Effect of Browning Reaction on the Metabolite Profile of Yogurt Analyzed by Untargeted Metabolomics Based on Ultra-high Performance Liquid Chromatography-Quadrupole Electrostatic Field Orbitrap Mass Spectrometry

In this study, untargeted metabolomics based on ultra-high performance liquid chromatography-quadrupole electrostatic field orbitrap mass spectrometry (UPLC-QE-MS) was used to explore the differences in metabolite profiles between ordinary yogurt and brown yogurt, and the differences between them were evaluated from the perspective of metabolites. The metabolite information of yogurts was collected in both the positive and negative ion modes, and the metabolites were screened by multivariate statistical analysis. A total of 117 differential metabolites were obtained. Compared with ordinary yogurt, the relative contents of 106 metabolites were up-regulated and 11 metabolites were down-regulated in brown yogurt. Compared with ordinary yogurt, the contents of 3 flavor amino acids, 8 peptides, 12 sugars, 2 Maillard reaction products and one quinone in brown yogurt changed significantly. The results of this study can provide some theoretical support for the future research and development of brown yogurt.