Pit-wall mud (PWM) fosters bacterial communities involved in Baijiu production. PWM varies depending on pit age and height. In this study, we explored the bacterial communities in PWM and factors driving their evolution. The abundance and diversity of bacterial communities were low in new PWM (NPWM). In old PWM (OPWM), similar but diverse bacterial communities were observed at different heights. Lactobacillus was the predominant genus in NPWM, and Caproiciproducens, Aminobacterium, Hydrogenispora, Lactobacillus, Petrimonas, Syntrophomonas, and Sedimentibacter were the dominant genera in OPWM. A decrease was noted in the abundance of Lactobacillus, which indicated evolution. Among all the physicochemical properties, pH had the highest degree of interpretation with an R² value of 0.965. pH also exerted the strongest effect on bacterial communities. The path coefficients of pH on bacterial community diversity and abundance were 0.886 and 0.810, respectively. Caproiciproducens and Clostridium sensu stricto 12 metabolized lactic acid, inhibiting the growth of Lactobacillus at a suitable pH, which led to the maturation of PWM. Our findings enrich the literature on the evolution of bacterial communities in PM and the maturation of PM.

The succession of microbial communities during the fermentation process in sesame-flavored Baijiu cellars profoundly influences the flavor profile of the liquor. However, the key factors driving microbial succession in these cellars remain unclear. This study focuses on the fermentation process of sesame-flavored Baijiu Zaopei in traditional Tongcheng cellars. Samples were collected from the surface, middle, and bottom of the cellar, categorized by fermentation time. Various techniques were employed to analyze the physicochemical properties (including moisture, ethanol, total acid, starch, and reducing sugars), flavor compounds (volatile substances and amino acids), and microbial communities (bacteria and fungi) of the Zaopei during fermentation. A total of 68 flavor compounds were detected, with 16 key flavor compounds and 16 amino acids identified. Microbiologically, the Lactobacillus genus dominated in the later stages of fermentation, while the Issatchenkia species were the predominant fungi. Correlation analysis indicated that environmental factors play a significant role in driving microbial community succession. Acetobacter, Staphylococcus, Pichia, Bacillus, and Kroppenstedtia species may contribute to the synthesis of key flavor compounds. The relative contents of acetic acid, 2-phenylethyl ester, and Benzenepropanoic acid ethyl ester were influenced by multiple microbial groups, suggesting a synergistic fermentation effect. PICRUSt2 predictions revealed significant differences in 41 KEGG pathways at level 2 and 293 pathways at level 3 across different fermentation intervals. These pathways are primarily associated with amino acid, ester, and nucleotide metabolism, as well as bacterial transcription, translation, and signal transduction. This research provides a theoretical foundation for understanding the fermentation mechanisms of sesame-flavored Baijiu.

This work evaluated how ferulic acid (FA) impacted the conformational properties of whey protein isolate (WPI) and altered the environmental tolerance of oleogel/water (Og/W) emulsions formulated with Ganoderma lucidum spore oil (GLSO). Molecular dynamics simulation analyses revealed that FA interacted with α-lactalbumin via hydrogen bonding and hydrophobic interactions, whereas it bound into the hydrophobic cavity of β-lactoglobulin through a “lock-and-key” mode driven primarily by hydrophobic forces. Fourier transform infrared spectroscopy analysis verified that such non-covalent forces triggered the dissociation and structural extension of WPI, which was manifested as a significant loss of α-helix and β-sheet architectures along with a corresponding rise in random coils. FA addition increased the positive charge, mean droplet size, interfacial contact angle and antioxidant stability of WPI-FA nanoparticles when the WPI-to-FA ratio exceeded 1:2 (i.e., WPI was in excess relative to FA). The GLSO-based Og/W emulsions exhibited a weak gel structure with predominantly elastic characteristics. Furthermore, WPI-FA nanoparticles fabricated at a 2:1 ratio minimized emulsion droplet size and imparted optimal stability to the Og/W emulsions, demonstrating superior freeze–thaw and salt resistance, alongside suppressed GLSO flavor release. This work provides critical insights into tailoring protein-polyphenol interactions to stabilize GLSO-based Og/W emulsion delivery systems for food applications.

Probiotics exert profound health benefits via the modulation of the intestinal microbiota. However, the efficacy of orally administered probiotics is severely constrained by a cascade of physiological barriers, including gastric acid inactivation, suboptimal intestinal release, and inadequate mucosal colonization. In response to these challenges, hydrogel-based delivery platforms have garnered considerable interest as versatile carriers capable of providing protective encapsulation, enabling spatiotemporally controlled release, and augmenting intestinal retention. This narrative review presents recent progress in the design and application of hydrogel-based oral delivery systems tailored for targeted probiotic release and effective colonization. First, the key gastrointestinal obstacles to successful probiotic delivery are delineated. Hydrogel design parameters are then critically appraised, with particular emphasis on material selection and network design. The underlying release mechanisms are subsequently examined. These encompass pH-responsive, enzyme-triggered, and inflammation-responsive modalities. Emerging colonization-enhancing strategies are discussed in detail. These include mucoadhesive hydrogel architectures and the nascent paradigm of “living hydrogels” functioning as dynamic bioreactors. The translational potential of these systems for health management is illustrated through applications in inflammatory bowel disease, colorectal cancer, and gut–brain axis modulation. Finally, key challenges in manufacturing, viability, and translational feasibility are evaluated. These include regulatory, safety, and encapsulation-related constraints. To address these, multi-responsive platforms, machine learning-assisted design, and synbiotic hydrogels are proposed. These hydrogels synergize with probiotics to target dysbiosis and repair mucosal damage for improved gastrointestinal health management.