Abstract
A novel method to evaluate rice drying method was investigated based on water migration and molecular motion law analysis. Three typical drying methods were selected, including continuous constant temperature drying at 50 °C (CCTD), constant temperature drying at 50 °C combined with tempering at 50 °C (CTD-T), and constant temperature drying at 50 °C combined with tempering at 65 °C (CTD-HT). Before sample analysis, single-husked rice was cut into four parts equally with its central axis. During rice drying, the smallest cytoplasmic viscosity (1.28 × 10−10 poise) was observed in CTD-HT samples, compared with CCTD (1.45 × 10−10 poise) and CTD-T (1.36 × 10−10 poise) samples, which resulted in the highest drying efficiency of CTD-HT. After rice drying, the smallest moisture gradients (only 1.25%) between adjacent parts of rice and the lower molecular mobility were found in CTD-HT samples, which gave rise to the highest physicochemical, texture, and storage quality of dried rice. Optimal drying method can be identified quickly and accurately as CTD-HT. Reliability and accuracy of the evaluation method were confirmed by the classic methods.