采用代谢组学分析技术分析工业啤酒发酵过程中风味物质生成规律

啤酒风味是保证啤酒品质的关键因素之一。运用代谢组学的方法，分析工业啤酒发酵过程中酵母胞内代谢物和啤酒风味物质的对应关系，从代谢水平上研究风味物质形成过程中的关键影响因素。在啤酒发酵过程中，同时检测风味物质的含量变化和酵母胞内代谢物的变化，对得到海量的、多维的代谢数据采用主成分分析（PCA）和偏最小二乘分析（PLS）的多元统计分析方法进行处理。由PCA分析结果可知：磷酸、海藻糖、琥珀酸、谷氨酸、天冬氨酸、丙氨酸对主成分贡献比较大，说明这些代谢物在不同发酵阶段含量变化显著。由PLS分析结果可知：对啤酒风味影响最大的物质主要为氨基酸，包括丝氨酸、缬氨酸、苏氨酸、赖氨酸、丙氨酸、亮氨酸和天冬酰胺等，这为啤酒中风味物质的调控提供了一定的理论指导。

Analyze the Mechanism of Flavor Compounds Formation Using Metabonomics Method During Industrial Beer Fermentation

Flavor compounds is one of the most factors for beer quality. In order to obtain the key factor which influences the formation of flavor from the metabolic level, metabonomics was used to analyze the connection between the lager yeast intracellular metabolites and flavor compounds. The content of flavor compounds and lager yeast intracellular metabolites were measured simultaneously during beer fermentation. Then using principal component analysis (PCA) and partial least squares (PLS) to process the high-throughput data. PCA results showed that phosphoric acid, trehalose, succinic acid, glutamine, aspartate and alanine contributed to the principal components significantly, which means that these metabolites varied obviously in different stages of fermentation. PLS results showed that the greatest impacting factor on flavor compounds was mainly intracellular amino acids, including serine, valine, threonine, lysine, alanine, leucine and asparagine. These results provide theoretical guidance for beer flavor control.