The functional properties of four cassava varieties as affected by fermentation time

Freshly harvested cassava varieties (NR 8082, TMS 419, TMS 4(2) and TMS 30572) were each divided into 5 portions, peeled, washed, soaked and fermented for different times (0, 24, 48, 72, 96 hours) in water. The water was regularly changed at 6-hour intervals. Both the fermented and unfermented (fermented for zero hours) tubers were mashed, bagged, de-watered (with a hydraulic press), oven-dried, milled, sieved and packaged. The zero-fermented or unfermented cassava flour represented high-quality cassava flour (HQCF). The flours obtained (HQCF and fermented odourless cassava flours) from the four cassava varieties were used to study the effect of fermentation time on quality characteristics of odourless flours from four cassava varieties comparatively. Most of the measured quality characteristics of cassava flour were affected by varietal differences. The results showed that fermentation, irrespective of cassava variety, influenced progressive increases in foaming capacity (3.76 - 4.19%), water absorption capacity (1.27-1.53g/g), oil absorption capacity (2.99~3.23g/g), emulsion capacity (40.65-46.68%), The longer the period of fermentation, the higher the level of increases for the above-stated quality parameters. However, beyond 48 hours of fermentation, the quality parameters started decreasing with an increase in fermentation time. And there were decreases in bulk density (0.74-0.72g/cm3), swelling index (1.18-1.07%), gelation temperature (71.33-68.67°C), viscosity (0.182-0.176Pa.s), wettability (11.59-7.49s) and photometric colour index (7.71-5.84) as time of fermentation increase from 0-96 hours. Therefore, cassava tubers should be fermented for 48 hours to obtain cassava flours with good functional properties.