24 Commercialization of Fermented Foods in Sub-Saharan Africa
Fermented foods form an important part of the diets of people throughout the world, and the people of sub-Saharan Africa are no exception. In many parts of the world, as urbanization increases, the preparation of fermented foods moves from the small-scale household level to large-scale operations. Under these new conditions the foods are prepared with better scientific knowledge. For this reason large scale factory procedures may differ from traditional approaches. For example, cheese that used to be produced with protease present in rennet may now be produced with protease produced by fungi.
With this in mind, a review was carried out in 1981 (1) to learn the extent to which some important fermented foods of sub-Saharan Africa had progressed toward commercialization. The stage that each food had attained was measured on a scale of 8, as shown in Table 1.
The purpose of this paper is to indicate to what extent various sub-Saharan fermented foods have progressed in the past decade toward being industrialized and to examine the role, if any, that modern techniques of biotechnology, particularly genetic engineering, have played in commercialization.
INDUSTRIALIZATION OF FERMENTED FOODS
Table 1 lists the fermented foods about which information is available, including those reviewed earlier (1). A review of the extent of progress toward industrialization of alcoholic beverages of sub-Saharan Africa was recently published (2) and is incorporated here into Table 1.
The following conclusions can be drawn:
· In 1981 the following foods had been produced on an industrial or semiindustrial scale: ogi, garri, palm wine, mahewu, and sorghum (kaffir) beer.
Two new products are now being produced on an industrial or semiindustrial scale. The first is a Nigerian condiment known as dawa-dawa. It is being produced under the trade name of Dadwa by the firm of Cadburys in Nigeria from Parkia seeds as in the traditional fermentation. The second is a Zimbabwean fermented milk product known as Lacto. It is similar to the traditional fermented milk of Zimbabwe (3).
· The organisms involved in the fermentation of several foods that were unknown in 1981 have now been identified. They are foo-foo (4), kokonte (5), ugba (ukpaka) (6), and ogili (7,8).
The case of dawa-dawa is interesting. In 1981 the organisms involved were unknown; in 1991 not only are they known (9), but the food itself has been commercialized.
· Some foods not previously recorded have been added: tej from Ethiopia (10); nono, a milk-based product from Nigeria; and Zimbabwean fermented milk (3).
TABLE 1 Fermented Foods of Africa South of the Sahara
DISCUSSION AND CONCLUSIONS
As can be seen, very little has changed in the progress of the fermented foods of Africa toward industrial production. The 1990s are the era of biotechnology, especially genetic engineering. Fermented foods are brought about by microorganisms, and one would expect that these organisms would be subjected to the technology of gene cloning to improve their activity in the fermentation of foods.
For example, the fermentation of most carbohydrate foods such as cassava or maize is brought about by lactic acid bacteria. One would therefore have expected that these organisms would be targeted for improvement by gene cloning. Only one example of the advantage of the use of this technique will be given.
In garri fermentation lactic acid bacteria play an important part in producing the flavor of the food (11). Yet these organisms cannot split starch. If the amylase gene can be cloned into a lactic acid bacterium involved in garri fermentation, it is conceivable that fermentation will occur faster. If the gene for linamarase production can also be simultaneously cloned, then not only will the fermentation be faster but detoxification also will occur (12).
The only work having any relationship to gene cloning in organisms involved in fermentation was the isolation of plasmids from cassava fermenting organisms by Nwankwo et al. (13). They found that they could not transfer the plasmids to E. cold and there the work ended.
The lack of ability to exploit this new technique in an area of vital importance to Africa south of the Sahara is a clear example of (an almost?) missed opportunity in an age when seemingly everyone is cloning a gene from one source or another. Nevertheless, there have been some developments in other directions. For example, Ofuya and Nnajiofor (14) have developed a starter culture for garri that should prove useful in the commercialization of the food. Also, Ofuya and Fiito (15) have developed a rapid method for assessing the quality of garri based on an iodine reaction.
1. Okafor, N. 1981. A scheme for the improvement of fermented foods of Africa, south of the Sahara. Pp. 61-69. In: Global Impacts of Applied Microbiology. S. O. Emejuaiwe, O. Ogunbi, and S. O. Sanni (Eds.). London: Academic Press.
2. Okafor, N. 1990. Traditional alcoholic beverages of tropical Africa: Strategies for scale-up. Process Biochemistry International 25:2 13-220.
3. Feresu, S. B., and M. I. Muzondo. 1990. Identification of some lactic acid bacteria from two Zimbabwean fermented milk products. World Journal of Microbial Biotechnology 6:178-186.
4. Okafor, N., C. O. Oyolu, and B. C. Ijioma. 1984. Microbiology and biochemistry of foo-foo production. Journal of Applied Microbiology 55:1-13.
5. Mensah, P., A. M. Tomkins, B.S. Drasar, and T. J. Harrison.
1991. Antimicrobial effects of fermented Ghanaian maize dough. Journal of Applied Bacteriology 70:203-210.
6. Obeta, J. A. N. 1983. A note on the microorganisms associated with the fermentation of the seeds of the African oil bean tree. Journal of Applied Bacteriology 54:433-435.
7. Ogundana, S. K. 1980. The production of ogiri: Nigerian soup condiment. Lebensmittel Wissenschaff und Technologia 13:334-336.
8. Onunkwo, A. U. 1982. Some edible fermentation products of Nigeria. M.Sc. thesis, University of Strathclyde, Glasgow.
9. Odunfa, S. A. 1981. Microorganisms associated with the fermentation of the African locust bean, Parkia filicoidea, during iru preparation. Journal of Plant Foods 3:245-250.
10. Girma, M., B. A. Gashe, and B. Lakew. 1989. The effect of fermentation on the growth and survival of Salmonella typhimurium, Staphylococcus aureus, Bacillus cereus, and Pseudomonas aeroginosa in fermenting tef (Eragrostis tef). Mircen Journal of Applied Microbiology 5:61-66.
11. Okafor, N., and J. Uzuegbu. 1987. Studies on the contributions of microorganisms on the organoleptic properties of garri, a fermented food derived from cassava (Manihot esculenta Crantz). Journal of Food Agriculture 2:99-105.
12. Okafor, N., and A. O. Ejiofor. 1990. Rapid detoxification of cassava mash fermenting for garri production following inoculation by a yeast simultaneously producing linamarase and amylase. Process Biochemistry International 25:82-86.
13. Nwankwo, D., E. Anadu, and R. Usoro. 1989. Cassava fermenting organisms. Mircen Journal of Applied Microbiology 5:169179.
14. Ofuya, C. O., and C. Nnajiofor. 1989. Development and evaluation of a starter culture for the industrial production of garri. Journal of Applied Microbiology 66:37-42.
15. Ofuya, C. O., and J. Fiito. 1989. A rapid method for determining the quality of garri based on iodine reduction test. Letters in Applied Microbiology 9:153-155.
16. Ashenafi, M. 1990. Effect of curd cooking temperatures on the microbiological qualities of ayib, a traditional cottage cheese. World Journal of Microbial Biotechnology 6:159-162.
17. Odibo, F. J. C., and A. I. Umeh. 1989. Microbiology of the fermentation of Telfaria seeds for ogiri production. Mircen Journal of Applied Microbiology and Biotechnology 5:217-222.
[Украинский] [английский] [русский]