酿酒酵母超低温冷冻保藏稳定性的探究

酵母性能的稳定对产品质量具有重要的意义。本文通过跟踪酿酒酵母W34/70在超低温冷冻保藏过程中性能指标的变化,探究超低温冷冻保藏过程甘油添加量及保藏时长对酵母性能的影响。结果显示:保护剂-甘油的最终添加量为17%左右时,酿酒酵母的各指标与试管斜面酵母的各指标接近;冷冻保藏2年内菌种的性能指标无变化,但保藏至第三年酿酒酵母发酵速度略有下降、呼吸缺陷型升高、发酵液的双乙酰及乙醛含量明显升高。甘油管在超低温冰箱保藏2年后需要进行菌种的活化及复壮工作,保证菌种性能的稳定性。

The stability of yeast performance is of great significance to product quality.In this paper,we tracked the changes in the performance indexes of Saccharomyces cerevisiae W34/70 during ultra-low temperature freezing and storage,and explored the effects of glycerol addition and storage time on yeast performance during ultra-low temperature freezing and storage.The results showed that when the final addition of protective agent-glycerol was about 17%,the indexes of Saccharomyces cerevisiae were close to those of test-tube bevel yeast.There was no change in the performance indexes of the strains during the two years of cryopreservation and storage,but the fermentation rate of Saccharomyces cerevisiae decreased slightly,the respiratory defect type increased,and the contents of diacetyl and acetaldehyde in the fermentation broth increased significantly.After 2 years of storage in the ultra-low temperature freezer,the glycerin tube needs to be activated and rejuvenated to ensure the stability of the strain.