Effect of rapid fermentation on the quality of northeastern sauerkraut analyzed based on HSSPME-GC-MS and LC-MS

To investigate the status of flavor components and metabolites in rapidly fermented northeastern sauerkraut from Leuconostoc mesenteroides and Lactobacillus paracasei, volatiles and metabolite changes as well as metabolic pathways of rapidly fermented northeastern sauerkraut were studied using Head Space Solid Phase Microextraction (HSSPME) and Gas Chromatography-Mass Spectrometry (GC-MS) coupled with non-targeted metabolomics analysis. A total of 27 volatile substances were detected by GC-MS analysis, and 20 compounds with VIP >1 were obtained. The results of the analysis of differences in volatile flavor components indicated that rapid fermentation improved the flavor of northeastern sauerkraut. A total of 290 differential metabolites were screened using Liquid Chromatograph-Mass Spectrometer (LC-MS) based non-targeted metabolomics, of which 120 were up-regulated and 170 were down-regulated by differential expression. Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis revealed significant differences in the metabolic levels of amino acid substances after rapid fermentation of sauerkraut, mainly involving metabolic pathways related to amino acid metabolism. This study lays a theoretical foundation for the further development of northeastern sauerkraut.