Antioxidant properties of wild rice.

Wild rice (Zizania aquatica) seeds were extracted with methanol, ethanol, and ethyl acetate. The yields of extracts were 3.9%, 1.9%, and 1.0%, respectively. The antioxidant activities of the extracts were measured by thiobarbituric acid reactive substance values in ground beef and by peroxide values in lard. The methanol and ethanol extracts showed a significant antioxidant activity when added to ground beef and lard. Wild rice hull extract also showed appreciable antioxidant activity in ground beef. Pulverized cooked and uncooked wild rice substantially reduced rancidity in ground beef, and therefore can be used as an antioxidant ingredient for commercial applications in food products. By using both 31P and 13C nuclear magnetic resonance, it was established that the isolate from the wild rice extract is phytic acid.