Hakutsurunishiki is a sake rice variety developed by Yamadabo for the seed parent and Wataribune 2 for the pollen parent, equivalent to a sibling of Yamadanishiki. Although Hakutsurunishiki has different characteristics from Yamadanishiki, its genetic characteristics have yet to be determined. We therefore attempted to clarify the genetic characteristics of Hakutsurunishiki by the whole genome information among both varieties and the parents. There was a different inheritance of genomic regions derived from the parents between Hakutsurunishiki and Yamadanishiki. In addition, there were DNA polymorphisms at several starch-related genes and the quantitative trait loci related to white-core expression in the rice grain, suggesting phenotypic differences between the two varieties.
The authors investigated the methanol content in potato shochu(137 samples of sweet potato shochu, 6 samples of potato shochu, and 3 samples of Japanese yam shochu. There were no samples which exceeded the regulation level of methanol of the Japanese Food Sanitation Act. In sweet potato shochu made from Koganesengan, the methanol content using sweet potato koji was significantly higher than that using rice koji. The methanol content of sweet potato shochu made from purple lineages was significantly higher than that made from Koganesengan.
The authors investigated the quantitative scale evaluation of barley shochu and sweet potato shochu. Five kinds of evaluation items(body, sweetness, bitterness, aftertaste and overall evaluation) were used for the scale evaluation. The evaluation of sweetness had a significant correlation with that of the overall evaluation in both barley shochu and sweet potato shochu. As a result of a multiple regression analysis, it was found that sweetness and aftertaste were important to the overall evaluation. Futhermore, the correlation analysis between scale evaluation values, general components, and flavor components was investigated.