优选发酵毕赤酵母与酿酒酵母混合发酵的葡萄酒酿造应用潜力

实验基于主要发酵副产物的生成含量评价优选发酵毕赤酵母与酿酒酵母混合发酵对葡萄酒质量的影响。采用优选发酵毕赤酵母Z9Y-3和商业酿酒酵母F33设计同时和顺序两种接种方式启动模拟葡萄汁的酒精发酵,以酿酒酵母和发酵毕赤酵母单菌株发酵为对照。琥珀酸和乳酸利用高效液相色谱法测定,甘油采用高碘酸钠氧化法分析,挥发酸采用水蒸气蒸馏法测定。结果显示,优选菌株参与下的发酵没有显著影响酒精发酵的进程,但在发酵过程中发酵毕赤酵母生长速率低于酿酒酵母。与酿酒酵母纯发酵相比,混合发酵提高了甘油的含量,降低了挥发酸的含量,其中顺序接种的发酵过程中酿酒酵母活菌数最高,发酵毕赤酵母存活期最长(7d),发酵过程中甘油累积量最高(2.7g/L),挥发酸含量最低(0.2g/L)。不同发酵处理中,琥珀酸和乳酸含量均呈现先增后降的趋势,但其最终含量变化不显著。综上可得,优选发酵毕赤酵母和酿酒酵母的混合发酵具有应用于葡萄酒酿造的应用潜力。

Evaluating Application Potential of Mixed Fermentation with Pichia fermentans and Saccharomyces cerevisiae

Productions of fermentative by-products, like glycerol, succinic acid, lactic acid and volatile acid, were used to evaluate the influence of the mixed fermentation with Pichia fermentans and Saccharomyces cerevisiae on wine quality. The mixed fermentations of the P. fermentans strain Z9Y-3 and the commercial S. cerevisiae F33 were performed in model grape juice with simultaneous and sequential inoculation protocols, two single-yeast pure fermentations were as controls. In the fermentative by-products analysis, the succinic acid and lactic acid were measured by liquid chromatography, the glycerol was measured by the method of sodium periodate oxidation, and the volatile acid was measured by steam distillation. Results showed that the participation of the P. fermentans isolate didn''t change the fermentation course significantly, but the growth rate of P. fermentans is lower than that of S. cerevise during fermentation. Comparing with the pure S. cerevise fermentation, mixed fermentation enhanced the level of glycerol and decreased the volatile acid content. The sequential inoculation protocol had the highest number of active S. cerevise cells, the survive period of P. fermentans strain was the longest (7d), while the accumulation of glycerol was the highest (2.7g/L) and that of the volatile acid was the lowest (0.2g/L). During different fermentations, the levels of succinic acid and lactic acid rose firstly, and then declined, but the variation of their final amounts was little. It was concluded that the mixed fermentation of the P. fermentans isolate and S. cerevisiae had the application potential in winemaking based on the productions of the main fermentative by-products.