Evaluation of Antioxidants Extraction from Germ and Bran of Wheat Grain

Abstract

This study was conducted to investigate and test the activity of three essential parts of wheat seed such as germ, bran and Aleurone, which were used as secondary products from grinding grain to feed animals. The diversity of solvents was applied to extract the bioactive compounds in both conventional and modern extractions. The total phenolic compounds, antioxidant activity, reducing power, metal chelating, and scavenging of hydrogen peroxidase were determined for all three essential parts of wheat. The stability of the extracts was studied toward temperature and pH at the interval time. In addition, the synergistic effect of the extracts. The microwave-assisted extraction was able to extract the highest level of phenolic compounds from wheat germ . The microwave-assisted extraction was able to give the highest antioxidant activity 53% at concentration 100 mg.ml-1 from ethanolic wheat germ extraction. In addition, the wheat germ had the highest reducing power 163.88 % at concentration 5 mg.ml-1 , while the percentage of reducing power for both ethanolic extraction of aleurone and ethanolic extraction of wheat bran were 112.63 % and 79.68 %, respectively. Moreover, the wheat Grem had the highest percentage for both Ferrous chelating and scavenging of hydrogen peroxidase. Ethanolic extracts of aleurone, bran and germ had a higher antioxidant activity in natural pH while decreased when treated with acid and alkaline. In addition, the ethanolic wheat germ was able to give the highest antioxidant activity at 100°C for 100 min 62.2% compared to others and give synergistic effect for both ascorbic acid and alpha tocopherol exhibited 91.90 % of antioxidant activity at concentration 60 mg.ml-1. Ethanolic extracts of germ with different concentration was added to corn, the result showed that the ethanolic wheat germ at 0.25 mg.g-1 had the ability to decrease the hydrogen peroxide for the corn oil 6.8 meq.kg-1 oil at end of stored time compared to BHT 0.05 % 4.3 meq.kg-1 oil at the same conditions.