The catalytic effect of enzymes exerts a decisive impact on the taste and quality of finished products in Baijiu brewing. Regulating enzyme activity during the brewing process is a pivotal strategy for increasing liquor yield and enhancing the flavor and taste of Baijiu. Since the enzymes involved in Baijiu brewing are predominately hydrolytic enzymes, research into this class of enzymes is of paramount importance. This paper provided a systematic review of the sources, composition, functions and applications of hydrolases, alongside their synergistic mechanisms during the fermentation process. These insights offered theoretical support for optimizing fermentation performance and improving both the yield and quality of Baijiu through enzymatic regulation.

Pyrazines are an important class of nitrogen-containing heterocyclic flavor compounds, which contribute greatly to the aroma and quality of Baijiu, particularly sauce-flavor (Jiangxiangxing), sesame-flavor (Zhimaxiangxing) and blended-flavor (Jianxiangxing) Baijiu. Among them, tetramethylpyrazine also exhibits multiple functional activities, including anti-inflammatory, antioxidant, cardiovascular protective, liver-protective and antitumor effects. This paper systematically summarized the categories, contents and distribution characteristics of pyrazines in Baijiu; elaborated on their structural features and flavor contributions; reviewed their detection technologies and formation pathways; and discussed strategies for improving the yield of pyrazines via microbial biosynthesis, aiming to provide a reference for further research on health-promoting active components in Baijiu.

Baijiu is facing challenges such as rising labor costs, increasing demands for quality stability, and greater pressure on energy conservation and emission reduction. Based on bibliometrics, a total of 622 articles from 2010 to 2025, collected from the China National Knowledge Infrastructure (CNKI) and the Web of Science (WOS) Core Collection, were analyzed. Keyword co-occurrence analysis showed that automation technology had been applied in major aspects of Baijiu brewing, including raw material processing, Jiuqu making, fermentation of fermented grains, steaming and distillation, aging in Baijiu cellars, blending and flavoring, and packaging. However, the promotion of automatic brewing technology of Baijiu was constrained by insufficient compatibility of technology integration, a lack of standard systems, a shortage of composite talent, high investment costs, and long return periods. Looking ahead, digital twins, edge computing, modular flexible production lines, green energy and carbon footprint management, and human-machine collaboration in “smart factories” will become breakthrough paths, facilitating the transition from “experience-driven” to “data-driven”. While inheriting the essence of solid-state fermentation, these technologies will promote high-quality and sustainable development of the Baijiu industry.

Using Saccharomyces cerevisiae A9 as the starting strain, a mutagenesis library with enhanced genetic diversity and improved environmental tolerance was first constructed through multiple rounds of atmospheric and room-temperature plasma mutagenesis, combined with adaptive evolution under gradually increasing concentrations of sugarcane molasses and elevated temperatures. Subsequently, a two-step screening strategy was applied: primary screening on 2,3,5-triphenyltetrazolium chloride (TTC) plates followed by secondary screening in microplates using the sodium periodate method, aiming to isolate superior mutants with reduced glycerol synthesis and enhanced ethanol production. The results demonstrated that two thermotolerant S. cerevisiae mutants, designated E40 and K36, were successfully bred under high-concentration sugarcane molasses conditions, both capable of tolerating 395 g/L sugarcane molasses and 37 ℃. After 24 h of fermentation, compared with the parent strain A9, mutants E40 and K36 exhibited reductions in glycerol production by 27.56% and 23.35%, respectively, while their ethanol yields increased by 8.04% and 7.46%, respectively. The successful breeding of the two strains held significant industrial value for improving substrate conversion efficiency and economic viability in ethanol production. Furthermore, the methodology developed here provided a valuable reference for breeding industrial microbial strains with low-glycerol and high-ethanol output using molasses-based substrates.

Using fermented grains of sauce-flavor (Jiangxiangxing) Baijiu as the research subject, variations in polypeptide content, protease activity, total nitrogen and protein hydrolysis degree were compared among fermented grains from different fermentation rounds. Polypeptides were identified and screened by liquid chromatography-tandem mass spectrometry. Candidate peptides were selected based on antioxidant activity prediction and abundance characteristics, and antioxidant mechanisms were explored by molecular docking. The results showed that obvious protein degradation was observed in fermented grains of the 4^th, 5^th and 7^th rounds. A total of 204 polypeptides were isolated and identified, and the highest quantity of specific polypeptides was found in the 4^th round. MLPAGCGLLSCLRR and QYAAGMPMMCR possessed strong scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radicals. The half maximal inhibitory concentrations of MLPAGCGLLSCLRR toward the two radicals were 0.126 and 1.764 mg/mL, respectively. Molecular docking results indicated that the binding energies of both MLPAGCGLLSCLRR and QYAAGMPMMCR with ABTS cation radicals were lower than those with DPPH radicals, with the MLPAGCGLLSCLRR-ABTS complex showing the lowest binding energy (-4.55 kcal/mol), and hydrophobic interaction and hydrogen bond served as major interaction forms. It is concluded that distinct differences in protein degradation existed in different fermentation rounds. Natural antioxidant peptides acquired from fermented grains can provide a theoretical basis for high-value utilization of raw materials and development of functional peptides.

To explore the flavor differences of Baijiu with different flavor types, four typical flavor types, including light-flavor (Qingxiangxing), strong-flavor (Nongxiangxing), sauce-flavor (Jiangxiangxing), and rice-flavor (Mixiangxing) Baijiu, were selected. The sensory characteristics and 40 skeleton flavor substances were analyzed via sensory evaluation, gas chromatography-flame ionization detector, and ion chromatography-conductivity detector. The results showed that sauce-flavor and strong-flavor Baijiu presented a prominent aged aroma, fullness, and taste persistence, while light-flavor and rice-flavor Baijiu were characterized by high purity, mildness, and a sweet and mellow taste. Ethyl caproate was the dominant ester in strong-flavor Baijiu; furfural and acetaldehyde were the major aldehydes and ketones in sauce-flavor Baijiu; β-phenylethanol was the principal alcohol in rice-flavor Baijiu; and acetaldehyde and acetal were the main aldehydes and ketones in light-flavor Baijiu. A total of 31 and 33 key aroma substances were identified in strong-flavor and sauce-flavor Baijiu, respectively, and 26 key aroma substances were detected in both light-flavor and rice-flavor Baijiu. Correlation analysis between sensory quality and flavor substances indicated that esters such as ethyl caproate and ethyl octanoate showed an extremely significant positive correlation with fruity aroma, floral aroma, and sweet taste (P < 0.01); furfural, isovaleraldehyde, and other components were extremely positively correlated with bitter taste (P < 0.01). Mildness was negatively correlated with most flavor substances, whereas fullness and harmony were positively correlated with most indexes. This study revealed that the interaction among flavor substances jointly shaped the complex and harmonious sensory characteristics of Baijiu.

Bacterial and fungal community structure and diversity in naturally fermented Guilin Douchi samples fermented for 1 year and 4 years were analyzed by Illumina MiSeq high-throughput sequencing. The results showed that Firmicutes dominated the bacterial communities at the phylum level. The relative abundance of Bacillus increased gradually while that of Staphylococcus decreased continuously at the genus level with the extension of fermentation time. Functional prediction indicated that the bacterial communities were primarily involved in carbohydrate and amino acid metabolic pathways. Regarding the fungal community, Ascomycota and Basidiomycota were the dominant phyla. At the genus level, the relative abundance of Starmerella decreased with increasing fermentation time, while the relative abundance of Candida increased. This study provided a theoretical reference for the industrial development of Guilin Douchi.

To realize the resource utilization of Huangshui, a by-product from the brewing of Fuyu-flavor Baijiu, esterase-producing Bacillus strains were screened from Huangshui and identified via morphological observation, physiological and biochemical tests, and molecular biological techniques. Single-factor experiments and response surface methodology were employed to optimize the esterification conditions, and the esterification effect of the crude enzyme in the Huangshui system was verified. The results showed that nine esterase-producing Bacillus strains were obtained, among which strain AY-6 was selected as the superior strain with the highest esterase activity of 14.35 U/mL and identified as Bacillus tequilensis. The optimal esterification conditions determined by response surface methodology were as follows: temperature 36 °C, pH 4.5, and ethanol volume fraction 18%, under which the enzyme activity reached 15.97 U/mL. After treating Huangshui with the crude enzyme solution for 96 h, the total ester content increased to 0.86 g/L, and the formation of key esters such as ethyl hexanoate and ethyl acetate was directionally promoted. This study provides an excellent strain and technical support for the resource utilization of Huangshui and the quality improvement and flavor enhancement of Fuyu-flavor Baijiu.

To address the bottlenecks of unstable saccharifying activity and difficult standardized production of traditional sweet Jiuqu, high glucoamylase-producing Rhizopus strains were isolated from 15 traditional sweet Jiuqu samples collected from multiple regions in China. Strains were screened via the transparent halo method and solid-state fermentation assay, and their environmental tolerance was evaluated, followed by fermentation verification. The results showed that a superior high glucoamylase-yielding strain, Rhizopus oryzae A2, was screened out. This strain presented excellent environmental adaptability, with tolerance to ethanol 4% (V/V), lactic acid 0.6% (V/V), glucose 20% (m/m), and sodium chloride 1.5% (m/m). The optimal Jiuqu-making conditions for the strain A2 were determined as follows: incubation temperature 30 ℃, cultivation duration 60 h, and moisture content 35%. Fermentation tests indicated that the maximum of saccharifying power and liquefying power of strain A2 reached 506.0 mg/(h·g) and 0.418 g/(h·g), which were 6.2% and 17.4% higher than those of the control strain Q303, respectively. The characteristic aroma compound (phenethyl alcohol) in fermentation broth inoculated with the strain A2 was enriched. The strain could rapidly synthesize esters, including ethyl octanoate and ethyl decanoate, and simultaneously reduce the metabolic accumulation of the bitter substance (furfural). This study demonstrated that the strain A2 featured strong enzyme production capacity, stable fermentation performance, and superior flavor metabolism, serving as a highly promising fermentative strain for the development of novel rice wine production processes.

To investigate the differences in microbial communities of straw from different regions and their impact on microbial community succession during Daqu fermentation, the microbial community structure of rice straw from Guizhou (GZ) and Sichuan (SC) was analyzed with high-throughput sequencing technology during the Daqu fermentation process. The results showed that the microbial communities in straw differed across regions, and the diversity and richness of the microbial community in straw from the Sichuan region were higher than those from the Guizhou region. During the Daqu fermentation process, a total of eight dominant bacterial genera and six dominant fungal genera (relative abundance ≥ 1%) were identified. In the GZ group, the dominant bacteria mainly included Saccharopolyspora, Bacillus and Pseudonocardia, while the SC group was dominated by Staphylococcus, Virgibacillus, Kroppenstedtia, Oceanobacillus and Saccharomonospora. The dominant fungi in the GZ group were mainly Thermoascus, Millerozyma and Leiothecium, while the SC group was enriched with Aspergillus, Thermomyces and Monascus. The microbial community in Daqu prepared with straw from the Guizhou region is predominantly characterized by synergistic and mutualistic relationships, whereas that from the Sichuan region exhibits greater community complexity and potential stability. This study provides a reference for the selecting of straw as auxiliary material for high-temperature Daqu.

Using fresh raw Daqu of low (36%), medium (38%) and high (40%) initial moisture contents as research objects, physicochemical indexes, variations of volatile flavor substances and succession dynamics of microbial community structure of Daqu samples during the active fermentation period were systematically analyzed by conventional detection methods, headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry, and metagenomic sequencing. The results showed that there was no significant difference in acidity, starch and reducing sugar contents among the three groups at the second Fanqu. Both species quantity and total content of volatile compounds in medium and high moisture groups were higher than those in the low moisture group, with 76 species and 786.13 μg/g in the low moisture group, 83 species and 884.91 μg/g in the medium moisture group, and 87 species and 880.12 μg/g in the high moisture group. Microbial community diversity decreased with the increase in the initial moisture content of the fresh raw Daqu. Caldibacillus dominated microbial communities of all groups, and its relative abundance was markedly higher in medium and high moisture groups. Correlation analysis revealed that Limosilactobacillus, Pediococcus, Lactiplantibacillus and Weissella could mutually facilitate growth and regulate community succession. Meanwhile, microorganisms showed potential contribution to the synthesis of volatile substances. Genera including Saccharomonospora, Thermobifida, Weizmannia and Clostridium were positively correlated with ethyl heptanoate, ethyl hexanoate, hexyl octanoate and trimethylpyrazine. In conclusion, initial moisture content regulated microbial community structure and further affected the formation and accumulation of flavor substances in the sauce-flavor Daqu. Moisture content of 38% and 40% were beneficial to volatile compound production. This study provided scientific reference for technological optimization of sauce-flavor (Jiangxiangxing) Daqu production.

Referring to the ‘Huizao' process of Baoning vinegar, vinegar was fermented with distillers' grains instead of vinegar residues. The physicochemical indices of vinegar grains were determined before and after the fermentation, while microbial community composition was profiled via amplicon sequencing and metagenomics, with subsequent annotation of microbial metabolic functions. The results indicated that significant reductions in starch, protein, and fat contents were observed in the vinegar grains after the fermentation. Conversely, moisture content, total acid and amino acid nitrogen were significantly increased to 57.90%, 5.08 mmol/10 g, and 1.80 g/kg, respectively (P < 0.05). Proteobacteria and Ascomycota remained the dominant phyla in the vinegar grains throughout the fermentation. In contrast, Pantoea (11.69%) and Alternaria (23.07%) were the predominant genera before the fermentation, whereas Acetobacter (62.93%) and Pichia (36.94%) became the dominant genera after the fermentation. A total of nine genera were found to be differential in the vinegar grains before the fermentation, while the seven were identified after the fermentation. Correlation analysis indicated that moisture content was extremely significant negatively correlated with multiple bacterial genera such as Pantoea (P < 0.01), while protein and starch contents exhibited an extremely significant negative correlation with Pichia (P < 0.01). Co-occurrence network analysis indicated remarkable shifts in microbial interaction patterns in vinegar grains following fermentation. Functional annotation indicated that higher gene abundances in major functional categories associated with macromolecular metabolism, small-molecule biosynthesis and transformation were detected in the microbiota of vinegar grains after the fermentation.

To achieve efficient separation and purification of iturin A from fermentation broth, a combined process of activated carbon decolorization and multi-stage gradient chromatography purification was established. Decolorization conditions were optimized using decolorization rate and product recovery rate as evaluation indices. Stepwise purification was performed sequentially by n-butanol extraction, HZ816 macroporous resin chromatography, and silica gel column chromatography. The entropy weight method was employed to assign objective weights to relevant indicators for comprehensive process evaluation and selection of the optimal purification scheme. The results showed that the optimized activated carbon decolorization process achieved a decolorization rate of 65.37% and iturin A recovery rate of 89.48% from fermentation broth. The product purity increased from 3.91% to 19.23% with a recovery rate of 83.19% after n-butanol extraction. The purity increased to 35.36%, and the recovery rate was 66.21% after HZ816 macroporous resin purification. The final purity after silica gel column chromatography purification reached 84.66% with a total recovery rate of 46.91%, which was 21.4 times as high as the initial purity. The integrated purification route featuring decolorization, extraction, resin adsorption and silica gel refining is simple to operate and presents satisfactory purification performance. It can provide technical support for the industrial large-scale preparation of iturin A and a reference for the separation of similar bioactive lipopeptides.

Fungal community structures of fermented grains by Houhuo, Qingcha and Hongxin low-temperature Daqu were analyze by Illumina MiSeq high-throughput sequencing technology, and then subjected to principal coordinate analysis (PCoA), linear discriminant analysis effect size (LEfSe) analysis and correlation analysis. The results showed that the Chao1 index in fermented grains by Houhuo Daqu was significantly higher than that by Hongxin Daqu (P < 0.05). The dominant fungal genera (relative abundance > 1%) across the three groups of fermented grains were primarily Saccharomyces (68.28%), Kazachstania (9.72%) and Saccharomycopsis (9.57%). Kruskal-Wallis test results showed that the relative abundances of Saccharomycopsis and Aspergillus in fermented grains by Houhuo Daqu, as well as Torulaspora and Pichia in fermented grains by Hongxin Daqu, were significantly higher (P < 0.05). A total of 119 core operational taxonomic units (OTUs) were detected in the three groups of fermented grains, with an average cumulative sequence relative abundance of 92.67%, which were predominantly affiliated to Saccharomyces (67.43%), Kazachstania (9.40%) and Saccharomycopsis (7.78%). A total of 64, 93 and 46 pairs of strong correlations (correlation coefficient ≥ 0.7, P < 0.05) were found in fermented grains by Houhuo, Qingcha and Hongxin Daqu, respectively, by correlation analysis. Kruskal-Wallis test results demonstrated that inter-group Mahalanobis distance in fermented grains by Houhuo Daqu was significantly smaller than those in that by Qingcha Daqu and Hongxin Daqu (P < 0.05). LEfSe and random forest analyses revealed that Aspergillus and Pichia were characteristic fungal genus (linear discriminant analysis score > 3) and important fungal genus (mean decrease Gini index > 3) in fermented grains by Houhuo and Hongxin Daqu, respectively.

To investigate the synergistic effects of pepper varieties and broad bean fermentation processes on the aroma characteristics of broad bean paste, the broad bean paste samples were prepared with five pepper varieties, including Hongguan No.3 (HG3), Hongguan No.4 (HG4), Hongguan No.5 (HG5), Chuanteng No.6 (CT6) and Chuanteng No.10 (CT10), combined with broad beans processed by either shade-fermentation (Y) or sun-drying (S). The aroma profiles were evaluated by electronic nose (E-nose) coupled with multivariate statistical analysis, and the correlations between sensor responses and physicochemical indicators were further analyzed. The results indicated that the samples from different treatment combinations could be effectively distinguished by the E-nose array, among which the W1S and W5S sensors were identified as the core primary indicators responsible for differentiating the overall flavor variations. Hierarchical cluster analysis divided all samples into two major clusters, with a unique aroma profile exhibited by the HG3 samples. Correlation analysis demonstrated that a highly significant positive correlation network (P < 0.001) was formed among the contents of amino acids, lactic acid, total pectin and flavonoids, which was driven by alcohol dehydrogenase. Furthermore, significant positive correlations at varying levels were observed between the primary sensor cluster (W1S, W5S and W2S) and both the moisture content and capsaicin content of the samples, whereas a highly significant negative correlation was found with the aroma-sensitive sensors (W1C, W3C and W5C). Combined with physicochemical data, it was revealed that amino acids (44.57 mg/g) and reducing sugars (15.38%) were significantly enriched and their highly efficient aroma-forming conversions were accelerated by the CT6 + S group (moisture content of 55.16%), resulting in an overall performance far exceeding that of the CT6 + Y group. This combination, Chuanteng No.6 + sun-drying, simultaneously achieved extremely high precursor abundance and optimal conversion efficiency (reaching a peak W5S response of 5.80), was determined to be the optimal fermentation combination with the most outstanding aroma-producing potential in this system. In conclusion, the decisive role of raw materials and broad bean fermentation processes in the aroma formation of broad bean paste was confirmed.

Using different varieties of highland barley (black, blue, and white highland barley) as fermentation substrate, highland barley Monascus was prepared via solid-state fermentation with Monascus purpureus. The contents of γ-aminobutyric acid (GABA), eight nucleoside components (uracil, cytidine, hypoxanthine, adenine, inosine, guanosine, thymidine, and adenosine), and anthocyanins in the highland barley Monascus were determined and analyzed using high performance liquid chromatography. The differences in active ingredient contents among different highland barley Monascus samples were compared. The results showed that the GABA content in black highland barley Monascus ((116.13 ± 3.76) μg/g) was significantly higher than that in blue ((68.85 ± 3.68) μg/g) and white highland barley Monascus ((51.17 ± 1.89) μg/g) (P < 0.000 1). The contents of the eight nucleoside components also exhibited significant differences among the different highland barley Monascus samples (P < 0.01, P < 0.001, P < 0.000 1), with black highland barley Monascus showing enrichment advantages in multiple nucleoside components. No anthocyanins were detected in white highland barley Monascus, while the anthocyanin content in black highland barley Monascus ((81.05 ± 5.51) μg/g) was significantly higher than that in blue highland barley Monascus ((61.82 ± 4.81) μg/g) (P < 0.01). In conclusion, black highland barley is a high-quality raw material for producing Monascus rich in GABA, nucleosides, and anthocyanins, providing a reference for the selection of raw material varieties in highland barley Monascus production.

To examine the effect of adding Lactiplantibacillus plantarum LL6-1 on the quality of highland barley and Potentilla anserine L. Jiaosu, a composite Jiaosu fermentation agent (JSJ) was used as the control, while the combination of the JSJ and L. plantarum LL6-1 (JSJ + LP) served as the treatment. Changes in physicochemical properties, sensory, flavor, and antioxidant activity during fermentation were analyzed. The results showed that the addition of L. plantarum rapidly reduced the pH value of the fermentation system, resulting in higher levels of lactic acid and total organic acids, which reached 8 867.69 and 12 769.70 mg/L at the end of fermentation, respectively. It effectively preserved sourness, richness, and umami, while reducing bitterness, bitter aftertaste, and astringent aftertaste of the Jiaosu. The diversity of volatile flavor compounds was enriched (36), and three new compounds, isobutyraldehyde, 2-methylbutyraldehyde, and 2-nonanone, were generated. Antioxidant activity assays indicated that L. plantarum enhanced the in vitro antioxidant capacity of Jiaosu, with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging activities reaching 806.44 μg/mL and 3 824.10 U/mL, respectively. Furthermore, it reduced serum protein carbonyl and malondialdehyde (MDA) levels, and increased reduced glutathione (GSH) content and superoxide dismutase (SOD) activity in rats. The physicochemical indicators of the final Jiaosu product met the relevant standard requirements. Therefore, L. plantarum LL6-1 can improve the flavor quality and antioxidant activity of Jiaosu, demonstrating its potential as a functional starter culture.

To explore the distillation patterns of volatile components in raisin distilled spirits, the volatile flavor components in six distillation fractions of Thompson seedless raisins spirits, namely head distillate (T1), early core distillate (T2), middle core distillate (T3), late core distillate (T4), early tail distillate (T5) and final tail distillate (T6), were analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry. The results showed that a total of 104 volatile flavor components were identified across all fractions, consisting of 48 esters, 27 alcohols, 7 acids, 11 aldehydes and ketones, and 11 other compounds. Ester content peaked at 106 354.15 μg/L in the T1 fraction, then dropped sharply from T2 to T3, and declined to 706.85 μg/L in the tail cut. Alcoholic substance contents decreased steadily from 33 523.27 μg/L in T1 to 735.72 μg/L in T6. Acidic and aldehyde/ketone compound contents showed a continuous upward trend with a slight reduction in the tail. The different fractions were clustered into four categories by hierarchical cluster analysis (HCA): T1 (head), T2 (early core), T3 and T4 (middle-to-late core), and T5 and T6 (early-to-final tail). A total of 9 key aroma compounds were preliminarily identified in distillate, including ethyl octanoate, ethyl decanoate, isoamyl acetate, ethyl caproate, phenylethyl acetate, ethyl laurate, isoamyl alcohol, phenylethyl alcohol, and isovaleraldehyde, based on odor activity values with reference to typical aroma components of classic brandy. This study provided theoretical support for revealing the variation characteristics of distillates and optimizing spirit-cut process of Thompson seedless raisin spirits.

The microbial composition and dynamic changes of rice straw during high-temperature Daqu fermentation were systematically analyzed using high-throughput sequencing technology. Differential analysis, correlation analysis and gene function prediction were further conducted to elucidate the distinct microbial taxa and functional characteristics present in the straw. The results showed that significant differences were observed in the relative abundances of fungal and bacterial genera in straw samples collected from different fermentation stages. The α-diversity of the fungal community was found to gradually increase throughout the fermentation process, while a general decreasing trend was observed in the bacterial community. The dominant fungal genera were identified as Aspergillus (20.49%-60.13%) and Nigrospora (0.10%-45.94%), whereas the dominant bacterial genera were Saccharopolyspora (27.03%-64.30%) and Pantoea (0%-13.65%). Linear discriminant analysis effect size (LEfSe) analysis revealed significantly differential microbial taxa among the straw samples from different fermentation stages. Microascaceae and Ascomycota_fam_Incertae_sedis were identified as representative fungal taxa in straw, while Comamonadaceae, Beijerinckiaceae and Methylobacterium-Methylorubrum were characterized as representative bacterial taxa. Correlation analysis showed that the network connectivity of bacterial communities was higher than that of fungal communities, and there were certain correlations among microorganisms. Bacterial functional prediction analysis indicated that the metabolic pathways of cofactors and vitamins were significantly enriched at the late fermentation stage. This study revealed the succession patterns of microorganisms on rice straw during high-temperature Daqu fermentation, which provided a theoretical basis for microbial regulation and process optimization of high-temperature Daqu fermentation.

To elucidated the influence of bottom and wall pit muds on the quality for strong-flavor (Nongxiangxing) Baijiu, the physicochemical indicators and bacterial community structures of bottom and wall pit muds were determined by conventional detection methods and high-throughput sequencing technology. The volatile flavor compounds in the base liquor brewed from corresponding pit mud were determined by gas chromatography, followed by correlation analysis. The results showed that the pH (6.53) and ammonium nitrogen content (944.13 mg/kg) of bottom pit mud were significantly higher than those of wall pit mud (pH 5.98, ammonium nitrogen: 849.19 mg/kg) (P < 0.05). Conversely, the reducing sugar content of bottom pit mud (310.40 mg/kg) was significantly lower than that of wall pit mud (493.60 mg/kg) (P < 0.05). In bottom and wall pit muds, a total of three dominant bacterial phyla and 12 dominant bacterial genera (relative abundance > 1%) were detected. Among these, the dominant genera unique to bottom pit mud were Hydrogenispora and Caldicoprobacter, while the dominant genus unique to wall pit mud was Clostridium_sensu_stricto_12. A total of 199 volatile flavor substances were detected in the base liquor from bottom pit mud fermented grains, and the content of its main ester substances and flavor substances such as caproic acid is higher than that of the base liquor from wall pit mud fermented grains. Correlation analysis indicates that the bottom pit mud is significantly correlated with humus and available phosphorus (P < 0.05). The wall pit mud was significantly positively correlated with ammonium nitrogen (P < 0.05). The synthesis of Clostridium_sensu_stricto_12 and Caproiciproducens were closely associated with the synthesis of ethyl hexanoate, and higher fatty acid ethyl esters had the strongest correlation with available phosphorus. This study provided a theoretical reference for the maintenance of fermentation pits.

To further explore probiotics in koumiss, traditional koumiss collected from the Nanshan area of Xinjiang was taken as the research material. Enterococcus strains were isolated and screened therefrom, and their safety and biological characteristics were assessed. Based on 21 indicators, principal component analysis (PCA) and Z-score comprehensive scoring were applied for the comprehensive evaluation of probiotic properties of all tested strains. The results showed that a total of 10 lactic acid bacteria were successfully isolated and identified. Among them, a strain 7879 was identified as Enterococcus faecium, and the remaining strains were classified as Enterococcus lactis. Safety evaluation revealed that all 10 Enterococcus strains presented γ-hemolytic activity and were susceptible to the most commonly used clinical antibiotics. Biological characteristics revealed that the strains had consistent carbon source utilization profiles, stable growth and acid production patterns, and heat resistance at 40-50 ℃. Comprehensive evaluation results demonstrated that the strain 7876 obtained the optimal comprehensive score. Its cell surface hydrophobicity was 85.83%, and the autoaggregation rate reached 58.05% after 8 h of cultivation. The survival rates were 62.77% at 60 ℃ and 59.37% at pH 4.0, respectively. This strain exhibited excellent acid resistance and bile salt tolerance, and presented inhibitory effects against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumonia, with strong potential for intestinal colonization and in vitro antibacterial capacity. In conclusion, the screened Enterococcus strains had favorable safety and superior probiotic properties, which can provide high-quality candidate strain resources for the development of probiotic preparations.

By establishing a hyperglycemic mouse model with pancreatic islet injury and conducting continuous intervention for four weeks, the hypoglycemic mechanism and metabolic pathways of a compound vinegar oral liquid, formulated with Shanxi aged vinegar and Chinese herbs, were explored through routine physiological and biochemical indicators as well as untargeted metabolomics of small intestinal contents, and the ameliorative effect of this product on glucose and lipid metabolism disorders in diabetic mice was evaluated. The results indicated that the compound vinegar oral liquid could alleviate the trend of body weight loss and effectively reduce food and water intake in diabetic mice. Compared with the model group, the organ indices, fasting blood glucose (FBG) levels and glucose intolerance were significantly reduced (P < 0.05) by medium and high doses of the oral liquid, and the abnormal changes in four blood lipid indices caused by hyperglycemia were also alleviated. Furthermore, non-physiological alterations in liver antioxidant levels and inflammatory factors in diabetic mice were significantly ameliorated by the treatment. Untargeted metabolomics analysis of small intestinal contents revealed that, compared to the model group, the medium-dose group exhibited significant upregulation of anti-inflammatory and antioxidant metabolites, downregulation of diabetes-related metabolites such as ceramide NS, and substantial improvements in pathways such as the adenosine 5′-monophosphate-activated protein kinase and bile secretion signaling pathways. In conclusion, the hypoglycemic compound vinegar oral liquid was demonstrated to help maintain healthy blood glucose levels in diabetic mice. Its mechanism was suggested to be associated with anti-inflammatory and antioxidant effects, alleviation of insulin resistance and the amelioration of glucose and lipid metabolism disorders.

To investigate the formation patterns of methanol and higher alcohols in purple sweet potato wine (PSPW) during fermentation process, the four commercial Saccharomyces cerevisiae (AQ, EC1118, SY and RW) were selected to ferment purple sweet potato pulp for PSPW production. A simulated brewing system supplemented with glycine was established. The contents of methanol and higher alcohols were determined by gas chromatography, and the formation mechanism of methanol and higher alcohols during fermentation were further elucidated by analyzing pectin contents and the activities of related enzymes. The results showed that the ethanol contents in PSPW brewed by different S. cerevisiae ranged from 14.3% to 15.4%. The total higher alcohol contents ranged from 491.08 to 926.74 mg/L, while the methanol contents ranged from 526.69 to 574.27 mg/L. During the fermentation process of PSPW, the pectin contents continuously decreased, and the activities of pectinesterase showed a characteristic of first increasing and then decreasing. In the glycine-supplemented simulated brewing system, the four yeast strains were all capable of converting glycine into methanol, among which strain SY produced relatively lower levels of methanol from glycine. Overall, both pectin degradation and glycine metabolism contributed to methanol formation in PSPW fermentation process, with pectin degradation being the dominant pathway. The four yeast strains exhibited differences in methanol production through the two pathways. Strain SY exhibited low methanol production capacity via both metabolic pathways. Meanwhile, the PSPW fermented by strain SY achieved the highest ethanol and anthocyanin content, with a moderate total acid content and the lowest higher alcohols content, showing the optimal comprehensive fermentation performance.

To investigate the role of the adenylyl-sulfate kinase gene MET14 in the antifreeze mechanism of yeast and enhance yeast survival, the strains LKF-1-MET14 and LKF-1-ΔMET14 were constructed by overexpression and knockout of MET14 in Saccharomyces cerevisiae LKF-1, respectively. The effects of the MET14 gene on the freezing tolerance of S. cerevisiae were further investigated. Results showed that the survival rates of LKF-1 after frozen storage for 1, 3 and 7 days were 61.60%, 19.37% and 8.50%, while those of LKF-1-MET14 were 71.17%, 47.40% and 21.60%, respectively. After 3 days of frozen storage, the time to reach the stationary phase of LKF-1, LKF-1-MET14 and LKF-1-ΔMET14 was 15, 13 and 19 h, respectively. Scanning electron microscopy observation revealed that the cell surface of LKF-1-MET14 was smoother than that of LKF-1 after 7 days of frozen storage. Furthermore, the fluorescence intensities of LKF-1 and LKF-1-MET14 stained with propidium iodide were 4 006 and 2 538 after 7 days of frozen storage, respectively. Concurrently, the intracellular malondialdehyde (MDA) levels in LKF-1 and LKF-1-MET14 were 239.20 and 171.90 μmol/mg, respectively. These results indicate that MET14 overexpression can effectively enhance the cell membrane integrity and antioxidant capacity of S. cerevisiae, thereby improving its freezing tolerance.

To investigate the effects of seasonal variations on the bacterial community in Dacha (the first) fermented grains of light-flavor (Qingxiangxing) Baijiu, the bacterial community structure of samples collected in different seasons (autumn, winter and spring) was analyzed by high-throughput sequencing. Seasonal difference was revealed by principal component analysis (PCA), linear discriminant analysis effect size (LEfSe), co-occurrence network analysis and correlation analysis. The results showed that the bacterial richness of fermented grains was highest in autumn, while there was no significant difference among the fermented grains from the three seasons. A total of 11 dominant bacterial genera (relative abundance > 1%) were identified in all samples, dominated by Lactobacillus and Pediococcus. PCA revealed that the bacterial community structure of autumn fermented grains differed considerably from that of winter and spring samples in the early fermentation stages. LEfSe analysis indicated six differential genera, including Pseudomonas, in autumn fermented grains; Candidatus_Vestibaculum in winter fermented grains; and three differential genera, including Bacillus, Thermoactinomyces and Kroppenstedtia, in spring fermented grains. Co-occurrence network analysis indicated that bacteria in autumn fermented grains presented a high degree of separation, while those in winter samples showed a low separation degree and close interaction relationships. Correlation analysis revealed that Staphylococcus was negatively correlated with Lactobacillus but positively correlated with Leuconostoc across the three seasons.

To investigate the effects of traditional and mechanized Daqu-making methods on the quality of Lidu Daqu, the physicochemical properties, volatile flavor compounds, and microbial community structures of the two types of Daqu were systematically compared by physicochemical analysis, headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry, electronic nose, and high-throughput sequencing. The results showed that traditional Daqu exhibited higher saccharifying activity and fermenting activity, reaching 691 mg/(g·h) and 0.62 g/(0.5 g·72 h), respectively, whereas mechanized Daqu showed higher acidity and liquefying activity, reaching 1.3 mmol/10 g and 2.30 g/(g·h), respectively. In terms of volatile compounds, the contents of ethyl acetate (3.57 mg/kg) and tetramethylpyrazine (6.57 mg/kg) in traditional Daqu were significantly higher than those in mechanized Daqu (P < 0.05), contributing to its more pronounced fruity and roasted aromas. Microbial analysis revealed that traditional Daqu was dominated by Pichia (43.94%), Kroppenstedtia (38.09%), and Bacillus (18.51%), whereas mechanized Daqu was mainly dominated by Thermoascus (59.11%) and Weissella (34.78%). Correlation analysis indicated that Weissella was positively correlated with acidity and liquefying activity, while Bacillus and Pichia were positively correlated with the synthesis of esters and pyrazines (P < 0.05). In conclusion, the traditional Daqu-making process showed greater advantages in flavor complexity, whereas the mechanized process performed better in terms of standardization and production efficiency.

Saccharomyces cerevisiae W34/70 was cultured on malt yeast glucose peptone (MYGP) solid medium, and whole wort solid medium and auxiliary material wort medium commonly applied in modern breweries with yeast extract peptone dextrose medium set as the control. Phenotypes related to brewing properties were identified in accordance with analytical methods formulated by the American Society of Brewing Chemists. Combined with differentially expressed genes (DEGs) and Gene Ontology (GO) enrichment analysis based on transcriptomics, the effect and underlying mechanism of culture media on the phenotypes of S. cerevisiae W34/70 were explored. The results revealed that S. cerevisiae W34/70 presented optimal brewing-related phenotypes when cultivated on MYGP medium, with a mortality rate of 6.17%, respiratory-deficient strain proportion of 1.34%, fermentation degree of 69.59%, acetaldehyde content of 9.02 mg/L, total ester content of 14.47 mg/L, total higher alcohol concentration of 81.00 mg/L, alcohol-to-ester ratio of 5.67 and lag time of 69.1 min in fermentation broth. Transcriptomic analysis identified a total of 3 738 DEGs, among which 1 603 were upregulated and 2 135 were downregulated. Furthermore, GO enrichment analysis revealed that the DEGs were predominantly enriched in protein refolding within the biological process category, cytoplasmic ribosome in the cellular component category, and oxidoreductase activity in the molecular function category.

To investigate the changes in antioxidant activity of chrysanthemums before and after fermentation, using fresh yellow chrysanthemum (Chrysanthemum morifolium) as the raw material, the fermentation process of yellow chrysanthemum liquid was optimized by single-factor and response surface tests. The differential metabolites between fermented and unfermented yellow chrysanthemum liquids were qualitatively and quantitatively analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that the total antioxidant capacity (T-AOC) of the fermented yellow chrysanthemum liquid was optimal at 82.363 U/mL under optimized conditions with a 1:1 ratio of Lactobacillus acidophilus and Lactobacillus bulgaricus at 2% addition, fermentation temperature of 38 ℃, fermentation time of 9 h, and glucose addition of 18%. After the fermentation, T-AOC increased by approximately 14.6%, indicating that fermentation enhanced the antioxidant capacity of yellow chrysanthemum liquid. Further verification through 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities confirmed that fermentation could indeed enhance the antioxidant activity of yellow chrysanthemum liquid. UPLC-MS/MS analysis revealed that a total of 484 differential metabolites were identified between fermented and unfermented chrysanthemum liquids, including 274 upregulated and 210 downregulated compounds. The increased contents of phenolic acids and flavonoids were the main contributors to the improved antioxidant activity, with caffeoyl-p-coumaroyltartaric acid showing the highest up-regulation after fermentation. This study provided a theoretical basis for the development of health products, functional foods, and fermented beverages based on yellow chrysanthemum.

Dendrobium devonianum Paxt. blended liquor was prepared via ultrasonic-assisted technology with D. devonianum Paxt. as raw material and corn spirits as base liquor. A comprehensive evaluation was conducted by fuzzy mathematical sensory evaluation method and entropy weight method, and preparation parameters were optimized by single-factor experiments and response surface methodology. Volatile flavor components were quantified by gas chromatography-mass spectrometry (GC-MS). The results revealed that the optimal ultrasonic treatment time, solid-liquid ratio, and ethanol volume fraction were 60 min, 12:100 (g/mL), and 52%, respectively. Under the optimized conditions, the comprehensive evaluation score was 0.89, and the sensory score was 82.08. The contents of polysaccharides, polyphenols, and triterpenoids were 18.04 mg/g, 11.72 mg/L, and 4.001 mg/kg, respectively. The ethanol volume fraction, methanol content, and total acid content were 50.4%, 0.43 g/L, and 1.5 g/L, which conformed to the specifications of relevant national standards. A total of 14 volatile flavor constituents were detected in the blended liquor by GC-MS, consisting of 5 alcohols, 3 esters, 3 aldehydes, and 3 other substances, with relative contents of 93.056%, 2.583%, 2.518%, and 1.843%, respectively. This study provided technical support for the development of D. devonianum Paxt. blended liquor.

To achieve the efficient utilization of wild kiwifruit peel and residue resources and develop new fermented fruit wine products, wild kiwifruit (with peel) and kombucha fermentation broth were selected as the raw materials. The fermentation process of compound fruit wine from whole kiwifruit and kombucha broth was optimized by a single-factor experiment combined with response surface methodology, with ethanol content and sensory score as evaluation indicators. Additionally, volatile components in the finished product were analyzed by gas chromatography-mass spectrometry. The results showed that the optimal fermentation conditions were as follows: initial sugar content of 219 g/L, yeast addition amount of 0.05%, fermentation temperature of 28.5 ℃, and fermentation duration of 6 days. Under the condition, the compound fruit wine had an ethanol content of 8.69% and a sensory score of 88.70. The contents of total acid, total sugar, and soluble solids were 7.15 g/L, 5.22 g/L, and 7.60%, respectively, with 1,1-diphenyl-2-picrylhydrazyl radical scavenging rate of 93.6%. A total of 22 volatile components were identified in the compound fruit wine, among which alcohols accounted for 86.09%, and phenethyl alcohol, with a relative content of 10.73%, was capable of endowing the product with a rose fragrance. Compared with the compound wine fermented by peeled wild kiwifruit, the relative content of esters was elevated from 2.70% to 4.35%, and typical characteristic esters, including ethyl octanoate and ethyl hexanoate, were significantly accumulated. This study provided a theoretical basis and technical support for the deep processing of whole wild kiwifruit (with peel) and the industrialization of kombucha fermented products.

Fermentation medium was prepared based on Huangjiangshui, and fermentation conditions for γ-aminobutyric acid (GABA) production by Lactiplantibacillus plantarum JY7 were optimized using a single-factor test and response surface methodology. The results showed that the optimal fermentation conditions were inoculum dosage 5%, initial pH 7 and fermentation duration 4 days. Under these conditions, the GABA yield reached 556.60 mg/L, which was 2.78 times that before optimization. During the fermentation, the content of glycosidic soybean isoflavones decreased significantly (P < 0.05). By contrast, the contents of GABA, total polyphenols, total flavonoids and aglycone soybean isoflavones increased remarkably (P < 0.05). The scavenging capacities against 1,1-diphenyl-2-picrylhydrazyl radicals, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radicals and hydroxyl radicals were also obviously enhanced (P < 0.05). Pearson correlation analysis revealed that total polyphenols, total flavonoids and aglycone soybean isoflavones were significantly positively correlated with antioxidant activity, while glycosidic soybean isoflavones showed a significant negative correlation (P < 0.01, P < 0.001). In conclusion, fermentation by L. plantarum JY7 effectively accumulates GABA and synergistically elevates multiple functionally active ingredients.

The effects of grain to distillers' grains ratio, rice husk addition and water addition on starch gelatinization degree, moisture content, acidity and starch retrogradation characteristics of pit-loading fermented grains were investigated. Ingredient proportion parameters were optimized via single-factor and response surface methodologies. The results indicated that the influencing order of factors on gelatinization effect was rice husk addition > water addition > grain-to-distillers' grains ratio. The optimal parameters were determined as a grain-to-distillers' grains ratio of 1:4, rice husk addition of 25.7% and water addition of 62.5%. Under the condition, starch gelatinization degree significantly increased to (69.28 ± 1.06)% (P < 0.01), the liquor yield increased remarkably to (22.49 ± 1.18)% (P < 0.05), and key flavor indicators such as total acid and total ester were slightly enhanced, with the base liquor quality meeting the standards for strong-flavor Baijiu. This study provided engineering references for parameter standardization, quality improvement and efficiency promotion in cooking and gelatinization procedures of strong-flavor Baijiu production.

Sorghum serves as the primary raw material for Baijiu brewing, and its physicochemical property directly influences brewing performance and base liquor flavor. In this study, four sorghum varieties (G1, G2, G3, G4) with distinct traits obtained from directional breeding of ‘Hongyingzi' sorghum, were used as raw materials. After the seven-round fermentation, their brewing characteristics and base liquor flavor differences were systematically analyzed. The results indicated that sorghums G1 and G4 had high amylopectin proportion (100.0%, 94.5%), and their water absorption rates (44.2%, 44.2%) and swelling rates (50.1%, 51.7%) were significantly higher than those of sorghums G2 and G3 (water absorption rates: 33.8%, 33.4%; swelling rates: 44.8%, 44.8%) (P < 0.05), resulting in more complete gelatinization. During the fermentation, the fermented grains of sorghums G2 and G3 exhibited low moisture content and delayed starch utilization, leading to poor fermentation performance. Their ethanol content (8.8%, 9.2%) was lower than that of sorghum G1 and G4 (11.8%, 12.0%), and their base liquor yields (45.6%, 42.9%) were significantly lower than those of sorghum G1 and G4 (55.4%, 55.3%). The total ester content of base liquor from seven fermentation rounds brewed with sorghum G4 (38.8 g/L) was higher than that of other three varieties (33.6, 34.5 and 35.2 g/L for G1, G2 and G3, respectively). The alcohol contents of sorghums G1 and G4 (54.1, 42.9 g/L) were significantly lower than those of sorghums G2 and G3 (137.9, 112.2 g/L) (P < 0.05), and sorghums G2 and G3 also showed higher total acid content (18.7, 18.1 g/L), contributing to a relatively sour and astringent taste. In conclusion, sorghums G1 and G4 demonstrated superior performance in ethanol yield and flavor balance, making them more suitable as raw materials for high-quality sauce-flavor (Jiangxiangxing) Baijiu.

Terpenoid-producing strains were isolated and screened from orange orchard soil. The obtained strains were subjected to morphological observation and molecular biological identification. The flavor-producing capacity, growth characteristics and safety profile of the screened strain were investigated. Tobacco flavor was prepared by fermentation with the screened strains, and the changes in aroma components were analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry. The results showed that one terpene-producing strain, JT-14, was isolated and screened, which was identified as Bacillus velezensis. The strain JT-14 could effectively convert α-pinene, β-myrcene and limonene into aroma components including α-terpineol, 4-terpineol, borneol, fenchol, (-)-trans-pinocarveol, carveol, citronellol and perillyl alcohol. The strain JT-14 showed no hemolytic activity and was susceptible to common antibiotics, indicating high biosafety. The tobacco flavor prepared by fermentation with strain JT-14 was rich in terpenoid aroma components and a variety of other characteristic aroma substances, which could increase the total content of aroma components.

A method for the simultaneous determination of 23 sulfur-containing compounds in light-flavor Baijiu was established by direct injection coupled with gas chromatography-mass spectrometry (GC-MS), and this method was further adopted for the analysis of key sulfur-containing compounds in sauce-, light-, strong-, and sesame-flavor Baijiu. The results demonstrated that satisfactory linear relationships for all 23 sulfur-containing compounds were achieved within the concentration range of 0.05-10 mg/L, with all determination coefficients higher than 0.990. The limits of detection (LODs) ranged from 0.004 to 0.021 mg/L, and the limits of quantification (LOQs) were in the range of 0.013-0.070 mg/L, while all relative standard deviations were no more than 5.97%. A total of 17 sulfur-containing compounds were detected in the four types of Baijiu, among which 14, 13, 11, and 11 compounds were separately identified in light-, strong-, sauce-, and sesame-flavor Baijiu, and seven sulfur-containing compounds were commonly present in all tested Baijiu samples. Methyl methylthioacetate and furfuryl mercaptan were only detected in light-flavor Baijiu, and allyl methyl disulfide was exclusively found in sesame-flavor Baijiu. Relatively high contents of 2-methoxythiazole and ethyl 2-thiophenecarboxylate were determined in sauce-flavor Baijiu; methyl thiobutanoate and ethyl 2-mercaptopropionate were abundant in strong-flavor Baijiu; furfuryl mercaptan and difurfuryl disulfide showed high levels in light-flavor Baijiu; allyl methyl disulfide and diethyl disulfide were predominant in sesame-flavor Baijiu. 2-Pentylthiophene, methyl(2-methyl-3-furyl)disulfide, and methyl furfuryl disulfide were confirmed as the key common sulfur-containing compounds in the four flavor types of Baijiu, and methyl(2-methyl-3-furyl)disulfide exhibited the highest aroma contribution. This study clarified the content profiles of sulfur-containing compounds in different flavor types of Baijiu and provided guidance for quality improvement and the development of characteristic aroma types.

Taking Dacha and Ercha original liquors of light-flavor (Qingxiangxing) Baijiu as research materials, a genetic algorithm-back propagation neural network (GA-BP) classification model for fraction grading and a partial least squares (PLS) regression model for volatile flavor substance content were established based on gas chromatography, near-infrared spectroscopy and machine learning algorithms. The results showed that orthogonal partial least squares-discriminant analysis could effectively distinguish the characteristics of volatile flavor compounds in the fractionation, and the Dacha and the Ercha original liquors were classified into three grades. Fourteen volatile flavor compounds contributing greatly to grade discrimination were screened out from each liquor type with variable importance in projection value > 1 and P < 0.05, including ethyl linoleate, ethyl oleate and ethyl palmitate. The GA-BP classification model achieved outstanding grading performance with an accuracy of 96.30% in the test set. Shapley additive explanation (SHAP) analysis revealed that wavenumbers of 11 958, 11 954, 5 917, 5 909, 5 311, 4 428, 4 424, 4 420, 4 293 and 4 289 cm^-1 presented high SHAP contribution values, which were identified as key spectral points for predicting the fraction grade. The PLS regression model exhibited favorable predictive performance for the content of volatile flavor substances such as furfural, butyric acid, isobutyric acid, ethyl formate, isoamyl acetate and acetone. All determination coefficients of cross-validation exceeded 0.90, and the root mean square errors of cross-validation were less than 1. The proposed grading method, GA-BP classification model and PLS regression model can provide theoretical support for rapid online grading of original liquor.

To explore the influence mechanism of the perceived value of Chinese Baijiu culture on customers' purchasing decisions, this paper adopts the stimulus-organism-response (SOR) theory as the analytical framework, constructs a theoretical model with brand identification as the mediating variable, systematically explains its mechanism of action, and then conducts empirical verification through hierarchical regression analysis and mediation effect testing. The results indicate that the perceived value of Chinese Baijiu culture (including six dimensions: communicative needs, psychology of reputation, historical accumulation, culture of poetry and Baijiu, regional customs and national customs) has a significant positive effect on purchase decisions; brand identification has a significant positive impact on purchase decisions and plays a partial mediating role between cultural perceived value and purchase decisions. Therefore, it is suggested that marketing strategies should be formulated from three aspects: systematic dissemination of cultural perceived value, strategic reinforcement of brand identification, and focused breakthroughs in high-impact dimensions, in order to facilitate the purchase decision. The findings provide a theoretical foundation for translating Chinese Baijiu cultural value and offer strategic insights for cultural marketing in the Baijiu industry.

Against the backdrop of prominent consumption upgrading and growing personalized consumption demands, customized services for sauce-flavor (Jiangxiangxing) Baijiu have evolved into a vital development orientation for the transformation and upgrading of the Baijiu industry. Centering on the sauce-flavor Baijiu industry in Guizhou Province, this paper explored the application scenarios and developmental paths of customized services on the basis of an in-depth analysis of the current industrial development status as well as the characteristics of consumer demands and market segmentation. The core innovation of this study lies in the establishment of a customer hierarchical model, which can precisely identify the differentiated demands of high-net-worth groups, corporate clients, and young consumer groups. On this foundation, a strategy integrating a flexible supply chain and lightweight customization is proposed, which enables efficient customized production via flexible supply chain management so as to satisfy the personalized demands of diverse customer groups; meanwhile, diversified approaches including immersive experience engagement, data-driven communication, cultural intellectual property empowerment, technical barrier establishment, segmented operation, and social circle ecosystem construction are adopted to achieve all-around market expansion. It is believed that customized services can not only accommodate the diversified and personalized demands of consumers but also create new profit growth points and brand development paths for Baijiu enterprises. This research is intended to provide a theoretical basis and practical reference for the strategic transformation of the Guizhou sauce-flavor Baijiu industry from product-oriented sales to lifestyle-oriented output, facilitate the sustainable development of the industry, and further consolidate the regional features and market competitiveness of Guizhou sauce-flavor Baijiu.

Alcoholic drinks enterprise industrial heritage serves as the core carrier of Qilu culture, and its digital-intelligent activation is a key driver for cultural inheritance and consumption upgrading. Taking 10 typical industrial heritages of alcoholic drinks enterprises in Shandong Province as cases, this paper systematically explored the core paths of digital-intelligent activation driving consumption upgrading by adopting the fuzzy-set qualitative comparative analysis method based on configuration theory, experience economy theory, and cultural identity theory. The results showed that a single element cannot independently drive consumption upgrading, and the realization of consumption upgrading relies on the collaborative promotion of multiple factors. Three core equivalent paths for consumption upgrading are identified, namely the in-depth digital-intelligent immersion type, heritage-digital intelligence integration type, and operation-digital intelligence empowerment type. These research conclusions can provide theoretical support and practical guidance for the digital-intelligent transformation and consumption potential release of industrial heritage of alcoholic drinks enterprises in the Qilu cultural region and similar regions.

‘Aged Baijiu tastes better' has been widely recognized by consumers. ‘Drinking fresh Baijiu, aging good Baijiu, and storing aged Baijiu' has gradually prevailed in the current Baijiu market. As the origin and core producing area of sauce-flavor (Jiangxiangxing) Baijiu, Guizhou features the brewing technology of Guizhou-style sauce-flavor Baijiu represented by Kweichow Moutai, which inherently possesses the technological attribute of long-term storage and aging, serving as a typical embodiment of the consumption philosophy that ‘aged Baijiu tastes more aromatic'. This paper systematically sorted out the industrial advantages of developing bottle-aged sauce-flavor Baijiu in Guizhou from the dimensions of brewing resources, production technology, historical heritage, and market foundation; constructed the value system of aged Baijiu from the three perspectives of brand, time, and producing region; and proposed the expression paths of aged Baijiu value including strengthening scientific research, consolidating quality advantages, building authoritative platforms, optimizing the consumption system, innovating business models, and reinforcing factor guarantees. This paper can enrich the systematic value expression of bottle-aged sauce-flavor Baijiu in Guizhou and is of great significance for clarifying the industrial chain positioning and national market layout of Guizhou sauce-flavor Baijiu, accurately interpreting its value and connotation in satisfying people's needs for a better life, as well as consolidating and enhancing its competitiveness and influence in domestic and overseas markets.