Development of an Extraction Procedure for Wheat Red Coat Pigments and Determination of Varietal Differences for This Trait

Abstract

The genes for red seed coat of wheat are known to have a relationship to tolerance to preharvest sprouting. We developed a method for extracting seed coat pigments controlled by the genes for red seed coat. Wheat cultivars used in this study were subjected to analysis of the genes for red seed coat prior to chemical analysis. The genotypes of Norin 66 and Fukuwasekomugi were identified as r1, R2, r3. Those of Norin 10 and Asakazekomugi were identified as R1, R2, r3. Those of Kitakamikomugi, Fukuhokomugi and Norin 61 were identified as R1, r2, R3, r1, R2. R3 and R1, R2, R3, respectively. Seed coat pigments were extracted from twelve cultivars (nine with red seed coat and three with white seed coat). The seeds were milled and the prepared bran was washed with hexane, acetone and diethyl ether to remove carotenoid pigments. The defatted bran was heated with 1M sodium hydroxide at 100°C for 30 min. The pigments were extracted with n-butanol after the pH of the solution was adjusted to acidic condition. The absorbance of the butanol extracts was determined at the region from 380 nm to 550 nm. The absorbance became higher as the number of the genes for red seed coat increased. The results showed that red seed coat pigments were extracted with these procedures.