酿酒酵母菌株的筛选与发酵特性分析

Isolation and Fermentation Characteristics of Saccharomyces cerevisiae

对河南本地苹果园土壤、果实及表皮中的酿酒酵母菌株进行分离、筛选、鉴定,并进行酒精、柠檬酸、葡萄糖和SO_2的耐受性测定,最后对发酵条件进行优化,以期选育出适合果酒发酵的优良酿酒酵母菌株。结果表明,共分离得到36株酿酒酵母,对其进一步进行发酵试验获得发酵性能较优的8株酿酒酵母,对这8株酿酒酵母进行耐受性试验发现,菌株Y-2和F-3在400 g/L葡萄糖下能够快速启动发酵,同时能够耐受酒精体积分数16%、柠檬酸质量浓度20 g/L和SO_2质量浓度200 mg/L。对Y-2、F-3菌株进行理化指标和感官评定,确定其最优发酵条件为:葡萄糖质量浓度200 g/L、温度25℃、pH值4.0。菌株Y-2和F-3酿造的苹果酒具有清新的果香味和浓郁的酒味,酒精度适中,口感清爽,这2株酵母发酵性能优良可以作为酿造果酒的开发菌株。

The yeasts strains were isolated from orchard soil,fruit and epidermis in Henan,then screened and identified,the tolerance to alcohol,citric acid,glucose and SO 2 were determined.Finally,the fermentation conditions were optimized,so as to select the best Saccharomyces cerevisiae for fermentation of fruit wine.The results showed that 36 strains of Saccharomyces cerevisiae were isolated,and 8 strains of Saccharomyces cerevisiae with better fermentation performance were screened through fermentation experiments.The tolerance test of these 8 strains of Saccharomyces cerevisiae showed that the Y-2 and F-3 strains could start fermentation quickly under 400 g/L glucose,16%alcohol,20 g/L citric acid and 200 g/L SO 2.The optimum fermentation conditions of Y-2 and F-3 strains were determined as follows:sugar content of 200 g/L,temperature of 25℃,and pH value of 4.0.The cider brewed by the Y-2 and F-3 strains had fresh fruit aroma and rich wine taste,moderate alcohol content,and refreshing taste.These two strains had excellent fermentation performance,and could be used as development strains for brewing fruit wine.