Microwave drying of sweet potato (Ipomoea batatas (L.)) slices: influence of the osmotic pretreatment

Abstract

Drying of sweet potato (Ipomoea batatas (L.)) slices by microwave with and without osmotic dehydration (OD) as a pretreatment was studied. Three osmotic agents (sucrose, sorbitol and fructose) were employed. Drying continued until final moisture content of 20 kg water 100 kg-1 sample. Two different microwave output powers (180 and 350W) were used. The drying kinetics was modeled by mathematical models from the literature. The use of OD and higher microwave power carried out to shorter drying time. Among the tested mathematical models, the Weibull distribution model presented good fitness for drying kinetics obtained in both microwave power.