Effect of fermentation periods on chemical and physicochemical properties of cocoyam starch

Abstract

AbstractThe effect of fermentation time on chemical and physiochemical properties of two varieties of cocoyam (Colocasia esculenta (white) and Xanthosoma sagittifolium (pink)) starch were evaluated. The cocoyam were fermented (24, 48, 72, and 96 h) and dried in cabinet dryer at 60°C for 24 h and subsequently milled into starch. The pasting properties, functional properties and chemical composition of the fermented starch were determined and compared with unfermented starch. Result showed that fermentation increased the peak viscosity of both varieties at 96 h with starch from white cocoyam having higher peak viscosity (6301), pink (5052). The pasting temperatures of fermented starch were not significantly different from unfermented starch for both pink and white cocoyam starch (84.0–82.0°C). White cocoyam starch had higher swelling power than pink starch (9.97–9.92) at 96 h. There were no significantly differences in the dispersibility value, bulk density, fat, crude fiber and carbohydrate for both varieties of control and fermented samples. Water solubility index (WSI) for white starch at control level was higher than that of pink (7.5, 4.5) but at 96 h, the pink variety was higher (3 and 1.5) and water absorption capacity increased markly due to fermentation period. Protein content was observed to increase during fermentation.