Luzhou-flavor baijiu is a grain-fermented product whose distinctive qualities result from the micro-ecological environment of the mud cellar. Generally, the development of fundamental flavors during the Luzhou-flavor baijiu fermentation is primarily influenced by the synergistic actions of microbial communities within the mud cellar environment. A comprehensive understanding of the spatial structure of the mud cellar and the composition of pit mud microorganisms is essential for enhancing the quality of Luzhou-flavor baijiu. Current research on the microbial composition of pit mud has been extensively studied, and the key flavor compounds have been well-identified. This review summarizes the micro-ecological characteristics of the mud cellar in the brewing of Luzhou-flavor baijiu, focusing on the construction mechanism of mud cellars, the microbiome of the pit mud, the mechanisms of fermentation metabolism, key acid-producing microorganisms and their flavor contributions. Additionally, it addresses the current applications, existing challenges, and future development prospects of mud cellars. It aims to encourage innovation, design, and optimization of mud cellar systems while offering multidimensional perspectives on how to modernize traditional brewing techniques and study solid-state fermentation ecosystems.

The production environment serves as a critical microbial reservoir that shapes the quality and stability of spontaneously fermented foods, yet the ecological rules governing its resident communities remain unclear. Through two-year monitoring of four core workshop habitats (indoor air (IA), equipment surface (ES), ground, and wall) in a strong-flavor Baijiu distillery, this study elucidated the spatiotemporal assembly of environmental microbiota. We identified ten fermentative genera, including Bacillus and Aspergillus, as the dynamic and stable core taxa across all habitats. Community assembly was dominated by stochastic processes, with dispersal limitation accounting for 48.64%-87.17% of the ecological dynamics. Interaction networks exhibited habitat-specific architectures, IA network displayed the highest complexity and modularity. Source tracking revealed the fermentation system as the main source of environmental microbes. Notably, eight genera, including Kroppenstedtia and Thermoactinomyces, were specifically enriched in IA. Partial least-squares path model further demonstrated that fungal communities were markedly more sensitive than bacteria to environmental factors, particularly the workshop's years of use and habitat type. Collectively, this work redefined the production workshop as a dynamically assembled microbial ecosystem. By analyzing the assembly patterns of the environmental microbiota and the driving environmental factors that drive them, it identifies potential control points that could inform future efforts to modulate microbial communities and manage the "microbial terroir". These findings lay a theoretical foundation for stabilizing product quality and for advancing traditional fermentation toward a more scientific and controllable production.

Ethanol- and water-soluble polysaccharides were extracted from Baijiu vinasses (EP and WP), respectively. EP was dominantly composed by arabinose, glucose and xylose with molar ratio of 8.81: 76.82: 6.9. While, WP was dominantly composed by galactose, glucose and mannose with molar ratio of 8.32: 56.05: 25.19. The molecular weights and reducing sugar contents in EP and WP were 6.2 kDa vs. 16.1 kDa and 24.52 +/- 0.97 % vs. 19.77 +/- 0.75 %, respectively. Alterations in activation of the Nrf2/HO-1 signalling pathway and increases in the abundance of Lachnospiraceae and Akkermansia and their associated metabolisms could be the general mechanism by which Baijiu vinasses (BV) polysaccharides alleviated alcohol-induced liver disease (ALD) in mice. Due to the different physicochemical characteristics, the ALD alleviation efficiency was different. EP exhibited higher efficiency in oxidative stress suppressing and lipid alternation by activating the peroxisome proliferators-activated receptors (PPAR) signalling pathway. WP exhibited higher efficiency in liver damage repairing with the controlment in tryptophan metabolism pathway. This study exhibited the potential biofunction of BV polysaccharides in ALD alleviation and could promote the BV upcycling.

Fermented foods are valued for their diverse flavor and health benefits, but the formation of ethyl carbamate (EC), a potential carcinogen, during production and storage poses challenges. Current EC reduction methods often compromise flavor and bioactive components. This study exemplifies a novel adsorbent combining activated carbon with metal-organic framework (MOF) chemistry for semi-selective EC removal. Structural analysis confirmed that in situ grown UiO-66-NH2 nanoparticles retain MOF crystallinity while fully modifying the surface and porous properties of AC. Adsorption studies showed UiO-66-NH2@AC achieves comparable EC removal efficiency mainly through chemisorption. In both simulated and actual rice vinegar samples, UiO-66-NH2@AC-3 exhibited superior semi-selective adsorption, with selectivity coefficients increasing up to 6987.47 % for volatile flavor components and 4353.06 % for organic acids, compared to AC. The study also highlights the robustness of UiO-66-NH2@AC-3 and underlying EC adsorption mechanisms. These findings pave the way for removing harmful substances from fermented foods while maintaining quality profile.

Strong-flavor Baijiu (SFB) production has relied on pit mud (PM) as a starter culture. The maturation time of natural PM (NPM) is about 30 years, so artificial PM (APM) with a shorter maturation time has attracted widespread attention. This study reveals the microbial and functional dissimilarities of APM and NPM, and helps to elucidate the different metabolic roles of microbes during substrate degradation and flavor formation. Significant differences in the microbial community were observed between APM and NPM, manifesting as variations in the abundance of core microorganisms. Total of 187 high-quality metagenome-assembled genomes (MAGs) were obtained based on the metagenomic binning technology, mainly including Firmicutes (n = 106), Bacteroidota (n = 15) and Chloroflexota (n = 14). Furthermore, the relative concentration of flavor compounds in 4-year APM was similar to those in 30-year NPM, but different from those in 100-year NPMs. Methanosarcina, Methanobacterium, Methanoculleus, Anaerolineae bacterium and Aminobacterium were the key bacteria responsible for the flavor differences. From a functional perspective, amino acid and carbohydrate metabolism were key functions of PM microbial, and showed differences between APM and NPM. Finally, substrate degradation and flavor generation pathways were found to exist in multiple microorganisms. Combine the relative abundance of microorganisms with the absolute abundance of enzymes, Clostridium, Lactobacillus, Petrimonas, Methanoculleus, Prevotella, Methanobacterium, Methanosarcina, Methanothrix, Proteiniphilum, Bellilinea, Anaerolinea, Anaeromassilibacillus, Syntrophomonas and Brevefilum were identified as the key microorganisms in APM and NPM.

This research examined the influences of electric field strength and pulse frequency of pulsed electric field (PEF) treatment, along with the combined effects of dissolved oxygen and ferrous iron ions on the aroma and components of strong-flavor baijiu. PEF treatment improved fruity aromas and decreased the pit mud odor. Electric field strength promoted the production of short-chain fatty acid esters, while pulse frequency facilitated the formation of acetal oxidation products. The most notable changes were observed at an electric field strength of 25 kV, and a pulse frequency of 350 Hz. Increasing dissolved oxygen significantly improves fruity and mellow aromas and promotes the generation of 17 compounds including ethyl lactate, ethyl butyrate, hexan-1-ol, octanoic acid, and 3-methylbutanal, while Fe2⁺ treatment reduces the fruity aroma of baijiu and significantly suppresses the production of 15 esters including ethyl hexanoate, hexyl hexanoate, and ethyl lactate. Dissolved oxygen may contribute to the generation of hydroxyl radicals and regulated oxidation reactions partially in baijiu. And, Fe2+ may react with organic acids to promote the hydrolysis of ester compounds. This study aims to offer valuable insights into the practical application of PEF in the flavor regulation of baijiu.

BACKGROUND:Lead ion (Pb2+) is a toxic heavy metal that poses severe threats to food safety. Traditional methods like inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) rely on bulky instrumentation, which are limited by high costs, complex sample preparation requirements, and inability to meet the demands for rapid on-site testing. Nanozyme-based biosensors have emerged as promising alternatives, yet single-mode sensors often suffer from matrix interference in complex food samples. Therefore, developing a rapid and reliable on-site method is critical for Pb2+ detection. RESULTS:To address this challenge, a CRISPR/Cas12a-driven dual-mode biosensor integrating Pt/CeO2 nanozyme-mediated peroxidase activity with GR-5 DNAzyme recognition was developed. The biosensor's design capitalizes on GR-5 DNAzyme for Pb2+-specific recognition, triggering CRISPR/Cas12a-mediated cleavage of electrochemical/colorimetric signal probe SH-ssDNA-Pt/CeO2 to generate dual signals. This innovative platform synergizes electrochemical precision and colorimetric simplicity for Pb2+ detection in complex food matrices. The biosensor achieved an ultra-sensitive electrochemical response (linear range: 0.002-200 nM; limit of detection: 0.14 pM) alongside a robust colorimetric readout (linear range: 0.5-2000 nM; limit of detection: 0.47 nM), representing significant sensitivity improvements over conventional single-mode sensors. Crucially, the intrinsic cross-verification mechanism between orthogonal signal modalities minimized false positives while ensuring >90.5 % recovery in spiked corn, edible oil, beef and red wine samples with RSD <5 %. These results highlight the potential of the dual-mode sensor as a practical, field deployable sensing platform for the detection of Pb2+. SIGNIFICANCE:This work innovatively integrates the specificity of CRISPR with the catalytic properties of nanozymes into a self-validating electrochemical/colorimetric dual-mode system. The detection method not only establishes a robust platform for highly sensitive, reliable and visualized detection of Pb2+ in complex food matrices, but also pioneers a new paradigm for multi-modal biosensor design.

Baijiu is highly dependent on open Daqu fermentation, which is easily affected by seasonal fluctuations. This study systematically analyzed winter (WID) and summer (SUD) strong flavor Daqu by integrating physicochemical analysis, microbial community detection, volatile component determination, and metabolomics technology. Results showed SUD had significantly higher starch consumption and acidity than WID, directly attributed to enhanced microbial activity and enzymatic efficiency. Metagenomic studies have identified key enzymes including α-amylase (EC:3.2.1.1) and carboxylic esterase (EC:3.1.1.1), as well as CAZy families such as GH65 and GH73. Based on this finding, the dominant microbes in SUD, such as Lactobacillus, Weissella, and Thermoactinomyces, can not only increase community diversity but also play a promoting role in starch saccharification and ester synthesis. Metabolomics detected 1034 differential metabolites, with SUD enriched in acetic/lactic acids and lipids that are critical flavor precursors. Redundancy analysis confirmed temperature as the core factor driving microbial succession and metabolic pathways. Thermoascus is enriched in high-temperature environments, and the affected metabolic pathways include cofactor biosynthesis and amino acid metabolism. This study clarified seasonal impacts on Daqu quality via microbe-enzyme-metabolite synergy, providing a theoretical and technical basis for stabilizing Baijiu production through microbial regulation and precise fermentation parameter control.

In food safety testing, simultaneous detection of multiple harmful residues is crucial because pesticide and veterinary drug residues often occur together. A method was developed for the simultaneous determination of residues of 20 pesticide and veterinary drug compounds in both buffalo and cow milk, utilizing a modified QuEChERS method combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The targeted analytes were efficiently extracted from milk matrices using a 10 % formic acid solution in acetonitrile. Optimization of both pre-treatment and analytical parameters significantly enhanced the method's sensitivity. Quantification was performed using matrix-matched calibration curves, which demonstrated exceptional linearity (R2 > 0.9990) across all analytes. Method validation, conducted with fortified blank milk samples at concentrations of 5, 10, and 50 mu g/L, yielded recoveries ranging from 73.1 % to 111.6 %. The relative standard deviations for all analytes were consistently below 15 %, confirming the method's precision. The limits of detection (LOD) and quantification (LOQ) were determined to be between 0.7 and 1.7 mu g/L and 2.0 and 5.0 mu g/L, respectively. This method is straightforward, sensitive, accurate, and environmentally friendly, making it well-suited for the detection of multiple pesticides and antibiotics in milk.

To determine the unique contribution of the bioturbation to the properties of the medium-temperature Daqu, we investigated the differences in microbiota and metabolic composition using the meta-omics approach. Bioturbation increased the amounts of microbial specie and influenced the contribution of the core microbiota to the metabolome. Specifically, inoculated synthetic microbiota (MQB) enhanced the abundance of Bacillus amyloliquefaciens, while Bacillus licheniformis (MQH) increased the abundance of the two Aspergillus species and four species level of lactic acid bacteria. These changes of the microbial profiles significantly increased the potentials of carbohydrate metabolism, amino acid metabolism, and biosynthesis of ester compounds. Consequently, both patterns significantly increased the content of volatile compounds and free amino acids, which were 27.61% and 21.57% (MQB), as well as 15.14% and 17.83% (MQH), respectively. In addition, the contents of lactic acid in MQB and MQH decreased by 65.42% and 42.99%, respectively, closely related to the up- or down-regulation of the expression of their corresponding functional enzyme genes. These results suggested that bioturbation drove the assembly of the core microbiota, rather than becoming critical functional species. Overall, our study provides new insights into the functional role of exogenous isolates in the Daqu microecosystem.

The spoilage of post-harvest fruits caused by physiological metabolic activities can affect people’s consumption. Therefore, the development of effective packaging material for fruits is beneficial in ensuring the quality of fruits and avoiding wastage. In this study, we developed a multifunctional and biodegradable fruit packaging material using Rhizopus oryzae for the first time. Ag@PCN-222 (Zn) was introduced into the mycelium to endow the bio-film with antibacterial properties and pesticide degradability. The bio-film had nearly 100% biodegradability only after one week. The bio-film exhibited excellent antioxidant properties, as well as effective antibacterial activity. The prepared bio-film maintained high CO2 permeability and low O2 permeability, which was beneficial for shelf-life extension of fruits. The result of pesticide degradation experiments showed that the Bio-Ag@Zn film could effectively degrade the organophosphorus pesticide methyl parathion and improve the safety of fruits. At the same time, experiments on fruit preservation demonstrated that composite biofilms effectively inhibit fruit decay and prolong shelf life. The experimental results indicated that the Bio-Ag@Zn film was expected to be a green and multifunctional fruit packaging material.

Pit mud (PM) is fermenting agents in the strong-flavor baijiu (SFB) production. In this paper, the discrepancies in fermentation parameters, microbial community succession patterns and metabolic phenotypes were compared in multidimensional PMs. The results showed that pyruvic acid, succinic acid, S-Acetyldihydrolipoamide-E, glycerol and glyceric acid were the key metabolites responsible for the metabolic differences between the 2-, 30-,100- and 300-year multidimensional PMs, while the butanoic acid, heptyl, heptanoic acid, heptanoic acid ethyl ester, hexanoic acid and octanoic acid were the key differential flavor compounds in the 2-, 30-,100- and 300-year multidimensional PMs. Concurrently, the diversity and abundance of microbial community also exhibited significant differences between the new and old multidimensional PMs, the assembly pattern of bacterial communities changed from deterministic to stochasticity from lower (bottom of the pit and under the huangshui fluid) to upper PM (up the huangshui fluid and top of the pit). Key microorganisms related to the succession process of the lower PM were Clostridium, Methanobacterium, Petrimonas, Lactobacillus, Methanobrevibacter, Bellilinea, Longilinea, Bacillus. In contrast, the upper PM were Caproicibacter, Longilinea, Lactobacillus, Proteinphilum, Methanobrevibacter, Methanobacterium, Methanobacteriaceae, Petrimonas, Bellilinea and Atopobium. Redundancy analysis (RDA) indicated that the key environmental factors regulating the succession of microbial in upper PM were lactic acid, moisture, pH and available phosphorus. In contrast, the lower was lactic acid, acetic acid and ammonia N. Based on these results, heterogeneous mechanisms between new and old multidimensional PMs were explored, providing a theoretical support for improving the quality of new PM.

Extrusion has been proven to be a novel approach for modifying the physicochemical characteristic of Baijiu vinasses (BV) to extract polysaccharides, contributing to the sustainable development of brewing industry. However, the comparison of the bioactivity and bioavailability of extruded (EX) and unextruded (UE) BV polysaccharides was unclear, which impended the determination of the efficacy of extrusion in BV resourcing. In this study, in vitro digestion and fecal fermentation experiments were conducted to investigate the bioavailability, and the results showed that EX exhibited less variation in the monosaccharide composition and molecular weight, while exhibiting a stronger antioxidant capacity compared to UE. Moreover, during fermentation EX increased the abundance of Parasutterella and Lachnospiraceae, while UE promoted the proliferation of Bacteroides, Faecalibacterium, and Dialister, resulting in variation in short-chain fatty acids. These findings indicate that extrusion can enhance the capacity of antioxidants and bioavailability of BV polysaccharides.

Elevating the flavor profile of strong flavors Baijiu has always been a focal point in the industry, and pit mud (PM) serves as a crucial flavor contributor in the fermentation process of the fermented grains (FG). This study investigated the influence of wheat flour and bran (MC and FC) as PM culture enrichment media on the microbiota and metabolites of FG, aiming to inform strategies for improving strong-flavor Baijiu flavor. Results showed that adding PM cultures to FG significantly altered its properties: FC enhanced starch degradation to 51.46% and elevated reducing sugar content to 1.60%, while MC increased acidity to 2.11 mmol/10 g. PM cultures also elevated FG’s ester content, with increases of 0.36 times for MC-FG60d and 1.48 times for FC-FG60d compared to controls, and ethyl hexanoate rising by 0.91 times and 1.39 times, respectively. Microbial analysis revealed that Lactobacillus constituted over 95% of the Abundant bacteria community, with Kroppenstedtia or Bacillus being predominant among Rare bacteria. Abundant fungi included Rasamsonia, Pichia, and Thermomyces, while Rare fungi consisted of Rhizopus and Malassezia. Metagenomic analysis revealed bacterial dominance, primarily consisting of Lactobacillus and Acetilactobacillus (98.80–99.40%), with metabolic function predictions highlighting genes related to metabolism, especially in MC-FG60d. Predictions from PICRUSt2 suggested control over starch, cellulose degradation, and the TCA cycle by fungal subgroups, while Abundant fungi and bacteria regulated ethanol and lactic acid production. This study highlights the importance of PM cultures in the fermentation process of FG, which is significant for brewing high-quality, strong-flavor Baijiu.

为酿造具有复合香的调味酒,分别考察高温大曲+中温大曲Ⅰ+麸皮(1#)、高温大曲+中温大曲Ⅱ(2#)、高温大曲+中温大曲Ⅱ+麸皮(3#)对复合香调味酒酒醅堆积过程中理化指标及微生物指标的影响,并基于高通量测序技术探究堆积过程中微生物群落结构变化.结果表明,3组酒醅样品的理化指标在堆积过程中均处于适宜的范围内,堆积结束时,样品3#中细菌总数、酵母菌数对数值和芽孢杆菌生物量均最高.此外,醋酸杆菌属(Acetobacter)、芽孢杆菌属(Bacillus)、高温放线菌属(Thermoactinomyces)和乳杆菌属(Lactobacillus)为酒醅堆积过程中主要优势细菌属;伊萨酵母属(Issatchenkia)、毕赤酵母属(Pichia)和嗜热真菌属(Thermomyces)为堆积过程中主要优势真菌属.相关性分析结果表明,酒醅堆积过程中微生物群落结构的变化与理化因子有显著相关关系,说明添加麸皮和中温大曲Ⅱ有利于堆积过程中功能微生物的生长繁殖.

Pit mud (PM) prokaryotic community is essential for the solid-fermentation of Luzhou-flavor baijiu. In this study, the multidimensional (four vertical positions) microbial communities of different PMs were investigated. Microbial communities were significantly different in multidimensional PMs (p = 0.001). Horizontally speaking, the relative abundance of Longilinea at the position 1 (bottom of the cellar) was highest in 30-year PMs (16.19%) and decreased gradually in 100- (11.95%) and 300-year (0.27%) PMs. Methanobrevibacter had the highest relative abundance at the position 3 (up the huangshui fluid) in 100-year PMs (18.98%), and decreased in 300-year PMs (8.73%), at the position 4 (top site of the cellar), Clostridium had the highest abundance in 100-year PMs (8.24%). Vertically speaking, Petrimonas had the highest abundance (17.4%) at the position 3 in 100-year PMs, while for the 300-year PMs, Lactobacillus and Caproiciproducens had the highest abundance at the position 1. RDA analysis indicated that lactic, caproic, butyric, and acetic acids were the four key physicochemical factors. Amino acids, peptides, fatty acids, and conjugates were the main metabolites of PMs, and S-Acetyldihydrolipoamide-E, succinic acid, aspartic acid, asparagine and valine were key differential metabolites. Based on OPLS-DA analysis, 20 differential flavor compounds were identified, mainly including esters such as hexanoic acid methyl ester, ethyl acetate, hexanoic acid ethyl ester, butanoic acid hexyl ester and acids such as hexanoic acid, butanoic acid and heptanoic acid. Moreover, hexanoic, octanoic acid and their corresponding esters were concentrated on 300-year PMs. This study provides theoretical support for improving the quality of PM.

白酒酿造过程实质上是相关微生物的系列代谢过程.因此,研究现代微生物技术在中国白酒酿造中的应用尤为重要.本文综述了基因工程、酶工程、PCR技术、高通量测序等微生物技术在酿酒原料、制曲、酿酒生产(窖池、糟醅、酿造副产物)、酿酒废弃物等方面的应用,以期为建立酿酒微生物库、提升白酒产业高质量发展等提供理论指导与参考依据.

Microbial terroir is essential to the development of regional fermented food characteristics. Environmental microbiota participates in the fermentation process and fermentation process also domesticates the microorganisms in the environments, leading to an interaction between the fermentation process and the fermentation environment. Here, we reported microbiota from different environments (fermentation process, fermentation environment, and ecological environment) of two distilleries. We used amplicon full-length sequencing to study the regional microbial characteristics and the domestication of the fermentation process on environment. Fungi in the Chishui River producing region contributed more to the brewing, which contained many functional fungi, such as Pichia, Wickerhamomyces anomalus, and Debaryomyces. The fermentation process had a strong domestication effect on microbiota in the fermentation environment. Fermented grains and Daqu were the primary microbiota sources in the fermentation environment. Microorganisms in the producing area exhibited a distance decay relationship. With increasing distance from the distillery, the dissimilarity between microbial communities increased and the microbial community showed an obvious deterministic-stochastic pattern. The ecological environment 50m away from the distillery was less domesticated by the fermentation process. Abiotic factors (pH, acidity, and water content) and microbial interactions synergistically led to microbial differences across environments. These results first determined that a regional microbial model had been established in sauce-flavor Baijiu and comprehensively clarified the interaction between the fermentation process and the environment. It laid the foundation for further elucidation of the influence of microorganisms on the yield and flavor quality of sauce-flavor Baijiu.

Distillers' grains of Chinese Baijiu (DGS) presents a significant challenge to the environmentally-friendly production of the brewing industry. This study utilized screw extrusion to modify the morphological and crystalline characteristics of DGS, resulting in a 316 % increase in the yield of non-digestible polysaccharides extraction. Physiochemical characteristics of extracted polysaccharides were variated, including infrared spectrum, monosaccharide composition, and molecular weight. Polysaccharides extracted from extruded DGS exhibited enhanced inhibitory capacity on α-amylase activity and starch hydrolyzation, as compared to those extracted from unextruded DGS. Additionally, the ABTS, DPPH, and OH radical scavenging efficiencies took a maximum increase of 1.20, 1.38, and 1.02-fold, correspondingly. Extrusion is a novel approach for the recycling non-digestible polysaccharides from DGS, augmenting the bioactivity of extracts and their potential application in functional food.

Distillers grains are fermentation by-products of traditional Baijiu production process,which are huge in quantity and rich in nutrients.This paper systematically elaborates on the resourcezation methods of distillers grains in recent years,including organic fertilizer,clean fuel,protein foaming agent,and the extraction of melanoid,polypeptide,prolamin,etc.,so as to provide reference for the diversified utilization of by-products of Baijiu industry.