发酵低醇西瓜果酒产香酵母的分离筛选及香气成分分析

Screening and identification of aroma-producing yeast strains for low-alcohol watermelon wine and characterization of aromatic compounds

为获得适宜低醇西瓜果酒发酵的酵母菌株,以嗅闻香气和总酯产量为指标,从传统白酒酒曲中分离筛选获得5株产香酵母。通过菌株形态、生理生化特征,结合26S rRNA序列分析,将菌株Z133鉴定为异常威克汉姆酵母(Wickerhamomyces anomalus),菌株Z2、Z31、Z32和Z43鉴定为扣囊复膜酵母(Saccharomycopsis fibuligera)。菌株Z133可产浓郁的果香气味,对糖、SO2及乙醇均有良好的耐受性,可发酵西瓜汁获得乙醇体积分数5.6%的低醇西瓜果酒。采用顶空固相微萃取-气质联用法分析发现,酒体中醇类和酯类香气成分种类和相对含量高于未发酵西瓜汁,主要香气成分苯乙醇、乙酸香叶酯和乙酸异戊酯的相对含量分别为25.65%、6.41%和3.93%。结果表明,从酒曲获得的产香酵母菌株Z133在低醇西瓜果酒发酵中具有一定的应用价值。

To obtain yeast strain for low-alcohol watermelon wine production, five aroma-producing yeast strains were isolated from traditional Chinese wine starter by olfactometry and ester production determination. Based on mor- phological, physiological and biochemical characteristics and 26S rRNA D1/D2 domain sequence analysis, strain Z133 was identified as Wickerhamomyces anomalus and Z2, Z31, Z32 and Z43 were identified as Saccharomycopsis fibuligera. Strain Z133 could produce enjoyable fruit aroma flavor and showed well tolerance to sugar, SO2 and ethanol. The aroma compounds in low-alcohol watermelon wine （ethanol concentration was 5.6% ） fermented with strain Z133 were analyzed by headspace solid phase microextraction combined with gas chromatography-mass spectrometry, and the main volatile aroma compounds in low-alcohol watermelon wine were benzene ethanol, geranyl acetate and isoamyl acetate, which represented 25.65% , 6.41% and 3.93% of the total volatile compounds, respectively. The results showed that strain Z133 had great potential for producing low-alcohol watermelon wine.