Ultra-performance liquid chromatography coupled with a quadrupole-time-of-flight mass spectrometryElevated Energy was used to investigate changes in the metabolite profile of brown milk and fermented brown milk produced using Streptococcus thermophilus S10. Samples were analyzed in both positive and negative electron ionization modes. Data were analyzed by multivariate statistical methods for biomarker metabolites that were differentially abundant in brown milk and fermented brown milk. We identified 43 differentially abundant metabolites based on mass spectrophotometry fragmentation patterns. These metabolites included peptides, AA, fatty acids and related metabolites, carbohydrate metabolites, vitamins, and nucleosides. Some of these metabolites are known to alter the sensorial quality of fermented dairy products. Thus, it is likely that some of the currently identified differentially abundant metabolites also contribute to the unique flavor, taste, and aroma of fermented brown milk. The bitterness and astringency of fermented brown milk are likely to be due to some of these peptides, whereas the sweetness and sourness could be a result of changes in carbohydrate levels. No previous study has analyzed metabolomics changes during fermentation of brown milk. Thus, our data are a valuable reference for future development and improvement of fermented brown milk products.

中文翻译：

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代谢足迹显示使用嗜热链球菌在棕色发酵乳制品中的关键生化变化。

超高效液相色谱与四极杆飞行时间质谱联用升高的能量用于研究使用嗜热链球菌S10生产的棕色牛奶和发酵棕色牛奶的代谢产物谱变化。以正电子和负电子电离模式对样品进行分析。通过多元统计方法分析了在棕色牛奶和发酵棕色牛奶中差异丰富的生物标志物代谢物的数据。我们基于质谱分光光度法模式鉴定了43种差异丰富的代谢产物。这些代谢物包括肽，AA，脂肪酸和相关代谢物，碳水化合物代谢物，维生素和核苷。已知其中一些代谢物会改变发酵乳制品的感官品质。从而，当前鉴定出的一些差异丰富的代谢物也可能有助于发酵棕色牛奶的独特风味，味道和香气。发酵棕奶的苦涩味可能是由于其中一些肽引起的，而甜味和酸味可能是碳水化合物含量变化的结果。以前没有研究分析棕色牛奶发酵过程中的代谢组学变化。因此，我们的数据为将来开发和改进发酵棕奶产品提供了宝贵的参考。而甜味和酸味可能是碳水化合物含量变化的结果。以前没有研究分析棕色牛奶发酵过程中的代谢组学变化。因此，我们的数据为未来发酵棕奶产品的开发和改进提供了宝贵的参考。而甜味和酸味可能是碳水化合物含量变化的结果。以前没有研究分析棕色牛奶发酵过程中的代谢组学变化。因此，我们的数据为未来发酵棕奶产品的开发和改进提供了宝贵的参考。