Goji berry (Lycium barbarum L.) is a medicinal and edible plant widely cultivated in China. Currently, most fruit vinegar fermentation in China relies on the commercial strain HN 1.01, which was originally isolated from grain vinegar. However, this strain exhibits low ethanol tolerance and produces vinegars with limited aroma diversity, highlighting the urgent need for a specialized starter culture for goji berry vinegar (GBV) production. In this study, a novel strain J-224 (Acetobacter senegalensis) suitable for GBV fermentation was developed through natural selection from goji berries combined with atmospheric and room-temperature plasma (ARTP) mutagenesis. Under 8% (v·v−1) ethanol stress, J-224 exhibited superior acid production and antioxidant activity. Compared with the original strain J-5, J-224 increased acid yield and ethanol conversion rate by 32.5% and 15.4%, respectively. Furthermore, GBV fermented by J-224 showed 8.8%, 16.7%, 16.7%, and 22.0% increases in reducing power, DPPH scavenging rate, total phenolic content, and total flavonoid content, respectively, compared to J-5-fermented GBV. The volatile organic compounds of GBV fermented by J-5, HN 1.01, and J-224 were systematically characterized using GC-E-nose, GC-IMS, and GC-MS. Combined with principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), the volatile profiles of different GBV samples were effectively discriminated. The total volatile compound content of J-224-fermented GBV was 1.25-fold and 1.98-fold higher than that of HN 1.01- and J-5-fermented GBV, respectively. Notably, n-octanol, ethyl caproate, and 2-acetylfuran were identified as characteristic aroma contributors of J-224-fermented GBV.

Non-biological haze in beer severely impacts product stability and consumer acceptance, yet conventional control strategies targeting protein-polyphenol interactions fail to resolve sporadic batch-specific turbidity, indicating unrecognized haze-forming factors. To identify these factors, this study focused on a haze-prone beer batch and investigated its potential turbidity-causing components. Through membrane filtration, centrifugation, and purification (protease hydrolysis, ethanol precipitation), combined with compositional analysis, enzymatic hydrolysis, spectral techniques, high-performance gel filtration chromatography, and simulated beer system validation, the core haze-forming substance was identified as the limit dextrin with a molecular weight of 1-2 kDa, featuring α-glycosidic bonds as the main chains. Further mechanism analysis revealed that this dextrin does not induce turbidity independently; instead, it forms composite colloidal particles with polyphenols via hydrogen bonds or undergoes oxidative cross-linking/aggregation under free radical action to cause haze. This study uncovers a novel haze-causing factor in beer, elucidates its structural characteristics and haze-forming mechanism, and provides targeted technical references for optimizing beer production processes and improving product stability. PRACTICAL APPLICATIONS: This study identifies a novel haze-causing factor (the limit dextrin with a molecular weight of 1-2 kDa) and its mechanism, providing targeted guidance for optimizing beer production (e.g., polyphenol control) to improve product stability.

As a nutrition-balanced pseudocereal, quinoa is gaining attention in beer brewing. This study comprehensively characterized volatile organic compounds (VOCs) in quinoa-adjunct beer using GC-E-Nose, GC-IMS and GC-MS. These techniques totally identified 117 VOCs and discriminated the VOC characteristics of all-malt beer and quinoa-adjunct beer brewed with differently colored quinoa varieties efficiently combined with principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). In contrast to all-malt beer, quinoa-adjunct beer contained 9 unique VOCs and exhibited a 69.72% higher total VOC content (particularly RB). Based on variable importance prediction (VIP) and odor activity value (OAV), 9 key differential odor-active compounds (VIP > 1 and OAV > 1) were selected. Quantitative descriptive sensory analysis (QDA) and partial least squares regression (PLSR) demonstrated these 9 compounds correlated highly with floral and fruity notes. Correlation analysis linked increased glucose level in quinoa-adjunct wort to enhanced VOC formation, especially esters.

Fusarium graminearum infects barley easily, causing Fusarium head blight and the subsequent production of mycotoxin deoxynivalenol, which poses significant health risks to both humans and animals. Grains contaminated with deoxynivalenol can only be discarded, resulting in enormous waste. In previous study, carvacrol-loaded chitosan nanoparticles that inhibited the growth of F. graminearum were developed to save the economic losses caused by deoxynivalenol contamination in barley malt. However, its antifungal efficacy and mechanism of action remain unclear, and the present study therefore seeks to elucidate both. The results demonstrated that these nanoparticles effectively inhibited spore germination and germ tube elongation of F. graminearum when the concentrations exceeding 200 µg·mL− 1, thereby impeding its mycelial growth. Furthermore, the measurement of relative electrical conductivity revealed that treatment with carvacrol-loaded chitosan nanoparticles significantly increased the relative electrical conductivity of F. graminearum cells, which was attributed to severe disruption of cell membrane integrity and consequent leakage of intracellular proteins and nucleic acids. In the barley storage experiment, the content of ergosterol and deoxynivalenol in rehydration spray-treated barley malt was 2.2 times (with 200 mg carvacrol-loaded chitosan nanoparticles addition) and 7.3 times (with 500 mg carvacrol-loaded chitosan nanoparticles addition) higher than that of carvacrol-loaded chitosan nanoparticles treated barley malt. At the same time, they maintained the malt quality parameters (including moisture, extract content, saccharification time, etc.) without significant alteration. These findings carvacrol-loaded chitosan nanoparticles can serve as an environmentally friendly and highly effective antifungal agent, and their large-scale application will help promote global food security and sustainable agricultural development.

Beer, a globally popular alcoholic beverage, maintains its commercial value through visual clarity, a key quality trait affecting consumer acceptance. As a colloidal system, the non-biological turbidity of beer is a key issue affecting its shelf-life stability. This review elucidates the molecular interactions among essential colloidal components that induce turbidity formation: (1) The formation of chill haze is primarily driven by protein-polyphenol complexes, which arise through hydrophobic interactions and hydrogen bonding. The haze-active proteins include proline-rich prolamins (15–32 kDa), lipid transfer protein 1 (LTP1), protein Z, and serpins, all of which contribute to turbidity. (2) Dextrins, particularly the understudied low-molecular-weight (LMW) fraction, are proposed to exacerbate turbidity via hydrogen-bond aggregation and oxidative cross-linking. Emerging albeit indirect evidence suggests that residual LMW dextrins may act as oxidative stimuli or nucleation sites, interacting synergistically with protein-polyphenol complexes and other polysaccharides to accelerate haze formation. (3) β-glucan and arabinoxylan facilitate particle aggregation by enhancing viscosity and promoting gelation. Environmental factors that affect the stability of beer colloids, such as temperature fluctuations, ionic strength, dissolved oxygen, mechanical vibrations, and light, significantly accelerate the turbidity process. In addition, a comprehensive stabilization strategy was proposed for the above mechanisms, including barley genotype selection and enzymatic clarification technology. As a critical review that systematically integrates existing research, these insights and technological advancements offer solutions for extending beer shelf life while preserving sensory quality, effectively addressing key challenges in modern brewing.

The lack of research on the tolerance mechanism of Acetobacter to citric acid has limited the efficient production of acetic acid in high citric acid environments, such as lemons and their processed by-products. In this study, comparative resequencing and transcriptomics of two homologous Acetobacter tropicalis strains with divergent citric acid tolerance (JY-135, tolerant; J-2736, sensitive) identified 13 candidate genes with both sequence variation and differential expression. Among these, gcvP encoding glycine decarboxylase P (GcvP) was validated as a key determinant. A non-synonymous substitution (Ala219Val) in GcvP of JY-135 enhanced conformational stability, correlating with elevated intracellular ammonia accumulation under citric acid stress (1.49-fold compared to J-2736). Knockout of gcvP in JY-135 resulted in a 61.11% reduction in survival, impaired amount and efficiency of acid production, and a 44.42% decrease in intracellular ammonia concentration. Conversely, exogenous glutamine supplementation, an upstream substrate of the GcvP reaction, significantly enhanced acid production efficiency in the sensitive strain J-2736, and ammonia levels increased by 2.37-fold. These findings establish gcvP-mediated ammonia homeostasis as a critical mechanism of citric acid stress resistance in A. tropicalis, providing a rational engineering target to enhance vinegar fermentation efficiency under high-acidity conditions.

High salt conditions negatively affect the fermentation efficiency of soy sauce and human health. This study aimed to construct a synthetic microbial community based on dominant functional microorganisms for salt-reduced soy sauce fermentation by investigating the succession and function of the microbial community during factory soy sauce fermentation. The findings revealed that the interplay between salinity and microorganisms influenced the dynamic changes of microbial communities. Furthermore, Aspergillus, Wickerhamomyces, Zygosaccharomyces, Staphylococcus, Weissella, and Tetragenococcus were analyzed to play key roles during soy sauce fermentation. Subsequently, the core strains were isolated and their strains and metabolic characteristics were evaluated. Finally, six strains (Aspergillus oryzae JQ09, Wickerhamomyces anomalus HJ07, Zygosaccharomyces rouxii JZ11, Staphylococcus carnosus QJ26, Weissella paramesenteroides ZJ19, and Tetragenococcus halophilus GY03) were employed to reconstruct the synthetic microbial community and conduct salt-reduced soy sauce fermentation. Biofortification increased the accumulation of metabolites in salt-reduced soy sauce. When the salt content was reduced to 14%, the sensory characteristics of soy sauce were closest to those of traditional soy sauce. Overall, this research presents a bottom-up approach to establish a simplified microbial community model with desired functions through deconstructing and reconstructing microbial structure and function. It has the potential to enhance the fermentation efficiency and realize the fermentation of salt-reduced traditional fermented food.

Pro-Xylane (boseine), a key cosmetic ingredient renowned for its anti-wrinkle effects and bioaffinity, has drawn considerable attention for its efficient biosynthesis. In this study, a NADP(H)-dependent carbonyl reductase from Canariomyces notabilis (CnCR) was identified through in silico screening. Using alanine scanning and semi- saturation mutagenesis, the double mutant Y98K/N208Q was obtained, exhibiting a 15.8-fold increase in specific activity (60.11 U mg-1) and an 11.5-fold improvement in catalytic efficiency (kcat/Km = 0.25 mM-1 s-1) compared to the wild-type enzyme. Mechanistic insights into the improved performance of Y98K/N208Q were revealed through molecular docking. In the enzyme-(3-acetone xyloside complex, Y98K/N208Q showed enhanced hydrogen bonding and a refined active site, which improving substrate binding and anchoring. The shorter distance to NADPH and stronger interactions with the substrate boosted the mutant's catalytic efficiency compared to the wild-type. To enable efficient cofactor regeneration, glucose dehydrogenase from Bacillus amyloliquefaciens was integrated into the Y98K/N208Q-mediated Pro-Xylane biosynthetic pathway. Under optimized conditions (30 degrees C, pH 7.5, 40 g L-1 cells, and a co-substrate-to-substrate ratio of 1.5 : 1), the coupled system produced Pro-Xylane at a titer of 160 g L-1 within 10 h, achieving a conversion rate and diastereomeric excess (S-enantiomer) of >= 99 %. To our knowledge, this is the highest reported Pro-Xylane production to date. This study highlights the discovery and semi-rational engineering of a novel enzyme for efficient Pro-Xylane biosynthesis, offering a robust platform for industrial-scale production of this valuable compound.

Carbendazim (CBZ) is a broad-spectrum fungicide commonly used in agriculture, but its residue can contaminate beer ingredients, potentially affecting Saccharomyces cerevisiae and beer quality. In this work, the effect of CBZ on Saccharomyces cerevisiae Saflager S-189 (S-189) and beer quality was investigated. The results demonstrated that S-189 was inhibited at concentrations equal to or exceeding 150 μg/kg of CBZ, reducing its growth rate, cell number, viability, and damaging cell structure. The CBZ disrupted multiple metabolic pathways in S-189, including amino acid biosynthesis, tRNA biosynthesis, and ABC transporters, and negatively affected energy metabolism, antioxidant activity, nutrient transport, and fermentation performance. Compared with the control group, the fermentation degree, alcohol content, and total acidity of beer fermented with 300 μg/kg CBZ-contaminated wort decreased, while the true concentration, pH, turbidity, and alcohol-ester ratio increased. Furthermore, CBZ changed the content of key flavor substances in beer, which affected the flavor quality of beer.

Soybean saponins, a class of intricate oleanane-type triterpenoids predominantly present in soybeans, exhibit diverse biological activities. This overview summarizes recent progress in elucidating the biological roles of soybean saponins and their glycosides, encompassing anti-inflammatory, antimutagenic, anticancer, and antimicrobial effects, viewed through a tectonic lens. Additionally, it explores modification methodologies encompassing physical, chemical, and biological strategies. Existing data underscore the significance of progressing integrated biotransformation techniques to augment the health-enhancing attributes of distinct saponin monomers.

As the primary raw material for beer production, barley is classified into two-row barley and six-row barley. The nutrient content is different in the different row-types of malts, and the beer volatile compounds (VCs) will be influenced when using them. The results showed that the wort produced from six-row malt contained more fermentable sugars (FSs) (26.3%) compared to two-row malt, and their free amino acid (FAA) profiles were apparently different. These differences were translated into variations in the VCs of beer. Six-row malt beer contained a higher content of total VCs (6354.80 μg/L), and most of the content of individual VC (66.7%) was significantly higher than two-row malt beer. In contrast, two-row malt beer showed a higher content of 1-propanol, ethyl caprate, and octanoic acid isoamyl. Eight key volatiles contributed to the differences in beer flavor, and these differences (62.5%) were related to the major amino acids (alanine, arginine, phenylalanine, tyrosine, and threonine). This study clarified how barley with different row-types affected beer VCs and offered guidance for selecting raw materials in beer production.

Beer, the most popular alcoholic beverage, poses health risks for individuals with gout and hyperuricemia due to its high purine content. Herein, we identified a novel purine nucleoside phosphorylase (AbPNP) from the edible mushroom Agaricus bisporus and heterologously expressed it in Pichia pastoris. The recombinant AbPNP exhibited optimal activity at 60 °C and pH 7.0, retaining >80% activity at pH 6.0–9.0 and >85% activity after 3 h at ≤60 °C. Kinetic analysis revealed high catalytic efficiency (kcat/Km = 2.02 × 106 s−1⋅M−1) toward inosine, with strong resistance to metal ions except for Co2+ and Cu2+. The application of AbPNP (1.0–5.0 U/mL) during wort saccharification reduced purine nucleosides by 33.54% (from 151.53 to 100.65 mg/L) while increasing yeast utilization of free purine bases. The resulting beer showed improved fermentation performance (alcohol content increased by 3.6%) without compromising flavor profiles. This study provides the food-grade enzymatic strategy for low-purine beer production, leveraging the GRAS status of both A. bisporus and P. pastoris.

Purine is a major factor contributing to the development of hyperuricemia and gout, and it is found in large quantities in Huangjiu as free bases. Purine production in Huangjiu is strongly associated with microbial metabolism. However, to the best of our knowledge the microorganisms responsible for and the mechanisms of purine formation during Huangjiu fermentation are yet to be evaluated. Herein, changes in purine levels during Huangjiu fermentation were analyzed. Further, the microbes responsible for purine production were identified and their gene abundance was studied. Results revealed that adenine, guanine, hypoxanthine, and xanthine are produced during Huangjiu fermentation. The total purines content on day 0 (27.99 mg/L) was found to be considerably lower than that produced on day 24 (122.15 mg/L) during Huangjiu fermentation. Metagenomics showed that the composition of the microbial community fluctuates sharply during five fermentation periods of Huangjiu, with the microbial community richness and diversity being the most prominent on day 3. At the genus level, Klebsiella, Lactobacillus, Staphylococcus, Saccharopolyspora, and Saccharomyces were abundant during Huangjiu fermentation and were involved in purine metabolism. Relationships between the dominant microorganisms and key enzyme genes of the purine pathways were also established based on the Kyoto Encyclopedia of Genes and Genomes database. Correlation analysis showed that Lactobacillus and Saccharomyces were the main genera involved in purine formation. Saccharomyces cerevisiae, Lactobacillus paralimentarius, and Lactiplantibacillus plantarum were involved in purine formation during Huangjiu fermentation. Overall, this study improves our understanding of the purine formation mechanism during Huangjiu fermentation and provides valuable insights into the regulation of purine formation by microorganisms.

Aroma is one of the most critical determinants of the sensory quality of fruit wines and directly influences consumer preference. As aroma analysis strategies evolve, aroma enhancement in fruit wines has become a key focus in winemaking. Therefore, it is essential to summarize the technological approaches employed in the aroma analysis and enhancement of fruit wine production. This review summaries the analytical techniques used for fruit wine aroma profiling and the principal volatile compounds identified in fruit wine and their formation mechanisms. Key factors influencing the aromatic characteristics of fruit wines are also analyzed, emphasizing the critical role of microbial communities in modulating aroma profiles. Significant differences in volatile compounds have been observed between fruit wines produced from different fruit varieties, ripeness levels, origins, and fermentation processes. Alcohols and esters are the primary contributors to the overall aroma, mainly generated through microbial metabolism. And a strong link between multi-microorganism fermentation and enhanced flavor formation has been demonstrated. Future research should focus on using multi-omics techniques to better understand the synergistic interactions between aroma compounds and microbial metabolism. This article can provide a theoretical basis for improving the production processes of fruit wine and enhancing the aroma quality.

The rising prevalence of hyperuricemia and gout, driven by dietary purine intake, has intensified demand for healthier alcoholic beverages. Beer, a major contributor to exogenous purines, poses significant health risks despite its cultural and economic importance. This review systematically analyzes purine sources in beer, metabolic pathways leading to uric acid production, and cutting-edge strategies for purine reduction. We evaluate physical adsorption, enzymatic degradation, microbial fermentation, and yeast metabolic engineering, highlighting their efficacy and limitations in industrial applications. Challenges such as flavor preservation, regulatory compliance, and scalability are critically discussed. By integrating multidisciplinary approaches ranging from synthetic biology to process optimization, this work provides a roadmap for developing commercially viable low-purine beers, bridging the gap between public health priorities and brewing industry innovation.

Aging plays a crucial role in enhancing the flavor of Huangjiu. This study aims to elucidate the changes in taste attributes of aged Huangjiu and explore the correlation between non-volatile compounds. It showed that aging made the sourness, bitterness, and astringency more pronounced. The content of organic acids and amino acids exhibited specific patterns with aging years. The total taste activity value of organic acids showed an increasing trend, peaking at 54.40 in Huangjiu aged 15 years, which served as a key indicator of sourness intensity. A total of 22 potential contributors to umami and 18 to bitterness were screened based on weighted gene coexpression network analysis. The total content of potential umami contributors was significantly higher in fresh Huangjiu and aging stage I, but declined in later periods, while bitterness contributors increased gradually throughout the aging process. This study provided theoretical support for the taste characteristics of aged Huangjiu.

Acetobacter is one of the main species producing fruit vinegar and its tolerance mechanism to citric acid has not been fully studied. This limits fruit vinegar production from high-citric-acid fruits, which are excellent materials for fruit vinegar production. This study analyzed the metabolic differences between two strains of A. tropicalis with different citric acid tolerances using non-targeted metabolomics. Differential metabolites and metabolic pathways analysis showed that the enhanced amino acid metabolism significantly improved the citric acid tolerance of A. tropicalis and the deamination of amino acids may also play a role. In addition, the up-regulated phosphatidylcholine (PC) and N-heptanoylhonoserine lactone indicated decreased membrane permeability and enhanced quorum sensing (QS), respectively. The analysis of the interaction between pathways and metabolites indicated that Gln, Cys, and Tyr contribute to improving citric acid tolerance, which was also confirmed by the exogenous addition. After adding the amino acids, the down-regulated qdh, up-regulated ggt, and improved glutathione reductase (GR) activity in J-2736 indicated that glutathione metabolism played an important role in resisting citric acid, and cellular antioxidant capacity was increased. This study provides a theoretical basis for efficient fruit vinegar production from citric-acid-type fruits.

As a vital microorganism during Huangjiu fermentation, fungi have not been thoroughly evaluated for their potential relationship with total purine levels in Huangjiu, which is a major contributing factor to hyperuricemia (HUA) and gout. In this study, we revealed the correlation between the succession of fungal communities and total purine content during Huangjiu fermentation. Our results demonstrated a continuous increase in total purine content during fermentation, rising from 13.08 to 72.12 mg/L. We observed significant dynamic changes in fungal community composition and diversity throughout the fermentation process, with the highest fungal species richness occurring on the third day. At the phylum level, Ascomycota dominated throughout fermentation (92.5–97.4

Yeast culture, a product of anaerobic solid-state fermentation of plant-based substrates inoculated with yeast strains and dehydrated, is widely used in animal production. Studies show its diverse benefits, including improved feed palatability, increased feed intake, enhanced gastrointestinal and immune health, and better productivity and reproduction in various animal species. However, the specific bioactive components responsible for these effects remain unclear. In the context of postbiotics, yeast culture from solid-state fermentation contains a mix of cellular lysates, metabolites, and growth substrates, fitting the postbiotic definition. These components can be classified into six main groups: proteins, polysaccharides, organic acids, enzymes, vitamins, and nucleotides. Research gaps exist in understanding how these components interact with animal physiology. This review consolidates data on yeast culture postbiotics, explores their metabolic effects in animals, and proposes strategies for targeted accumulation of these compounds to drive innovation in yeast culture applications to more effectively improve animal production performance such as weight gain rate, milk production, and health levels such as improving intestinal barrier function. These improvements reduce the feed cost per unit product by improving the overall breeding efficiency.