Zhenjiang aromatic vinegar (ZAV) is one of the famous Chinese vinegars, which contains various physicochemical and bioactive compositions. In the present study, physicochemical properties and total antioxidant activity were detected in ZAV samples. The correlation between of organic acids, amino acids, phenolic compounds, and the antioxidant activity of ZAV were explored. The results showed that contents of total acids, soluble solids, reducing sugar and total antioxidant activity in ZAV were increased with aging time, and those in ZAV-5 were the highest. Organic acids and amino acids exhibited weak antioxidant activity, while phenolic compounds had higher antioxidant ability. In addition, amino acids had synergistic effect on the antioxidant activity of phenolic compounds, whereas organic acids inhibited the antioxidant activity of phenolic compounds. Moreover, it was found that phenolic compounds including catechin, vanillic acid and syringic acid showed higher contribution rates to antioxidant activities of mixed phenolic compounds. In conclusion, these findings would provide references to control the antioxidant characteristic of vinegar through regulating the main compositions, and further improve the quality of vinegar production.

Zhenjiang aromatic vinegar (ZAV) is one of the well-known fermented condiments in China, which is produced by solid-state fermentation. It can be classified into traditional Zhenjiang aromatic vinegar (TZAV) and industrial Zhenjiang aromatic vinegar (IZAV) because of different production methods. The purpose of the study was to evaluate the variations and differences on chemical compositions and antioxidant activities of TZAV and IZAV during the aging process. The proximate composition, organic acids content, total phenolic content (TPC), total flavonoid content (TFC), total antioxidant activity (TAA) and phenolic compounds composition of TZAV and IZAV were detected during the aging process. Organic acids contents, TPC, TFC, TAA and phenolic compounds contents in ZAV were increased during the aging process. Acetic acid, lactic acid and pyroglutamic acid in ZAV were major organic acids. With the extension of aging time, TZAV and IZAV had similar proximate compositions and organic acids content. The values of TPC, TFC and TAA were higher in TZAV than in IZAV when aging is more than 3 years. Rutin and p-coumaric acid were detected in TZAV but not in IZAV. In principal component analysis (PCA), TZAV and IZAV can be divided into two groups according to their phenolic compounds composition. These findings provide references for evaluating TZAV and IZAV on the basis of their characterizations.

Shanxi aged vinegar (SAV) is a typical fermented and antioxidant food, which has various health-promoting effects. This work aimed to explore the effects of SAV on alcohol-induced liver injury. A mice model of alcoholic liver injury was established to illuminate its potential mechanisms. All mice pretreated with SAV and then received an ethanol solution (50% w/v, 4.8 g/kg b.w.). The results showed that SAV ameliorated alcohol-induced histological changes and elevation of liver enzymes. SAV attenuated alcohol-induced oxidative stress by declining levels of hepatic oxidants, and restoring depletion of antioxidant enzyme activities in mice livers. Moreover, SAV alleviated alcohol-induced oxidative damage by activating nuclear factor erythroid-2-related factor 2 (Nrf2)-mediated signal pathway. In addition, SAV prevented alcohol-induced inflammation by suppressing lipopolysaccharide (LPS) level and activities of pro-inflammatory enzymes, and regulating inflammatory cytokines. SAV inhibited alcohol-induced inflammation through down-regulating the expression of Toll-like receptor 4 (TLR4)-mediated inflammatory response. The findings provide crucial evidence for elucidating the hepatoprotective mechanisms of SAV and encourage the future application of SAV as a functional food for liver protection.

Zhenjiang aromatic vinegar (ZAV) is a kind of traditional fermented food worldwide. In this study, the changes of physicochemical properties, total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant activity (TAA) were evaluated during the brewing process of ZAV. In addition, the correlation between phenolic compound contents and antioxidant activities was investigated during the aging process (AP) of ZAV. The results showed that total acids, non-volatile acids, and amino nitrogen increased gradually during the brewing process. Reducing sugar decreased sharply at the early fermentation stage and then increased during the AP. Meanwhile, TPC, TFC, and TAA kept a very low level at the stage of alcohol fermentation (AF), and increased to the highest level at the sixth year of the AP. TAA has a high positive correlation with TPC and TFC during the brewing process of ZAV. In addition, the contents of p-hydroxybenzoic acid, vanillic acid, and catechin were higher than other phenolic compounds and reached the highest level at the sixth year of the AP, and were the main composition of phenolic compounds during the AP. Moreover, gallic acid, ferulic acid, and sinapic acid had the higher contribution at the early stage of the AP, and then declined to a lower level. Catechin, vanillic acid, and syringic acid had a higher contribution during the AP. These findings would be helpful in controlling the quality of vinegar and improving its functional properties.

Cereal vinegar sediment (CVS), a byproduct of traditional vinegar fermentation, has been regarded as a health-promoting product. However, its role in genetically induced hyperlipidemia remains unclear. This study systematically evaluated the effects of Dade-CVS (DD-CVS) and Hengshun-CVS (HS-CVS) on apolipoprotein-E-deficient (Apoe^−/−) mice. Both CVS varieties significantly improve certain serological parameters of Apoe^−/− mice, although the overall impact on serum indicators remains limited. Nevertheless, 16S rRNA sequencing revealed that CVS treatment reshaped gut microbial communities to a notable extent. Compared with the Apoe^−/− mice, the DD-CVS treatment significantly increased the relative abundance of Dubosiella while reducing the genus Desulfovibrio, whereas the HS-CVS treatment inhibited the growth of Bifidobacterium and Akkermansia. The pathways predicted in the KO-DD group included vitamin, amino acid, and energy metabolism, while HS-CVS treatment was associated with bile acid biosynthesis and energy pathways. Metabolomic analysis showed that several key metabolites, including N1-acetylspermidine, succinic acid, and 25-hydroxycholesterol, were significantly altered following CVS supplementation. Correlation analysis revealed significant associations between serum indicators and these metabolites. Alistipes, Enterorhabdus, and Romboutsia were also correlated with serum indicators. Overall, these findings indicate that CVS primarily modulated the gut microbiota–metabolite axis and partial lipid modulation in hyperlipidemic mice. The study provides a reference for studies on the beneficial functions of CVS in hyperlipidemia.

Background: Cereal vinegar sediment (CVS), a byproduct formed during traditional grain vinegar storage, possesses lipid-lowering, glucose-lowering, and antioxidant properties. However, its effects on gut microbial and metabolic responses to short-term high-fat diet (HFD) exposure remain unclear. This study aimed to characterize the compositional profiles of Dade CVS (DD-CVS) and Hengshun CVS (HS-CVS) and investigate their effects on host metabolism and gut microbiota in mice with short-term HFD exposure. Methodology: The physicochemical properties of CVSs were evaluated, and their chemical compositions were characterized via untargeted metabolomics. Mice were fed a short-term HFD and administered DD-CVS or HS-CVS. Fecal microbial communities were characterized by 16S rRNA gene sequencing, whereas cecal contents and serum were analyzed using untargeted metabolomics. Results: Both CVSs were rich in amino acids, their derivatives, and polyphenolic compounds. CVS treatments attenuated body-weight gain and reshaped the gut microbiota composition of mice, including changes in the relative abundance of Allobaculum, Akkermansia, and Lachnospiraceae_Clostridium. Differentially, DD-CVS enriched Blautia and Ruminococcus, whereas HS-CVS enriched Bacillus. The results of the gut microbial metabolic profiles showed that DD-CVS treatment regulated amino acid metabolism, while HS-CVS treatment influenced bile acid and arachidonic acid metabolism. Furthermore, serum metabolomics revealed that CVSs modulated systemic metabolic profiles and enriched CVS-associated compounds, such as α-linolenic acid. The candidate microbiota-sensitive metabolites, including lithocholic acid and 9(S)-HPODE, showed significant correlations with specific microbial taxa. Conclusions: DD-CVS and HS-CVS induced distinct gut microbial and metabolic responses during short-term HFD exposure, supporting further evaluation of CVS as a potential functional food.