Abstract:In order to study the fermentation optimization for polysaccharide from Rosa roxburghii Tratt pomace，polysaccharide from Rosa roxburghii Tratt pomace was selected as raw material，and yeast as the fermentation starter.The effects of inoculating volume，fermentation temperature and fermentation period，pH value on the polysaccharides yield were explored by single factor experiments.Then orthogonal experiment was designed to study the optimal techniques on promote polysaccharides from Rosa roxburghii Tratt pomace，and the in vitro antioxidant activity of the polysaccharides was studied.The results showed that the optimal fermentation condition of polysaccharides was as follows：inoculating volume 3%，fermentation period 84 h，pH 4.0，fermentation temperature 32.5 ℃.The ratio of polysaccharides was increased under the optimal condition.Antioxidant tests showed that the radical scavenging rate on DPPH and reducing capacity of Rosa roxburghii Tratt residue polysaccharides by fermentation was superior to crude polysaccharide.