Effects of germination time and drying temperature on drying characteristics and quality of germinated paddy

Germination time and drying temperature are very important parameters affecting the quality of the germinated paddy (GP) since the microstructure of starch granules is modified during germination. The experimental results showed that the germination time increasing from 60 to 68 h provided more loosely-packed starch granules, lower hardness of cooked GP, higher gamma-aminobutyric acid content (GABA) and larger number of fissured GP after drying. However, the modified microstructure did not cause a difference between drying curves at each germination time. Prediction results of the moisture content from the two-layer model were in good agreement with the experimental results and also showed that the effective moisture diffusion coefficient values of husk were significantly lower than those of germinated brown rice. Drying at a higher drying temperature could reduce the number of fissured GP more significantly. The hardness of cooked GP samples and their GABA contents obtained from drying temperatures changed insignificantly from that of the shade-dried GP. The sensory analysis results revealed that the texture of GP was better than that of the rice without germination and the longer germination time provided the adverse effect on the fermentation odour and texture. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.