Traditional Chinese vinegar offers an exceptional flavor and rich nutrients due to its unique solid-state fermentation process, which is a multiple microbial fermentation system including various bacteria, fungi and viruses. However, few studies on the virus diversities in traditional Chinese vinegar have been reported. In this paper, using Zhenjiang aromatic vinegar as a model system, we systemically explored the viral communities in the solid-state brewing process of traditional Chinese vinegar using bacterial and viral metagenomes. Results showed that the viral diversity in vinegar Pei was extensive and the virus communities varied along with the fermentation process. In addition, there existed some interactions between viral and bacterial communities. Moreover, abundant antibiotic resistance genes were found in viromes, indicating that viruses might protect fermentation bacteria strains from the stress of antibiotics in the fermentation environment. Remarkably, we identified abundant auxiliary carbohydrate metabolic genes (including alcohol oxidases, the key enzymes for acetic acid synthesis) from viromes, implying that viruses might participate in the acetic acid synthesis progress of the host through auxiliary metabolic genes. Taken together, our results indicated the potential roles of viruses in the vinegar brewing process and provided a new perspective for studying the fermentation mechanisms of traditional Chinese vinegar.

The production of Chinese Baijiu relies on the synergistic metabolism of multi-species microbial communities in an open environment. Its intricate microbial succession and flavor formation mechanisms have long been considered complex systems that are difficult to fully deconstruct. Traditional culture-dependent techniques inherently fail to comprehensively capture the actual functional roles and dynamic regulation of “viable but non-culturable” (VBNC) microorganisms within this complex system. In recent years, the rapid advancement of multi-omics technologies has offered a novel perspective for elucidating the underlying fermentation mechanisms of Baijiu. This paper systematically reviews the recent progress in the application of metagenomics, metatranscriptomics, metaproteomics, and metabolomics in Baijiu research. Specific focus is placed on the unique contributions of these tools to resolving microbial community structural diversity, mining key functional genes and enzymes, uncovering microbial stress response mechanisms under environmental fluctuations, identifying phages and spoilage microorganisms, and tracing the metabolic pathways of flavor substances. Furthermore, the pivotal role of multi-omics integration strategies in constructing “microbe–metabolite” regulatory networks is highlighted. Finally, current challenges regarding standardization and data integration are discussed, with an outlook on leveraging omics big data to promote digital monitoring and intelligent brewing in the Baijiu industry.

Traditional plum wine brewing mostly relies on experience, with problems such as lack of standardized production parameters and easy formation of sediment after fermentation. This study systematically optimized the key production processes. Based on the results of a single-factor experiment, the Box–Behnken design of the response surface method (RSM) was employed to determine the optimal fermentation parameters, which included a fermentation temperature of 31 °C, fermentation duration of 12 days, yeast inoculation rate of 0.86%, initial pH of 3.5, and sugar content of 28.5%. Under these conditions, the alcohol content reached 13.7%vol. On this basis, emphasis was placed on evaluating the effects of various clarification techniques (clarifying agents, heat treatment, membrane filtration, static clarification at different temperatures) on optimized base wine clarity, stability and quality. The results showed that chitosan exhibited excellent overall performance, not only obtaining the highest light transmittance (89.8%) but also the best effect in enhancing the iron stability (88.6%) and oxidative stability (88.9%) of the wine. Additionally, while membrane filtration, heat treatment, and freezing treatment all served to clarify and stabilize the wine, they significantly reduced the polyphenol content, thereby diminishing the wine’s quality. Therefore, the clarification process needs to be selected in practical production by considering the clarification effect and functional ingredient retention in conjunction with the production cost. This study provides key process parameters for the production of high-quality plum wine and theoretical guidance for reductions in sediment formation.

Plum pomace (PP), a key by-product of plum juice processing, is a rich yet underutilized source of dietary fiber. However, its high-value exploitation is severely limited by the lack of efficient extraction and modification technologies. This study optimized the extraction of soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) from plum pomace (PP) via Design of Experiments (DOE), and evaluated their modification effects. Alkaline extraction was screened as the optimal method for IDF, and orthogonal experiments determined the optimal conditions: solid-to-liquid ratio 1:20 g/mL, 14 g/L NaOH, 60 °C, and 80 min, achieving a high extraction yield of 62.18%. For SDF, enzymatic extraction was superior, and response surface methodology (RSM) optimized the process to a solid-to-liquid ratio of 1:15.5, 1.0% enzyme dosage, 61.5 °C, and 92 min, with a yield of 29.3%. Physical, chemical, and biological modifications all significantly enhanced SDF’s water/oil-holding capacity, cholesterol/glucose adsorption capacity, and cation exchange capacity. Biologically modified SDF showed the most significant enhancement, with WHC of 5.58 ± 0.05 g/g, OHC of 4.38 g/g, CAC of 7.68 mg/g, and CEC of 3.28 mmol/g. These results provide technical support for the high-value utilization of PP and lay a foundation for its application in functional foods and nutraceuticals.