Classified processing of different rice bran fractions according to their component distributions

Abstract

SummaryRice grains were obtained from two Chinese provinces (Hubei and Guangxi) and then their rice bran was abraded into four equal fractions by weight from outside to inside. The component distributions in these four fractions were then investigated. The contents of total lipid‐soluble antioxidant showed no significant difference between rice bran from the Hubei province and the Guangxi province. But the content of total water‐soluble antioxidant was 1690.20 ± 86.40 mg kg−1 for rice bran from the Hubei province, significantly higher than those from the Guangxi province (1014.67 ± 71.09 mg kg−1). Obvious differences between four rice bran fractions or two provinces were proved by principal component analysis (PCA). Lipase activities decreased significantly from outer fractions to inner fractions, and lipids mainly distributed in three outer fractions. The essential element contents decreased significantly, but a main heavy metal element (Pb) in cereal increased significantly to 0.36 mg kg−1 from outer fractions to inner fractions, which was just slightly below the upper limit of Chinese Standard (0.40 mg kg−1). Although protein contents had no significant difference in four fractions, the amino acid compositions were quite different. In summary, different fractions of rice bran had different compositions, which could provide guidance for the classified processing of rice bran.