Characterization of Kimchi by Ultra-Performance Liquid Chromatography (UPLC) and High-Resolution Mass Spectrometry (HR-MS) with Principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA)

The geographic origin of kimchi is of interest to both consumers and producers as the prices of these products vary substantially depending on the geographic origin. Therefore, social problems related to the geographic origin of kimchi in Korea are of concern. In this study, nine types of kimchi from Korea and China were analyzed, each of which was fermented for one or four weeks. This is the first report on mass spectral profiling of kimchi using liquid chromatography-high resolution-mass spectrometry (LC-HR-MS), from which 1552 kinds of spectral peaks were obtained. Distinguishing the geographic origins of kimchi was possible by analyzing the mass spectral profiles of the Korean and Chinese kimchi samples using multivariate analyses, irrespective of the fermentation period. Based on the variable importance in projection (VIP) scores from the partial least squares (PLS) and the p-values from the t-test, 25 spectral peaks were selected that exhibited the potential to be biomarkers. Therefore, LC-HR-MS is a powerful tool for clearly distinguishing kimchi samples with different origins. This study forms a basis for mass spectral profiling analyses of other fermented vegetables.