摘要
以智能、传统车间不同轮次堆积发酵酒醅为研究对象,测定其理化指标、酶活力、酵母菌总数以及挥发性风味物质,并且结合堆积温度系统解析堆积发酵机理.结果表明,随着堆积轮次的增加,酒醅的水分、酸度、乙醇、L-乳酸含量显著上升(P＜0.05),葡萄糖含量先增加后减小,淀粉含量降低;堆积温度是由内到外发散,腰部表层顶温可达50℃;关键酶系糖化酶、液化酶活力显著性降低(P＜0.05);酵母菌总数及发酵力在3轮次达到峰值后降低;智能、传统车间堆积酒醅共检测出95种共有香气成分,包括乙酸、乳酸乙酯、苯甲醇等;智能和传统车间进行风味物质差异分析表明,正交偏最小二乘判别分析(OPLS-DA)能较好地区分不同类型车间风味物质差异,利用变量重要性投影值(VIP)确定出关键差异挥发性风味物质(VIP＞1)14种.此项研究阐明了智能、传统车间不同轮次堆积酒醅理化因子、酶活力、风味物质、酵母菌总数、活菌率变化规律,为解析堆积发酵机理和两种生产模式下酒醅各项指标差异提供理论参考.
Abstract
The physicochemical indicators,enzyme activity,total yeast count,and volatile flavor compounds of fermented grains stacked in different rounds in intelligent and traditional workshops were measured,and the stacking fermentation mechanism was analyzed by combining the stacking temperature system.The results showed that with the increase of stacking cycles,the moisture,acidity,ethanol,and L-lactic acid content of the fer-mented grains significantly increased(P＜0.05).The glucose content first increased and then decreased,and the starch content decreased.The stacking temperature was divergent from inside to outside,and the top temperature of the waist surface could reach 50 ℃.The activities of key enzyme systems,such as saccharifying enzymes and liquefying enzymes,were significantly reduced(P＜0.05).The total number of yeast and fermentation capacity decreased after reaching their peak in three rounds.There were 95 common aroma components detected in the intelligent and traditional workshop of stacking fermented grains,including acetic acid,ethyl lactate,benzyl alcohol,etc.The differences analysis of flavor substances between intelligent and traditional workshops showed that orthogonal partial least squares discriminant analysis(OPLS-DA)could effectively distinguish flavor differences between different types of workshops,and 14 key differential volatile flavor components(VIP＞1)were determined by variable importance in the pro-jection(VIP).The study elucidated the changes rules in physicochemical factors,enzyme activity,flavor substances,total yeast count,and viable bacte-rial in fermented grains of different stacking cycles in intelligent and traditional workshops,providing theoretical references for analyzing the mecha-nism of stacked fermentation and the differences in various indicators of fermented grains under two production modes.
基金项目
国家重点研发计划重点专项(2016YFD0400500)
天津市科技计划项目(22ZYJDSS00050)
校企合作项目(1900040006)
NETL
NSTL
万方数据