The changes of yeast count, ethanol, reducing sugar, pH, titratable acidity and total phenols as well as antioxidant properties such as hydroxyl and superoxide anion radical scavenging activities and reducing power during Suaeda salsa fermentation by yeast were studied. The SGompertz, DoseResp, Logistic and Boltzmann models were used to investigate the fermentation kinetics. Meanwhile, a comprehensive evaluation index (CEI) system of S. salsa fermentation was developed by correlation analysis (CA) and principal component analysis (PCA). The growth kinetic model of yeast was established using the DoseResp and Boltzmann equations, the kinetic model of ethanol production was established using the SGompertz equation, and the kinetic model of reducing sugar consumption was established using the Logistic equation. The fitting coefficients (R²) of these models were 0.977, 0.995 and 0.982, respectively, indicating excellent goodness of fit. CA showed that total phenols and organic acid were the major contributors to the antioxidant capacity of fermented S. salsa. PCA showed that the CEI value increased first, then leveled off, and finally decreased. The fermentation endpoint was on the eighth day in overall consideration. The results of this study provide a theoretical basis for the precision preparation of fermented S. salsa.

The protective effect of edible grass jiaosu (EGJ) on alcohol-induced injury in HepG2 cells was evaluated in terms of cell viability, alcohol dehydrogenase (ADH) activity, lactate dehydrogenase (LDH) activity, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity. The effects of alcohol and EGJ on the metabolite profile of HepG2 cells were analyzed by gas chromatography-mass spectrometry (GC-MS), and differential metabolites and related metabolic pathways were identified to explore the protective mechanism of EGJ against alcoholic injury in HepG2 cells from a metabolomic perspective. Results showed that EGJ significantly inhibited alcohol-induced cell death by enhancing ADH and SOD activities and reducing LDH leakage and MDA content. A total of 11 intracellular and 16 extracellular differential metabolites were identified by cell metabolomics, the key intracellular metabolites were L-alanine, L-norleucine, L-proline, glycine, L-threonine and L-valine, and the key extracellular metabolites were arabitol, D-galactopyranose, glycerol monostearate, butanedioic acid and octadecanoic acid. EGJ can protect against alcoholic injury in HepG2 cells by regulating amino acid metabolism and energy metabolism. The results provide a theoretical basis for the application of EGJ as an ingredient in functional foods with hepatoprotective activity.