The fermentation process of polysaccharides from Bletilla striata by high temperature resistant Saccharomyces cerevisiae was investigated.Using water-soluble polysaccharides content as the evaluation index,the fermentation process was optimized by single factor experiments and response surface experiments,and the antioxidant capacity of water-soluble polysaccharides were determined.The results showed that the optimal fermentation conditions were as follows:fermentation time 24 h,inoculum 10％,fermentation temperature 38 ℃,shaker speed 120 r/min,initial pH 5.5.Under the optimal conditions,the water-soluble polysaccharides content reached 2.80 mg/ml.The infrared spectra of the extracts showed that it had the charac-teristic absorption peak of polysaccharides.The antioxidant tests results showed that the maximum 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging rate in the fermentation group was 66.5％,which was higher than that in the water extraction group.When the mass concentration of polysaccharides was 4 mg/ml,the DPPH free radical scavenging rate was 2.15 times that in water extraction control group.In conclusion,compared with the water extraction group,the water-soluble polysaccharides produced by liquid fermentation with S.cerevisiae had stronger antioxidant activity.
关键词
耐高温酵母菌/白芨/多糖/发酵工艺/优化/抗氧化活性
Key words
high temperature resistant Saccharomyces cerevisiae/Bletilla striata/polysaccharide/fermentation process/optimization/antioxidant activity
维普
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