Influence of Cultivation Regions on Chemical Contents of Rice Kernel and Stickiness of Cooked Rice
In 29 samples of Koshihikari (japonica variety) from 26 agricultural experiment stations located south of the northeastern part of Japan, the differences in eating quality and chemical composition of rice were studied. The stickiness of the samples which was determined by the sensory test and compared to that of Nipponbare ranged from 0.2 to 1.60. These samples contained 1.10 to 1.63% nitrogen and 16.2 to 20.0% amylose. Both the nitrogen content and amylose content were not significantly correlated with the stickiness when individual samples were considered. However, the temperature after heading was found to affect the stickiness of Koshihikari. The optimum mean daily air temperature during 30 days after heading for stickiness was found to be around 25.5℃. Since the amylose content was negatively correlated with the stickiness when the mean daily temperature was less than 26℃, it is assumed that the higher amylose content observed in cold regions may reduce the stickiness. On the other hand, the nitrogen content was found to be negatively correlated with the stickiness for samples at similar temperature levels.
|作成者||Masahiro OKAMOTO Toshiro HORINO|