Abstract:Based on analysis of the commonly used microbial metabolomics research methods, UPLC-Q-TOF MSE (ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometric) metabolomics technology combined with principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) was used to conduct a metabolomics study of probiotic yogurts produced using different fermentation methods. The results showed that the base peak intensity (BPI) of the sample “p” obtained by fermentation using probiotic bacterium Lactobacillus plantarum P-8 alone was significantly different to that of the sample “bp” obtained by fermentation using a combination of L. plantarum P-8 and the traditional starter culture YC-X11, indicating that their metabolites were significantly different. Further, the UPLC-Q-TOF MSE analysis identified 38 metabolites, including leucine, methionine, phenylalanine, tryptophan, 4-hydroxyphenyllactic acid, pantothenic acid, 4-pyridoxic acid, L-carnitine, 2-hydroxy-2-methylsuccinic acid, histidinol, aspartic acid-proline-proline, methionine-serine-hydroxyl, L-prolyl-L-Proline, alanine-alanine-isoleucine-tryptophan, histidine-histidine, alanine-glycine-asparagine-asparagine, aspartic acid-methionine-methionine-glutamine, alanine-glutamic acid-proline-cysteine, and tyrosine-aspartic acid. In addition, the differences in the metabolites obtained after fermentation by the two methods were specifically analyzed, providing new directions for the application of metabolomics in studying probiotic yogurt.
