一株粉状米勒氏酵母的耐受性及所产挥发性风味物质研究

Tolerance and volatile flavor substances produced by Millerozyma farinose

该研究以分离自浓香型白酒酿造环境中的粉状米勒氏酵母(Millerozyma farinose)WLY-Y-91为研究对象,通过对其耐受性能及风味物质代谢情况进行分析,考察该菌在浓香型白酒窖池环境中的适应性,并利用糟醅进行发酵。结果表明,粉状米勒氏酵母WLY-Y-91具有良好的耐受性,可以耐受乙醇体积分数16%、NaCl 200 g/L和葡萄糖1000 g/L,耐受最高温度和最低pH值分别为50℃、pH 2.0。菌株WLY-Y-91的YPD发酵液和五粮粉发酵液中共检出15种相同挥发性风味物质,在五粮粉发酵液中特有的挥发性风味成分有18种,主要为醇、酯类以及乙偶姻;在菌株WLY-Y-91 YPD发酵液中特有的挥发性风味成分有23种,主要为吡嗪类物质。通过实验室水平模拟白酒固态发酵发现,接种菌株WLY-Y-91发酵使粮食糟和丢糟中的残淀和残糖含量分别降低25.50%、76.27%和20.52%、90%,乙酸乙酯、正丙醇及异戊醇含量分别升高143.8%、20.3%、132.1%和44.2%、13.89%、32.67%,说明该菌株可以利用粮食糟和丢糟合成挥发性风味物质乙酸乙酯、正丙醇和异戊醇。这对研究粉状米勒氏酵母在浓香型白酒酿造窖池中的发酵有一定的引导作用。

Using Millerozyma farinose WLY-Y-91 isolated from the brewing environment of strong-flavor(Nongxiangxing)Baijiu as research object,through tolerance and flavor substances metabolism analysis,the adaptation of the strain to the environment of strong-flavor pits were investigated and it was utilized by fermented grains for fermentation.The results showed that M.farinose WLY-Y-91 had good tolerance,it could tolerate 16%ethanol,200 g/L NaCl and 1000 g/L glucose,and it could tolerant high temperature of 50℃and pH 2.0.A total of 15 common volatile flavor compounds were detected in YPD and Wuliang powder fermentation broth of strain WLY-Y-91,and 18 characteristic volatile flavor compounds were detected in Wuliang powder fermentation broth,mainly alcohols,esters and ethoin.There were 23 characteristic volatile flavor components detected in YPD fermentation broth of strain WLY-Y-91,which were mainly pyrazines.By simulating Baijiu solid fermentation at laboratory level,it was found that inoculation with strain WLY-Y-91 could reduce the residual starch and residual sugar content in pit-entry fermented grains and surface fermented grains by 25.50%,76.27%,20.52%and 90%,respectively.The contents of ethyl acetate,n-propanol and isoamyl alcohol were increased by 143.8%,20.3%,132.1%and 44.2%,13.89%,32.67%,respectively,indicating that the strain could synthesize ethyl acetate,n-propanol and isoamyl alcohol by utilizing pit-entry fermented grains and spent grains.It had a certain guiding effect on the study of the fermentation of M.farinose in strong-flavor Baijiu pit.