Functional and pasting characteristics of modified water yam flour (Diocorea alata)

Autoclaving-cooling treatment was introduced in order to produce the physically modified water yam flour. Water yam (Dioscorea alata) tuber of three varieties (purple, yellow, and white) were autoclaved-cooled (3 cycles) prior to the determination of their functional and pasting properties of their flours. Autoclaving-cooling treatments resulted in a significant increase in crystallinity of the starches, swelling power, and water absorption capacity; whereas solubility and oil absorption capacity were lowered by autoclaving-cooling process. When compared to the native, and modified water yam flours showed lower peak viscosity, breakdown viscosity, final viscosity, pasting temperature and shorter pasting time, but the differences were insignificant (p > 0.05). Low viscosities of the modified water yam flours make it suitable for a wide application in the food industry. The objective of this work is to study the effect of autoclaving-cooling treatments and the varieties of water yam on the pasting and functional properties of modified water yam flours.