Fruit vinegar is typically produced through a two-stage deep liquid fermentation involving alcohol fermentation (Saccharomyces cerevisiae) and acetic acid fermentation (Acetobacter pasteurianus). In order to enhance the flavor and texture of sea buckthorn fruit vinegar, Lactobacillus fermentum was introduced into the alcoholic fermentation stage. At the end of fermentation, the total acid and acetic acid of sea buckthorn (Hippophae rhamnoides L.) fruit vinegar were both enhanced compared with sea buckthorn vinegar brewed through the traditional liquid fermentation method, and in terms of the main active ingredients, the total flavonoid content was slightly enhanced. Non-targeted metabolomics (LC-MS) was used to characterize the characteristic metabolite profiles during the fermentation process. A total of 55 differential metabolites, including organic acids, flavonoids, and amino acids, were identified, and the contents of citric acid, malic acid, and manganic acid, which are the sources of the irritating taste of sea buckthorn berry vinegar, were significantly reduced. In addition, the co-fermentation of Lactobacillus fermentum promoted both glycolysis and the TCA cycle and also led to a significant up-regulation of aromatic metabolites, such as ethyl acetate, ethyl lactate, and ethyl caproate. These results will provide new information on the dynamics of the characterized metabolites during the fermentation of sea buckthorn fruit vinegar.

As a fruit with both medicinal and edible value, red jujube (Ziziphus jujuba Mill.) is abundant in polyphenols and other bioactive components, exhibiting potent antioxidant potential. However, fresh jujubes are highly susceptible to spoilage, while existing processed products suffer from low added value and severe homogenization, restricting the upgrading of the jujube deep-processing industry. In this study, a strain suitable for jujube juice fermentation was selected from six lactic acid bacteria (LAB) strains. Using single-factor tests and response surface methodology, the fermentation conditions of fermented red jujube juice (FRJJ) were optimized. Systematic analysis was performed on the dynamic evolution of physicochemical properties, color, flavor, and bioactive compounds throughout the fermentation process. Additionally, a C2C12 cell model subjected to H₂O₂-induced oxidative stress was employed to evaluate the cytoprotective effects and antioxidant activity of FRJJ. The results demonstrated that LAB fermentation increased superoxide dismutase activity and total phenolic content, while improving flavor and sensory quality. Furthermore, FRJJ effectively mitigated oxidative stress damage and enhanced cell viability by reducing intracellular reactive oxygen species levels and maintaining mitochondrial membrane potential. These findings offer a theoretical basis for the value-added utilization of jujube resources and the formulation of functional fermented beverages.

The inconsistent flavor of traditionally fermented camel milk (CM) limits its standardization and broader consumer acceptance. A total of 198 lactic acid bacteria (LAB) strains and 120 yeast strains were isolated and identified from traditionally fermented camel milk samples collected in Xinjiang, China. Following taxonomic classification and preliminary screening of the isolates, 39 LAB strains (designated DL1–DL39) and 25 yeast strains (designated DY1–DY25) were selected for further investigation. LAB were first screened for acidification capacity and proteolytic activity, and yeasts were screened for aroma and gas production and acid tolerance; promising strains were then refined by integrating textural properties, E-nose, E-tongue, and sensory evaluation, and their key volatiles were characterized by gas chromatography–mass spectrometry (HS-SPME-GC-MS) combined with relative odor activity values (rOAVs). Two optimal LAB strains, DL19 (Lacticaseibacillus paracasei) and DL29 (Lactiplantibacillus plantarum), and one superior yeast strain, DY3 (Kluyveromyces marxianus), were finally selected. CM fermented by strain DL19 achieved the highest overall sensory acceptability, whereas that fermented by strain DL29 received a significantly higher odor score. HS-SPME-GC-MS analysis identified the compounds responsible for the creamy, buttery, and floral notes in the fermented products, namely 2,4-undecadienal, (2E,4Z)-2,4-decadienal, and δ-nonalactone. DY3 produced the richest odor-active substances, with 2-phenylethanol and γ-undecalactone endowing CM with distinct floral, fruity, and creamy flavors. WGS analysis provided a preliminary assessment of safety-related genomic features of DL19, DL29, and DY3. In conclusion, these indigenous strains show great potential as starter or adjunct cultures for precise flavor regulation of fermented CM. The established multi-index evaluation system effectively supports the standardized production of high-quality fermented CM, facilitating the high-value sustainable utilization of underutilized regional CM resources within the future food supply chain.