Microwave and blanch-assisted drying of white yam (Dioscorea rotundata).

The effect of microwave and blanch pretreatments on the drying kinetics and quality of white yam (Dioscorea rotundata) was investigated. Yam cubes destined for hot air drying at temperatures 70-90°C were predried in a domestic microwave or blanched in hot water for 1-5 min. Microwave pretreatment time had a positive significant effect on drying rate but both pretreatments had a negative influence on the ascorbic acid content and the nonenzymatic browning.