Antioxidant Properties of Milled‐rice Co‐products and Their Effects on Lipid Oxidation in Ground Beef

Antioxidant properties were analyzed for methanolic extracts of rice seeds, milled‐rice co‐products, and other selected plant seeds, including cottonseed, soybean, and corn. Values of antioxidant effectiveness ranged from 45% to 86%, based on 100% activity at no change in color during the p‐carotene bleaching test. A correlation exists between the antioxidant activity and the total phenolic content of the rice ingredient extracts ( r 2 = 0.81). When selected extracts were applied to ground beef, the lipid oxidation was inhibited by, in relative effectiveness, rice hull > rice bran > brown rice. When applied directly to the beef, both defatted brown rice flour and rice bran strongly retarded the lipid oxidation.