Pretreatment to increase yield and antioxidant activity of aγ-oryzanol in rice bran oil

Abstract

Six pretreatment processes to extract oil from Khao Dok Mali 105 rice bran were tested to assess the effect of the processes on the ã-oryzanol content and DPPH scavenging activity of the extract. The pretreatment processes consisted of the following: microwave heating (60-110 ° C), hot air heating (70-180 ° C), roasting (60-80 ° C), parboiling (70 ° C), autoclaving (121 ° C), and enzyme (amylase) treatment (50 ° C). The highest amount of oil was obtained by hot air heating (70 ° C) of 0.27 g/g of dried rice bran, whereas the highest ã-oryzanol yield was obtained by parboiling 9.8 mg/g of dried rice bran. The highest ã-oryzanol concentration obtained with a roasting pretreatment (60 ° C) was 46.9 mg/ml of rice bran oil.