Antioxidative Activity of Exopolysaccharide Extract from Fermented Wheat Distillers'dried Grains Using UV-Irradiation Degradation Pretreatment by Preussia aemulans

摘要

A novel approach for utilizing wheat Dried Distillers' Grains with Solubles (DDGS) to produce exopolysaccharide by Preussia aemulans was explored. For degrading the insoluble polymer of wheat DDGS, the UV-irradiation method was used. After irradiation of 24 h, the soluble saccharide content of wheat DDGS medium was increased by 67%. The optimum fermentation conditions were: 5% (w/v) of fructose, 0.5% (w/v) of yeast extract, 7.5 of pH value, 5% (v/v) of the inoculum size, 60 rpm of shaking condition and 5 days of the fermentation time. The maximum exopolysaccharides yield of fermented broth under the optimum fermentation conditions was 3.51±0.24 g/L. Comparing with the unfermented wheat DDGS water extract, the exopolysaccharide yield of fermented broth was increased by 36%. The crude exopolysaccharide (EPS) indicated remarkable antioxidative activities though four antioxidant assays. Therefore, the crude EPS could be utilized as antioxidative food additives and functional feed in the future.