葡萄酒活性干酵母直投和活化工艺对酒精发酵的影响

选取了6种国内外不同的葡萄酒活性干酵母，分别采用活化与直投工艺，在15 ℃和25 ℃条件下，验证其酒精发酵的代谢动力学及甘油产量的差异。结果表明，在15 ℃发酵条件下，部分活性干酵母直投接种比活化接种晚一天结束发酵；F1酵母活化与直投处理间甘油产量没有显著差异（P＞0.05），其他5种酵母活化工艺发酵的葡萄酒甘油产量显著高于直投工艺（P＜0.05）；在25 ℃发酵条件下，活化接种和直投接种均在同一天完成酒精发酵，最终残糖均＜4 g/L；F1酵母活化与直投接种之间的甘油产量没有显著的差异（P＞0.05），A2酵母活化接种后葡萄酒的甘油产量显著低于直投工艺（P＜0.05），其他4种葡萄酒活性干酵母活化后的甘油产量明显高于直投工艺（P＜0.05）。与活化后接种相比，直投接种可能延长发酵时间，降低甘油产量。

Effects of direct inoculation and re-activated inoculation of active dry yeast on wine fermentation

Six different domestic and international wine active dry yeasts were selected, using re-activated and direct inoculation processes, and the difference in alcohol fermentation and glycerol production was analyzed under the conditions of 15 ℃ and 25 ℃, respectively. The results showed that under the fermentation condition of 15 ℃, some active dry yeasts with re-activated inoculation finished the alcohol fermentation one day earlier than the direct inoculation one. There was no significant difference in glycerol production between F1 re-activated and direct inoculation (P＞0.05), and the glycerol production of the other five wine inoculated by re-activated dry yeasts was significantly higher than the direct inoculation process (P＜0.05). Under the conditions of alcoholic fermentation at 25 ℃, re-activated inoculation and direct inoculation completed the alcohol fermentation on the same day, and the final residual sugar was less than 4g/L. There was no significant differences in the yield of glycerol between F1 re-activated and direct inoculation (P＞0.05). The yield of glycerol after re-activated inoculation of yeast A2 was significantly lower than that of direct inoculation, and the yield of glycerol of the other four wine fermented by re-activated dry yeasts was significantly higher than that by direct inoculation (P＜0.05). Direct inoculation may prolong fermentation time and reduce glycerol production compared to re-activated inoculation.