Data_Sheet_1_Metabolomic analysis of the effects of a mixed culture of Saccharomyces cerevisiae and Lactiplantibacillus plantarum on the physicochemical and quality characteristics of apple cider vinegar.doc

IntroductionThis study compared differences in physicochemical characteristics of the vinegar made by a mixed culture (MC) of Saccharomyces cerevisiae and Lactiplantibacillus plantarum and a pure culture (PC) of Saccharomyces cerevisiae.MethodsThe fermentation process was monitored, and metabolomics analysis by Liquid Chromagraphy-Mass Spectrometry (LC-MS) was applied to the compositional differences between PC and MC vinegars, combined with quantification of organic acids, amino acids and B vitamins.ResultsA total of 71 differential metabolites including amino acids, organic acids and carbohydrates, and six possible key metabolic pathways were identified. MC enhanced the malic acid utilization and pyruvate acid metabolism during fermentation, increasing substrate-level phosphorylation, and supplying more energy for cellular metabolism. Higher acidity at the beginning of acetic acid fermentation, resulting from lactic acid production by Lactiplantibacillus plantarum in MC, suppressed the cellular metabolism and growth of Acetobacter pasteurianus, but enhanced its alcohol metabolism and acetic acid production in MC. MC vinegar contained more vitamin B, total flavonoids, total organic acids, amino acids and had a higher antioxidant capacity. MC enhanced the volatile substances, particularly ethyl lactate, ethyl caprate and ethyl caproate, which contributed to a stronger fruity aroma.DiscussionThese results indicated the mixed culture in alcoholic fermentation can effectively enhance the flavor and quality of apple cider vinegar.

引言
本研究对比了由酿酒酵母（Saccharomyces cerevisiae）与植物乳杆菌（Lactiplantibacillus plantarum）混合培养（MC）和纯培养（PC）的酿酒酵母所制得的醋的物化特性差异。方法
对发酵过程进行监控，并采用液相色谱-质谱联用（LC-MS）代谢组学分析PC与MC醋之间的组成差异，并结合有机酸、氨基酸和B族维生素的定量分析。结果
鉴定出包括氨基酸、有机酸和碳水化合物在内的71种差异代谢物，以及六个可能的关键代谢途径。混合培养在发酵过程中提升了苹果酸利用率和丙酮酸酸代谢，增加了底物水平磷酸化，为细胞代谢提供了更多能量。由于混合培养中植物乳杆菌产生的乳酸，导致醋酸发酵初期酸度升高，从而抑制了醋酸菌（Acetobacter pasteurianus）的细胞代谢和生长，但在混合培养中却增强了其酒精代谢和醋酸产量。混合培养醋含有更多的维生素B、总黄酮、总有机酸、氨基酸，并具有更高的抗氧化能力。混合培养增强了挥发性物质，尤其是乙酸乳、乙酸硬脂和乙酸辛酸，这些物质有助于增强果香。讨论
这些结果表明，在酒精发酵过程中，混合培养能有效提升苹果醋的风味和质量。