关键词: 流化床, 热风薄层, 干燥, 粳稻, 加工品质, 质构品质

Abstract:

The changes in water content in high moisture paddy were examined during fluidized-bed drying and thin layerhot
air drying at different drying temperatures such as 50, 60 and 70 ℃. The effect of drying temperature on the cracking
rate of paddy and texture characteristics (hardness, adhesiveness and chewiness) of cooked rice was investigated. The results
showed that the drying rate of paddy by fluidized-bed drying was higher than that by thin layer-hot air drying at identical
conditions of temperature and initial water content. In addition, fluidized bed resulted in faster drying rate but slightly lower
percentage of cracked paddy grains than thin layer hot air, with no difference observed between both drying methods as far
as the germination rate of rice was concerned. The texture qualities of cooked rice from paddy subjected to fluidized-bed and
thin layer-hot air drying were better when the drying temperature was 50 ℃. There was a significantly negative correlation
between drying temperature and head-rice yield. The cracking rate in paddy subjected to fluidized-bed drying showed a
significant correlation with the hardness, adhesiveness and gumminess of cooked rice. As for thin layer-hot air drying, paddy
cracking rate showed a significant correlation with the adhesiveness and gumminess of cooked rice, but the correlation with
all other texture qualities tested was insignificant.

Key words: fluidized bed, thin layer-hot air, drying, japonica rice, processing quality, texture quality