Studies on the microbiology of cassava retting for foo‐foo production

Okafor N. Ijioma B. Oyolu, C. 1984. Studies on the microbiology of cassava retting for foo‐foo production. Journal of Applied Bacteriology56, 1–13.Five bacteria (Bacillus, Lactobacillus, Klebsiella, Leuconostoc, and Corynebacterium) and a yeast (Candida spp.) were isolated from cassava being fermented for foo‐foo production. Retting of cassava was assessed by determining the weight required to crush cylindrical cassava pieces. A weight in excess of 2.5 kg was required to crush an unfermented peeled cassava cylinder 4 mm diameter and 4 cm long whereas a weight as small as 20 g could crush the same piece after retting. The organisms were studied for their ability to cause retting of sterile cassava pieces, alone or in various combinations. Retting did not occur unless either the Bacillus sp. or the Corynebacterium sp. was present. Only these two organisms hydrolysed starch. The lactic acid bacteria lowered the pH of the fermenting medium although they did not bring about retting. The typical aroma of foo‐foo was produced, however, only when the lactic acid bacteria were present in the mixture. Only the Corynebacterium sp., was, however, shown to produce pectinolytic enzymes and it is possible that the Bacillus sp. caused retting by disintegrating other cell components. The typical aroma of foo‐foo is disliked by some individuals and it seems possible that foo‐foo with a bland aroma, which will presumably be more acceptable to this group, can be produced by using organisms causing retting while excluding those forming lactic acid.