Antioxidant Activity of Whole Wheat Flour during in Vitro Simulated Digestion

The polyphenol and flavonoid content as well as antioxidant activity were determined during in vitro simulated digestion of three wheat varieties(AK58, xinong979, yangmai16). The results showed that enzymes had a significant effect on the release of polyphenols during the simulated digestion. The maximum release amount was 3.04~3.14 times that of 0~h stomach digestion, while the maximum release of intestinal digestion was 5.24~5.94 times that of 0~h stomach digestion and 1.77~1.94 times 0~h intestinal digestion. Stomach acid and enzymes had significant effects on the release of flavonoids. The maximum release during stomach digestion was 1.72~1.94 times of 0 h stomach digestion, while the maximum release during intestinal digestion was 2.34~3.14 times of 0 h stomach digestion and 1.57~1.71 times of 0 h intestinal digestion. The oxygen radical absorbance capacity(ORAC) of the wheat flour significantly increased during the digestion. The strongest ORAC during stomach digestion was 2.14~3.92 times that of 0 h stomach digestion, while that of intestinal digestion was 7.19~10.18 times that of 0 h stomach digestion and was 2.72~3.24 times that of 0 h intestinal digestion. In addition, there was a significant positive correlation between the antioxidant activity and the release of polyphenols(rs=0.90-0.99,p0.01).