Varietal differences of the change in the flour paste color with the time elapsed

Wheat produced domestically including the cultivar Norin61 is mainly used for Japanese noodles, but it is an important problem that saleability is relatively low because noodle color of domestic wheat is inferior to that of "ASW" wheat produced in Australia. Therefore, to clarify characteristics related to flour color, we investigated the change in the flour paste color with the time elapsed by using conventional cultivars (ex.Norin61) and superior noodle-colored new cultivars (ex.Kinunonami) for materials, and examined the varietal differences. These materials were milled by Brabender Quadrumat Junior mill, and the paste colors of A1 stream flour were measured with a spectrophotometer (CM-3500d) for time passed. In addition, pH of the solutions that 10 times diluted the pastes were measured at the same time. As the result, the L* value decreased in all cultivars/lines in progression of time, but the degree of decrease was different among cultivars. The a* value decreased three hours later, while the value tended to increase afterwards and the rate of increase was different between cultivars. As for the b*, an initial value was maintained, and little of the changes by progress of time were recognized. The materials tested in this study were classified into two groups by a state of a change of pH, and statistical significant difference occurred between delta values of a*(24a* value - 0a* value) of these two groups. Based on these results, we tried to classify the cultivars by using the initial color values (L*,a*,b*) and the after 24hours values (L*,a*) of 36 cultivars/lines which were investigated their paste colors for two years. Consequently, the clear noodle-colored cultivars (ex.Kinunonami, Iwainodaichi, Sanukinoyume2000) were classified in the first quadrant that all the factors of L*,a*,b* were superior. In addition, some varieties which held the unique characteristics about flour/paste colors (ex.Hatsuhokomugi, Saikai187) were classified respectively.