Temperature-Field Distribution and Dehydrated Quality of Lotus-Root Sticks during Microwave Rolling-Bed Drying

Abstract:

In order to solve the problem of non-uniform drying during microwave drying and improve the drying quality of lotus root, a microwave hot-air flow rolling-bed drying (MARD) device was developed by our team. The hot-air flow drying (AD) was used as a control, and the thermal image distribution of lotus root with boiling-water blanching and non-blanching at different drying stages of MARD and the dry-basis water contents were studied. The sensory quality and micro-morphology of materials in different processes were investigated. As a result, with hot air and microwave, the temperature of lotus-root sticks was gradually increased, and finally stabilized within a set range during MARD. Boiling-water blanching reduced the drying time of MARD by 10-15 minutes, but had no significant effect on the temperature distribution of the materials during MARD. Boiling-water blanching darkeddehydrated lotus root, and both boiling water blanching and microwave drying destroyed the microstructure of lotus-root sticks.