Traditional cereal processing in Nigeria and Ghana

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The traditional process described above is now being replaced in the larger towns by dieselpowered grinders (Fig. 7). Fig. 7. Machine-grinding of steeped maize (Accra, Ghana. Courtesy A. Andah). Cereal fermentation In very many of the traditional West Mrican processes the cereal is fermented as grain, as a slurry of ground material, or as a dough. Knowledge of the microorganisms involved and the types of acids produced during fermentation in West Mrica is exceedingly sketchy (Christian, 1966; Platt, 1964; Schweigert & Fellingham, 1963; Akinrele & Bassir, 1967). It is noteworthy that the type of spontaneous sour fermentation of cereals, so ubiquitous in Mrica today, was not at all uncommon in Europe up to the end of the 19th century. Maloin in 1767 referred to sour dough fermentation in France, while Parmentier in 1776 described the isolation of both alcohol and acid from such a dough. The latter also mentioned oxycrat, a sour, low-alcohol drink taken in France by poor country folk during hot weather and similar to the Mrican kaffir beer (see below). Maurizio (1924) referred to the fermented porridges of the Slavs and Letts, while the Russian drink kwass, German sour bread and Scottish, Irish and Danish barm bread are all sour cereal products which are still consumed in Europe today. The most thorough investigation of any sour cereal product is that on German sour rye bread, from which 106 different strains of lactobacillus and many acids have been isolated (Spicher, 1959; Spicher & Stephan, 1964; 1966). There is no reason to assume that Mrican fermented cereals contain fewer. Ankinrele & Bassir (1967) and W. F. K. Christian (personal communication) made preliminary studies of the bacterial flora of ogi and koko respectively. Akinrele also found lactic and acetic acids in ogi, while work at present in progress at Leeds showed additionally butyric, propionic and traces of formic acids. G.L.c. analysis is demonstrating several more. Classification of traditional cereal products Three surveys, which include cereal foods, have been made in Ghana by Whitby (1968) and Dovlo (undated; 1968). None has yet been made for Nigeria but the writer has collected a sufficient number of cereal recipes to be able to suggest a possible system of classification. Whitby and Dovlo have classified cereal products either according to geographical distribution or according to the cereal used. A different approach is adopted in this paper. There is little doubt that eventually the manufacture of cereal products in West Mrica will be mechanized. This will require mechanical handling systems such as fermenters, mixers, pumps and conveyors. The choice of equipment depends on the physical properties of the cereal product used and, therefore, the following classification is rheologically based. There are beverages, porridges, dumplings and fried or baked products and each group is discussed briefly in turn. Table 3 summarizes the products referred to. Beverages These are low-viscosity liquids with a water content of more than 94%. With mechanization, they would be processed in the usual beer or soft drink plant. The most important beverages are the beers made from kaffir com (sorghum) and referred to
Traditional cereal processing in Nigeria and Ghana TABLE 3 Classification of Some Typical Ghanaian and Nigerian Cereal Products Baked or Beverages Porridges Dumplings fried products Kaffir beer Ogi Hura Bread Pito Koko Eko Atshomo Burukutu Ekuegbemi Banku Togbei Kunnutsaki Tuo Fula Aliha Garin acha Kenkey Iced kenkey Ablemamu Akporhe akasa Nsihu Kunnu tsamia Kokui Abolo Sweet kenkey as kaffir beer. The alcohol content appears to vary from 1°/., to 4% and, in addition, there are significant amounts of lactic and acetic acids. It must be similar to the French oxycrat and the Russian kwass. For the manufacture of kaffir beer the sorghum is allowed to germinate and is then sun-dried. It is mixed with unsprouted ground sorghum, boiled and fermented. The relevant flow diagram is given in Fig. 8. The boiling, which is interposed between the I-day and 2-5-day fermentation periods, is curious. As with many traditional processes it may be a spurious step; it is possible, on the other hand, that boiling in the presence of lactic acid, produced during the first fermentation, causes a degradation of the starch since lactic acid is not volatile. Hence more substrate for bacterial fermentation would become available. Often the brew is consumed warm, as is the Hausa beer pito. Sometimes the sediment is stirred up before drinking (kunnu tzaki), and sometimes the liquid is carefully decanted (burukutu). The Ewes, Fantis and Gas of Ghana use maize rather than sorghum and may sweeten the drink with sugar or colour it with caramel (aliha). There are also non-alcoholic beverages such as iced kenkey (see below) dispersed in water and sweetened, or roasted maize (ablemamu) treated in the same way. Porridges The moisture content of these is about 90% and they would be processed like soups or yoghurt. The most important porridge is ogi which is eaten all over Nigeria and in parts of Ghana. The Ewes of Ghana and the Ibos and Yorubas of Nigeria prepare it from maize, the Hausas and Fulanis from sorghum or millet. Essentially the cereal is steeped, ground wet, sieved wet and allowed to sediment and ferment in water. The sediment is known as ogi and the boiled aqueous porridge as ogi porridge. Fig. 9 shows the wet-sieving of ogi. The Ghanaian koko is prepared in much the same way, except that it is fermented as a dough (referred to as mbor) and not as a suspension. Since less is discarded, the nutritional loss with koko is not as high as it is with ogi. Fig. 10 shows the flow diagrams of both these porridges.
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Traditional cereal processing in Nigeria and Ghana

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