BIOCHEMICAL-CHANGES IN CASSAVA TUBER DURING FERMENTATION AND ITS EFFECT ON EXTRACTED STARCH AND RESIDUE

The biochemical changes brought about in cassava tubers during fermentation (72 h) with a mixed culture inoculum are delineated. The initial starch content of the four cultivars studied ranged from 216 to 331.3 g kg(-1) and only slight decrease in starch occurred after 72 h fermentation, the final values being 200-302.2 g kg(-1). There was a considerable decrease in the sugar content with fermentation in all the cultivars, indicating a predominant utilisation of the easily assimilable sugars by the microorganisms. A sharp decrease in pH (4.3-4.7) was observed after 24 h fermentation itself, resulting from the production of organic acids. There was increased recovery of the starchy flour from the fermented cassava tubers with concomitant decrease in the residue yield. The starchy flour had higher fiber content than that obtained from the non-fermented tubers. Optical and scanning electron microscopy revealed clustering of starch granules in the starchy flour from fermented tubers.