Effect of post-milling process on the oxidation on the rice bran

Abstract

Abstract The rancidity of rice bran is predominantly triggered by lipophilic enzyme activities. Bran stabilisation and defatting are the typical processes to inactivate the processes that cause rancidity. However, little is known about how this impacts the development of volatile compounds related to odour in the rice bran. The effects of post-milling treatments, including the stabilisation and defatting process, on the nutritional properties and then on the development of secondary volatile oxidation compounds in the rice bran during storage were investigated. Butanal, hexanal, 2 hexenal, butanoic acid, hexanoic acid, pentanoic acid, and heptanoic acid were the discriminant volatile compounds in the non-defatted bran that were identified as the markers of rancidity of non-defatted stabilised rice. It can thus be suggested that the defatting process positively contributed to the low abundance of volatile oxidation products that are responsible for bran rancidity by slowing down the formation of lipid-derived oxidation products.