猕猴桃果酒专用酵母的筛选与鉴定

Screening and identification of special yeast for kiwi wine

旨在筛选酿制猕猴桃果酒专用酵母,为猕猴桃酒在生产过程中品质改善提供专用菌种资源。通过菌落形态和18SrDNA进行测序鉴定菌株,确定从猕猴桃表面筛选出的3株酵母菌的种属关系,并比较分析三者的发酵力、酒精和二氧化硫的耐受情况,采用3株酵母酿制猕猴桃酒,经陈酿后测定酒的理化指标、甲醇含量及挥发性风味物质,筛选最理想的菌株。通过分子生物学鉴定,3株菌株被鉴定为季也蒙毕赤酵母,其中菌株Q3的发酵力最强,能够耐受酒精体积分数为16%,可耐受SO_2的质量浓度为300 mg/kg,酿制的猕猴桃酒酒精度可达11.54%Vol,VC含量390.82 mg/L,残糖5.35g/L,甲醇含量87.7 mg/L,检测出挥发性风味物质25种。菌株Q3在发酵力、酒精和二氧化硫耐受方面都优于菌株Q1、Q2,能满足工业需求,且菌株Q3酿制的猕猴桃酒品质优良,甲醇含量低,在猕猴桃酒工业中具有良好的运用前景。

In order to screen raw and low yield methanol kiwil＇ruit yeast and provide special strains resources to the kiwifruit wine pro- duction. Strains were identified by colony morphology and 18S rDNA sequencing to determine the species relationship of the three strains of yeast. The fermentation capacity, alcohol and sulfur dioxide toler ance were evaluated. Additionally, the three strains were used for ki wilruit wine fermentation, and the physicochemical properties, methanol content and volatile flavor compounds ot the product were determined. The three strains were identified as Pichia guilliermondii by molecular biology. Among them, Q3 had the strongest fer-mentatinn capacity, it could tolerate 16% of alcohol and 300 mg/kg of SO2. The alcoholicity of brewed kiwifruit wine by Q3 was 11.54 Vol, the vitamin C 390.82 mg/L, the residual sugar 5.35 g/L, and the methanol 87.7 mg/L. In addition, there were 25 kinds of w）latile flavor compounds were detected. The strain Q3 screened from the surface of kiwifruit is superior to the strains Q1 and Q2 in the aspects of fermentation ability, alcohol and sulfur dioxide tolerance. And ki wifruit produced by Q3 has good quality and low methanol content, and has bright application prospect in the kiwifruit industry.