Protein removal and purification by chitosan method of Hericium erincaceus polysaccharide extract

Effects of solid-liquid ratio( v / v),p H,time and frequency on protein removal from Hericium erincaceus polysaccharide extract by chitosan method were studied,and the optimum conditions were obtained,the Hericium erincaceus polysaccharide was isolated and purified by column chromatography. The results showed that the optimum conditions were the ratio of extract to chitosan solvent( v / v) was 50 ∶ 1,original p H,and time of 2 h for a time.Under such condition,the removal rate of protein reached about 60.11% ± 0.47%,which was higher than Sevage method by 11.67% and the loss rate of polysaccharides was decreased to about 11.16% ± 0.48%,which was lower than Sevage method by 80.87%,and the residual of chitosan was detected about 1.01% ± 0.005%.Two kinds of polysaccharide,HEP-Ⅰ and HEP-Ⅱ,were isolated and purified from the crude Hericium erinaceus polysaccharide by DEAE Sepharose Fast Flow column chromatography.Sephadex G-75 column chromatography,UV spectrophotometer,and Fourier transform infrared spectroscopy were used to analyze HEP-Ⅰand HEP-Ⅱ.The results showed that both of HEP-Ⅰ and HEP-Ⅱ were in unique form. And HEP-Ⅰ contain carbohydrate pyran ring and furan ring,while HEP-Ⅱ only contain carbohydrate pyran ring. Chitosan method was reasonably practicable,and Hericium erinaceus polysaccharide was in high purity after column chromatography.