Abstract

Response surface methodology (RSM) was used to optimize the conditions of exopolysaccharides (EPSs) by Saccharomyces cerevisiae Y3. The results indicated that the yield of EPS reached 4.52 ± 0.14 g/L with 10.30% (w/v) sucrose, 0.64% (w/v) yeast extract, liquid volume 141.5 mL, which was 2.40 times the original EPS yield. Y3 EPS contained 83.65 ± 0.16% of total sugars, 15.27 ± 0.26% of uronic acid, 0.78 ± 0.02% of protein and 0.30 ± 0.12% of sulfuric acid groups. Y3 EPS maintained a relatively low viscosity, with intrinsic viscosities of 306.58 mL/g (25 °C) and 200.91 mL/g (35 °C), respectively. The EPS had high water solubility index (WSI), high water holding capacity (WHC) and good emulsifying ability (EA). Meanwhile, the EPS could absorb metal ions such as Cu²⁺, Fe²⁺ and Zn²⁺. In addition, Y3 EPS exhibited good antioxidant properties and coagulated skim milk with a concentration-dependent manner. These results indicated that S. cerevisiae Y3 EPS had applicable prospects in medicine, food, especially the dairy industry.

摘要

响应面法 (RSM) 用于优化酿酒酵母Y3 的胞外多糖 (EPS) 的条件。结果表明，用10.30%（w/v）蔗糖、0.64%（w/v）酵母提取物，液体体积141.5 mL，EPS的产量达到4.52±0.14 g/L，是原始EPS产量的2.40倍。Y3 EPS含有83.65±0.16%的总糖、15.27±0.26%的糖醛酸、0.78±0.02%的蛋白质和0.30±0.12%的硫酸基团。Y3 EPS 保持相对较低的粘度，特性粘度分别为 306.58 mL/g (25 °C) 和 200.91 mL/g (35 °C)。EPS具有高水溶性指数（WSI）、高持水能力（WHC）和良好的乳化能力（EA）。同时，EPS可以吸附Cu ²⁺、Fe ^{2+等金属离子。}和 Zn ²⁺。此外，Y3 EPS 表现出良好的抗氧化性能，并以浓度依赖性方式凝固脱脂牛奶。这些结果表明S. cerevisiae Y3 EPS在医药、食品，尤其是乳品行业具有应用前景。