Vinegar is one of the most widely used acidic condiments. In recent decades, rapid advances have been made in the area of vinegar research, and the intellectual structure pertaining to this domain has significantly evolved. Thus, it is important that scientists keep abreast of associated developments to ensure an appropriate understanding of this field. To facilitate this current study, a bibliometric analysis method was adopted to visualize the knowledge map of vinegar research based on literature data retrieved from the Web of Science Core Collection (WoSCC) database. In total, 883 original research and review articles from between 1998 and 2019 with 19,663 references were analyzed by CiteSpace. Both a macroscopical sketch and microscopical characterization of the whole knowledge domain were realized. According to the research contents, the main themes that underlie vinegar research can be divided into six categories, that is, microorganisms, substances, health functions, production technologies, adjuvant medicines, and vinegar residues. In addition to the latter analysis, emerging trends and future research foci were predicted. Finally, the evolutionary stage of vinegar research was discerned according to Shneider’s four-stage theory. This review will help scientists to discern the dynamic evolution of vinegar research, as well as highlight areas for future research.

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.

Shanxi aged vinegar (SAV) is a well-known vinegar produced by traditional solid-state fermentation and has been used in China for thousands of years. However, how microorganisms and their metabolites change along with fermentation is unclear. Here, 454 high-throughput sequencing and denaturing gradient gel electrophoresis were used to investigate the composition of microbial community. Metabolites were further analyzed by gas chromatography–mass spectrometry and high–performance liquid chromatography. Results showed that the composition of bacterial community changed dramatically at different stages of fermentation. The bacterial genera (relative abundance > 0.1%) decreased from 17 in daqu (starter used in starch saccharification) to 2 at the 12th day of alcohol fernemtation (AF). 15 bacterial genera at the 1st day of acetic acid fermentation (AAF) decreased to 4 genera, involving Acetobacter (50.9%), Lactobacillus (47.9%), Komagataeibacter (formerly Gluconacetobacter, 0.7%) and Propionibacterium (0.1%) at the 7th day of AAF. The structure of fungal community was more homogeneous. Saccharomyces and Saccharomycopsis were predominant in AF and AAF. A total of 87 kinds of nonvolatile metabolites were detected. Canonical correspondence analysis showed a significant correlation between the microbiota succession and the formation of metabolites during the fermentation of SAV. This study provides detailed information for the fermentation mechanism of traditional SAV.