Study On Preparation Of Yeast Polysaccharides

Yeast polysaccharide is a important kind of fungus polysaccharide，accounts for about80-85%of the dry weight of the yeast cell wall, and has many physiological function,such asenhance immunity, remove free radical, and have actions of antibiosis, antitumor and protectorganisms from being damaged in extreme environment. With beer yeasts thematerial, the yeastpolysaccharide weas simultaneous extracted that not only maked full use of the resource butalso could reduce the pollution of the environment and maked full use of the source ofsustainable development.The contents of main component in beer yeast were analysed. The results showed thatcontents of polysac charide，fat, protein and ash were36.2%,48.6%,4.8%,7.2%, respeetively.The best condition of enzymatic hydrolysis was obtained through the different proportion ofprotease enzyme activity: papain-neutral protease and the best proportion of protease enzymeactivity was9:1. The response surface methodology (RSM) was used for the optimizationcondition of simultaneous extraction. The optimal extraction parameters were NaOHconcentration of1.12%, extraction temperature of51.90℃and extraction time of0.96h.Under these optimal extraction conditions, the rate of glucan, mannan and trehalose were14.17%,11.81%,8.81%, respectively, which were consistent with the predicted value of14.14%,11.80%and8.86%.The hypolycemic and hyperlipemia function of glucan and mannan was evaluated. In theassay of hypoglycemic, when the mice weret reatment by gavage with200mg/(kg·d) mannanand glucan，the yeast glucan and mannan could lower blood sugar, and increase the content ofhepatic glycogen significantly and still could reduce weight loss of diabetic mice,and the yeastglucan and mannan could significantly relieve the symptoms of more drinking, eating, weightloss and have a hypoglycemic effect.And in the assay of hypoglycemic, when the mice weretreatment by gavage with200mg/kg·d-1mannan and glucan，the yeast mannan and glucancould lower triglyceride, cholesterol,, and increase the content of high-density lipoproteinsignificantly.A new method with the feature of simply operation，little environmental pollution, highpurity and yield was studied in isolation and purification of polysaeeharide in yeast was discussed. The polysaeeharide extracted from yeast indicated obvious hypolycemic andhyperlipemia function. It showed that they could be used as health care products andmedicinein treating human serious illness in the future.The studies above also lay a foundationin the high-value utilization of yeast effeetive cornponents.