Comparison of Antioxidant Activities by Different Extraction Temperatures of Some Commercially Available Cultivars of Rice Bran in Korea

This study was conducted to determine antioxidant compounds and antioxidant activities of rice bran at temperatures of 10℃, 25℃, and 60℃ using 70% ethanol solution. DPPH, ABTS radical scavenging activities and reducing power have been used to investigate the relative antioxidant activities of extracts. The contents of total polyphenol and total flavonoids in the 70% ethanol extracts were measured by spectrophotometer. The total polyphenol content in the rice bran extracts were 790.39 930.07, 782.71 1,039.57, and 848.22 1,052.96 ㎎ gallic acid eq./100 g in 10℃, 25℃ and 60℃, respectively. Antioxidant activities, such as DPPH, ABTS radical scavenging activity and reducing power, in all cultivars and temperatures was the highest in Cheonghaejinmi rice bran extracted at 25℃. The results obtained in the in vitro models suggest that extracts from rice bran, especially Cheonghaejinmi, has significant health-promoting effects, as it exhibits antioxidant activities.