摘要:
目的:在有氧条件下,对酿酒酵母YF1914产乙醇发酵条件进行优化,并研究其产香特性。方法:利用单因素方法优化葡萄糖浓度、氮源种类和浓度、发酵温度、pH、转速、时间等发酵条件,确定其产乙醇最佳发酵条件;在最优乙醇发酵条件基础上,采用高粱浸出液培养基发酵产香特性研究。结果:在乙醇发酵培养基基础上,通过单因素获得该酵母在有氧条件下发酵产乙醇的最佳条件为:葡萄糖350 g/L,酵母浸粉41.6 g/L,初始pH5.8,接种量1%,装液量50 mL/250 mL,在30 ℃、120 r/min条件下培养32 h。在此条件下,乙醇产量达到124.7 g/L;该酵母在高粱浸出液中能产生苯乙醇、乙酸乙酯、3-甲硫基丙醇等对白酒品质有重要影响的挥发性风味物质35种,具有重要的产风味物质功能特性。结论:本文系统优化了酿酒酵母YF1914在有氧环境下产乙醇的发酵条件,并研究了其产香特性,为未来白酒酿造方式变化提供理论依据。
Abstract:
Objective:The fermentation conditions of ethyl alcohol produced by Saccharomyces cerevisiae YF1914 were optimized in aerobic conditions, and its aroma-producing characteristics were investigated. Methods:The factors including glucose concentration, nitrogen sources and concentration, temperature, pH, agitation speed and time, which affected the yield of ethyl alcohol, were studied in single factor optimization test. On the basis of single factor test, the aroma products were studied in sorghum hydrolysate medium. Results:By the experiments of single factor, the optimal conditions for ethyl alcohol production in aerobic conditions were as follows:Glucose 350 g/L, yeast extract 41.6 g/L, initial pH5.8, the inoculation ratio of 1%, the volume of liquid of 50 mL/250 mL, incubated at 30℃ for 32 h. Under the condition, the yield of ethyl alcohol reached 124.7 g/L. And, a total of 35 volatile compounds such as β-phenylethanol, ethyl acetate and 3-methylthiopropanol were detected in sorghum hydrolysate medium. Conclusion:The conditions of ethyl alcohol produced by Saccharomyces cerevisiae YF1914 and its aroma-producing characteristics were studied systematically in aerobic conditions, providing theoretical support for the future changes in Baijiu brewing methods.
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