Abstract:
This study aims to analyze the variation patterns of volatile metabolites in ginseng after lactic acid bacteria fermentation combined with traditional processing and their influence on flavor. Ginseng was fermented with Lactobacillus pentosus and further processed. Non-targeted GC-MS metabolomics and electronic nose technology were used to conduct systematic analysis of the samples before and after treatment. The results showed that fermentation and fermentation-processing treatment significantly reduced the total sugar content from 556 mg/g to 335 mg/g and 221 mg/g, while the total saponin content first decreased from 194 mg/g to 140 mg/g and then rebounded to 221 mg/g. Fermentation and processing significantly changed the composition of volatile components in ginseng. A total of 77 significantly differentiated metabolites were identified, mainly including 11 major categories such as alcohols, terpenoids, hydrocarbons, ketones, heterocyclic compounds and esters. The changes in rOAV values of key aroma active components such as linalool and α -pinene indicate that the overall flavor of ginseng after treatment has transformed from grassy and pungent to a soft and harmonious fruity and caramel aroma. The analysis results of electronic nose were consistent with those of GC-MS and rOAV. Fermentation enhanced the sour and fruity aroma characteristics of ginseng, and the processing process generated caramel aroma and sweet aroma substances. This study reveals the synergistic mechanism of fermentation and processing, providing an important theoretical basis and technical reference for the deep processing of ginseng and the regulation of its flavor and quality.