Studies on Diagnosis of Rice Grains by Photometric Method : II. On the quality inspection of hulled nonglutinous rice, especially of the grade standard samples

[摘要] The author has described, in the previous report, an objective method for evaluating the quality of hulled rice in connection with the injured or inferior grain. In this report, practicability was investigated on nonglutinous rice especially on the grade standard samples of rice. And experiments were also made on the quality of the standard rice samples from verious prefectures. The results are summarized as follows: There were close relations among the grade of rice, percentage of injured or inferior grains and the relative transmittance values. Above all, the content of inferior grains and the transmittance were highly-significantly correlated. The corelation coefficients for lowland and upland rice were -0.92 and -0.91, respectively. Therefore, it can be said that the relative transmittance accurately indicate the degree and amount of inferior grains. The relative transmittance values of high grade rice were bigger than those of lower grade rice on the samples from each prefecture. But condiderable difference in the value were recogniged among prefectural standards. In view of the transmittance, these differences were rather evident for upland rice, rice for brewing, and lower-grade rice. The values of upland rice were distinctly lower than those of lowland rice, indicating an inferiority in grain quality of the former. Another investigation was conducted on the variental difference in the quality of normal grain. Higher transmittance values were shown by the varieties of good reputation and of rather small grain. The objective method, therefore, seems to be able to indicate not only the content of inferior grains but also the quality of normal grain which cannot be accurately evaluated by visual inspection.

[学科分类] 农业科学（综合）