Study on Optimum Extraction Conditions of Serratia polysaccharide in Chinese yam

The optimum conditions of water extraction for polysaccharide in Chinese yam were studied in this paper.Results showed that the optimum extraction conditions were as follows: 90 ℃ of extraction temperature,2 hours of extraction time,two times of extraction times;the ratio of material and water was 1∶30,and the effect of protein removed was the best when adding 3% trichloroacetic acid solution of concentrate 7.5% volume,and then polysaccharide of Chinese yam was isolated easily when adding 5 times volume absolute ethyl alcohol.