Improving the flavor components, metabolic characteristics, and antioxidant activity of American ginseng by lactic acid bacteria and yeast fermentation
Yu Ding, Yue Wang, X. Y. Mao, Ziqi Liu, Ruzhen Wang, Lanping Guo, Lei Fang, Jie Zhou
Abstract
ABSTRACT Effectively reducing the bitterness of American ginseng and elucidating its functional components are important directions for expanding the research on American ginseng in the field of food. Fermentation has been considered essential for improving raw materials and functional activity. This study aimed to investigate the effects of Lactobacillus acidophilus and brewing yeast fermentation on the volatile components, sensory characteristics, metabolites, and antioxidant activity of American ginseng so as to evaluate the effects of different probiotic fermentations on American ginseng. The flavor analysis results indicated that fermentation increased the sweetness and aroma of American ginseng by increasing the types of volatile components, such as esters and alcohols, which to some extent, improved the bitterness of American ginseng. The metabolomics results showed that the levels of rare saponins such as ginsenoside Rh1, F1, Rh2, and Ro, as well as metabolites such as alliin, oroxin B, asiaticoside, asperuloside, sphingosine, and spermine, increased in American ginseng after fermentation. Moreover, fermentation enhanced the in vitro antioxidant activity of American ginseng, and the content of phenolic and flavonoid compounds was significantly positively correlated with antioxidant activity. In summary, fermentation can effectively improve the flavor, enhance in vitro functional activity, increase the contents of nonvolatile metabolites, and boost antioxidant activity of American ginseng . This study provides a theoretical basis for the research on the fermentation of American ginseng, further promoting its high-value utilization in the food industry.