THE APPLICATION OF IMAGE-ANALYSIS TO VALU ATION ON WHITE-CORE IN KERNEL OF RICE FOR SAKE BREWERY

It is expected by rice breeders and sake brewers to establish the simp le means for evaluating the size of white-core in grains of rice for s ake brewing. In this study, we measured the white-core of each grain i n two cultivers, Ipponjime and Gohyakumangoku, by using the image anal ysis. The results showed that the relative size of white-core to the w hole size of grain, i.e. white-core rate, varied widely from grain to grain (0 similar to 100%) in the same cultiver. Although the average o f white-core rate in Ipponjime seemed to be larger than that in Gohyak umangoku, there was no significant difference between them. But the re gion where the white-core was expressed in grains was different betwee n two cultivars. Then we divided a grain in four parts, i.e. the 1 st, 2 nd, 3 rd and 4 th quadrants, and examined relative size of white-co re in each quadrant. The results showed that, in Gohyakumangoku, the w hite-core was expressed mostly in the 1 st and 2 nd quadrant, but in a ll quadrants in Ipponjime. Based on the findings, we made the standard image of grains which have variable size of white-core by superimposi ng the image of 85 grains in each cultiver.