不同分子量酿酒酵母甘露聚糖的理化性质及吸湿保湿性

Study on Physicochemical Properties of Mannan from Saccharomyces cerevisiae with Different Molecular Weights and Their Moisturizing Performances

摘要:

采用高温抽提和分级醇沉，制备出了大、中、小三种不同分子量的YM-30、YM-50和YM-90甘露聚糖，测定了这三种甘露聚糖的重均分子量、溶解度、pH值及黏度，研究了它们的吸湿、保湿性能。结果表明： YM-30、YM-50和YM-90的重均分子量分别为12.40×104 Da, 4.47×104 Da 和 2.16×104 Da。大分子量YM-30不溶或微溶于水，中等分子量YM-50和小分子量YM-90则易溶于水。YM-30溶液偏碱性，YM-50溶液为中性，YM-90溶液则偏酸性。YM-50和YM-90水溶液的黏度很低，几乎与水的黏度一样，且其黏度不受糖浓度和温度的影响。红外光谱分析表明，三种甘露聚糖的糖链均为是β-D-吡喃结构。在低湿度（RH 43%）环境下，YM-90吸湿性最强；而在高湿度（RH 81%）环境下，YM-30则吸湿性最佳。在RH 43%环境下，YM-30保湿性能最优，其保湿率达到了98.4%，稍高于透明质酸。酵母甘露聚糖具有优良的吸湿、保湿性能。

Abstract:

Three kinds of yeast mannan with different molecular weights, namely YM-30, YM-50 and YM-90, were prepared by extracting with water in high temperature and ethanol precipitation fractionation. The weight average molecular weights, solubility, pH and viscosity of three kinds of yeast mannan were determined, and their hygroscopicity and moisture retention were investigated. The results show that the weight average molecular weights of YM-30, YM-50 and YM-90 were 12.40×104 Da, 4.47×104 Da and 2.16×104 Da respectively. YM-30 with large molecular weight was not soluble or slight soluble in water, but YM-50 with medium molecular weight and YM-90 with small molecular weight were soluble in water. YM-30 solution was weakly-alkaline and YM-50 solution was neutral, but YM-90 solution was weakly-acidic. The solutions of YM-50 and YM-90 had very low viscosity which was almost the same that of water. Furthermore, their viscosities were not influenced by mannan concentration and temperature. The infrared spectroscopy spectra showed that the polysaccharide chains of three yeast mannan were β-D-pyran type structure. Under the condition of low moisture (RH 43%), YM-90 had the strongest moisture absorbability. However, under condition of high moisture (RH 81%), the moisture absorbability of YM-30 was the best. Under the environment of RH 43%, moisture retention of YM-30 was the best, and its moisture retention ratio was 98.4%, which was slightly higher than that of hyaluronic acid. Yeast mannan from Saccharomyces cerevisiae had perfect moisturizing performance.