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Members of one hundred and twenty five households from 19 villages producing dried cassava products were interviewed in Ghana. Kokonte was the most important cassava product in19% of the households processing it. Most kokonte was produced between January and March. Mould growth during processing or storage was a problem during June and July, which is part of the rainy season. Most producers and market traders preferred non-mouldy kokonte, although many (59%) would consume a mouldy product. There was a price premium for non-mouldy kokonte. The most commonly isolated fungi were yeasts and Cladosporium spp. (44 out of 49 samples). Other fungi isolated included Aspergillus spp. (20 samples); Penicillium spp. (15 samples) and Fusarium spp. (30 samples). Sterigmatocystin was detected in10 samples at 0.17^1.67 mg kg 21 ; patulin in 4 samples at 0.55^0.85 mg kg 21 ; cyclopiazonic acid in 4 samples at 0.08^0.72 mg kg 21 ; penicillic acid in 5 samples at 0.06^0.23 mg kg 21 and tenuazonic acid in 3 samples at 0.02^0.34 mg kg 21 .Mycotoxin contamination of mouldy kokonte was a potential problem; there is therefore the need to improve kokonte processing to avoid mould growth.

A total of 241 lactic acid bacteria belonging to Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus fermentum/reuteri and Lactobacillus brevis from various processing stages of maize dough fermentation were investigated. Results indicated that each processing stage has its own microenvironment with strong antimicrobial activity. About half of the Lact. plantarum and practically all of the Lact. fermentum/reuteri investigated were shown to inhibit other Gram-positive and Gram-negative bacteria, explaining the elimination of these organisms during the initial processing stages. Further, widespread microbial interactions amounting to 85% to 18% of all combinations tested were demonstrated amongst lactic acid bacteria within the various processing stages, i.e. raw material, steeping, 0 h and 48 h of fermentation, explaining the microbial succession taking place amongst lactic acid bacteria during fermentation. The antimicrobial effect was explained by the combined effect of acids, compounds sensitive to proteolytic enzymes and other compounds with antimicrobial activity with the acid production being the most important factor. The pattern of antimicrobial factors was not species-specific and the safety and storage stability of fermented maize seem to depend on a mixed population of lactic acid bacteria with different types of antimicrobial characteristics. This means that introduction of pure cultures as starters may impose a risk to the product.