Effects of different combined drying methods on drying uniformity and quality of dried taro slices

In this study, hot air drying (HAD), low power intermittent microwave vacuum drying (LPIMVD), and high power intermittent microwave vacuum drying (HPIMVD) were combined to dry taro slices. Microwave-only drying showed the highest drying rate, but the worst drying uniformity. Combined HAD and microwave drying improved uniformity and quality (color, ascorbic acid content, texture) of dried products. Taro slices dried by HAD + HPIMVD + LPIMVD showed high L* value, ascorbic acid content, and suitable texture. Furthermore, the drying time was reduced by 62.5%, as compared to IMVD + HAD. For HAD + HPIMVD + LPIMVD, the surface moisture evaporated during the HAD process, this may contribute to improve texture of samples and uniformity of temperature distribution during the subsequent microwave.