grated cassava and pressed to drain. The dewatered cassava mash were roasted, cooled and sieved before packaged inside the hessian bags. The proportions of soybean or groundnut added to cassava are; 100:0, 90:10, 80:20 and 70:30 respectively. The packaged fortified samples were stored for eight months under hermetic conditions at room temperature and were taken for analysis at the end of eight months storage.

Proximate Composition of Soy-gari and Groundnut-gari Samples Moisture content, protein, fat, ash, crude fibre and carbohydrate were determined according to the method of AOAC (1990).

Sensory Evaluation A preference test was carried out to determine the most acceptable sample. The samples were coded and presented to 10- member semi trained panelists who were familiar with cassava products. The samples were scored for the appearance, colour, aroma, texture, mouthfeel and overall acceptability using a nine point hedonic scale where 9 indicated `like extremely` and 1 indicated dislike extremely. Analysis of variance (ANOVA) was performed on the data gathered to determine differences, while the least significant test was used to detect significant differences among the means (Ihekoronye and Ngoddy, 1985).

Statistical Analysis Data collected were subjected to analysis of variance (ANOVA) using the Statistical Package for Social Statistics (SPSS version 20.0). Results were expressed as means and standard errors of the mean (SEM) while means were separated using The Duncan’s New Multiple Range Test (Steel et al.,1997).

RESULTS AND DISCUSSION

The results of the initial and eight months proximate analyses of soy-gari, groundnut-gari and control “gari” samples are shown in (Tables 1 and 2). The moisture content of the products obtained was between 7.97% - 8.93%: 8.93 % - 9.23% for soy-gari; groundnut-gari ranged between 7.97%-8.77% : 8.93% - 9.23% respectively. This shows that gari was well roasted (dried) and all the samples were below the safe moisture level for gari (12.7%). The fortified samples are good sources of protein, fat and ash. The protein significantly increased from 1.17% for the control to 1.37% - 1.57%: 2.50% - 3.80% (soy- gari), 1.77% - 2.60%: 3.50% - 4.47% (groundnut-gari). This is similar to earlier studies by Oluwamukomi et al., 2014, Arisa et al., 2011 who increased the protein content of “gari” by supplementing with legume protein sources. The fat content increased from 1.33% for the control to 1.20% - 1.47%: 3.07% - 3.73% (soy-gari), 1.37% - 1.63% : 3.53% - 4.17% (groundnut-gari). This trend could have been due to the fact that groundnut has a high percentage of fat as it is an oil bearing seed (Srilakshmi, 2006); Okaka, 2005. The increase in ash contents of the samples show that fortified produced “gari” were of higher nutritional value. This confirms the beneficial effect of vegetable protein enrichment which was recommended as a means of providing high nutrient and energy density weaning foods (Fashakin et al., 1985). The crude fibre content reduced from 1.67% for the control to 1.63% - 1.55%: 1.90% - 1.63% (soy-gari), 1.80% - 1.60%: 1.67% - 1.47% (groundnut gari).

Fortification resulted in decrease in the crude fibre and carbohydrate content of the gari as the level of fortification increased. The carbohydrate content showed a gradual reduction as the level of substitution increased (86.20% to 78.50%).These reductions could have been due to the fact that as the cassava mash was reduced and replaced with groundnut and soy-bean mash (which had lower fibre and carbohydrate contents than the cassava mash), the percentage of these nutrients in the resultant product became lower. These reductions are in accordance with Uzopeters et al., (2008) who reported a reduction in the crude fibre and carbohydrate content of kokoro substituted with different levels of defatted groundnuts and soybean cake flours. A panel of tasters was composed to evaluate the organoleptic properties of the food blends prepared from the fortified gari and the non-fortified one. The panel found that in terms of appearance, colour, aroma, texture, mouth feel and overall acceptability; there was slight significant difference between the two blends. Although sample 207 with 30% groundnut was most acceptable while the least was 10% soy-gari. Sensory evaluation conducted on the gari meal was based on the following parameters; appearance, color, aroma, texture, mouth feel and overall acceptability. Sample 204 (unfortified meal) was the most preferred while 30% groundnut gari meal was the least may be because the meal was too brownish and cannot made dough easily compare to the conventional one.

CONCLUSION

From the results it could be concluded that fortification improved the nutrient quality of “gari” especially the protein, fat, ash and the mineral contents. The result revealed that protein contents in groundnut-gari was higher than soy-gari this may be due to groundnut roasted .The acidity of the fortified samples was reduced thus lowering the sourness of “gari”. This may be an advantage for people who are not interested in sour taste of “gari”. Based on the evaluation, groundnut-gari may be good only for drinking not for making meal’eba’. Also, during the processing, it took longer time to roast gari with groundnut especially at 30% level of substitution. However a further research work must be carried out to evaluate its nutritive value when consumed by humans and commercial production of the product may also be embarked on to further add to the variety of snack drinks available.

REFERENCES

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Table 1: Initial Proximate Analysis (%) of Soy-gari and Groundnut-gari samples. Compositions Samples (%) 201 202 203 204 205 206 207 Moisture 8.27±1.53d 8.28±0.12d 8.93±0.06a 7.97±0.06 e 8.43 ±0.12cd 8.77±0.10bc 8.77±0.06ab Crude Protein 1.37±0.12e 1.49±0.06de 1.57±0.15d 1.17±0.06 f 1.77±0.06 c 2.27±0.15b 2.60±0.10a Crude fat 1.20±0.00d 1.35±0.10bc 1.47±0.06b 1.33±0.06c 1.37±0.06 bc 1.40±0.10bc 1.63±0.06a Ash 1.70±0.10a 1.73±0.06a 1.57±0.06bc 1.67±0.06 ab 1.53±0.06 c 1.63±0.06abc 1.63±0.06abc Crude fibre 1.60±0.10b 1.55±0.06b 1.63±0.06b 1.67±0.12ab 1.60±2.72 b 1.63±0.12b 1.80±0.00a Carbohydrates 85.87±0.31ab 85.62±0.31 abc 84.83±0.29cd 86.20±0.20a 85.33±0.12 abc 85.10±1.15bcd 84.33±0.15d Mean values followed by different alphabet within a row are significantly different (p ≤ 0.05). where: 201 is 10% Soy-gari, 202 is 20% Soy-gari, 203 is 30% Soy-gari, 204 is Control, 205 is 10% Groundnut-gari, 206 is 20% Groundnut –gari and 207 is 30% Groundnut – gari.

Table 2: Proximate Analysis (%) of Soy-gari and Groundnut gari at 8 Months of Storage. Compositions Samples (%) 201 202 203 204 205 206 207 Moisture 9.07±0.06ab 9.23±0.15a 8.67±0.15d 8.93±0.06bc 8.73±0.15cd 8.83±0.06cd 9.23±0.15a Crude Protein 2.50±0.10e 3.60±0.10d 3.80±0.10c 1.40±0.10f 3.50±0.10d 4.10±0.10b 4.47±0.15a Crude fat 3.07±0.06c 3.57±0.15b 3.73±0.12b 1.57±0.15d 3.53±0.06b 3.97±0.12a 4.17±0.12a Ash 2.33±0.06c 2.23±0.06c 2.50±0.10b 1.20±0.00d 2.27±0.15c 2.77±0.12a 2.53±0.06b Crude fibre 1.73±0.06bc 1.90±0.10b 1.63±0.12cd 2.80±0.10a 1.67±0.15c 1.47±0.06d 1.60±0.10cd Carbohydrates 81.10±0.30b 79.83±0.12d 79.50±0.26d 84.10±0.17a 80.23±0.15c 78.45±0.21e 78.60±0.17e Mean values followed by different alphabet within a row are significantly different (p ≤ 0.05). where: 201 is 10% Soy-gari, 202 is 20% Soy-gari, 203 is 30% Soy-gari, 204 is Control, 205 is 10% Groundnut-gari, 206 is 20% Groundnut –gari and 207 is 30% Groundnut – gari.

Table 3: Sensory qualities of Soy-gari and Groundnut- gari Samples Parameters 201 202 203 204 205 206 207 Appearance 2.14±1.61e 4.85±1.83cd 5.85±1.09bc 2.35±1.44e 4.42±1.65d 6.35±1.54b 8.92±0.26a Colour 2.64±2.13de 5.28±1.85c 5.00±1.79c 2.07±1.14e 3.78±1.36d 6.57±1.39b 8.85±0.36a Aroma 3.14±1.83cd 4.78±1.92b 4.57±2.06bc 2.35±1.27d 4.57±2.06bc 5.92±1.97b 8.35±1.86a Texture 4.00±2.74cd 4.28±2.09cd 5.35±1.78bc 2.85±1.99d 4.71±1.85c 6.50±1.50ab 7.85±2.10a Mouthfeel 3.42±2.37c 4.78±2.00bc 5.92±1.73b 3.64±2.59c 3.85±2.24c 6.21±1.05b 8.00±1.83a Overall appearance 2.71±2.43d 4.78±1.84bc 5.85±1.61b 2.85±2.10d 3.92±1.77cd 6.14±1.95b 8.00±2.32a Mean values followed by different alphabet within a row are significantly different (p ≤ 0.05). where: 201 is 10% Soy-gari, 202 is 20% Soy-gari, 203 is 30% Soy-gari, 204 is Control, 205 is 10% Groundnut-gari, 206 is 20% Groundnut –gari and 207 is 30% Groundnut – gari.

Table 4: Sensory Qualities of Soy and Groundnut Eba

Samples Parameters 201 202 203 204 205 206 207 Appearance 7.00c ± 1.76 5.36b ± 1.00 4.73b ± 1.79 8.09c ± 0.34 4.73b ± 1.68 3.09a ± 1.50 4.36ab ± 2.20 Colour 6.27c ± 2.28 5.82bc ± 1.35 4.91bc ± 1.66 8.27d ± 1.35 4.82bc ± 1.51 3.00a ± 1.47 4.27ab ± 1.95 Aroma 6.18bc ± 2.15 5.64ab ± 1.33 4.46ab ± 1.90 7.46c ± 1.92 5.73ab ± 1.97 4.27a ± 2.01 4.36a ± 1.80 Texture 5.91b ± 2.74 4.64ab ± 1.64 4.27ab ± 1.49 8.00c ± 0.77 4.27ab ± 1.85 4.09a ± 1.08 4.55ab ± 1.75 Mouthfeel 5.64b ± 2.33 4.55ab ± 1.75 3.82a ± 1.79 7.46c ± 1.21 4.27ab ±1.66 4.27ab ± 1.92 3.91ab ± 2.12 Overall appearance 6.55cd ± 2.23 5.18bc ± 1.63 4.27ab ± 1.92 7.91d ± 1.14 4.55ab ± 1.56 4.18ab ± 1.33 3.46a ± 1.13 Mean values followed by different alphabet within a row are significantly different (p ≤ 0.05). where: 201 is 10% Soy-gari, 202 is 20% Soy-gari, 203 is 30% Soy-gari, 204 is Control, 205 is 10% Groundnut-gari, 206 is 20% Groundnut –gari and 207 is 30% Groundnut – gari

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Ajani, A.O.1*; Fasoyiro, S.B.2; Arowora, K.A.3; Ajani, O.O.4; Popoola, C.A.5 and Zaka, K.O.1

1Nigerian Stored Products Research Institute, Onireke, Ibadan, Oyo State, Nigeria. 2Institute of Agricultural Research and Training, Moor Plantation, Ibadan, Oyo State, Nigeria. 3Department of Biochemistry, Federal University of Technology, Wukari, Taraba State, Nigeria. 4Department of Chemistry, Covenant University, Canaanland, Ota, Ogun State, Nigeria. 5Department of Food Science and Technology, Federal University of Technology, Wukari, Taraba State, Nigeria. *Corresponding author: [email protected]

ABSTRACT

Breadfruit is one of the underutilized crops in Africa. It is a valuable food resource but the usage is limited due to poor storage properties of the fresh fruit. Breadfruit was processed hygienically into dried chips using NSPRI multipurpose drier powered by kerosene stove. The chips were milled into flour and mixed with wheat flour in the following ratio (wheat flour : breadfruit flour; 100:0, 90:10, 80:20, 70:30, 60:40, 0:100) packed in 0.04mm thick gauge transparent polyethylene nylon and evaluated for its functional properties. Water absorption capacity of the blend ranged from 161– 402 % while oil absorption capacity ranged between 106 – 160 %. The loose bulk density, packed bulk density, emulsion capacity, emulsion stability, foaming capacity, foaming stability and least gelation concentration of the breadfruit- wheat composite flour were in the range of 0.38 – 0.47g/ml, 0.62 – 0.66g/ml, 14.2 – 18.8%, 6.6 – 11.9%, 7.5 – 11.3%, 3.7 – 7.0% and 16.7 -27.8% respectively. The results from the flour blends showed that the flour may be useful for confectionery products, aerated foods and high nutrient density weaning foods.

Keywords: breadfruit; confectionery products; functional properties; multipurpose dryer; storage

INTRODUCTION

Breadfruit (Artocarpus communis) is a tree and fruit native to Malaysia and countries of the South Pacific and the Caribbean. Breadfruit has been an important staple crop and component of traditional agro-forestry systems in the Pacific for more than 3,000 years. It is an important food in these areas (Taylor and Tuia, 2007). The tree has a great productive ability with an average sized tree producing 400 to 600 fruits per year (Adepeju et al.,2011). It produces fruit twice a year, from March to June and from July to September with some fruiting throughout the year. Present level of breadfruit production in the South-Western Nigeria has been estimated to about 10million tonnes dry weight per year with potentials for exceeding 100million tonnes every year (Adewusi et al., 1995; Ajayi, 1997). Breadfruit is a versatile crop and the fruit can be cooked and eaten at all stages of maturity. It is an excellent dietary staple and compares favorably with other starchy staple crops commonly eaten in the tropics, such as taro, plantain, cassava, sweet potato and white rice. Breadfruits contain a sizeable quantity of carbohydrates with low levels of protein and fat and a moderate glycemic index. These carbohydrates, utilized as simple sugars (such as fructose and glucose) by the body are readily used to enhance the energy generation process in the body. Breadfruits contain essential vitamins and antioxidants, such as xanthin, which work to protect the body from the debilitating attacks of bacterial and viral agents. 100 grams of breadfruit contains an impressive inventory of vitamins which includes vitamin B1 (0.2 mg), vitamin B6 (0.1 mg), vitamin C (29.1 mg), vitamin E (0.1 mg), niacin (0.9 mg) and chloine (9.81 mg). It is a good source of dietary fiber, potassium, calcium, and magnesium with small amounts of thiamin, riboflavin, niacin and iron. Some varieties contain small amounts of folic acid. Yellow-fleshed varieties can be a good source of provitamin A carotenoids (NTBG, 2013). It is typically consumed when mature, but still firm and is a delicious substitute for any starchy root crop, vegetable, pasta, potato or rice. Sliced breadfruit can be fried to make chips or French fries and pounding like pounded yam (Morton, 1987). The breadfruit pulps are made into various dishes; it can be pounded, fried, boiled, or mashed to make porridge; it can also be processed into flour and used in bread and biscuit making (Amusa et al., 2002). Breadfruit is highly nutritious, cheap and readily available in overwhelming abundance during its season, it has found limited applications in the food industries (Omobuwajo,2003). Although, a lot of work has been done on breadfruit but the objective of this work is to assess the functional properties of composite flour from breadfruit and wheat flour.

MATERIALS AND METHODS

Material Collection

Matured green ripe and wholesome fruits of breadfruit (Artocarpus communis) were obtained from Ajifowobaje – Ilode market in Ile-Ife, Osun State. Commercial wheat flour (Eagles flour Mill, Ltd, Ibadan, Nigeria) was purchased from Bodija market in Ibadan, Nigeria.

Production process of breadfruit flour

Breadfruits were processed into flour as shown in Figure 1. Wholesome breadfruit samples were washed, peeled and sliced manually into 1cm thick slices using stainless steel knife. The washed sliced breadfruit pieces were immersed in a 70ppm solution of sodium metabisulphite. The sulphited slices were steam blanched at 70oC for 10mins in a water bath (Clifton model) and then dried at 550C for 16hrs using a cabined dryer. The dried chips were sieved (Model BS 410) (Giami et al.2004). The flour was packaged in thick gauge (0.04mm) transparent polyethylene nylon for further use.

Matured Breadfruit

Washing

Peeling

Slicing

Washing

Sulphiting

Steam Blanching (10mins)

Draining

Drying (55oC for 16hr)

Milling

Sieving

Packaging

Breadfruit flour

Figure 1: Flow Chart for the Processing of Breadfruit Flour

Functional properties determination of flour

Water absorption capacity The WAC was determined at room temperature and at temperatures ranging between 60 to 90°C using a combination of the AACC (1995) method and those of Sosulski (1962) and Rutkowski and Kozlowska (1981). A 2 g sample was dispersed in 20 ml of distilled water. The contents were mixed for 30s every 10 min using a glass rod and after mixing five times, centrifuged at 4000 g for 20 min. The supernatant was carefully decanted and then the contents of the tube were allowed to drain at a 45° angle for 10 min and then weighed. The water absorption capacity was expressed as percentage increase of the sample weight.

Oil Absorption Capacity Oil absorption capacity of the flour samples was determined by the centrifugal method elicited by Beuchat (1977) with slight modifications. One gram of sample was mixed with 10 ml of pure canola oil for 60 s, the mixture was allowed to stand for 10 min at room temperature, centrifuged at 4000 g for 30 min and the oil that separated was carefully decanted and the tubes were allowed to drain at a 45° angle for 10 min and then weighed. Oil absorption was expressed as percentage increase of the sample weight.

Emulsion Capacity This was determined using Beuchat (1977) method. 16g of the sample was suspended in 100ml of distilled water in a jar and blended for 30 seconds using an osterizer blender. Peanut oil from a burette was added to the blending sample at a rate of 0.5ml per second until the emulsion breakpoint was reached. Results were expressed as the percentage of oil emulsified per gram of flour used.

Foaming capacity and stability The procedure of Lawhom et al (1971) was used. Two grams of flour sample and 50ml distilled water were mixed in a Braun blender at room temperature. The suspension was mixed and shaken for 5 minutes at 1600rpm. The content along with the foam was poured into a 100ml graduated measuring cylinder. The total volume was recorded after 30seconds. Then the content was allowed to stand at room temperature for 30 minutes and the volume of foam only was recorded.

Foaming Capacity (FC) = Vol. of foam AW – Vol. of foam BW X 100 Vol. of foam BW Where: AW = After Whipping BW = Before Whipping FS: The volume of foam only (Total volume – liquid volume) after the 30 min standing is taken as foam stability.

Gelation Capacity The least gelation concentration was determined by a modification of the method of Coffman and Garcia (1977). The flour dispersions of 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20% (w/v) were prepared in 5ml distilled water in test tubes, which were heated at 90oC for 1 hour in water bath (Gallenkamp). The heated dispersions were cooled rapidly under running tap water and then at 4oC for 2 hours. The least gelation concentration was determined as that concentration when the sample from the inverted tube did not slip or fall.

Bulk Density The bulk density was determined according to the method described by Wang and Kinsella (1976). A 20g sample was put into 50ml measuring cylinder. The cylinder was gently tapped on the bench top 10 times from a height of 5cm. The bulk density was calculated as weight per unit volume of sample. Calculation: Bulk Density (g/ml or g/cm3) = Weight of sample Volume of sample after tapping

RESULTS AND DISCUSSION

Data on selected functional properties of the composite flours are given in Table 1. Water absorption capacity ranged from 161 – 402%. High water absorption capacity may be attributed to the breakdown of starch during blanching and ease of absorption of water by partly gelatinized starches (Ogbugu et al., 2005). At 100%, breadfruit flour had the highest water absorption capacity (402%). This implied that blanching enhanced the water absorption capacity. Water absorption characteristics represent the ability of a product to associate with water under conditions where water is limiting such as dough and paste (Nwoji, 2004).

Table 1: Functional properties of wheat and breadfruit flour sample missed in different proportions Wheat and Breadfruit flour samples Properties A B C D E F Water Absorption Capacity 161+1.0 202.5+1.5 253+1.0 247.5+1.5 367+2.0 402+1.0 Oil Absorption Capacity 106.5+1.5 109+1.0 118+1.0 113.5+0.5 128.5+1.0 160+2.0 Foaming Capacity 11.3+0.10 9.45+0.15 8.75+0.15 8.40+0.10 7.55+0.15 8.20+0.10 Foaming Solubility 7.0+0.1 6.2+0.1 5.2+0.1 4.5+0.1 4.0+0.1 3.7+0.1 Emulsion Capacity 14.24+0.02 17.93+0.01 14.41+0.03 10.05+0.03 18.86+0.02 14.70+0.04 Emulsion solubility 6.60+0.02 7.88+0.00 9.40+0.04 9.27+0.03 11.80+0.04 11.96+0.01 Least Gelation Capacity 27.84+0.00 25.49+0.00 22.56+0.00 19.34+0.00 17.66+0.00 16.74+0.00 Loosed Bulk Density (g/ml) 0.44+0.00 0.38+0.00 0.48+0.00 0.40+0.00 0.44+0.00 0.48+0.00 Packed Bulk Density (g/ml) 0.63+0.00 0.67+0.00 0.67+0.00 0.63+0.00 0.63+0.00 0.63+0.00 All the parameters are in percentages with the exception of both bulk densities. A=Wheat flour (100%), B=Wheat flour (90%) and breadfruit flour (10%), C=Wheat flour (80%) and breadfruit flour (20%), D=Wheat flour (70%) and breadfruit flour (30%), E=Wheat flour (60%) and breadfruit (40%) and F=Breadfruit (100%).

Oil absorption capacity increases with increase in level of substitution (106 – 160%).The oil absorption capacities of the flour blends suggests that they may be useful in food preparation that involve mixing like bakery products where oil is an important ingredient (Banigo and Mepba, 2005). The oil absorption capacities of the composite flours tended to increase with increase in protein content since the protein in foods influences fat absorption.

Foam capacity ranged from 7.55-11.30%. The higher foaming capacity in the flour blends shows that breadfruit flour is a good foaming agent and is useful in aerated foods. Also, the foam stability decreases with increase in level of substitution (7.0 – 3.7%). It was noticed that as the level of substitution increases, the values for foam stability kept decreasing. Hence, it is not a native proteins crops; it’s expected to have lower stability. At 100% wheat flour had the highest stability than other flour blends. This suggests that wheat flour is more stable. Protein foams are important in many processes in the beverage and food industries and this has stimulated interest in their formulation and stability. Foams are used to improve texture, consistency and appearance of foods.

The least gelation concentration varies from 27.84% to 16.74%. That is, as the proportion of breadfruit flour in the mixture increased, the least gelation concentration decreased in value. The variation in gelation of samples suggests that interactions between such components may have significant role in functional properties. It was observed that 100% breadfruit flour had the lowest least gelation concentration. Also, the values suggesting that the flour blends may not be a good binder in breakfast foods (Osundahunsi, 2006).

Emulsion capacity ranged from 14.2 – 18.85%. This is suggesting that the flour blends may be a good emulsifying agent. Increase in protein content with increase in substitution level aid in formulation and stabilization of emulsion (Abbey et. al., 1998). Emulsion stability increased with increase in level of substitution. This ranged between 6.60 – 11.96%. At 100%, breadfruit flour had the highest emulsion stability while 100% wheat flour had the lowest. The flour blends had stable emulsions because the protein content of the blends was not denatured by heat.

For all the flour blends, it was observed that both the loose and packed bulk densities increased considerably with increase in level of substitution. This is because the breadfruit flour is high in carbohydrate content. Loose and packed densities ranged between 0.38 – 0.47g/ml and 0.62 – 0.66g/ml respectively. The relative high bulk density of the flour blends indicates that packaging would be economical as observed by Osundahunsi and Aworh (2002). Breadfruit flour may be more useful in preparing high nutrient density weaning foods.

CONCLUSION

Breadfruit has immense potential; not only does it provide food security but the fruit is nutritious and versatile. There is need for commercial awareness, more support with production and processing techniques in order to put this time-honoured staple crop back on the menu. Also, with the recent policy of 10% cassava flour supplement for wheat flour in Nigeria, incorporating breadfruit flour into some of our products as a result of its functionality is therefore recommended.

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