Differential metabolites analysis in Lycium barbarum and Platycodon grandiflorus fermented wine by untargeted metabolomics

Abstract

In this work, Lycium barbarum and Platycodon grandiflorus were combined with highly active Saccharomyces cerevisiae and Hansen de Bary yeast to perform mixed-yeast fermentation for 0d, 14d, and 30d During the fermentation process, pH showed a decreasing trend from 6.95 to 2.95, and titratable acid content showed a increasing trend from 2.86 to 4.94.The alcohol content peaked at 7.79 %Vol on the 14th day of fermentation. Then, we used untargeted metabolomics to ascertain the types and metabolic pathways of differential metabolites of L. barbarum and P. grandiflorus wine (LPW) during the fermentation process. They yielded significant differential metabolites of 6930 (LPW 30 vs. LPW 0), 6825 (LPW 14 vs. LPW 0), and 833 (LPW 30 vs. LPW 14), respectively. Phenylcyclic compounds, sulfadiazine, lipids and lipid-like molecules, and organic acids were the principal differential metabolites, such as avenalumic acid, trans-4-hydroxy-3-methoxycinnamate, phenol, succinic acid. Phenylcyclic compounds were the most significant among these and would have a considerable impact on the wine's flavor. The main hubs of the significant metabolite pathways in the LPW were the flavonoid biosynthesis, amino acid metabolism, secondary metabolite biosynthesis, and TCA cycle. This study highlights the internal mechanism of wine flavor creation and offers a theoretical basis for the raw plant processing of LPW.

Keywords

• Lycium barbarum and Platycodon grandiflorus wine
• Non-targeted metabolomics
• Fermentation time
• Mechanism analysis
• Differential metabolites