Original Research Article

Nutritional and Anti–Nutritional Evaluation of Garri Processed by Traditional and Instant Mechanical Methods

ABSTRACT

Aim : The aim of this study is to evaluate the nutritional and anti-nutritional composition of garri processed by traditional and instant mechanical methods.

Place and Duration of Study : This study was carried out in Achara, Uturu and analyses were done at the Biochemistry and Central Laboratories of Gregory University, Uturu, Abia State between March and July, 2017.

Methods : was harvested and processed in Achara area of Uturu, Abia State. For garri processed by instant mechanical method, cassava was grated and dewatered using hydraulic press and were roasted (fried) within 24 hours of harvest. For garri processed by traditional method, the grated garri was allowed to stay for 24 hours in the sack before dewatering using sticks. The dewatering process took 3 days before roasting. The nutritional and anti-nutritional composition of raw cassava mash, garri processed by traditional and instant mechanical methods were evaluated using standard methods.

Results : The result of the analysis showed that garri processed by traditional method was higher in most of the nutritional factors but lower in all of the anti-nutritional factors investigated when compared with those of garri processed by instant mechanical method and raw cassava mash. Garri processed by traditional method was significantly higher in vitamin A but lower in vitamin C when compared with garri processed by instant mechanical method at p<0.05. Garri with palm oil has its cyanogenic glucoside significantly reduced when compared with garri without palm oil at p<0.05.

Conclusion : Long period of fermentation (3 – 5 days) of cassava product is recommended as garri processed by traditional method was nutritionally better than that processed by instant mechanical method due to the longer period of fermentation.

Keywords : Nutritional content, Anti-nutritional content, Garri processed by Traditional method, garri processed by instant mechanical method, fermentation period

1. INTRODUCTION carbohydrates in the tropics, after rice and . It is a major staple food in the developing Cassava ( Manihot esculenta Cranz) is a woody world, providing a basic diet for over half a billion shrub native to South America of the spurge people [3] . It is one of the most drought-tolerant family, Euphorbiaceae [1]. It is extensively crops, capable of growing on marginal soils. In cultivated as an annual crop in tropical and 2014, global production of cassava root was 268 subtropical regions for its edible starchy million tonnes, with as the world's largest tuberous root, a major source of carbohydrates producer of nearly 55 million tonnes or 21% of [2]. Cassava is the third largest source of food the world total [4].

Cassava is classified as either sweet ( Manihot Abia State, Nigeria. More recently, it was also palmata ) or bitter ( Manihot esculenta or Manihot reported in the national dailies on Tuesday 1 st utilissima ). Like other roots and tubers, both November, 2016 that six persons (including a bitter and sweet varieties of cassava contain mother, her three children and her two anti-nutritional factors and toxins, with the bitter neighbours) died after consumption of cassava varieties containing much larger amounts [5] . It product (‘lafun’) in Ogaminana area of Okene in must be properly prepared before consumption, Kogi State, Nigeria [11]. as improper preparation of cassava can leave enough residual cyanide to cause acute cyanide Fermentation is an important processing intoxication, goiters, and even ataxia, partial technique for cassava, especially in . paralysis, or death [6]. The more toxic varieties Three major types of fermentation of cassava of cassava are a fall-back resource (a "food roots are recognized: the grated root security crop") in times of famine or food fermentation, fermentation of roots under water insecurity in some places. Farmers often prefer and mould fermentation of roots in heaps [12]. the bitter varieties because they deter pests, The grated cassava roots are allowed to ferment animals, and thieves [7]. in sacks for 3-7 days, which encourages lactic acid fermentation. The pH after 3 days In Nigeria, as in most African countries, cassava decreases from 6 to 4 and the fermentation is is one of the most important carbohydrate dominated by lactic acid bacteria [5]. Grating is sources. About 95 percent of cassava is important for bringing linamarin into contact with consumed as food and less than 5 percent of it linamarase allowing its hydrolysis to glucose and is used for industrial purposes [8]. It is usually cyanohydrin and then to HCN [13]. The consumed in processed forms. In recent times, hydrolysis continues during the fermentation several processing options have emerged from process. Lactic acid fermented products are cassava such as garri, , starch, flour, reported to have significant concentrations of and chips. Irrespective of these options, garri cyanohydrins because pH decreases during (roasted granules) and edible starch (which is a fermentation and cyanohydrin is stable at low by-product from drying the grated tubers) have pH. The processes of garri production reduce maintained an important position in the food cyanogen contents by more than 95 % [12]. timetable of many households in Nigeria and Fermentation of cassava roots under water, other countries of the world, although starch followed by sun drying, is reported to be the best consumption is most notable in the south-south for cyanogens removal [14]. This type of region of Nigeria [9]. fermentation is used more in areas where there is a sufficient supply of water such as near a Toxicity of cyanide in cassava products has river or lake, and is common in countries such been reported. There are as well few reported as Nigeria, Democratic Republic of Congo, cases of death linked to consumption of cassava Tanzania and Malawi [12]. Heap fermented meals [10]. The incidents of cassava toxicity cassava root products are produced in Tanzania parallel severe hunger condition associated with [15], Uganda and Mozambique [16]. The drought or wartime when processors adopt process involves peeling of cassava roots, sun “shortcut” (shortened process time) in order to drying for 1 to 3 days, heaping and covering, meet market demand. Consumption of garri has fermentation, scraping off the molds, crushing always been a trend in Nigeria and some other into crumbs, sun drying, pounding and sieving parts of the world. The consumption of this into flour. During the fermentation of the roots, product has been accompanied with some side the temperature inside the heaps increases effects like food poisoning and other related between 23 and 29 ℃ higher than the effects due to inefficiency in the course of temperature outside the heaps (2 to 12 ℃). production, which inevitably leads to improperly According to Sani and Farahni, [16], heap processed product, and when this product is fermentation is dominated by the Neurospora consumed, it results to food poisoning and its sitophila, Geotrichum candidum and Rhizopus effect can be fatal [10]. oryzae. Heap fermentation of cassava roots followed by sun drying is capable of reducing the On 20 th March 1994, one Mrs. Loveth Osueke cyanogen levels by 95 % [16]. was reported in the National dailies to have died after eating African Salad made from cassava 2. MATERIALS AND METHODS which she bought from Ariaria market in Aba,

2.1. Production of Garri 24 hours of harvest. For garri processed by traditional method, the grated cassava mash Cassava was harvested and processed in was allowed to stay for 24 hours in the sack Achara area of Uturu, Abia State. For garri before dewatering using sticks. The dewatering processed by instant mechanical method, process took 3 days before roasting. The two cassava was grated and dewatered using methods of processing were as described by hydraulic press and were roasted (fried) within Olukosi et al ., [17].

Fresh Cassava tubers

Peeling off the cortex

Washing

Grating

Bagging

Dewatering with hydraulic press for few hours

Sieving

Roasting (with or without addition of palm oil)

Garri

Figure 1: Stages of processing Garri by Instant Mechanical Method

Fresh Cassava tubers

Peeling off the cortex

Washing

Grating

Bagging

Dewatering with sticks for 3 – 5 days, fermentation takes place

Sieving

Roasting (with or without

addition of palm oil)

Garri

Figure 2: Stages of processing garri by traditional method

2.2 Determination of Parameters 2.3 Statistical Analysis

Nutritional and anti-nutritional analyses of raw Data were subjected to analysis of variance cassava mash, garri processed by instant using the Statistical Package for Social Sciences mechanical method and garri processed by (SPSS), version 20.0. Results were presented traditional were carried out according to the as Mean ± Standard Error of the mean (SEM). methods described by AOAC [18]. Vitamin A 2–tailed t–test was used for comparison of the content was determined as beta-carotene means. Differences between means was spectrophotometrically using the low volume considered to be significant at p<0.05. hexane extraction method described by Fish et al . [19] while the vitamin C content was determined using the method of Benderitter et al . [20].

3. RESULTS AND DISCUSSION

Table 1: Proximate Composition of Garri Samples (%)

Parameters Raw Cassava Mash Instant Mechanical Garri Traditional Garri

Moisture 6.16 ±0.21 a 4.04 ±0.06 b 4.22 ±0.12 b

Crude Fibre 3.81 ±0.25 a 2.35 ±0.02 b 2.77 ±0.05 b

Ash 2.00 ±0.10 a 1.91 ±0.12 ab 1.78 ±0.13 b

Crude Fat 2.27 ±0.05 a 3.86 ±0.02 b 4.69 ±0.04 c

Crude Protein 2.14 ±0.06 a 3.93 ±0.02 b 5.08 ±0.15 c

Carbohydrate 83.64 ±2.90 a 83.92 ±1.63 a 81.43 ±1.97 a

Values are presented as Mean ±S.E.M, n =3.

Values with different superscript along the same row are significantly different at p<0.05

Table 2: Composition of Vitamins A and C in Garri Samples

Vitamins Raw Cassava Instant Mechanical Traditional Garri Mash Garri

Vitamin A ( g/g) 0.92 ±0.08 a 0.37 ±0.04 b 0.57 ±0.05 c

Vitamin C (mgAAE/mg) 23.27 ±0.99 a 35.43 ±2.82 b 28.28 ±2.02 c

Values are presented as Mean ±S.E.M, n = 3.

Values with different superscript along the same row are significantly different at p<0.05

Table 3: Anti–Nutritional Composition of Garri Samples

Anti -Nutrients Raw Cassava Mash Instant Mechanical Traditional Garri Garri

Phytate (g/100g) 17.61 ±0.80 a 15.25 ±0.39 b 13.11 ±0.89 c

Alkaloid (g/100g) 0.33 ±0.04 a 0.31 ±0.03 a 0.29 ±0.06 a

Oxalate (g/100g) 1.13 ±0.12 a 1.12 ±0.04 a 1.11 ±0.02 a

Saponin (g/100g) 0.22 ±0.03 a 0.15 ±0.02 b 0.09 ±0.02 b

Flavonoid (g/100g) 6.16 ±0.44 a 5.19 ±0.39 a 3.17 ±0.71 b

Lignin (g/100g) 0.18 ±0.02 a 0.15 ±0.02 ab 0.13 ±0.02 b

Tannin (g/100g) 0.37 ±0.02 a 0.30 ±0.02 b 0.22 ±0.04 b

Cyanide ( g/g) 32.00 ±1.67 a 21.07 ±1.68 b 8.15 ±0.44 c

Values are presented as Mean ±S.E.M, n =3.

Values with different superscript along the same row are significantly different at p<0.05

Table 4: The Effect of Palm Oil on the Cyanogenic Glucoside of Garri

Cyanogenic Cyanogen ic Glucoside Cyanogenic Glucoside of Raw of Instant Mechanical Glucoside of Cassava Mash Garri ( g/g) Traditional Garri (g/g) (g/g)

Without Palm Oil 32.00 ±1.67 a 21.07 ±1.68 a 8.15 ±0.44 a

With Palm Oil 22.26 ±1.45 b 12.01 ±0.74 b 3.82 ±0.93 b

Values are presented as Mean ±S.E.M, n =3.

Values with different superscript along the same column are significantly different at p<0.05

Cassava ( Manihot esculenta Crantz) and its constituents is required to avoid chronic cyanide products have been widely studied and reported intoxication [22]. This study focuses on the to have beneficial effect, and sometimes with evaluation of the nutritional and anti-nutritional toxic effects [21]. Most of these effects are due composition of garri processed by the traditional to the presence of some non-nutrient factors in method and those processed by the instant them. Cassava is a staple food in human diets in mechanical method. over 80 countries [21]. Starch, a product of cassava tubers is one of the most popular staple The proximate composition of garri samples is foods of the people of the rain forest belt of West shown in Table 1. Moisture content estimates Africa and contains mainly starch-20% amylase directly the water content and indirectly the dry and 70% amylopectin having lost the soluble matter content of the sample. It is also an index carbohydrates (i.e. glucose and sugar) during of storage stability of the flour samples. processing. Cassava can be processed into Substances with moisture content less than 14 different products such as garri, tapioca, Africa % can resist microbial growth and thus have salad, ‘lafun’ etc., the most common being garri. better storability [23]. In this study, a significant Cassava products are used as a primary staple decrease was observed in the moisture content food; careful processing to remove these toxic of garri samples when compared to that of raw

cassava mash at p<0.05. This is due to the fact being used by the microorganisms during that the processing of garri in both methods fermentation [27]. involves dewatering. Most of the water in the garri samples has been removed in this process. In this study, it was observed that the fat content Conversely, no significant difference was of garri processed by tradition method was observed when the moisture content of garri significantly higher than that in garri processed processed by traditional method was compared by instant mechanical method at p<0.05. This with that processed by instant mechanical corresponds to the work done by Irtwange and method. This is in agreement with the work done Achimba [24] who studied the effect of the by Irtwange and Achimba [24] who studied the duration of fermentation on the quality of garri. effect of the duration of fermentation on the The decrease in crude fat could be attributed to quality of garri. Moisture removal in garri is a the rising temperature of fermentation. As the function of many factors such as temperature, duration of fermentation increases, the time, humidity, etc. The available moisture in temperature also increases [28]. Temperature is garri solely depends on the degree of dryness known to have an effect on physical during frying. Generally, a well dried garri stores characteristics of food fats. Weiss [29] has well as there would be no free moisture to established that as temperature increases, the encourage microorganisms multiplication in garri solid fat index of certain foods decreases. which otherwise would have had adverse effect Temperature could probably be the reason for on the quality. the rate of decrease of crude fat in garri during fermentation. Garri samples with low fat content The crude fibre (2.35 – 2.77%) of the garri will not undergo rancidity during storage. This samples were close to the range (2-3%) of crude indicates that garri processed by traditional fiber recommended for garri [25]. A significant method could be stored for longer period without decrease was observed when the fibre content any discolouration or development of off-odour of garri samples were compared with that of raw when compared with that processed by instant cassava mash at p<0.05. This might be due to mechanical method. the fact that the processing of garri in both methods involved sieving. Most of the fibres in Fermentation of cassava improved the utilisation the garri samples have been removed in this of the diets, measured as protein efficiency ratio process. However, an insignificant increase was and biological value [30]. The crude protein observed when the fibre content of garri content of raw cassava mash, garri processed processed by traditional method was compared by instant mechanical method and garri with that processed by instant mechanical processed by traditional method are 2.14, 3.93 method. This is in agreement with the report of and 5.08 % respectively. The protein content Bolarinwa et al. [27] who studied the effect of increased significantly with fermentation. This processing on beta-carotene content and other might be mainly due to the reproduction of quality attributes of cassava flakes (garri) microorganisms and their metabolic activity produced from yellow cassava varieties. Crude during fermentation, as reported by previous fibre has been reported to aid digestion of food studies [31, 32]. Enzymatic proteins are through peristalsis movement of the bowel [25]. produced by the lactic bacteria that represent This indicates that garri processed by traditional the dominant microflora. They hydrolyze the method might be digested easily when starch of the composite leading to the production compared with that processed by instant of sugar, lactic acids, acetaldehyde, diacetyl, mechanical method and will not cause peptides, and amino acids, which are precursors constipation. of flavor [33].

In this study, a significant decrease was A decrease in the carbohydrate level observed observed in the ash content of garri processed in garri processed by traditional method when by traditional method when compared with that compared to garri processed by instant of raw cassava mash at p<0.05. The decrease mechanical method was due to fermentation . was however not significant when compared to This might be due to the production of hydrolytic that of garri processed by instant mechanical enzymes by the microbial flora present which method. Since ash content is a measure of the they used as carbon source and transformed total minerals present within a food, a reduction them to other macromolecules or metabolites in its level might be as a result of the minerals such as protein and fat [34]. Increase in alpha-

amylase activity during fermentation has been processes caused noticeable reductions in reported [35]. The alpha-amylase breaks down vitamin C content of Vigna sinensis and Lupinus complex carbohydrates to simple sugar. Panda albus [42, 43]. It was observed in this study that et al . [36] demonstrated that Lactobacillus as the fermentation time increased, ascorbic plantarum could produce α–amylase and acid content of garri decreased. This is shown reducing sugars from hydrolyzed starch and as a significant decrease was observed in the convert them into energy for their growth hence ascorbic acid content of garri processed by the carbohydrate was degraded faster to traditional method when compared with that of reducing sugar in the sweet cassava variety in garri processed by instant mechanical method. their study. This in agreement with the work of Adetuyi and Ibrahim [41] who reported an increase in vitamin Vitamin A content of garri samples were C content when okro seeds were fermented for determined as beta-carotene and are presented 24 hours but the vitamin C content however in Table 2. Once ingested, beta-carotene is decreased with increased duration of converted to vitamin A in the body [35] . In this fermentation. The decrease in vitamin C content study, a significant decrease was observed in observed in garri processed by traditional the beta-carotene content of garri samples when method may be as a result of the increase in the compared with that of raw cassava mash at activity of the enzyme, ascorbate oxidase that p<0.05. Similarly, the beta-carotene content of might have been produced by the fermentation garri processed by traditional method was microorganism which strongly depends on the significantly higher than that in garri processed pH of the fermentation environment. The by instant mechanical method. This corresponds enzymes convert ascorbic acid to with the report of Bolarinwa et al. [26] who dehydroascorbic acid [44]. studied the effect of processing on beta- carotene content and other quality attributes of In this study, there was a general noticeable cassava flakes (gari ) produced from yellow reduction in the entire anti-nutrient constituents cassava varieties. Generally, traditional method quantified for in the garri samples. This could be retained the beta-carotene content of the garri attributed to the activities of the indigenous better than the instant mechanical method. This microbes as well as processing methods which could be because leaching of beta-carotene was could initiate the activities of some indigenous minimal during traditional processing due to less enzyme that degrade these anti-nutrients during pressure applied to the cassava mash during fermentation [45]. It should be noted that the dewatering [26]. anti-nutrient constituents could be influenced by the type of cassava, soil condition, the Ascorbic acid is an effective quencher of singlet age/maturity of the roots, the time and the oxygen and other radicals. It has a vitamin E prevailing relative humidity during the harvesting sparing antioxidant action, coupling lipophilic and processing of the roots [46]. All the garri and hydrophilic reactions [37]. It reacts with samples used in this study were harvested from superoxide and a proton to yield hydrogen the same farm. The anti-nutritional composition peroxide or with the hydroxyl radical to yield of the garri samples are presented in Table 3. water . It also enhances absorption of inorganic These anti-nutrients are used by the plant iron and inhibits the formation of nitrosamines in probably for defense [30]. The lower the stomach [38]. In this study, it was observed concentration of anti-nutrients in the garri that fermentation caused a significant increase processed by traditional method corroborated in the ascorbic acid content of garri processed with the study of Aro et al . [47] on cassava by instant mechanical method when compared starch residues and that of Oboh and with that of raw cassava mash at p<0.05. This Oladunmoye [48]. increase in the ascorbic acid content by fermentation is consistent with the report of In this study, a significant decrease was other investigators. It has been reported that observed in the phytate content of garri vitamin C content of citrus peels and white processed by traditional method when compared cabbage increased with fermentation [39, 40]. with those of raw cassava mash and garri Adetuyi and Ibrahim [41] also reported an processed by instant mechanical method increase in vitamin C content when okro seeds respectively at p<0.05. This corresponds to the were fermented for 24 hours. On the contrary, findings of Oboh and Elusiyan [49] in different authors have found that fermentation determining the phytate content of fermented

cassava varieties. Knowledge of phytate levels below the detrimental dose of 0.7–0.9%. These in food is necessary because a high content can anti-nutrients form complexes with metals. The cause harmful effects on digestibility [50]. lower concentration of the anti-nutrients in garri Phytate has been recognized as an anti-nutrient processed by traditional method may enhance due to its adverse effects. It reduced the absorption when they form complexes with bioavailability of minerals and caused growth these metals. inhibition. Phytate is capable of chelating divalent cationic minerals like calcium, iron, In this study, a significant decrease was magnesium and zinc thereby inducing dietary observed in the cyanogenic glucoside of garri deficiency [51, 52]. Wise [53] suggested that the processed by traditional method when compared solubility of phytate and proportion of minerals with that of garri processed by instant bound to the complex depend on dietary calcium mechanical method and raw cassava mash levels. respectively at p<0.05. This could be attested to by the report of Endris [66] who stated that there The reduction observed in the alkaloid, oxalate, is a proportional reduction of residual saponin, flavonoid, lignin and tannin contents in hydrocyanic acid in garri samples from 0 to 96 garri processed by traditional method when hours of processing. This could be as a result of compared to that of garri processed by instant several reasons: Firstly, the grating of the mechanical method corresponds to the report of peeled cassava roots/tubers to obtain the mash Bolarinwa et al. [26] who studied the effect of disrupts the structural integrity of plant cells, processing on beta-carotene content and other thus allowing the cyanogenic glucosides from quality attributes of cassava flakes (garri) storage vacuoles to come in contact with the produced from yellow cassava varieties. enzyme linamarase on the cell wall [67]. When Though, alkaloids comprise a large group of plant tissues are crushed (mashed roots), the nitrogenous compounds widely used as cancer plant cell structure may be so damaged that the chemotherapeutic agents; they interfere with cell enzymes can meet with and act on the division and almost uniformly invoke bitter taste cyanogenic glucoside [67]. The action of in foods [54]. Oxalic acid and its salts occur as linamarase on linamarin and lotaustralin is the end products of metabolism in a number of plant hydrolytic release of acetone cyanohydrin and tissues. Oxalates can bind to calcium and other butan-2-one which is unstable. At pH above 5, metals rendering these metals unavailable for they spontaneously decompose to the normal physiological and biochemical roles such corresponding ketone and HCN which is lost by as maintenance of strong bones, teeth and volatilization [67]. As the fermentation time nerve transmission [55]. The low lignin content increases, the decomposition of cyanide to the in garri processed by traditional method corresponding ketone and HCN also increases, indicated breakdown action by microorganisms thereby reducing the cyanide left. The second during the fermentation process [56] . Saponins reason could be the high temperature at which are phytonutrients found in particular abundance garri was roasted and dried. The heat resulting in various plant species and are grouped by the from high temperature reduced the HCN content soap-like foaming they produce when shaken in of the garri. This is in agreement with the aqueous solution. Saponins when present in observation of Meuser and Smolnik [68] on the large amounts impart bitter taste to plant food effect of heat on hydro-cyanic acid content. and induce haemolysis and cholesterol binding Cyanide is poisonous because it binds with [57]. Flavonoid has been reported to be an cytochrome oxidase and stops its action in important phytochemical due to its antioxidant respiration in the body. properties [58]. Some plants have been reported to prevent ulcer due to their flavonoid content The HCN levels in garri processed by both [59, 60, 61]. The consumption of food high in traditional and instant mechanical methods used tannin can cause oesophageal cancer [62]. in this study are 8.15 and 21.07 µg/g Tannins have been reported to form complexes respectively on dry matter basis. A value of < 50 with proteins and reduce their digestibility and µg/g has been regarded as acceptable level of palatability [63]. They also bind iron, making it cyanide in garri [69]. However, long-term unavailable [64]. However, tannins are water consumption of garri containing low levels of soluble compounds and as such can be HCN produces goiter and neuropathy and 50 mg eliminated by soaking followed by cooking [65]. of cyanide per 50 kg body weight could be lethal The tannin content in both garri samples were to man [70]. This implies that an average person

of 70 kg body weight will have to consume palm oil) for raw cassava mash, garri processed between about 53 to 1944 kg dry garri flour by instant mechanical method and garri before the lethal effects of cyanide poisoning will processed by traditional method respectively set in. The short-cut method of production of (Table 4). These differences were found to be garri (as in the case of instant mechanical statistically significant as determined by t-test at method) results in incomplete hydrolysis of p<0.05. Various reasons have been advanced acetone cyanohydrins [71]. Thus acetone for the reduced HCN level in yellow garri. The cyanohydrins is the major cyanogen found in time of addition of palm oil to the grated cassava insufficiently detoxified garri flour [72] and are during processing, i.e., prior to fermentation or hydrolyzed rapidly to poisonous hydrogen during roasting had little or no influence on the cyanides on consumption, due to high pH of HCN content of the produced garri flour. The human gut into acetone and poisonous cyanides rate of hydrolysis of cyanogenic glucoside in [73]. Prolonged high dietary exposures to cassava to produce the poisonous hydrogen cyanogen have been implicated in various cyanide is affected by the addition of palm oil in diseases such as tropical ataxic neuropathy, garri [79]. However, the low level of cyanide in goiter and konzo in population with monotonous palm oil garri flour could be related to the cassava meal consumption [74, 75]. The sequestration of CN – by palm oil components increasing incidences of cyanides related into a complex and therefore unavailable for complications like dizziness; headache, quantitative measurement. Cardoso et al. [80] blindness, deafness, abdominal pains, vomiting, reported that palm oil delays the decomposition diarrhea and unsteady walking observed in of the cyanogenic glycosides. This could be people especially among the poor rural elderly responsible for the low concentration of population might be an upshot of high dietary hydrocyanic acid in the yellow garri. Again, palm exposure to unhydrolyzed acetone cyanohydrins oil has been reported to contain sulphur- in garri and other cassava products. These containing amino acids which bind HCN forming metabolic disorders are most often associated thiocyanide thereby reducing the cyanide level in with interplay of supernatural forces or divine the garri containing palm oil. punishment or sorcery in Africa [76]. Its specific prevalence among the older and rural poor with All these anti-nutritional constituents in garri monotonous diet of cassava diets, may be processed by both traditional and instant explained by the fact that, rhodanase an enzyme mechanical methods were found below the located in all tissues, but mainly in the liver acceptable level which shows that the samples performs the function of detoxification and were safe for consumption. This result is transformation of cyanides to thiocyanate before consistent with the findings of Bamidele et al. urine excretion. The process requires sulphur [81]. donors, provided by a corresponding dietary rich source of protein, which are lacking in cassava 4. CONCLUSION diets [77, 78]. Moreover, as aging process progresses, the liver ability to secrets rhodanase Long period of fermentation (3 – 5 days) of reduces, causing cyanides level in the blood to cassava products is recommended as garri increase; this explains the preponderance of the processed by traditional method was nutritionally resulting metabolic disorders amid the aging better and with less cyanogenic glucoside population. Since the longer the fermentation content than that processed by instant period the less the residual cyanide content of mechanical method due to the longer period of the final garri product, it is necessary to fermentation. Similarly, addition of palm oil discourage, for toxicological reasons, the during processing also reduced the cyanogenic common practice by many garri processors of glucoside of garri samples in this study. reducing fermentation period of cassava mash Processors of garri should be enlightened on the from three days in an attempt to increase dangers of garri high in cyanide to human health turnover rate. and should be encouraged to avoid short-cut practice in the production of garri. Garri should The effect of addition of palm oil on the cyanide be allowed to ferment for at least 72 hours content of garri samples was also investigated in before roasting. this study. It was observed that white garri (garri without palm oil) had significantly higher levels of residual HCN than the yellow garri (garri with

REFERENCES 9. Erhabor, P. O., Azaiki, S. S. & Ingawa, S. A. (2007). Extension guidelines for growing 1. Zagrobelny, M., Bak, S., Rasmussen, A.V., cassava and rapid production of quality Jørgensen, B., Naumann, C.M. & Møller, cassava planting materials, Ravel Fortune B.L. (2004) Cyanogenic glucosides and Resources. 300-382. plant-insect interactions. Phytochemistry. 65: 293–306. 10. Sanni, L. O. and Jaji, F. F. (2013 ). Effect of drying and roasting on the quality attributes 2. Lunsin, R., Wanapat, M. & Rowlinson, P. of fufu powder. International Journal of (2012). "Effect of cassava hay and rice Food Properties , 6 (2): 229-238. bran oil supplementation on rumen fermentation, milk yield and milk 11. Odogun, G. (2016). Cassava Flour kills six nd composition in lactating dairy cows". Asian- people in Kogi. Punch Newspaper, 2 Australasian Journal of Animal Sciences November, 2016 . Available on (AAJS). 25 (10): 1364–1373. www.punchng.com .

3. Dziedzoave, N.T., Abass, A.B., Amoa- 12. Westby, A. (2002). Cassava utilization, Awua, W.K.A and Sablah, M. (2006). storage and small-scale processing. In: Quality Management manual for Production Cassava biology, production and utilization. of High quality cassava flour. (Adegoke, Hillocks, R. J., Thresh, J. M. and Bellotti, A. G.O. and Brimer, L., Eds.). International C. (edition). CABI Publishing, Wallingford, Institute of Tropical Agriculture (IITA), xii + UK, 281-300. 68pp. 13. Shepherd, A. W., & Ilboudo, J. (2010). 4. Coyne, D. L., Kagoda, F., Wambugu, E. & Marketing of agricultural products. Food Ragama, P. (2006). "Response of cassava and Agriculture Organization, Rome. to nematicide application and plant- parasitic nematode infection in East Africa, 14. Cardoso, A. P., Mirione, E., Ernesto, M., with emphasis on root-knot nematode". Massaza, F., Cliff, J., Haque, M. R. & International Journal of Pest Management . Bradbury, J. H. (2005). Processing of 52 : 215–223. cassava roots to remove cyanogens. 5. Sanni, L. O., Babajide, J. M. & Ojerinde, M. Journal of Food Composition and Analysis, W. (2007). Effect of chemical pre- 18 :451-460. treatments on the physico-chemical and sensory attributes of Sweet potato-gari. 15. Ajao, K.R. & Adegun, I.K. (2011). ASSET-An International Journal of “Performance Evaluation of a Locally Agricultural Sciences, Environment and Fabricated Mini Cassava Flash Dryer”. Technology series B , 6(1): 41-49. Journal of Science Publication . 1(3):54-60. 6. Pope, K., Pohl, M. E. D., Jones, J. G., 16. Sani, B., & Farahni, H. A. (2011). Lentz, D. L., von Nagy, C., Vega, F. J. & Determination of seasonal price variations Quitmyer, I. R. (2001). Origin and for some food crops in Iran at karaj zone to Environmental Setting of Ancient achieve sustainable Agriculture. Journal of Agriculture in the Lowlands of development and agricultural economics, Mesoamerica", Journal of Science . 292 3(1), 7-12. (5520): 1370–1373. 7. Linley, C. K., Chrissie, K., James, N., 17. Olukosi, J. O., Isitor, S. U., & Ode, M. O. Felistus, C., Jonathan, M., Sidney, S. & (2007). Introduction to Agricultural Janice, J. (2002). "Bitter cassava and marketing and prices: principles and women: an intriguing response to food applications living Books Serves. GU. security", LEISA Magazine , 18 (4):18-23. Publications Abuja, FCT. p. 142.

8. Awoyinka, Y. A. (2009). Economic Analysis 18. AOAC (2010). Official Methods of Analysis. of Cassava Production in Obubra L.G.A of Association of Official Analytical Chemists. Cross-River State, Nigeria. Asian Journal of (20 th edition), Washington D.C., U.S.A. Agricultural science 3(3), 205-209. 19. Fish, W. W., Perkins-Veazie, P. & Collins J. K. (2002). A Quantitative Assay for

Lycopene That Utilizes Reduced Volumes 29. Weiss T. J. (1983). Food Oils and their of Organic Solvents. Journal of Food Uses. 3rd Edn. AVI Publishing Co., Composition and Analysis . 15 :309–317 Westpost, C. T. 20. Benderitter, M., Maupoli, V., Vergely, C., 30. Aletor, V.A. (1993). Allelochemicals in plant Dalloz, F., Briot, F. & Rochette, L. (1998). food and feeding stu ffs: nutritional, Studies by electron paramagnetic biochemical and physiopathological resonance of the importance of iron in the aspects in animal production. Veterinary hydroxyl scavenging properties of ascorbic and Human Toxicology . 35 : 57-67. acid in plasma: Effects of iron chelators. 31. Hayat, Z. E. (2008). Biochemical Fundamental of Clinical Pharmacology 12 : characteristics of Sorghum ( Sorghum 510 – 516. bicolour L. Moench) flour supplemented 21. Gomez, G., Aparich, M.A. & Wallite, C.C. with cluster bean (Cyamopsis tetragolaba (1988). Relationship between dietary L.): Influence of fermentation and or cassava cyanide levels and brailer cooking. Journal of Biological Sciences, performance. Nutrition Report International; 8(4): 722-729. 37 :63-67. 32. Inyang, C. U. & Zakari, U. M. (2008). Effect of Germination and fermentation of Pearl 22. Onabolu, A. O., Oluwole, O. S. A., millet on proximate, chemical and sensory Bokanga, M. & Rosling, H. (2001). properties of instant “Fura”- a Nigerian Ecological variation of intake of cassava cereal food. Pakistan Journal of Nutrition , 7 food and dietary cyanide load in Nigerian (1): 9-12 communities. Public Health Nutrition, 33. Agbor, E. T. (1995). The e ffectiveness of 4:871-876. cyanogens reduction during cassava processiong into miondo. Transformation 23. Birk, R., Bravado, B. & Shoseyov, Alimentaire du manioc. Paris: Orstom . 307- O. (2006). Detoxification of cassava 318. by Aspergillus niger . Applied Microbiology and Biotechnology. 45 :411–414. 34. Oboh, G., Akindahunsi, A. A. & Oshodi, A. 24. Irtwange, S.V. & Achimba, O. (2009). A. (2002). Nutrient and antinutrient Effect of the Duration of Fermentation on contents of Aspergillus niger fermented the Quality of Garri. Current Research cassava products (flour and garri). Journal Journal of Biological Sciences 1(3): 150- of Food Composition and Analysis 15 : 617- 154. 622. 25. Castellanos, R., Altamirano, S.B. & Moretti, R. H. (2004). Nutritional characteristics of 35. Chavez, A.L., Sanchez, T., Tohme, cassava (Manihot esculenta Crantz) leaf J., Ishitani, M. & Ceballos, H. (2004). Effect protein concentrates obtained by of processing on beta-carotene content of ultrafiltration and acidic cassava roots. Poster. Sixth International thermocoagulation. Plant Foods Human Scientific Meeting of the Cassava Nutrition. 45 :357–363. Biotechnology Network, 8–14 March 2004. 26. Bolarinwa, I. F., Ogunleye, K.Y. & Centro Internacional de Agricultura Rasheed, G. A. (2017). Effect Of Tropical, Cali, Colombia. Processing On Beta-Carotene Content And 36. Panda, S.H., Swan, M.R., Kar, S., Ray, Other Quality Attributes Of Cassava Flakes R.C. & Montet, D. (2008). Statistical (Gari) Produced From Yellow Cassava optimization of α – amylase production by Varieties. Nigeria Food Journal. 82 :25-34. Lactobacillus plantarum MTCC 1407 in 27. Aderiye, B.J. & Ogunjobi, A. A. (1998) submerged fermentation. Polish J Fermentation of yam: microbiology and Microbiol . 57 : 149-55. sensory evaluation of cooked fermented 37. Oboh, G. (2006). Antioxidant properties of yam tissues. Plant Foods for Human some commonly consumed and Nutrition . 52 : 49-54. underutilized tropical legumes. European 28. Collard, P. & Levi, S. (1959). A two stage Food Research and Technology 224: 61 – fermentation of cassava. Nature , 183 : 620- 65. 621. 38. Bender, D.A. (2009). Nutritional Biochemistry of the Vitamins, 2 nd edition.

Cambridge University Press, New York, pp. Society for Animal Production (NSAP) 362 – 371. Ayetoro, Ogun State, Nigeria 248-251. 39. Oboh, G., Ademosun, A.O., Adefegha, S.A. 48. Oboh, G. & Oladunmoye, M.K. (2007). & Lajide, L. (2011). Enhancement of Biochemical changes in microfungi antioxidant properties and neuroprotective fermented cassava flour produced from low potentials of citrus peels using Aspergillus and medium cyanide variety of cassava niger solid substrate fermentation tubers. Nutrition and Health 18 : 355-367. technology. Fermentation Technology and Bioengineering 1: 49 – 61. 49. Oboh, G. & Elusiyan, C. A. (2007). 40. Kusznierewicz, B.S., Miechowska, A., Changes in the nutrient and antinutrient Bartoszek, A. & Namies´nik, J. (2008). The contents of micro-fungi fermented cassava effect of heating and fermenting on flour produced from low and medium antioxidant properties of white cabbage. cyanide variety of cassava tubers. African Food Chemistry 108 : 853 – 861. Journal of Biotechnology . 6: 2150-2157. 41. Adetuyi, F.O. & Ibrahim, T.A. (2014). Effect of Fermentation Time on the Phenolic, 50. Nwokolo, E.N. & Bragg, B.B. (2007): Flavonoid and Vitamin C Contents and Influence of phytic acid and crude fiber on Antioxidant Activities of Okra ( Abelmoschus the availability of minerals from protein esculentus ) Seeds. Nigerian Food Journal . supplements in growing chicks. Journal of 32 (2):128 – 137. Animal Science 57 : 475-477. 42. Doblado, R., Zielinski, H., Piskula, M., 51. Airaodion, A. I., Olatoyinbo, P. O., Kozlowska, H., Muñoz, R., Frías, J. & Ogbuagu, U., Ogbuagu, E. O., Vidal-Valverde, C. (2005). Effect of Akinmolayan, J. D., Adekale, O. A, processing on the antioxidant capacity of Awosanya, O. O., Agunbiade, A. P., Vigna sinensis var. carilla. Journal of Oloruntoba, A.P., Obajimi, O.O, Adeniji, A. Agricultural and Food Chemistry . 53 : 1215 R. and Airaodion, E. O. (2019). – 1222. Comparative Assessment of Phytochemical 43. Frias, J., Miranda, L.M., Doblado, R. & Content and Antioxidant Potential of Vidal-Valverde, C. (2005). Effect of Azadirachta indica and Parquetina germination and fermentation on the nigrescens Leaves. Asian Plant Research antioxidant vitamin content and antioxidant Journal , 2(3): 1-14. capacity of Lupinus albus L. var. multolupa. 52. Airaodion, A. I., Ibrahim, A. H., Ogbuagu, Food Chemistry 92 : 211 – 220. U., Ogbuagu, E. O., Awosanya, O. O., 44. Adetuyi, F.O., Osagie, A.U. & Adekunle, Akinmolayan, J. D., Njoku, O. C., Obajimi, A.T. (2008). Antioxidant Degradation in six O. O., Adeniji, A. R., and Adekale, O. A. indigenous okra ( Abelmoschus esculentus (2019). Evaluation of Phytochemical (L) Moench) varieties during storage in Content and Antioxidant Potential of Nigeria. Journal of Food Technology . 6(5): Ocimum gratissimum and Telfairia 227 – 230. occidentalis Leaves. Asian Journal of 45. Mubarak, A.E. (2005). Nutritional Research in Medical and Pharmaceutical composition and antinutritional factor of Sciences , 7(1), 1-11. mung beans ( Phaseolus aureus ) as https://doi.org/10.9734/ajrimps/2019/v7i130 affected by some home traditional 110 processes. Food Chemistry . 89 : 489-495 53. Wise, A. (1993). Dietary factors 46. Idowu, M. A. & Akindele, S. A. (1994). determining the biology activities of phytate Effect of storage of cassava roots on the nutrition. Abstract Rev Clini Nutr . 53 :791- chemical composition and sensory qualities 806. of gari and fufu. Food Chem . 51 (4): 421- 54. Valero, M. & Salmeron, M.C. (2003). 424. Antibacterial activity of 11 essential oils 47. Aro, S.O., Aletor, V.A., Tewe, O.O., against Bacillus aureus in tyndallized carrot Fajemisan, A.N. & Usifo, B. (2008). broth. International Journal of Food and Preliminary investigation on the nutrients, Microbiology. 85 :73-81. antinutrients and mineral composition of 55. Ladeji, O., Akin, C.U. & Umaru, H.A. (2004) microbially fermented cassava starch Levels of antinutritional factors in residues. Proc 33rd Annual Conf Nigeria vegetables commonly eaten in Nigeria. African Journal of Natural Science. 7: 71-73

56. Aderemi, F. A. & Nworgu, F. C. (2007). 64. Aletor, V.A & Adeogun, O.A (1995). Nutritional status of cassava peels and root Nutrient and antinutrient components of seviate biodegraded with Aspergillus niger . some tropical leafy vegetables. Food American-Eurasian Journal of Agricultural Chemistry . 53 :375-379. and Environmental Science. 2: 308-11. 65. Singh, U. (2008): Anti-nutritional factors of 57. Nijveldt, R.J., Van-Nood, E., Van-Hoom, chickpea and pigeon pea and their removal D.E.C., Boelens, P.G. & Van-Norren, K. by processing. Plant Foods for Human (2001). Flavoids: A review of probable Nutrition 38 : 251-261. mechanism of action and potential 66. Endris, S. (2007). Cyanogenic potential of application. American Journal of Clinical cassava cultivars grown under varying Nutrition. 74 : 418-25. levels of potassium nutrition in 58. Airaodion, A. I., Ogbuagu, U., Ogbuagu, E. Southwestern Ethopia. Ethiopian Institute O., Airaodion, E. O., Agunbiade, A. P., of Agricultural Research (EIAR), Jimma Oloruntoba, A. P., Mokelu, I. P. and Ekeh, Center, PO Box 192, Jimma. S. C. (2019). Investigation of Aqueous 67. Bokanga , M. (1995). Biotechnology Extract of Zingiber officinale Root Potential and cassava processing in Africa. Food in the Prevention of Peptic Ulcer in Albino Technology. 49 (1): 86-90. Rats. International Journal of Research and 68. Meuser, F. & H.D. Smolnik, (1980). Innovation in Applied Science . 4(2):64-67. Processing of Cassava into Garri and 59. Airaodion, A. I., Obajimi, O.O, Ezebuiro, other Foods tuffs Starch/Staerke, 32 (4): C.N., Ogbuagu, U., Agunbiade, A. P., 116-122. Oloruntoba, A.P., Akinmolayan, J.D., Adeniji, A. R. and Airaodion, E. O. (2019). 69. IITA, (2015). Cassava illustration guide Prophylactic Efficacy of Aqueous Extract of book, growing cassava commercially in Curcuma longa against Indomethacin- Nigeria. International Institute of Tropical Induced Ulcer. International Journal of Agriculture, Ibadan, Nigeria. pp 21-22. Research . 6(1):87-91. 60. Airaodion, A. I., Olayeri, I. M., Ewa, A. O., 70. Nartey, F. (2001). Biosynthesis of Ogbuagu, E. O., Ogbuagu, U., cyanogenic glycosides in cassava ( Manihot Akinmolayan, J. D., Agunbiade, A. P., spp ). In Chronic Cassava Toxicity, ed B. Oloruntoba, A. P., Airaodion, E. O., Adeniji, Nestle & B. Maclintyre. IDRC, Ottawa, A. R., Obajimi, O. O. and Awosanya, O. O. Canada, 73 - 87. (2019). Evaluation of Moringa oleifera Leaf 71. Onwuka, N.D.K. (2003). Essential Potential in the Prevention of Peptic Ulcer Elements of Food and Related Processes in Wistar Rats. International Journal of Engineering. UCO-Academic Pub., Nsukka, Research . 6(2):579-584. Nigeria, pp: 116-118. 61. Airaodion AI, Adekale OA, Airaodion EO, Ogbuagu EO, Uloaku Ogbuagu U, 72. Ingawa, W. A., Oyebanagi, T., & Olokum, Osemwowa EU. Efficacy of Combined C. C. (2008). Tone serves analysis of Garri crude Extract of Curcuma longa and Prices, 1993-2007. Proceedings of 10th Moringa oleifera in the Prevention of Peptic Annual National conference of Nigeria Ulcer in Albino Rats. Asian Journal of Association of Agricultural Economists , p. Research in Medical and Pharmaceutical 509. Sciences. 2019; 7(2), 1-8. 73. Oluwale, A.S.A., Onabolu, O.A. Cotgreave, 62. Shils, M.E., Shike, M., Ross, A.C., I.A. Rosling, H. Parson, A. & Link, H. Caballero, B. & Cousings, R.J. (2006). (2003). Incidence of endemic ataxic Modern nutrition in health and disease. polyneuropahthy and its relation to 10th Edn., Lippincott Williams and Wilkins, exposure to cyanide in a Nigerian A Wolters Klumer Company , pp 280-281. community. J. Neurol. Neurosurg. Psycho., 63. Eka, O.U. (2005). The Chemical 74 :1417-1422. Composition of Yam Tubers In: Advances 74. Akintonwa, A., O. Tunswashe & A. Onifade, in Yam Research. The Biochemistry and (1994). Fatal and non-fatal acute poisoning Technology of Yam Tubers. Osuji, G. (ed.). attributed to cassava-based meals. Acta Biochemical Society of Nigeria , Horticulture. 375 : 285-288. Nigeria. 1:51–75.

75. Madhusudanan, M., M.K. Menon, K. Umner & K. Radhakrishnanan (2008). Clinical and etiological profile of tropical ataxic neuropathy in Kerela. South India Euro. Neurol. 60 : 21-26. 76. Tyllester, T., (1994). The association between cassava and the paralytic disease konzo. Acta Hort., 375: 331-340. 77. WHO/FAO (2003). Diet, nutrition and the prevention of chronic diseases. Report of the joint WHO/FAO expert consultation; WHO technical report series, nr 916. Geneva, Switzerland. 78. Cliff, J., Martelli, A., Molin, A. & Rosling, H. (2004). Mantakassa: an epidemic of spastic paraparesis associated with chronic cyanide intoxication in a cassava staple area of Mozambique. WHO Bull., 62 : 477- 484. 79. Chinwendu, S., Ekaiko M. U., Ukpabi E. O. & Chukwu, H. C. (2015). Assessment of cyanide content in white, light yellow and deep yellow Garri flour produced from CASSAVA ( Manihot esculenta Crantz ) in four L.G.A of Abia State, Nigeria. Standard Research Journal of Microbiological Sciences . 2(2): 031-036.

80. Cardoso, A. P., Mirione, E., Ernesto, M., Massaza, F., Cliff, J., Haque, M. R. & Bradbury, J. H. (2005). Processing of cassava roots to remove cyanogens. Journal of Food Composition and Analysis, 18 :451-460.

81. Bamidele, O. P., Ogundele, F. G. Ojubanire, B. A. Fashogbon, M. B. &. Bello, O. W. (2014). Nutritional composition of gari analog produced from cassava (Manihot esculenta ) and Cocoyam (Colocasia esculenta ) tuber. Food Science and Nutrition . 2:706–711