Study On Extraction, Purification And Antioxidative Activity Of Polysaccharides From Pleurotus Eryngii

Pleurotus eryngii(Pleurotus eryngii(DC.ex.FR) Quel.) belongs to Eumycota, Basidiomycotina, Hymenomycetes, Homobasidiomy cetidae, Agaicales, Pleurotacea, Pleurotus. With a super quality, fleshy and crisp, Pleurotus eryngii has a special almond fragrance and tastes like abalone. It is the new rare varieties of edible fungi that combined with medicinal and edible value. Extraction technology, purified technology, the primary structure analysis and anti-oxidative effect of Pleurotus eryngii polysaccharides have been studied in this paper. The purpose is to expand the application of Pleurotus eryngii polysaccharides, improve its added value and provid the important basis for the high-value processing of Pleurotus eryngii.1. With the fruiting body of Pleurotus eryngii as experiment material, the best water extraction technology of Pleurotus eryngii polysaccharides was studied. The results showed that the optimal conditions of polysaccharides extraction were obtained as following:the extraction temperature100℃, extraction time2.5h, material/water ratio1:30(g/mL), and that extraction rate could reach to2.31%.2. With the fruiting body of Pleurotus eryngii as experiment material, the best enzymatic method extraction technology of Pleurotus eryngii polysaccharides was studied. The results showed that the optimal hydrolysis conditons of polysaccharides extraction were obtained as following:the enzyme/substrate900U/mL, pH6.0, material/water ratio1:25(g/mL), enzymolysis time70min, enzymolysis temperature55℃, and that extraction rate could reach to3.74%.3. With the fruiting body of Pleurotus eryngii as experiment material, the best ultra-high pressure extraction technology of Pleurotus eryngii polysaccharides was studied. The results showed that the optimal conditons of polysaccharides extraction were obtained as following:temperature40℃, time30min, material/water ratio1:10(g/mL), pressure500MPa, and that extraction rate could reach to6.91%. The result was obviously better than the water extraction technology and enzymatic method extraction technology. 4. After concentrating and freeze drying, the dry powder of Pleurotus eryngii crude polysaccharides (PEP-I) was obtained. Taking PEP-I as experiment material, the best technology of deproteinization of polysaccharides were studied by Sevag method combined with papain. The optimum technology of removed protein was as follows:enzymolysis temperature55℃, pH6.0, enzymolysis time90min, the enzyme/substrate500U/mL. The loss rates of polysaccharide could reach to82.93%when handed with Sevag reagent for four times, but the rate of losing polysaccharides was12.81%.Then decolor the polysaccharides with D101macroreticular resin, and purify it by DEAE-52and Sephadex G-150, which contained three components:PEP1-. PEP2and PEP3. By IR analysis, these three components are all composed of pyranose, and the PEP1was bonded by the β-glucoside.5. PEP-II was obtained from PEP-Ⅰ after deproteinization, decolorization, reversed water dialysis24h, concentration and freeze drying.The antioxidant activity in vitro of PEP-Ⅰ and PEP-Ⅱ were studied, which were compared with the effect of Vc. The results showed that the PEP-Ⅰ and the PEP-Ⅱ could inhibit and clear the ROS such as DPPH free radical, hydroxyl radical and superoxide anion free radical effectively, and the effect on the total antioxidant capacity were both satisfactory. The above four indicators are positive correlation between the concentration of the polysaccharide, and the antioxidant activity of the PEP-Ⅰ was better than the PEP-Ⅱ. Scavenging abilities of the hydroxyl radical and superoxide anion free radical of polysaccharides in Pleurotus Eryngii were better than Vc, but inferior to it in eliminating DPPH free radical and total antioxidant capacity.