Nigerian Indigenous Fermented Foods: Their Traditional Process Operation, Inherent Problems, Improvements and Current Status

Food Rrscwch Infernutionol~ Vol. 29, Nos 5-6, pp. 527-540, 1996 Copyright 8 1996 Published by Elsevier Science Ltd on behalf of the Canadian Institute of Food Science and Technology Printed in Great Britain ELSEVlER 0963-9969196 $15.00 + 0.00 0963-9969(95)00045-3

Nigerian indigenous fermented foods: their traditional process operation, inherent problems, improvements and current status

Chinyere I. Iwuoha* & Onyekwere S. Eke Department of Food Science und Technology, Federal Universit_v qf Technology, Owrrri, P.M. B. 1526. Owrri. Imo State, Nigeriu

Nigerian indigenous fermented foods (NIFF) are reviewed in this report outlin- ing their traditional status as well as any significant scientific and/or technological steps or modifications introduced towards developing them to the status of modern processed food. The NIFF consist of a wide range of products sourced from cereals (‘burukutu’, ‘pito’, ‘kwunu’, ‘ogi’, ‘otika’), fruits (‘agadagidi’, cacao wine, ‘eketeke’, ‘ugba’), legumes (‘daddawa’, ‘iru’. ‘ogiri’, ‘ogboroti’), tubers (‘abacha’, ‘elubo’, ‘fufu’, ‘gari’, ‘loiloi’, ‘kokobele’). tree sap (‘ogogoro’, palm wine), meat and seafoods (‘afonnama’. ‘azu-okpo’, ‘nsiko’. ‘oporo’), and milk (‘maishanu’, ‘nono’, ‘warankasi’). The problem inherent in the technology of their process operations forms part of the characteristic features of the traditional family and/or ethnic method of fermenting local staples. These were found to result from the following limitations associated with different aspects of indigenous fermentation processes, thus: a production environment which fails to observe good manufacturing practice (GMP) or code of hygiene; lack of knowledge of the culture of the process(es) and their characteristics; absence of any control in that the processing variables like pH, temperature, humidity. and quality of water were then unknown and were unable to be used to regulate the process; lack of awareness of the nutritional and/or toxicological implications of fermentation and its products. Development came up as results of assessing the characteristics of the NIFF systems with a view to improving on the equipment, substrates, culture as well as process control and product quality. These efforts have yielded a reduction in the duration of fermentation, and emergence of products that were free of health risks and which were of consistent quality capable of mass production through the use of mechanized equipment and sterile packages. These include ‘dadawa’ cubes, bottled palm wine, packaged dry cassava flours, ‘gari’, ‘soy-ogi’ and palm oil. Copyright c 1996 Published by Elsevier Science Ltd on behalf of the Canadian Institute of Food Science and Technology

Keywords: Nigerian indigenous fermented foods, traditional process operations, inherent problems, research, assessment, microbiology, process control, nutritional, toxicological, improvement, development, current status.

I. INTRODUCTION Ekundayo, 1977; Onyekwere, 1977; Ogundiwin, 1978a,b; Tehinse & Ogundiwin, 1978; Achinewhu, 1983a,b; Chemical changes in foods brought about by enzymes Kuboye, 1985; Odunfa & Oyeyiola, 1985; Pierson et al., from living microorganisms constitute fermentation. It 1986; Uzogara et al., 1990). has been established that there are nutrient-rich crops Generally, these crops are not used as foods in their in Nigeria which are fermented and used as foods or as unfermented state because some of them contain toxic food condiments (Collard & Levi, 1959; Akinrele, 1970; or anti-nutritional factors. Fermentation leads to a gen- eral improvement in the shelf life, texture, taste, aroma, as well as nutritional value (Kuboye & Akinrele, 1977; *Author to whom correspondence should be addressed. Odunfa & Oyeyiola, 1985; Uzogara et al., 1990). 528 C. I. Iwuoha. 0. S. Eke

The Nigerian indigenous fermented foods (NIFF) paste and is very popular in northern Nigeria, where it constitute a group of foods that are produced in serves as a breakfast dish. homes, villages and small scale cottage industries. They To prepare it, the millet (Penn&e&m typhoideum) is are sold to the rural populace who buy them for food ground in a mortar and pestle to remove the husk or and social ceremonies. The fermented foods are derived testa and release the kernels. The kernels are washed from substrates like roots, legumes, cereals, oilseeds, and left to dry on a mat out in the sun. The dried ker- nuts, meat, fish, milk, palm tree, sap, etc. (Oguntunde, nels are ground into flour, which is then suspended in a 1989; Uzogara et al., 1990; Akobundu & Iwuoha, little cold water and stirred into a pot of hot water - 1992). continuous stirring is effected until a thick smooth In the distant past, there were no verified data on the paste is formed. The paste is left to ferment and cool to economic, nutritional, technical and quality control ambient temperature for l-3 days, which leads to the implications of the NIFF. Only recently have food development of a sour flavour (Uzogara et al., 1990). technologists, human nutritionists, microbiologists and (c) ‘Ogi’ other applied scientists carried out multi-faceted, com- This is a fermented cereal gruel. Its porridge has a plementary studies on NIFF so that developments can smooth texture and a sour taste reminiscent of yogurt, be achieved. with a characteristic aroma (Umoh & Fields, 1981). The aim of the present paper is to present the NIFF Steinkraus (1983) quoted Banigo (1977) and Onyek- in their traditional preparation and uses and to discuss were & Akinrele (1977a) as reporting that the colour of significant scientific or technological steps or modifica- ‘ogi’ depends on the cereal grain used for its produc- tions introduced in NIFF towards improvements tion: cream-white for maize (Zea mays), reddish-brown and/or advancements which contribute to development. for sorghum (Sorghum vulgare), dirty grey for millet. It serves as a weaning food all over Nigeria (Akinrele & Bassir, 1967; Banigo & Muller, 1972b; Okoli & 2. INDIGENOUS FERMENTED FOODS IN NIGERIA Adeyemi, 1989). The method of traditional Nigerian ogi production 2.1. Classification and processing methods was reported by Steinkraus (1983) as described by Banigo et al. (1974). The cereal grains of interest are Nigerian indigenous fermented foods (NIFF) can be steeped in earthenware, plastic or enamel pots for l-3 classified according to the food groups from which they days to ferment. The fermented grains are wet-milled were derived. and wet-sieved to yield the ogi slurry. In some communities there is a further optional fermentation for l-3 2.1.1. Plan t-based days after wet-sieving. The plant-based fermented foods consist of those (d) ‘Otika ’ sourced from cereal, legumes, fruits, tree crops and ‘Otika’ is an alcoholic beverage traditionally brewed root and stem tubers. from sorghum malt and drunk in some parts of Nigeria (Tehinse & Ogundiwin, 1978). 2.1.1.1. Cereal-sourced The production method is thus: grains of the red (a) Pito and Burukutu variety of guinea corn or sorghum (Sorghum guineese) ‘Pito’ is a cream-coloured liquor while ‘Burukutu’ is a are malted as in the ‘pito’ production. Mortar and pes- brown-coloured suspension. Both are brewed concur- tle are used to mill the malted sorghum into flour. The rently by fermenting malted or germinated single cereal flour is suspended in water and boiled for at least 3 h, grain type or a mixture of grains. cooled and filtered. The filtrate is left at the prevailing The method is thus: Soaking the grains for 1 day, room temperature to ferment for 3 days (or it may be draining of soak water, germinating for 2 days, sundry- inoculated with liquor from a previous ferment). The ing, milling into flour, mixing the flour with water, fermented beverage is again filtered using ‘ogi’ sieve boiling for 3-4 h to form slurry, settling and decanting, cloth prior to consumption. addition of fresh water and reheating for 3 h. The mixture is allowed to stand at room temperature for 24 h. 2.1.1.2. Fruit-sourced More water is added and the mixture is reheated for 3 (a) ‘Agadagidi’ h. Cooling and separation follow. A supernatant and This is a fermented beverage prepared from soft, over- sediment are obtained which are allowed to ferment for ripe banana/plantain. 1 day at room temperature resulting in ‘pito’ (top clear The preparation method, according to Uzogara et al. supernatant) and ‘burukutu’ (a thick brown suspen- (1990) and Abiose & Adedeji (1992) involves packing sion), (Ekundayo, 1969, 1977; Faparusi et al., 1973; of peeled, sliced plantains/bananas in an earthenware Uzogara et al., 1990). pot and covering with water. The pot is covered tightly (b) ‘Kwunu-zaki and allowed to ferment at room temperature for a This is a watery gruel made from fermented millet period of l-5 days after which the juice is strained and Nigerian indigenous fermented foods 529 used as a drink, ‘Agadagidi’, especially in southwestern unwrapped and salt is added, the wraps are replaced Nigeria. and fermentation is allowed for 1 day after which ‘ogiri- (b) Fermented cocoa sap ugba’ is ready for use as a soup flavouring. This is a common traditional alcoholic beverage produced from cocoa sap, drunk in Cross River State. 2. I. I. 3. Legume and seed-sourced Oyo, Ondo and Ogun States of Nigeria. (a) ‘DuddaJva’ According to Uzogara et al. (1990) the preparation ‘Daddawa’ is a fermented soya bean (Glycine max Merrill) simply involves: cutting open ripe cocoa pods (Theo- product used as a food condiment in northern Nigeria, hroma cacuo), the seeds of which, with their surrounding especially Abuja, Benue and Plateau States. sugary pulp, are collected and placed in porous raffia Its production is described by Uzogara et al. (1990) baskets and covered with leaves. They are left to ferment thus: soya beans are sorted, cleaned and washed in for 556 days. The fleshy cocoa pulp solubilizes and the water then soaked in water overnight. The seed coats are seeds are released; the sap (from the pulp) drips from the removed and the cotyledons washed. The cotyledons porous baskets into a calabashiearthenware pot from are boiled in water in an earthenware or aluminium pot where it is later consumed as a refreshing drink. for 2-3 h after which excess water is decanted. The (c) ‘Eketeke’ boiled kernels are placed inside a calabash container This is fermented palm oil which is traditionally used in lined with blanched plantain leaves which are also used the preparation of ‘ugba’ (fermented African oilbean in covering the seeds. This is left to ferment at room seeds) salad. temperature for up to 5 days. It may also be wrapped Production of ‘eketeke’ involves placing the freshly- in small flat portions and smoked prior to pounding harvested oil palm bunches in a shade, covering com- into flour for use in soup or stew. pletely with leaves for 1 week to ferment. The fruits are (b) ‘Zru ’ ( ‘Dm~uduwu ‘) removed, cleaned and pounded into a cake in a mortar ‘Iru’ (Yoruba) [‘Dorowa’ (Hausa), ‘Ogiri-igala’ (Ibo)] is and pestle. The cake is dry-heated in an open cast iron an important food condiment and protein source pro- pan, and finally pressed to release the slightly ‘rancid’ duced from the fermented African locust bean (Purkia fermented oil, having characteristic flavour (Uzogara et filicoideu Welw) (Campbell-Platt. 1980; Odunfa, 1981a; al., 1990). lkenebomeh et d., 1986). (d) ’ Ughu’ According to Odunfa (1985~) Steinkraus (1985) and ‘Ugba’ refers to fermented oil bean (Pentaclethru Uzogara rt ul. (1990). ‘Iru’ is produced thus: locust macrophyllu) seeds which are utilized by the Ibo and bean seeds are boiled for between 12 h and 2 days to some other ethnic groups in southern Nigeria as a deli- soften the hard seedcoats after which they are dehulled by cacy and soup flavouring (Ikenebomeh et al., 1986). hand or by gentle pounding. The separated cotyledons The processing of the large brown glossy seeds of the are boiled in water with ‘kanwu’ (potash) for 2 h to African oil bean to obtain ‘ugba’ involves the follow- soften them. The boiled cotyledons are spread in a ing: oil bean seeds are boiled in water in a metallic pot raffia basket lined with blanched banana leaves and the over an open fire for 4-12 h to soften the hard brown cotyledons are covered with several layers of banana testa (called the shell). The shells are removed and leaves and left to ferment for 2 to 3 days at the prevail- the kernels are washed. The kernels (cotyledons) are ing temperature of the day. Wood ash may be added. boiled in water overnight over a low flame. allowed to The fermented product is then sun-dried for l-2 days cool, drained, and washed with cold water several yielding a dark brown or black product. Alternatively, times. The washed cotyledons are cut into long thin before use, the sun-dried mass can be made into a paste slices. These slices are mixed with salt, wrapped in of varying shapes and textures depending on the cus- small packets with leaves and lightly tied. These are tom of the ethnic group consuming it. placed in a basket to ferment at room temperature for (c) ‘Ogiri-ep.ri 225 days to yield ‘ugba’. A three-day fermentation pro- ‘Ogiri-egusi’ is a condiment prepared from melon (Cit- vides the delicacy, while 5 days of fermentation pro- rullus wlguris Schrad) seeds through fermentation. It is duces the soup condiment (Odunfa & Oyeyiola, 1985; used as a flavouring in sauces, soups and stews in east- Pierson et al., 1986). ern Nigeria (Achinewhu, 1987h). ‘Ogiri-ugba’, is a food condiment prepared from 3-day The preparation method as reported by Steinkraus fermented oil bean seeds described earlier. To prepare (1985). Iwuoha & Onuoha (1988) and Barber & this, according to Uzogara et al. (1990), the fermented Achinewhu (1992) involves the following: melon seeds slices are pounded/blended into a meal and mixed until (dry) are moistened and dehulled. The cotyledons are then a creamy paste is produced. Some charcoal powder is boiled for 2-3 h, the boiled seeds are wrapped tightly in added (optional) to impart a black colour, and the layers of blanched plantain leaves, and left to ferment at paste is wrapped in small portions with blanched the prevailing ambient temperature for 335 days. At the banana leaves, placed in a raffia basket and hung above end of the fermentation period, the seeds are ground the fireplace in the kitchen. After 2-8 h the leaves are into a paste with ash from burnt oil palm leaves and 530 C. I. Iwuoha, 0. S. Eke palm shaft is added to impart a grey colour to the paste. raphia palm (‘mmanya-ngwo’) or oil palm (‘mmanya- The paste is distributed in small portions into leaves, nkwu’) (Uzogara et al., 1990; Uzochukwu et al., 1991). wrapped up and left near the hearth (fireplace) until the According to Kuboye (1985) and Uzogara et al. unique (characteristic) aroma of ‘ogiri-egusi’ develops. (1990), the palm sap is obtained by the tapping of the (d) ‘Ogboroti’I’Agbaratii’ inflorescence of these palm trees. The sap is left to fer- This is fermented African oil bean seed-melon mix ment for a few hours and the fermentation is complete used as soup flavouring or as delicacy when boiled. in about 2 days, giving rise to a milky suspension of According to Uzogara et al. (1990), the preparation microorganisms in a fermented sap that tastes sour and is effected thus: oil bean seeds and melon seeds are fer- harsh. mented separately for 3 days. Equal measures of the two are mashed together to make a paste. The paste is 2.1.1 S. Tuber - sourced distributed in small portions into blanched leaves which (a) ‘Abacha ’ are wrapped and placed near the fire for proper flavour ‘Abacha’ or ‘Akpu-mmiri’ refers to wet cassava chips development, giving rise to ‘ogboroti’. consumed as a popular snack in southeastern Nigeria. (e) ‘Ogiri-isi’ To prepare ‘abacha’, the cassava root tubers (Mani- This is also known as ‘ogiri-igbo’ and ‘ogiri-agbor’ hot escufenta Crantz) are washed, peeled, boiled in (Odunfa, 1985a). It is a condiment prepared from fer- water for about 1 h and cut into longitudinal slices or mented castor seeds (Ricinus cummunis) and used in chips. These chips are steeped in water for l-2 days soups and stews in eastern Nigeria (Achinewhu, 1987a). during which the water may be changed once or twice. The preparation according to Anosike & Egwuatu At the end of the fermentation (during which the taste (1981) and Uzogara et al. (1990) is thus: the castor of the chips becomes almost bland), the chips are seeds are dehulled, the dehulled seeds are wrapped in finally washed two or three times with fresh cold water. blanched plantain leaves and boiled in water for 6-8 h. An alternative handling for long term storage is to dry The boiled seeds which are still wrapped in the leaves the chips under the sun for several days (Uzogara et are left for 4-6 days to ferment. Later the seeds are al., 1990). mixed with ash from burnt palm leaves and then (b) ‘Efubo ’ ground into a paste. The resultant paste is re-wrapped This is also called ‘lafun’ (Kuboye, 1985; Uzogara et and left for another 3 days near the fire to develop the al., 1990). It is a fermented cassava dry flour commonly characteristic flavour (aroma) of ‘ogiri-isi’. consumed in the western states of Nigeria. (f) ‘Ogiri-ugu ’ The production involves peeling of cassava roots, This is also referred to as ‘ogiri-nwan’. It is the washing and cutting into chunks. The chunks are fermented product from fluted pumpkin (Telfairea occi- soaked in water in pots or at edges of stream and left dentafis) beans. It is produced and used as a soup for 34 days to ferment and soften. At the end of fer- flavouring in southeastern Nigeria (Odunfa, 1985; mentation the softened chunks are dried under the sun Achinewhu, 1987a). for 2 days, ground and sieved to produce ‘lafun’ or The production of ‘ogiri-ugu’ involves extraction of ‘elubo’ (Uzogara et al., 1990). bean seeds from the pod, boiling for 2 h in water to According to Kuboye (1985), another method soften the seedcoat after which the dark coloured water involves soaking of cassava roots to ferment after is discarded. The cotyledons are washed and placed in which they are peeled, dewatered, sun-dried, milled and a pot, covered and left near the fireplace for 2 days to sieved to yield ‘lafun’. ferment and soften. They are then ground into a paste, (c) ‘Fufu ’ wrapped in small portions in leaves and placed near a ‘Fufu’ (also called ‘utara akpu’) is the meal of soaked fire until used (Uzogara et al., 1990). fermented cassava roots which is widely consumed in eastern Nigeria. 2.1.1.4. Tree sap - sourced The production is effected thus: the tubers are (a) ‘Ogogoro ’ ( ‘Kaikai’) peeled, washed, cut into thick chunks and steeped in ‘Ogogoro’ is a highly alcoholic liquor obtained through water in earthenware pots or in a slow-flowing stream the distillation of fermented palm wine (Kuboye, 1985; for 4-5 days to ferment, soften and produce a charac- Uzogara et al,, 1990). teristic of retted cassava meal. The tubers are dis- According to Uzogara et al. (1990) the sap tapped integrated in clean water, sieved and allowed to settle from the various palm viz: raphia palm (Raphia hookeri., for decantation of water. The sediment is the ‘fufu’ R. vine-j&a) and oil palm tree (Efaeis guineensis) (raw) which can be consumed by hydrothermal gela- (Kuboye, 1985), is fermented under the prevailing am- tinization to form stiff dough (Hahn, 1989; Uzogara et bient temperature of the room for 7 days before distil- al., 1990). lation. The distillate is ‘ogogoro’. (d) ‘Gari’ (b) Palm wine ‘Gari’ is a granular starchy food made from the bitter Palm wine is the fermented sap of palm trees, either variety of cassava root (Manihot utifissima Pohl; M. Nigerian indigenous fermented foods 531 esculenta Crantz) tubers by fermenting the grated pulp, Nigeria, as well as the Lake Chad area of northern followed by semi-dextrinizing, drying, and grading Nigeria. (Ogunsua, 1977; Okafor, 1977~; Onyekwere & Akin- The processing varies but basically consists of hang- rele, 19776). It is popular among Nigerians, especially ing the product at the prevailing tropical climate as in the south (Uzogara et al., 1990). conditioning prior to preparation for final consumption The traditional gari production procedure involves or spreading in a thick heap to dry for l-5 days, peeling of cassava roots, grating into fine pulp using during which fermentation takes place resulting in the aluminium sheets perforated with nails and fixed on development of a characteristic aroma. Examples of wooden frames. The grated pulp is placed in Hessian products produced from this process are beef tripe sacks which are tied up and compressed with heavy (‘afonnama’), fish (‘azu-okpo’), crab (‘nsiko’), crayfish stones or wood. The sacks are left outside or under a or shrimp (‘uponi’ or ‘oporo’) (Uzogara et al., 1990). shed to drain and ferment for up to 4 days. The fermented pulp, which is semi-dry and harsh to taste, is 2.1.2.2. Milk-sourced sifted using hand-made fabrics, and the finer grains are (a) ‘Muishanu ’ and ‘Nono ’ toasted (with or without palm oil) on shallow cast iron These are the soft butter and cheese, respectively pans heated on an open fire, sifted again and packaged obtained from fermented cow’s milk, common in (Collard & Levi, 1959; Okafor, 1977~; Onyekwere, northern Nigeria. 1977; Kuboye, 1985; Steinkraus, 1985; Hahn, 1989; Fresh raw milk from cow is boiled for up to 3 h and Uzogara et ul., 1990). allowed to stand for 1 day at room temperature inside (e) ‘Loi-loi ’ a calabash pot. Butter floats on top of the suspension ‘Loi-loi’ is a kind of ‘fufu’ which is popular among the while sediments (cheese) are also obtained after Riverine States of Nigeria, especially Rivers, Cross decantation. The soft butter is ‘maishanu’ while the River and Akwa Ibom States. cheese is moulded to give ‘nono’ (Uzogara et al., 1990). The preparation is thus: cassava roots are peeled, (b) ‘Wurankasi’ washed, and soaked for 2 days in water to partially This is a soft unripened cheese obtained by fermenting soften and ferment them. The roots are then ground milk from either goat or cow. This food is popular into a paste using the village mill. The paste is mixed among the Fulanis. with fresh cold water and left to ferment for 1 day. According to Ogundiwin (19786) Uzogara et al. Sieving is carried out to obtain a crude starch suspen- (1990) and Fashakin & Unokiwedi (1992), ‘warankasi’ sion. This is put into a cloth bag and dewatered result- is produced thus: milk is manually drawn from the ani- ing in starch which can be dispersed in a little cold mal udder and mixed with some drops of the juice water and stirred into hot boiling water until a smooth from the leaves, buds or stems of the Sodom apple paste (stiff dough) is formed to produce prepared ‘loi- plant (Calotropis procera). The mixture is allowed to loi’ (Uzogara et al., 1990). sour by a natural fermentation at ambient temperature (f) ‘Kokobele’ for over 12 h. The fermented mixture is heated gently This is a dried flour derived from fermented cocoyam for 40-75 min during which the contents form a junket. tubers - the tannia variety (Xanthosoma sugittlfolium). This is allowed to ‘break’ or form a streak on the sur- It is usually reconstituted in water and boiled with pep- face scum which is carefully removed with a calabash per, tomatoes, palm oil, fish and spices to enhance its scoop and the white curd is exposed. Intensified heating flavour. It is a common food in Ondo State in western is carried out to stop the (enzyme) activities, to allow Nigeria. for flavour development and texture formation in the It is produced thus: the cocoyam tubers are peeled, finished product. The resulting ‘wara’ is put into washed, sliced and steeped in water at room tempera- moulds and the whey is allowed to drain off for a few ture, and left to ferment for 2-3 days. At the end of minutes. The carrot-shaped cheese is thrown back into fermentation the steep liquor is drained off and dis- its whey from where it is consumed. carded while the cocoyam slices are sun-dried for 3-5 Table 1 shows the distribution of NIFF in Nigeria at days and then milled into flour, giving rise to ‘koko- a glance. bele’ (Uzogara et al., 1990). 2.2. Problems associated with Nigerian indigenous 2.1.2. Animal- and seajbod-based fermented food (NIFF) The animal- and seafood-based foods are made up of the fermented foods sourced from flesh and milk. A critical view of the NIFF as they are used in traditional family or ethnic arts reveals that the production 2.1.2. I. Flesh-sourced processes are laden with problems. Meat and fish products with strong smells resulting The problems can be considered in the categories of from fermentation are used as soup flavouring and in production environment, microbiology in processing, certain other dishes along the coastal areas of southern process control, and nutritional and toxicological status. 532 C. I. Iwuoha, 0. S. Eke

Table 1. Distribution* of indigenous fermented foods (NIFFs) in Nigeria

Class of foods NIFFs Specific food sources Indigenous places

Cereals Burukutu and Pito Sorghum, Maize North, Mid-West Ogi Maize East, West Fruits Agadagidi Over-ripe plantain or Banana South-West Cacao wine Cocoa pod pulp South-East, West Ugba African oilbean cotyledons South Legumes Iru (Dawadawa) African locust bean North Daddawa Soya beans Middle belt Ogiri-egusi Melon seeds East Ogiri-isi Castor oil seeds East Ogiri-ugu or Ogiri-nwan Fluted pumpkin seeds South-East Tree sap Palm wine Raphia palm or Oil palm tree South Tuber Gari Cassava roots South, North Fufu Cassava roots East Lafun Cassava roots West Abacha Cassava roots East, South-East Elubo Cassava roots West Loiloi Cassava roots Riverine States Kokobele Cocoyam corms West Flesh Afonnama Beef tripe East, Mid-West Azu-okpo Fish South Nsiko Crab South Uponi or Oporo Crayfish or shrimps South Milk Maishanu and Nono Cow’s milk North Warankasi Goat/Cow milk North (Fulani)

*The places listed are birthplaces for the arts of production and predominant utilization but inter-ethnic/state trades and relocation have widened the scope of the spread of each NIFF throughout the country and beyond.

2.2.1. Production environment entific protocol in food process operations, the practice In our traditional setting where the production level of process control was virtually impossible to maintain. is that of subsistence housekeeping, the processing Fermentation periods were chosen according to human environment is very unpredictable: the equipment used judgement. The quality and quantity of water and sub- is rudimentary (calabash, earthenware, leaves, baskets strate to be used was not regulated or standardized, heat- and cloth), the hygiene of handlers, equipment and ing processes were not controlled or measured. All the facilities is not checked, the water used, especially at above-mentioned factors resulted in inconsistent quality. the edges of streams cannot be said to be potable; tropical climate (temperature and humidity) cannot be said 2.2.4. Nutritional toxicological status to be the optimum for all fermentation and storage The lack of knowledge or information on the effect of purposes. All these factors affect the quality of final fermentation on the nutritional quality of the final product and the health of ultimate consumers. products stood as a problem in that consumers were unaware of the actual nutritional worth of the foods 2.2.2, Microbiology of process except the organoleptic attributes. Also the type and A lot of the information was flawed - there was no degree of danger posed by the consumption of fer- way to assure a consistently uncontaminated environ- mented products which are unfit for human consump- ment for the fermentation: the microbial composition tion due to the handling process or post-fermentation of the inocula was unknown - identification of type, contamination were not known, Any death resulting the identity of the contaminating microbes, the age and from these above-named sources could not be estab- purity of each culture, the predominant microbes, and lished conclusively. the conditions of pH, temperature, ionic strength, information on foods that best favoured the microbial 2.2.5. Basic food preservation ethics performance in fermentation. Local processing centres will have to be established in order to control or forestall the inherent problems 2.2.3. Process control (2.2.1-2.2.4) and their perpetuation. At the moment, In view of the limitations in NIFF as outlined in health personnel from some government hospitals from section 2.2.1 above, and also because there was no sci- time to time organise good manufacturing practice Nigerian indigenous fermented foods 533

(GMP) and basic hygiene workshops for the women have been conducted by several workers concerning and girls who engage in street foods trade and sell different food groups. NIFFs and other ‘ready-to-eat’ foods (Oguntunde, Cereal-based the production of lactic, acetic and butyric 1989) in school premises. The impact of this training is acids (the main acids contributing to the desired flavour not far-reaching because it does not touch all the or sourness of ogi) have been found to be directly effected diverse NIFFs being distributed to consumers and the by Lactohacillus plantarium, the predominant organism staff involved are not grounded in food processing in the fermentation (Banigo & Muller, 1972a). During technology. They are mostly home economists, medical fermentation, hydrolysed starch of maize is converted microbiologists and dietitians. to organic acids at reduced pH (Akinrele, 1970). When the ‘otika’ wort was separately inoculated with cultures of baker’s yeast (Saccharomyces cerevisae), 3. IMPROVEMENT IN THE NIGERIAN brewer’s yeast (S. carlsbergensis) and palm wine trub, INDIGENOUS FERMENTED FOODS all samples reached < 50 ‘%Iattenuation in less than 30 h (Tehinse & Ogundiwin. 1978). The advent of education, training and specialization Fruit-bused NIFF: results of gas-liquid chromato- affecting some Nigerians and other interested foreign graphic (GLC) analysis of ‘Agadagidi’ process showed nationals in the fields of food microbiology, food sci- that methanol was formed and predominated in the ence, biochemistry, human nutrition, fermentation first 2 days but was replaced by ethanol from the third technology, food processing and related fields coupled to the last (5th) day of the fermentation. with very little data on the significance of Nigerian In the production of cacao wine, Adesioye (1991) indigenous fermented foods (NIFF) led to the modern observed that cocoa pod (fruit) juice containing 18.6 ‘XI development in this area of traditional food processing soluble solids, yielded up to 10.5 ‘%Ialcohol (v/w) at the and preservation technology. end of fermentation even when Succhurom~~ces .spp iso- These new food researchers set out to carefully identify lated from oilpalm sap or cashew juice were used. methods involved in fermentation and the features of During ‘ugba’ processing, fermentation was found to the original/traditional treatment and uses of the NIFF cause reduction in its minerals (Ca, Mg, K and P) con- as well as the problems associated with those foods (see tents (Achinewhu, 1983~) effect substantial increase in section 2 above). The next efforts were to study the thiamin (vitamin Bl), riboflavin (B2) and niacin indigenous fermentation processes in order to assess (Achinewhu & Ryley, 1986) and also increased the pro- the characteristics (Table 2) with a view to introducing tein content (Achinewhu, 1983~; Iwuoha & Ike, 1991). systematic modifications with resulting improvements Soluble nitrogen increased, total unsaturated fatty acids in various aspects of the NIFF technology (Table 3). increased (Achinewhu, 1986) which aided hydrolysis of protein, leading to increase in pH from 5.0 to 8.7 (Pier- 3.1. Scientific evaluations of characteristics of NIFF son et ul., 1986). Alpha-amylase, proteolytic and lipoly- processes tic enzymes activities (which reached a maximum at Systematic studies have been carried out over the years 2436 h) were found to relate to changes in the chemical to evaluate the characteristics of the cultures involved composition of ‘ugba’ (Njoku & Okemadu. 1989). in NIFF (Table 2). Also the biochemical, nutritional Legume-bused NIFF a sequence of microbial succession and toxicological changes in the food systems brought has been reported in ‘daddawa’ processing: Bacillus spp about by fermentation have been assessed. were consistent throughout while StaphJVococcus spp occurred only during the last 3 days of fermentation 3. I. 1. Microbial assessments (Popoola & Akueshi, 1985). Achinewhu (1978~) Microbiological studies were carried out to determine observed that niacin, riboflavin and thiamin were the cultures and their characteristic features as regards produced during the fermentation of fluted pumpkin “1 the following NIFF: ‘Agadagidi’ (Abiose & Adedeji, (‘ogiri-ugu’), and castor seeds (‘ogn-i-n ). Also 1992) ‘fufu’, ‘gari’ and ‘lafun’ (Collard & Levi, 1959; Achinewhu et ul. (1991) reported that free amino nitro- Okafor, 1977b; Oyewole & Odunfa, 1988) ‘ogi’ (Akin- gen (FAN) and total microbial counts increased during rele, 1970; Banigo, 1977; Onyekwere & Akinrele, fermentation of melon seeds (‘ogiri- egusi’) and were at 1977a; Odunfa & Adeyele, 1985) palm wine (Faparusi, their maximum at 35°C 1 ‘%I NaCl and 43.2% mois- 1971, 1973; Okafor, 1975, 1978; Ojomo rt al., 1984; ture. Barber and Achinewhu (1992) reported that in Uzochukwu et al., 1991) ‘pito’ and ‘burukutu’ (Ekun- ‘ogiri-egusi’, fermentation effected pH increase from 6.5 dayo, 1969; Faparusi et al., 1973), ‘ugba’ (Odunfa & to 8.1 and that a combination of Bacillus sp and Alcali- Oyeyiola, 1985; Pierson et nl., 1986). The key findings genes sp is capable of producing the quality characteris- are presented in Table 2. tics of a good ‘ogiri-egusi’; that beyond the maximum titratable acidity (which occurs at 35°C about the 3.1.2. Assessments ofthe biochemical and related changes 1st day), it decreases by as much as 27.42 ‘%Iat the Research on biochemical and related changes in NlFF 7th day. 534 C. I. Iwuoha, 0. S. Eke

Table 2. Predominant microbes involved and their optimal conditions for activity in the Nigerian Indigenous Fermented Foods (NIFF)

Class of NIFF Predominant microbes Optimum conditions for Reference foods involved performance/fermentation

Cereals Burukutu Lactic acid bacteria Ekundayo (1969), and pito and feast Faparusi et al. (1973), Chukwurah (1982)

Ogi Lactobacillus plantarum, pH 6-35-3.42, Banigo & Streptococcus lactis, 1-3 days, Muller (1972a), Saccharomyces cerevisiae 27°C f 1°C Banigo et al. (1974), Fields et al. (1981), Odunfa (1985a)

Fruits Agadagidi Brettanomyces intermedius, 4 days, pH 6.2-3.6, Abiose & Adedeji (1992) Kloekera apiculata, 27” + 1°C Candida tropicalis, C. krusei, Hansenula anomala, Pediococcus cerevisiae, L. mesenteroides, Staphylococcus epidermidis, Micrococcus leteus Cacao wine Yeast Odunfa (1985a) Ugba Bacillus subtilis, 3-5 days, pH 50-8.7, Obeta (1983), Staphylococcus spp, 25-33°C Kolawole & Micrococcus spp, Okonkwo (1985), Corynebacterium spp Odunfa & Oyeyiola (1985), Pierson et al. (1986), Njoku & Okemadu (1989)

Legumes ‘Dawadawa’/‘Iru’ Bacillus subtillis, B. Licheniformis, 3 days 35”C, RH.Sl% Odunfa (1981a), Kuboye Staphylococcus saprophyticus (1985). ‘Daddawa’ Bacillus spp, Staphylococcus spp 4 days, 37” + 2°C Popoola & Akueshe (1985) ‘Ogiri-egusi Bacillus subtillis, B. megaterium, 3 days, 29”-3O”C, Odunfa (1981b), jirmus, Esubherichia, Proteus, pH 8.1-6.5 Barber & Pediocococcus & Acaligehes spp Achinewhu (1992) ‘Ogiri-isi’ Bacillus spp, Pseudomonas spp, 3 days, 29”-30°C Barber et al. (1988), Micrococcus. spp. Streptococcus pH 8.1-6.5 Uzogara et al. (1990)

Tree sap Palmwine and Sarcina lutea, Shizo-saccharomyces Bassir (1962), Faparusi ‘ogogoro’ pombe, saccharomyces cerevisiae, 2 days, 27” f l”C, (1971, 1973), Okafor (1974), S. fiurentius, S. chevelleri, S. makii, pH 6.5-3.5 Ojoma et al. (1984), Leuconostoc mesenteroides, Uzochukwu et al. (1991) Lactobacillus plantarum. Sarcina lutea, Acetonacter, Leuconostoc dextranicum, Lactobacillus casei ‘Ogiri-ugu’/ Bacillus spp, E. coli, Staphylococcus 3 days, 29”-30°C Odunfa, (1985a), Ogiri-nwan spp, Pseudomonas spp pH 8.1-6.5 Barber et al. (1989)

Tuber ‘Fufu’, ‘lafun’ Carynebacterium manihot, Collard & Levi (1959) and ‘gari’ Geotrichum candida, Streptococcus 3-5 days, 28’45”C, Okafor (19776), lactis, Aspergilus niger, pH 4.2-3.6 Onyekwere (1977), Oyewole this, Rhodotorula spp, Penicillum & Odunfa (1988), spp, Leuconostoc spp, Klebsiella spp Hahn (1989)

Tuber-based: during cassava processing, linamarin is Animal (milk)-based: the active enzyme in the process- hydrolysed in the presence of native linamarase to glucose ing of ‘warankasi’ is calotropain, which hastens the and cyanohydrin, and subsequently the latter is broken coagulation of milk protein to yield a curd (Ibiama & down to acetone and hydrocyanic acid by hydroxynitrile Griffith, 1987). The composition, biochemical and lyase. At pH 5-6, free cyanide is released, more rapidly chemical characteristics of the product depend on under gentle heating of the cassava mash (Oke, 1984; method employed and composition of milk (Ogundiwin Cooke and Cock, 1989). & Oke, 1983, 1985). Nigerian indigenous .fermented foods 535

Table 3. Some improvements introduced in the processes/productsof the Nigerian Indigenous Fermented Foods (NIFF) ______- NIFF Highlights of some improvements in the processes/products Reference/Source

‘Ogi’ (a) Use of improved grains, pure culture and coupled with mechanised handling of Banigo rt al. (1974) operations to improve organoleptic quality of product. Adeniji and Potter (1978) (b) Steeping of whole grains in hot water to soften them prior to milling to reduce Banigo & Adeyemi (1975) steep duration. (c) Use of dry-milling of maize in ogi production as a convenient method. Umon & Fields (1981) Adeyemi ( 1983) (d) Use of boiling to replace steeping of grains leading to the production of acceptable ogi within 24 h as against the traditional 72-96 h. Sokari et (I/. (1991) ‘Gari’ (a) Use of 4-day culture as starteriinculum to effect fermentation in 24 h on a succeeding cassava root tuber steep. (b) Achieving longer shelf-life in gari through mechanised system with hygienic Collard & Levi (1959) processing environment, better sizing of particles and packaging of end product. Onyekwere (1977) (c) Use of process variables to control fermentation process. Steinkraus (1985) Palm-wine Use of sterile implements as well as introduction of pure culture to effect fermentation for consistent quality palmwine production. Uzochukwu et ul. (1991)

3.1.3. Nutritional assessments Animal (milk)-based ‘Warankasi’ was reported to con- Several workers have assessed the nutritional levels and tain 4456% protein, 47.50% fat, ash 6.82%,, carbohydrate qualities of some of the NIFF products. 1.12% (Fashakin & Unokiwedi, 1992). The protein Cereal-based: during the fermentation of ‘ogi’, phos- efficiency ratio (PER) and net protein ratio (NPR) phorus is released from phytate (Lopez et al., 1983). (Fashakin & Unokiwedi, 1993) were 92.80% and During this period, niacin and riboflavin contents are 89.73% of casein, respectively. increased (Kuboye, 1985). Furthermore, in a feeding trial with 50 suckling rats at birth, the pups became 3.1.4. Toxicological and other health-related assessments malnourished and most of them died, showing that Several studies have been carried out on the toxicological ‘ogi’ was inadequate as a weaning food. Further analy- and other health-related status of some NIFF products: ses showed that the indigenous fermentation process Cereal-based: there have been reports that fermented effected the following reductions (‘Xl)in the ‘ogi’: 13.86 products involving Lactobacillus spp and lactic acid (protein), lipid (9.33), fibre (53.95) and ash (38.46) bacteria (LAB) have the following effects: viricidal (Ebuchi & Akinwande, 1991). (Gilbert rt al., 1983). anti-leukenic (Esser et al., 1983), A report on ‘burukutu’ and ‘pito’ by Ihekoronye & antitumour (Oda et al., 1983; Shahani et al., 1983). Ngoddy (1985) suggested that fermentation enhances B This is important in that acidic fermentation processes vitamins in the drinks. of cereals in Africa (West Africa) have Lactobacillus ‘Otika’ was reported to contain maltose 18 mg ml ‘, spp and some LAB as the predominant micro-organ- alcohol 5.4% (v/w), sucrose 3.67% (w/v), and lactic acid isms (Akinrele, 1970; Okafor, 1979; Fields et al., 1981; 0.048% (w/v) (Tehinse & Ogundiwin, 1978). Odunfa & Adeyele, 1985). Fruit-based: Kuboye et al. (1978) reported that Fruit-based: fermentation has been reported to consid- ‘agadagidi’ contains up to 6.57% alcohol. Fermentation erably reduce/eliminate flatus-forming oligosaccharide improved the protein quality (Achinewhu, 19836) and (stachyose, verbascose, and raffinose) in ‘ugba’ nutritive value (Isichie & Achinewhu, 1988) of ‘ugba’. (Achinewhu. 1986). There are strong indications of Legume-based: ‘Iru’ (‘dawadawa’) contains 18847% residual growth-depressing factors (e.g. caffeoyl-pu- protein, 3143% fat (Eka, 1980). It is high in Ca, Fe trescine) in ‘ugba’ (Mears & Mabry, 1971; Mbadiwe, and lysine but lacks methionine and cystine (Uzogara 1978, 1979). et al., 1990); it is also high in riboflavin (Odunfa, Legume-based traditionally-fermented castor oil seeds 19856). There is a marked increase in reducing sugars (‘ogiri-isi’) has been reported to be contaminated by in ‘iru’ (Odunfa, 1985c) and ‘ogiri’ (Odunfa, 1982) due fungi (Mazi & Ekwujuru, 1992) possibly from the pro- to fermentation. cessing environment. This is indicative of possible Tree sap-based fermented palm sap (palm wine) is a good exposure of its consumer to mycotoxin (e.g. aflatoxin). source of biomass (protein/yeast), amino acids and organic Tree sap-bused: traditionally fermented palm sap acids (Uzogara et ul., 1990; Uzochukwu et al., 1991). (palm wine) has been reported to contain precursors of Tuber-based: Gari contains (‘% d.b) starch (87,8), sugars N-nitrosamines (nitrates, nitrites, and dimethylamine) (0,5), protein ( 1.O), minerals (1. l), fibre (0.6) and lipids which have carcinogenic potentials (Maduagwu & (0.1) (Oke, 1984). Bassir, 1979). ‘Ogogoro’ has a high (35.2%) alcoholic 536 C. I. Iwuoha, 0. S. Eke content (Goma, 1989) which would expose consumers Federal Institute of Industrial Research, Oshodi, to intoxication. FIIRO, Ikeja), ‘soy-ogi’ (FIIRO), palm oil (NIFOR Tuber-based inadequate processing leads to residual and LBN), cassava products (gari, flour, chips) (Onyek- cyanide up to toxic level (i.e. >50 ppm) (Coursey, 1973; were, 1977). Other processes and/or products that have Oke, 1984; Cooke & Cock, 1989). A nutritional prob- been improved upon but not mentioned in this section lem (the tropical ataxic neuropathy) has been observed are highlighted in Table 3 and Figures l-3. in Nigeria due to intake of cyanide (Osuntokun, 1973) The diverse endeavours made towards developing while in eastern Nigeria, an endemic goitre associated NIFF have resulted in the following levels of advance- with consumption of cassava diet has been reported ment: isolation of micro-organisms; determination of (Ekpechi, 1973). However ‘gari’ has generally been the roles of the organisms; selection and genetic improve- noted for safe cyanide levels (i.e. << 50 ppm, Omueti et ment of organisms for improved performance; process al., 1993) among cassava products. improvement; improvement in raw materials used; lab- Miscellaneous: most processing/preservation operations oratory simulation of NIFF production; pilot plant of NIFFs frequently involve the use of a local food production; and industrial plant production. additive, ‘kanwa’ or trona (i.e. sodium sesqui-carbon- Despite the establishment of small-scale gari indus- ate) which is known to be high in sodium (Uzogara et tries which operate on the industrial principles as al., 1988). Hypertensives are exposed to greater danger when they consume these foods which are prepared Cassava with both the table salt and ‘kanwa’ because such foods become sodium-laden (Wilson, 1986). This situa- tion is of great significance especially as it is known Peel that ‘kanwa’ is the second most used salt in Nigerian rural homes (Abiose and Adedeji, 1992). t 3.2. Efforts to upgrade NIFF technology Grate (Hammer mill)

Over the years, systematic and deliberate efforts were made by researchers through the introduction into Ferment in tanks some of the NIFF processes well co-ordinated trials to cause improvements through hygienic handling by the use of sanitary facilities (Onyekwere, 1977; Uzochukwu et al., 1991), production and utilization of pure culture Centrifuge to remove water (Collard & Levi, 1959; Banigo et al., 1974), process control by carefully manipulating process variables like inocula, pH, substrate quality, substrate particle size, Granulate and pass through BS 10 sieve temperature (Banigo et al., 1974; Onyekwere, 1977; Kuboye, 1985; Odunfa, 1985a; Steinkraus, 1985; Fashaki & Unokiwedi, 1993). Specific examples are Gelatinize and toast (Garigy) shown in Table 3. heat to 80°C

3.3. Effects of the scientific developmental efforts on NIFF technology

The results of the research and improvement efforts above brought the current state of development in the NIFF technology: the cumulative outcomes of the Screen through BS 18 sieve events reported above (see 3.2) are that processing/fermentation durations were drastically reduced in many / \ instances; health risk-free, consistent-quality products Gari Flour Mill coarse particles were produced and preserved in packaged forms; products and processes were adapted to mass production.

New products with tested longevities are available in Screen through BS 14 sieve the market, (at least in the rural and urban Nigeria and West Africa), like ‘dadawa’ cubes (improved ‘dawadawa’ by Cadbury Nigeria plc based on the technology described in Figure 3), bottled palm wine (Nigerian Gari Institute for Oil Palm Research, NIFOR, Benin, and Fig. 1. Nigerian gari pilot plant process (Akinrele et al., 1971). Nigerian indigenous fermented foods 537

Maize Raw locust bean (or millet or wrphum) J i , Clean Dchulling (Burr mill)

1 Boiling in retort (15 Ih:\q in for I II)

Dchull - * Air separation (Palyi mill) c Draining and cooling (40°C‘) / 1 i Hammer mill Elammer mill Discard hulls c Inoculation 1 1 (Dehydrated B. subtili\ spores) Roller mill Roller mill 1 Spreading on stainless \tcel tray\ lined with sterilized absorbent Whole grain flour Dehullcd flour paper

1 (‘ovcring with sheet of uaxed paper

I Cook Incubation (.i?“C)

I Cool c Mixing with NaCl (7’~ w:w)

I I Ogi (uncooked) Inoculate Drying in ;i vacuum

i 1 Add water Incubate 32°C Packaging 74-2X hr

i 1 1 Boil Ogi (partially cooked)w Dehydrate DLlVG;ldaWLi Fig. 3. Modern production of dawadawa (iru).

Ogi porridge Add water Dried instant Ogi and community leaders (titled men) opt for the NIFF type, except when it is in short supply. Boil Add water 4. CONCLUSIONS t c Ogi porridge Ogi porridge Nigerian indigenous fermented foods (NIFF), which Fig. 2. Improved Nigerian ogi manufacturing system (Banigo number about 30, are prepared from seven categories rt al.. 1974). of local staples at the household and cottage level through the traditional family and/or ethnic methods of specified by FIIRO (Adeyemi & Balogh, 1984) the food processing and preservation. local manufacturers who still depend on the age-old These NIFF have inherent problems as they were traditional art still dominate the markets. The reason is processed and used in their purely traditional setting. that their product is relatively cheap; only the top- Recently, Nigerians and some foreigners who acquired bracket income group can purchase the modernized expertise in the fields of food processing, human nutri- gari. tion and health sciences have identified those problems, Dadawa cubes are inexpensive, and therefore, within set out and effected improvements so that currently a the purchasing power of many individuals among the very substantial percentage of NIFF have been improved local and urban communities. Organised food prepara- to the status of modern processed foods. tion outfits like urban public canteens, schools and companies’ cafeterias/restuarants, and hospital kitchens ACKNOWLEDGEMENTS utilize the modernized condiments. The improved palm wine is more costly than the The authors thank Dr J. 0. Uzuegbu for his encour- traditional type but cheaper than conventional beers: agements and Mrs 0. N. Nsofor for kindly providing the rich choose it while the peasants, uneducated elders relevant literature used in this report. 538 C. I. Iwuoha, 0. S. Eke

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