Fermentation of cassava into foofoo : effect of time and temperature on processing and storage quality

The preparation and distribution of foofoo comprises several stages, namely soaking, dewatering and storage prior to sale. The effects of four different time/temperature soaking processes on the quality of foofoo (pH, microbial load, residual cyanogens) were determined. The processes were chosen as they gave roughly equivalent degrees of retting (the softening of cassava during soaking) by which the progress of the initial fermentation is normally judged. Instrumental measurement of cassava hardness confirmed that the processes were equivalent within experimental limits. The four soaking processes had no significant effect on the water content of foofoo, nor did this change during storage. Processing did affect the pH, total titratable acidity and microbial profiles. Analysis of the aqueous extracts from the processes showed that the glucose present in the fresh cassava was fermented into a mixture of acetic, butyric, isobutyric and lactic acids with some ethanol. The lowering of the pH reduced the number of Enterobacteriaceae to the limit of detection and also affected the types of microbe present. The different processes also affected the removal of cyanogens from the product and the processes at 20 degrees C and 35 degrees C led to unacceptable levels of cyanogens (mainly cyanohydrin) in foofoo eng