As a traditional Chinese distilled spirit, Baijiu has attracted wide spread attention for its unique flavor and complex aroma components. As consumers' demand for Baijiu quality increases, in-depth research on Baijiu flavor has become more and more important. As a systematic and standardized tool, the flavor wheel can effectively describe and evaluate the flavor characteristics of Baijiu, which is important for improving the quality of Baijiu. In this paper, the development of Baijiu sensory evaluation methods and their sensory descriptive analysis tools were summarized, and the construction of the flavor wheel and the preparation of standard reference samples were focused on and discussed. The construction paradigms of flavor wheels for different flavor types of Baijiu in the past ten years were reviewed, the differences in their construction methods were discussed in depth, and the concept of an overall flavor wheel for Baijiu across flavor types was proposed. In addition, in view of the difficulty in standardizing the aroma intensity of Baijiu reference samples in the existing studies, the development of a unified Baijiu flavor wheel and the establishment of a sensory dictionary of Baijiu suitable for the general public were envisioned in the future, aiming to provide a scientific tool for the design of Baijiu styles and the development of products.

Baijiu, as an alcoholic beverage with regional characteristics, is made from grains and fermented by a variety of microorganisms. With its unique color, aroma and taste, it is loved by people. Physicochemical indicators and sensory indicators are the key points for the quality inspection of Baijiu. Therefore, the advantages and disadvantages of traditional and innovative technologies from the two aspects of physicochemical indicators and sensory indicators were compared, and the current situation and development of the quality inspection technology of Baijiu were reviewed, aiming to provide a scientific reference for the standard quality analysis of Baijiu. However, due to its complex production process and long production cycle, Baijiu is prone to introducing impurities during production, which can lead to various quality and safety issues. Therefore, the quality inspection and evaluation of Baijiu is one of the important measures to prevent the quality and safety problems of Baijiu and ensure people's health and safety. From the perspective of the Baijiu production process, the endogenous and exogenous risks of Baijiu safety were clarified, and its detection techniques were mainly reviewed. At the same time, the relevant regulations on Baijiu quality of national standards and countermeasures were also involved, aiming to provide reference and inspiration for the detection of risk components by Baijiu enterprises. Finally, it was pointed out that technological innovation and advanced equipment play a decisive role in the Baijiu analysis, which was of great significance for promoting the high-quality development of the Baijiu industry.

Aroma is one of the important sensory qualities of fruit wine. Compared with single fermentation of Saccharomyces cerevisiae, non-Saccharomyces cerevisiae can produce more aroma components, which has a positive effect on improving the aroma quality of fruit wine. In this paper, the main aroma components, classification of non-Saccharomyces cerevisiae and common aroma-producing yeasts in fruit wine were summarized. Based on the interaction between non-S. cerevisiae and S. cerevisiae, the application of different mixed fermentation methods on improving the aroma components of fruit wine was systematically summarized, in order to provide reference for the subsequent aroma improvement of fruit wine and the development of fruit wine industry.

As a class of bioactive components with health benefits, anthocyanins play an important role in the color, taste characteristics and stability of fermented wine. In this paper, the composition and characteristics of anthocyanins in common anthocyanin-rich brewing raw materials were summarized. The principles of anthocyanin dissolution, transformation, and degradation during the brewing stage of fermented wine, as well as the principles of thermal degradation, oxidation, and cleavage of anthocyanins in fermented wine during the aging period were explored. To enhance the stability of anthocyanins in fermented wine, three effective measures were proposed, including co-pigmentation, covalent and non-covalent interactions, and non-thermal processing methods such as pulsed electric field, ultrasound, and ultra-high pressure. This research provided a reference for improving the retention and stability of anthocyanins in fermented wine.

Red sour soup is a unique fermented food in Guizhou region. It is highly favored by consumers due to its distinctive taste and abundant nutrients, and it is one of the key characteristic ecological food industries developed in Guizhou province. In this paper, the main fermentation strains of red sour soup in recent years, including the formation of organic acids, volatile flavor compounds, and taste during the fermentation process were summarized and analyzed, the improvement of the quality of red sour soup was discussed from four aspects: fermentation strains, raw material varieties, sterilization methods, and exogenous additives, the possible limitations of current research methods were analyzed, in order to provide theoretical references for further research on the fermentation quality of red sour soup.

The microbial flora structure of Hongqu, Jiuqu and Hongqu rice wine during fermentation process was analyzed by high-throughput sequencing technology. The physicochemical indexes and volatile flavor components of Hongqu rice wine during fermentation process were analyzed by conventional physiochemical detection and solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS) technology. The key volatile flavor components (OAV≥1) were screened in combination with the odor activity value (OAV), and the correlation between microbial flora and volatile flavor components was analyzed. The results showed that the dominant fungal and bacterial genera (relative abundance>1%) in Hongqu and Jiuqu were 6 and 8, respectively. During Hongqu rice wine fermentation process, there were 9 dominant fungal and 8 dominant bacterial genera, mainly including Rhizopus, Saccharomyces and Lactobacillus, etc. During Hongqu rice wine fermentation process, the total sugar contents decreased from 85.17 g/L to 1.97 g/L, the total acid contents and alcohol content increased from 5.42 g/L and 6.17%vol to 11.30 g/L and 16.77%vol, respectively. A total of 17 volatile flavor components were detected, based on OAV≥1, 9 key volatile flavor components were screened out. The results of correlation analysis indicated that the n-propanol, isobutanol, active amyl alcohol and isopentanol were significantly negatively correlated with Alternaria (P<0.05), and extremely significantly negatively correlated with Leuconostoc (P<0.01).

This study took the 1st-7th rounds of sauce-flavor (Jiangxiangxing) base liquor in Renhuai Famous Liquor Industrial Park as the research object, the physiochemical indicators, volatile flavor components were determined, and sensory evaluation were conducted. Combined with orthogonal partial least squares discriminant analysis (OPLS-DA) and correlation analysis, the flavor characteristics of different rounds of base liquor were examined. The analysis of physiochemical indicators showed that with the increase of the rounds, the alcohol content and total acid content in the base liquor generally showed a downward trend, and the total ester content showed a trend of increasing first and then decreasing. The analysis results of volatile flavor components showed that the odor activity values (OAV) of eight substances such as acetaldehyde, furfural and ethyl butyrate in the framework components of different rounds of base liquor were greater than 10, which played an important role in the aroma characteristics. The framework components of the base liquor from the 2nd to the 5th round were similar, and those from the 6th and 7th rounds were also similar, but they all different significantly from those of the base liquor from the 1st round. Further, based on the variable importance projection (VIP) value>1, 14 differential aroma substances such as isobutanol, ethyl acetate, and ethyl octoate were screened out. The sensory evaluation results showed that the base liquor of the 1st and the 2nd rounds had a prominent raw sand aroma in style. The liquor in the 3rd to 5th rounds highlighted the sauce aroma, richness, cleanliness and aftertaste. The burnt aroma and bitterness in the wine body increased significantly in the 6th and the 7th rounds. The results of the correlation analysis indicated that there was a certain correlation between the skeletal components of the base liquor and its sensory attributes.

In this study, endophytic fungi which could improve the antioxidant capacity of green tea were isolated from fresh Huangjingui tea leaves by coating separation method, and their strains were identified by morphological observation and molecular biology techniques, and their effects on functional components and biological activities of green tea fermentation products were investigated. The results showed that a strain of endophytic fungus capable of enhancing the antioxidant capacity of green tea was isolated and screened, and was numbered T12. It was identified that strain T12 was Debaryomyces hansenii. After green tea was fermented by the strain T12, the pH decreased to 4.37. The contents of polyphenols, total flavonoids and total catechins increased by 34.01%, 25.13% and 63.60%, respectively. The content of free amino acids decreased by 35.52%, and the content of ester catechins decreased extremely significantly (P<0.01). However, the contents of non-ester catechins and gallic acid increased extremely significantly (P<0.01). The scavenging capabilities of both DPPH radicals and hydroxyl radicals increased, and the antioxidant capacity was enhanced. It significantly promoted the proliferation activity of human immortalized keratinocytes (HaCaT), enhanced the protective effect against HaCaT cell injury induced by ultraviolet B (UVB) radiation, and reduced the generation of intracellular reactive oxygen species (ROS). In conclusion, the strain T12 had a significant impact on the functional components and biological activities of green tea, providing a new approach for the inoculation and fermentation of green tea.

In this study, the ethyl 2-hydroxy-3-methylbutyrate (E2H3MB) in Baijiu was analyzed by liquid-liquid extraction (LLE) combined with gas chromatography (GC) and Chiral gas chromatography-mass spectrometry (Chiral-GC-MS), the gas chromatography analysis conditions were optimized, and the enantiomeric distribution of E2H3MB in 12 flavor types Baijiu was investigated. The olfactory threshold and sensory characteristics of the E2H3MB enantiomer in water and volume fraction 46% ethanol solution were evaluated by three-alternative forced-choice (3-AFC) threshold determination method. The results showed that the CYCLOSIL-B chromatography column (30 m×0.25 mm×0.25 μm) had a good separation effect on E2H3MB. When the heating rate was 1.5 ℃/min and the carrier gas flow rate was 1.0 ml/min, the separation of E2H3MB enantiomer was the optimal, and the separation degree (R)=5.0>1.5. Except for rice-flavor, light-flavor (Qingxiangxing) and Chi-flavor Baijiu, only (R)-configuration E2H3MB ((R)- E2H3MB) was detected in other types of Baijiu, and there were significant differences in the (R)-E2H3MB contents in the same type of Baijiu (P<0.05). The results of sensory characteristics results indicated that in water and volume fraction 46% ethanol solution, the olfactory threshold of (R)-E2H3MB was approximately 2.1 times that of (S)-configuration E2H3MB ((S)-E2H3MB) ((R)-configuration 38 μg/L); (S)-configuration 18 μg/L, and about 1.9 times ((R)-configuration 322 mg/L; (S)-configuration 173 mg/L), both configurations exhibited pleasant sweet and fruity aromas. The research results were conducive to the refinement of Baijiu flavor wheel, providing a reference basis for studying the distribution of enantiomers of chiral flavor substances in Baijiu and enriching people's understanding of chiral flavor substances in Baijiu.

In order to analyze the difference in volatile flavor components of base liquor of the first to the seventh rounds of sauce-flavor (Jiangxiangxing) Baijiu from different producing areas of Guizhou (numbered as CS, XS, MT, YQ, XY, respectively), taking the base liquor of the first to the seventh rounds of sauce-flavor Baijiu from 5 different production areas in Guizhou as the research objects, the volatile flavor components of liquor samples from different production areas were qualitatively and quantitatively analyzed by GC. The key flavor substances were screened based on the odor activity value (OAV). The model was constructed by principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). The different flavor components were screened by variable projection importance (VIP) value, and cluster analysis (CA) was conducted. The results showed that the 56 volatile flavor components were identified in the base liquor of the first to the seventh rounds of sauce-flavor Baijiu from different producing areas of Guizhou, including 20 esters, 11 alcohols, 9 acids, 8 aldehydes and ketones, 2 pyrazines, 2 furans and 4 aromatics. A total of 43 key flavor components were screened (OAV>1). PCA and PLS-DA could effectively distinguish the base liquor of the first to the seventh rounds of sauce-flavor Baijiu from 5 production areas, and a total of 21 different flavor components were identified by VIP values (VIP>1). The CA results indicated that the aggregation degrees of CS and XS, MT and YQ were relatively high, XY was grouped independently.

In order to study the brewing characteristics of Hanseniaspora uvarum and determine its mixed fermentation inoculation process with Saccharomyces cerevisiae, the activities of glycosidase, esterase and pectase of H. uvarum were evaluated, and 'Cabernet Sauvignon' dry red wine was prepared with mixed fermentation by simultaneous inoculation of H. uvarum and S. cerevisiae (group TS-1-1) and sequential inoculation at 3 d intervals (group SX-G-N, group SX-N-G). With S. cerevisiae fermentation as the control (CK), the growth changes of yeasts, physicochemical indicators, volatile flavor components and sensory qualities of wine during the fermentation process were analyzed. The results showed that, compared with S. cerevisiae, H. uvarum had higher activities of β-D-glucosidase, β-D-xylosidase and pectinase. The growth of H. uvarum in the later stage of fermentation was significantly inhibited during simultaneous inoculation, and the viable bacterial count remained at 10⁶-10⁷ CFU/ml during sequential inoculation. Compared with the control group, the ethanol content of all wines fermented by mixed strains decreased by 0.16%vol-0.80%vol, and the anthocyanin content increased by 14.46-94.55 mg/L. The reducing sugar content and alcohol content of dry red wine with simultaneous inoculation could meet the requirements of dry red wine. The anthocyanin content was 207.01 mg/L, and the sensory score was the highest (86.89) in SX-G-N group. The total aroma substances contents were the highest, increasing by 15.56% compared with the CK group. The characteristic aroma substances were well distinguished from the CK group, mainly consisting of ethyl octoate, methyl methylene and ethyl laurate, etc. Therefore, the pre-inoculated H. uvarum mixed-strains fermentation scheme could be applied to brew 'Cabernet Sauvignon' dry red wine to improve the quality.

In order to improve the efficiency of hydrogen production from cellulose by fermentation, using microcrystalline cellulose as the limiting substrate, and cow manure compost as the bacterial source, the thermophilic hydrogen-producing flora that could efficiently degrade cellulose were obtained after enrichment and domestication, and the bacterial flora structure of the domesticated flora was analyzed by high-throughput sequencing technology. On the basis of single factor tests, the fermentation process was optimized by response surface tests. The results showed that the thermophilic hydrogen-producing bacteria, which could efficiently degrade cellulose to produce hydrogen, were obtained after 30 rounds of enrichment and domestication. The structure and quantity of the flora changed significantly before and after domestication. The main bacterial phyla were Firmicutes, Proteobacteria and Bacteroidetes, and the main bacterial genera were Clostridium, Anaerofilum and Pseudomonas. The growth synergy among cellulose-degrading bacteria, hydrogen-producing bacteria by fermentation and degrading cellulose was formed in the fermentation system, which effectively improved cellulose degradation and hydrogen production. The optimal fermentation process for hydrogen production from microcrystalline cellulose fermented by domesticated flora was ammonium bicarbonate mass concentration 2.5 g/L, potassium dihydrogen phosphate mass concentration 1.8 g/L, and nutrient solution addition 8.2 ml/L. Under these optimal conditions, the maximum hydrogen production reached (267.50±0.50) ml/g.

In order to analyze the key aroma substances of Zaolajiao, the volatile flavor substances of Zaolajiao at different fermentation time (0, 15 d, 45 d, 90 d and 180 d) were detected and analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME- GC-MS), and the characteristic flavor substances were analyzed by combining with the odor activity value (OAV) and principal component analysis (PCA). The results showed that 166 volatile flavor substances were detected in Zaolajiao samples fermented for 0, 15 d, 45 d, 90 d and 180 d, including 20 alcohols, 36 esters, 36 olefins, 9 alkanes, 7 ketones, 16 acids, 7 aldehydes, 11 aromatic compounds, 18 sulfur-atom-containing compounds, and 6 others. The common volatile flavor substances in the five fermentation stages were β-elemene, methyl salicylate, phenylethanol, hexadecanoic acid and 2-methyltridecane, with 14, 27, 8, 4 and 17 unique volatile flavor substances, respectively. According to the screening conditions of OAV≥1 and present in more than three fermentation stages, there were 23 key volatile flavor substances including 2-heptanol, geraniol, trans-nerolidol, α-pinitol, phenylethanol, linalool, etc. The PCA results showed that sample ZLJ90d had the optimal aroma quality.

To investigate the potential of Latilactobacillus sakei L and Mammaliicoccus vitulinus AP2 as mixed starter cultures for sausage, the sausage was fermented by L. sakei L (L group) and L. sakei L mixed with M. vitulinus AP2 (1∶1, V/V) (L+AP2 group), respectively. Using naturally fermented sausage as blank control (CK), the effects of mixed starter cultures fermentation on the quality of sausage were explored by determining the microbial and physicochemical indexes, texture, color parameters, free amino acid content of the fermented sausage, and sensory evaluation. The results showed that the pH value (5.37-5.91), moisture (3.70%-4.30%), cooking loss rate (0.30%-0.37%) and nitrite content (5.58-5.75 mg/kg) of sausage in inoculation group were all significantly lower than those of sausage in CK group (P<0.05), but the number of lactic acid bacteria (7.00-7.49 lg(CFU/g)), hardness (283.46-323.88 N), chewiness (281.70-318.00 mj) and b* value (7.48-9.64) were all significantly higher than those of sausage in CK group (P<0.05). The pH value (5.91), a* value (9.61), C value (13.48) and free amino acid content (85.72 mg/kg) of sausage in L+AP2 group were all significantly higher than those of sausage in L group (P<0.05). In summary, the combined inoculation of L. sakei L and M. vitulinus AP2 (1∶1) could significantly improve the quality indicators of fermented sausage and enhance the flavor and taste of sausage.

In this study, soymilk was fermented using Bacillus coagulans (BC), Lactobacillus royale (LRL), Lactobacillus rhamnosus (LRS) and Lactiplantibacillus plantarum (LP), the physicochemical properties, volatile flavor substances and color parameter of soymilk fermented by different lactic acid bacteria were analyzed using HS-SPME-GC-MS, electronic nose (E-nose), and HPLC and colorimeter techniques, and sensory evaluation of fermented soymilk were also carried out. The results showed that all four strains of Lactobacillus were able to significantly reduce the total sugar content in soymilk, and at the same time significantly enhance the total acid and organic acid contents. Among them, the LP group had the optimal acid production capacity and fermentation capacity. A total of 31 volatile flavor substances were detected by GC-MS, and the LP group had the highest components (24 kinds), among them, the substances such as 1-octen-3-ol, nonyl aldehyde, and 1-nonanol were common volatile organic compounds (VOCs) of four kinds of soymilk. orthogonal partial least squares-discriminant analysis (OPLS-DA) model was effective in differentiating between groups of samples, and a total of 14 differential volatile flavor substances were screened based on variable importance in the projection (VIP>1), among which, (±)-6-methyl-5-heptenyl-2-ol, n-octanol, and 2-n-pentylfuran were the key substances for distinguishing different kinds of fermented soymilk. The electronic nose analysis further verified that fermented soymilk had higher response values to the nitrogen oxides and methyl analogues sensors, and the sensory evaluation results showed that LP group scored the highest in terms of flavor, aroma and overall acceptability. In conclusion, strain LP had the optimal fermentation effect on soymilk.

To compare the lipid-lowering effects of lactic acid bacteria compound agent and simvastatin in mice, simvastatin suspension and compound bacterial agents (Lactobacillus plantarum ∶ Lactobacillus pentosus ∶ Yarrowia lipolytica = 1∶1∶1) were gavaged to mice with successful high-fat modeling. The body mass, blood lipid indexes and arteriosclerosis indexes of the mice were measured, and toxicity tests were conducted on the compound strains. The results indicated that there were significant differences (P<0.05) in triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) levels in serum of mice between the compound microbial group and the simvastatin group, with the compound microbial agent showing superior efficacy in reducing TG and elevating HDL-C in serum of mice. No significant differences were found in low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) levels (P>0.05). Compared to the high-fat model group, reductions of 24%, 36% and 33% in TG, LDL-C, and TC levels in serum of mice were observed in the simvastatin group, while reductions of 45%, 34% and 32% were recorded in the compound microbial group. In the toxicity test, no abnormal clinical signs or deaths were observed in the mice, all organs exhibited intact morphology, and normal histopathology was confirmed in the liver and kidneys. Therefore, the compound microbial agent had excellent lipid-lowering effects and showed potential for further development.

To explore the extraction technology of mulberry polysaccharides by complex enzymatic hydrolysis, mulberry polysaccharides were extracted using compound enzyme (cellulose, pectinase, alkaline protease and papain), and the extraction technology was optimized by single factor and orthogonal tests. The structure of mulberry polysaccharides was characterized by infrared spectroscopy and scanning electron microscopy (SEM). An in vitro digestion model was established to simulate the in vitro digestion process of mulberry polysaccharides and explore their bioavailability. The results showed that the optimal extraction conditions of mulberry polysaccharides were cellulase 2.0%, pectinase 2.0%, alkaline protease 1.4%, papain 0.2%, material-liquid ratio 1∶80 (g∶ml), enzymatic hydrolysis pH 5, time 20 min, temperature 50 ℃. Under the optimal conditions, the extraction rate of mulberry polysaccharides was up to 65.64%. The molecular mass of mulberry polysaccharides was 250 139 kDa, which was mainly composed of glucose (26.25%) and galactose (25.20%). Mulberry polysaccharides had no crystal structure, and their morphological structure was layered and porous. The bioavailability analysis results showed that the composite enzymatic method for preparing mulberry polysaccharides had a higher bioavailability (37.69%) than the single enzyme extraction method (25.32%) and hot water extraction method (17.53%).

Vidal noble rot wine was prepared using artificial inoculation and natural infection of Botrytis cinerea, and normal maturity of Vidal grapes as raw material. The aroma components and sensory characteristics of Vidal noble rot wine under different treatments were analyzed using HS-SPME combined with gas GC-MS and sensory evaluation. The results showed that the total contents of aroma components in the noble rot wine made from Vidal grapes artificially inoculated with B. cinerea (201.55 mg/L) were lower than those made from Vidal grapes naturally infected with B. cinerea (285.75 mg/L), and higher than that of wine made from normally matured Vidal grape (172.58 mg/L). The contents of alcohols, esters, acids and aldehydes showed the same trend. The aroma balance of noble rot wine made from Vidal grapes artificially inoculated with B. cinerea was higher. Its pineapple, pear, peach, caramel, and jam flavor characteristics were similar to those of noble rot wine made from Vidal grapes naturally infected with B. cinerea, but the citrus, apricot, and beeswax flavor characteristics were not as good as the latter. The study could provide theoretical basis for the aroma improvement, process innovation, and new product development of Vidal noble rot wine fermented by Vidal grapes artificially inoculated with B. cinerea from the eastern foot of Helan Mountain.

After mixing high-temperature Daqu with pure water at a ratio of 3∶10 (g∶ml) and centrifuging to obtain the extract, it was inoculated into high- temperature Daqu at a ratio of 5∶100 (g∶ml). Based on the shake flask experiment, it was cultivated at 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃ and 65 ℃ respectively. The microbial groups in samples at different culture temperatures were analyzed based on Illumina MiSeq high-throughput sequencing technology, and the stability and function of microbial communities in samples at different culture temperatures were compared and analyzed. The results showed that the richness and diversity of the bacterial flora in the samples cultured at 45 ℃ and 50 ℃ were the highest, while the fungal flora was the highest in the samples cultured at 45 ℃. With the increase of the culture temperature, the relative content of Bacillus in the sample gradually increased, while the relative content of Pediococcus gradually decreased. The dominant fungal flora in the samples also varied at different culture temperatures. The fungal communities of the samples cultured at 40 ℃, 45 ℃, 50 ℃ and 55 ℃ were mainly composed of Pichia, Thermoascus, Aspergillus and Saccharomycopsis, respectively. It indicated that when the high-temperature Daqu microorganisms were cultured at a certain specific temperature, although the dominant bacterial community corresponding to that temperature was formed, no specific bacterial community corresponding to that temperature was formed. The bacterial and fungal flora compositions in the samples cultured at 50 ℃ and 55 ℃ were more abundant and the interaction relationships were stronger. The bacterial flora in the samples cultured at 50 ℃ had a relatively high defense function (P<0.05).

To investigate the influence of tartary buckwheat on the flavor characteristics of beer, tartary buckwheat beer was prepared by incorporating different additions (10%-50%) of tartary buckwheat into malt. The optimal addition was determined through sensory evaluation, physicochemical indexes, and volatile flavor compounds analysis. Furthermore, key differential volatile flavor compounds (OAV≥1, VIP>1) were identified based on odor activity values (OAV) and variable importance in projection (VIP) values. The results indicated that when the tartary buckwheat addition was 20%-35%, the sensory score of the beer was higher (88.1-90.5 points). Its chromaticity increased from 10.7 EBC to 14.8 EBC, while the original wort concentration, alcohol content and total acid decreased from 12.15 °P, 3.68%vol and 1.83% to 10.0 °P, 3.1%vol and 1.52% respectively. A total of 80 volatile flavor compounds were detected, including 36 esters, 6 alkanes, 20 alcohols, 4 aldehydes, 2 ketones, 7 organic acids, and 5 other compounds. The tartary buckwheat addition (30%) group demonstrated the highest volatile compound content (4 908.26 μg/g in pre-fermentation, 5 630.14 μg/g in post-fermentation). Through the odor activity values analysis, a total of 45 key volatile flavor substances (OAV≥1) such as ethyl acetate and ethyl butyrate were screened out. Based on VIP value>1 and OAV≥1, 32 key differential volatile flavor substances such as isobutanol and ethyl heptanate were screened out.

In order to realize the data evaluation and differentiation of sauce-flavor (Jiangxiangxing) Baijiu, using 7 different quality grades of sauce- flavor Baijiu (numbered as J1-J7) as the research objects. Sensory evaluation was carried out, and their volatile flavor compounds were detected by gas chromatography (GC). Based on the detection results, the seven different quality grades of sauce-flavor Baijiu were analyzed through principal component analysis (PCA). The results showed that a total of 30 common volatile flavor compounds were detected from 7 different quality grades of sauce-flavor Baijiu and there was strong correlation among them. The results of principal component analysis showed that the cumulative contribution rate of the first four principal components could reach 98.998%, which reflected most of the information of the original variable. The comprehensive score scatter plot could effectively distinguish different quality grades of sauce-flavor Baijiu. Sample J1 was different from other samples, while sample J6 and J7, J4 and J5, J2 and J3 were similar to each other respectively. The comprehensive score of each Baijiu sample was J7>J6>J5>J4>J3>J2>J1, which was generally consistent with the sensory evaluation. To sum up, the principal component analysis of common volatile flavor compounds could accurately and quickly distinguish and evaluate different quality grades of sauce-flavor Baijiu, and provide theoretical support for the identification of aging base Baijiu and finished Baijiu.

Samples were taken from the soil of soybean planting bases. After isolation and purification, combined with the transparent circle method and enzyme activity screening, the high-yield β-mannanase strain was screened, the screened strains were identified by morphological observation and 16S rDNA sequence analysis methods, and the fermentation enzyme production conditions were optimized by single factor and response surface methods. The results showed that a high-yielding β-mannanase strain D-1 was screened, which was identified as Bacillus subtilis. The optimal fermentation conditions of the strain were konjac flour 31 g/L, NaNO₃ 5 g/L, K₂HPO₄ 1 g/L, MgSO₄ 0.25 g/L, initial pH value 7, fermentation temperature 30 ℃, and time 24 h. Under the optimal conditions, the enzyme activity of β-mannanase reached 148.88 U/ml.

To address the key issues such as low conversion efficiency of lignocellulose and unbalanced utilization of carbon sources in the biological fermentation of beet, using engineered Escherichia coli capable of simultaneously utilizing sucrose and glucose as the fermentation strains, sugar beet powder as the carbon source, combined with potassium phosphate (K₃PO₄) and complex cellulase treatment, staged saccharification fermentation (SHF) as the control, the efficient conversion of beet for L-lactic acid production was promoted by semi-solid synchronous saccharification fermentation (SS-SSF). The results showed that pretreatment of beet powder with K₃PO₄ 4 g/100 ml could significantly improve the binding efficiency of substrate and enzyme. The contents of glucose and xylose in the pretreatment supernatant were the highest, which were 40.22 g/L and 4.50 g/L, respectively. Under the conditions, the lignin in beet decreased by 70% and the cellulose content increased by 53%. After secondary hydrolysis by cellulase (3 FPU/g), the total glucose yield increased by 23.88%. SS-SSF shortened the fermentation cycle by 24 h. The production and production rate of L-lactic acid were 44.51 g/L and 0.93 g/(L·h), respectively, which were 34% and 51% higher than those of staged saccharification fermentation (SHF) respectively.

Peanut natto was prepared by fermentation with Bacillus subtilis using peanut as raw material. The fermentation process of peanut natto was optimized by single factor tests and response surface tests using the comprehensive score of sensory score and nattokinase activity as the response value, and the volatile flavor components of peanut natto were detected by headspace solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The results showed that the optimal fermentation conditions of peanut natto were B. subtilis inoculum 12%, fermentation time 34 h, and temperature 39 ℃. Under the optimized conditions, the sensory score of peanut natto was 88.12, the natto kinase activity was 1 127.32 U/g, and the comprehensive score was 90.70. A total of 38 volatile flavor compounds were detected from peanut natto, among them, the relative contents of 2,5-dimethylpyrazine (20.72%), 2,3,5-trimethylpyrazine (3.89%), ethanol (18.19%), D-limonene (2.51%), longifolene (2.05%) and isovaleraldehyde (2.24%) were relatively high. Compared with traditional fermented natto, no sulfur-containing compounds, acetic acid, propionic acid or other sour and odorous substances were detected in peanut natto, and it had better sensory quality.

To address the issues of insufficient aroma and unprominent typical flavors in purple sweet potato wine, purple sweet potato wine was prepared using purple sweet potato as raw material, the volatile aroma components and sensory characteristics of purple sweet potato wine fermented by different yeasts were analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry (GC-MS) technology and sensory evaluation, and the yeast suitable for purple sweet potato wine fermentation was screened out, and the fermentation process of purple sweet potato wine was optimized by single factor and response surface experiments. The results showed that the DV10 yeast was the optimal strain for purple sweet potato wine fermentation, it had strong fermentation ability, and all the physicochemical indicators of the fermented purple sweet potato wine met the requirements of NY/T 1508—2017 'Green food-Fruit wine'. In terms of volatile aroma components, the purple sweet potato wine fermented by DV10 yeast had the most types and higher contents of aroma components. Particularly, the contents of the functional flavor compound 2,3,5,6-tetramethylpyrazine was significantly higher than that of other yeasts (P<0.05). These rich aroma components enhanced the flavor harmony and fullness of the wine body, and the sensory score was the highest (87.5). The optimal fermentation process conditions of purple sweet potato wine were: fermentation temperature 24 ℃, initial pH 4.3, and initial sugar content 22 °Bx. Under the optimal conditions, the alcohol content of purple sweet potato wine was (12.93±0.18)%vol, which was 5.98% higher than that before optimization. This research provided technical support for improving the flavor quality of purple sweet potato wine and was conducive to promote the development of the purple sweet potato wine industry.

Wolfberry and jujube compound fermented beverage was prepared using wolfberry and jujube as the experimental materials, and Lactiplantibacillus plantarum, Lactobacillus acidophilus and Lactobacillus reuteri as compound fermentation strains, the fermentation process conditions of wolfberry and jujube compound beverage were optimized by single factor and response surface tests, and the physicochemical indicators and antioxidant activities of the fermented and unfermented samples were determined and analyzed. The results showed that the optimal fermentation process of wolfberry and jujube compound beverage were as follows: initial pH 5.5, inulin addition 0.12%, mixed bacteria (1∶1∶1) inoculum 0.08%, and fermentation temperature 37 ℃. Under the optimized conditions, the sensory score of the compound fermented beverage was 92.5 points, and the viable bacteria count was 13.6 lg(CFU/ml). Compared with unfermented group, the contents of total phenols, total flavonoids and total carotenoids increased significantly (P<0.05), among them, the contents of total flavonoids increased from 0.97 mg/ml to 1.68 mg/ml, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rates increased from 28.61% to 78.62%, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) radical scavenging rates increased from 32.81% to 58.93%, and the ·OH scavenging rate increased from 38.12% to 83.61%, and the total antioxidant capacity increased from 6.78 mmol/L to 19.26 mmol/L, both showing a significant increase (P<0.05). Therefore, the fermentation of compound lactic acid bacteria could enhance the antioxidant activity of wolfberry and jujube compound fermented beverage.

In order to promote the application of domestic hollow fiber membrane technology in the field of beer filtration and promote the improvement of beer quality, in this study, the beer fermentation broth was filtered using a hollow fiber membrane based on hydrophilic polyethersulfone as the substrate, and the effects of different specifications of hollow fiber membrane on the changes of membrane filtration flux and fermentation broth quality indexes (yeast count, turbidity, original wort concentration, alcohol content) were explored, and the cleaning and recycling performance of the membrane were studied. The results showed that when the pore diameter of the polyether sulfone hollow fiber membrane was not less than 0.45 μm and the inner diameter of the membrane was 1.5 mm, no yeast cells were detected in the filtrate, the turbidity was significantly reduced, and the loss rates of original wort concentration and alcohol content were relatively low, being 0.7% and 1.5%-2.0%, respectively. When the polyether sulfone hollow fiber membrane with a pore size of 0.45 μm was filtered for 100 min, the membrane flux was close to 302 L/ (m²·h·bar). The reverse water rinsing and lye immersion for 5 min could obtain a good membrane cleaning effect, and the membrane flux could still be restored after 9 cycles (membrane flux of 8 000 L/(m²·h·bar)), indicating that the hollow fiber membrane had good cycling performance and was suitable for long-term use.

Using special malt as the raw material and commercial Saccharomyces cerevisiae Y71 as control, craft beer was brewed by two strains of S. cerevisiae Y3 and Y4, which isolated from traditional sourdough in China. The growth status and fermentation characteristics of three kinds of yeasts were compared by monitoring the mass loss of CO₂ and the number of yeast cells during fermentation process. The physicochemical indexes and volatile flavor components of three kinds of craft beers were analyzed by conventional detection methods and headspace solid-phase extraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) technique. The key flavor components were determined by relative odor activity value (ROAV), and analyzed by principal component analysis (PCA) and sensory evaluation. The results showed that, compared with yeast Y71, yeasts Y3 and Y4 exhibited more excellent fermentation characteristics and growth performance. The utilization rates of fermentable sugars of yeasts Y3 and Y4 were 70.3% and 70.0%, respectively. The fermentation degree and alcohol content of yeasts Y3 and Y4 were 77.06%, 3.77%vol and 76.54%, 3.74%vol, respectively. All the physiochemical indexes of craft beer brewed by yeasts Y3 and Y4 could meet the relevant national standards. The results of HS-SPME-GC-MS shown that a total of 67 volatile flavor compounds were detected in craft beer brewed by the three yeasts. Based on ROAV>1, a total of 26 key flavor components were screened out. Among them, ethyl hexanoate, 1-decanol and coconut aldehyde were the unique aroma substances in craft beer brewed by yeasts Y3 and Y4. The three samples of craft beers brewed by the three yeasts were well distinguished by PCA, and the craft beer brewed by yeast Y3 had harmonious flavor, prominent floral and fruity aromas, and harmonious and soft body.

In this study, fermented apple juice was prepared using Zhaotong plateau apple as raw material and Oenococcus oeni and Bifidobacterium as fermentation strains. Taking the sensory score as the response value, the fermentation process conditions were optimized by the single-factor tests and the response surface tests, and the quality indicators and volatile flavor substances were analyzed. The results showed that the optimal fermentation process conditions of fermented apple juice were as follows: white granulated sugar addition 6%, mixed bacteria (1∶1) inoculum 3%, fermentation time 42 h, and temperature 26 ℃. Under the optimal conditions, the sensory score of fermented apple juice was 90.45 points, and its pH value, lactic acid bacteria count, total acid, total sugar and soluble solid contents were 3.82, 7.4×10⁸ CFU/ml, 3.38 g/100 ml, 3.85 g/100 ml and 10.4%, respectively. A total of 21 volatile flavor substances were detected in fermented apple juice, including 6 alcohols, 4 ketones, 3 phenols, 2 alkenes, 1 aldehyde, 1 acid and 4 other compounds. The fermented apple juice showed good color, aroma, taste and tissue state.

To achieve automatic control of the fermentation production of fermented red raspberry juice by computer, the fermented red raspberry juice was prepared using red raspberries as raw materials and Issatchenkia terricola WJL-G4 as fermentation strain. During the fermentation process, the contents of total sugar, total acid, glucose, fructose, sucrose, citric acid, pH value and the yeast counts of the fermented red raspberries juice were determined every 12 h. The experimental data were subjected to nonlinear fitting using the Logistic, DoseResp and Boltzmann models, and the fermentation kinetics model was constructed and verified. Sensory evaluation of red raspberry juice during fermentation were carried out. The results showed that the total sugar content decreased from 61.50 g/L to 11.49 g/L, the total acid content decreased from 20.72 g/L to 2.03 g/L, and the glucose content decreased from 19.87 g/L to 0.13 g/L. The fructose content decreased from 25.13 g/L to 0.64 g/L, the citric acid content decreased from 18.21g/L to 1.28 g/L, the pH value increased from 2.91 to 5.84, the yeast counts increased from 4.00×10⁶ CFU/ml to 3.76×10⁸ CFU/ml, while the sucrose content remained basically unchanged during the fermentation process of red raspberry juice. The kinetic models of yeast growth, total sugar and total acid consumption could be fitted by the DoseResp model, and the pH value change could be fitted by the Logsitic model. The correlation coefficients (R²) were all more than 0.98, and the model verification error was less than 15%, which could accurately describe the fermentation process of red raspberry juice. The sensory evaluation results indicated that when the fermentation time was 36 h, the sensory score of the fermented red raspberry juice was the highest (79.50 points).

In order to achieve the comprehensive utilization of Procambarus clarkii head, the shrimp head seasoning was prepared with P. clarkii head as the main raw material, and mixed fermentation by Zygosaccharomyces rouxii and Lactobacillus. Taking the amino acid nitrogen content and sensory score as evaluation indicators, the fermentation conditions were optimized by single-factor tests and response surface tests, and the quality indicators were analyzed. The results showed that the optimal fermentation process conditions were as follows: mixed bacteria (1∶1) inoculum 17.4%, salt addition 6%, fermentation temperature 34 ℃ and fermentation time 20.6 h. Under the optimal conditions, the sensory score of P. clarkii head seasoning was 86, and the contents of amino acid nitrogen, protein, carbohydrates and sodium were 2.21 mg/ml, 4.58 g/100 ml, 6.2 g/100 ml and 2 650 mg/100 ml, respectively.

To improve biomass of Lactobacillus brevis as well as to study the rule of fermentation change, the high-density culture conditions were optimized through single factor and response surface tests, and a fermentation kinetic model was established. The results showed that the optimal medium composition were glucose 21 g/L, yeast extract powder 20 g/L, manganese sulfate 0.5 g/L, dipotassium hydrogen phosphate 2 g/L, diammonium hydrogen citrate 2 g/L, sodium acetate 5 g/L, and arginine 0.25 g/L. The optimal culture conditions were culture temperature 35 ℃, initial pH 6.5, loaded liquid 25 ml/150 ml, inoculum 2% (V/V). The bacteria dry mass, total acid and reducing sugar content were non-linear fitted based on the Logistic equation, the correlation coefficient R² were all over 0.99, and the average relative error was less than 10%. Under these conditions, the OD_{620 nm} value of fermentation broth and viable bacterial count reached 3.84 and 2.40×10⁹ CFU/ml, which increased by 55.47% and 90.48%, respectively. In conclusion, the biomass of L. brevis in the fermentation broth was significantly increased through optimization, and the established kinetic equation could well describe and predict the changes of L. brevis biomass and components in fermentation broth.

Licorice Huangjiu was prepared using licorice and broomcorn millet as raw materials. Using alcohol content as evaluation index, the fermentation process was optimized through single-factor tests and Box-Behnken response surface tests, and the digestion characteristics and antioxidant activity of licorice Huangjiu were investigated through in vitro simulation gastrointestinal digestion experiments. The results showed that the optimal fermentation process of licorice Huangjiu were obtained as follows: licorice enzymatic hydrolysate addition 17.8%, Jiuqu addition 11.0%, pre-fermentation temperature 26 ℃ and time 7 d. Under these optimal conditions, the total acid, total sugar, pH, total phenols, total flavonoids, alcohol content and sensory score of the licorice Huangjiu were 6.8 g/L, 33.58 g/L, 3.55, 1.32 mg/ml, 1.04 mg/ml, 17.0%vol and 91.44 points, respectively. The total phenol, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS⁺) radical scavenging rates of licorice Huangjiu and common Huangjiu during the in vitro simulation gastrointestinal digestion process all showed an overall upward trend. Moreover, the quality indexes of licorice Huangjiu were significantly higher than those of common Huangjiu (P<0.05). The total phenols, DPPH and ABTS⁺ free radical scavenging rates of licorice Huangjiu increased by 46.21%, 35.94% and 14.79%, respectively, compared with common Huangjiu after digestion for 4.0 h.

In order to explore the feasibility of combining two strains to make koji, two strains of Aspergillus oryzae (HT.AS1102 and HT.AS1103) with different characteristics were used to make koji and brew soy sauce, the growth characteristics and enzyme-producing abilities of koji mode by two strains of A. oryzae were studied, and the appropriate compound proportion of two strains for koji-making was selected by evaluating the physicochemical and sensory indexes of brewed soy sauce. The results showed that the appropriate compound proportion of strains HT.AS1102 and HT.AS1103 for koji-making was 2∶1. Under the optimal conditions, the amino acid nitrogen and glutamic acid contents of the soy sauce brewed by koji with two strains of A. oryzae increased by 3.3% and 23% compared with the soy sauce brewed by koji with strain HT.AS1102, respectively. At the same time, the total acid content decreased by 3% and the reducing sugar content increased by 8% compared with the soy sauce brewed by koji with strain HT.AS1103. The brewed soy sauce had the optimal overall taste combining the advantages of the two single strains.

In this study, the effects of different strains of Saccharomyces cerevisiae (numbered as HAG, XR, LAB, SY and RW) on the quality of longan jujube ginger wine fermented from fresh longan pulp, fresh jujube, and ginger were investigated, and the physicochemical properties, bioactive components, and sensory score of 5 types of longan jujube ginger wines were compared. The volatile flavor components of longan jujube ginger wine were analyzed using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS) technology, and the key aroma components were screened based on relative odor activity value (ROAV). The results showed that the alcohol content of longan jujube ginger wine brewed with 5 types of strains of S. cerevisiae ranged from 16.7%vol to 21.2%vol, and the total acid and volatile acid content met the relevant industry standards. The total flavonoids, total triterpenoids, and sensory scores of longan jujube ginger wine prepared by yeast RW were the highest, which were 543.14 mg/L, 86.32 mg/L and 82.3 points, respectively. A total of 51 volatile flavor components were detected in 5 types of longan jujube ginger wine, among which, the most aroma components (46) in longan jujube ginger wine fermented by yeast RW were detected. A total of 18 key aroma components of longan jujube ginger wine fermented by yeast RW were screened based on ROAV≥1. Overall, yeast RW was more suitable for brewing longan jujube ginger wine.

To investigate the differences in free amino acid (FAA) content and quality of Morchella sextelata from different producing area, the content of FAAs in 20 samples from different regions (numbered as SC1-SC6, GZ1-GZ6, HN1-HN3, SX, XJ, NX, XX, ZJ) were analyzed using amino acid analyzer. The taste characteristics of flavor-active amino acids were compared based on taste activity values (TAVs), and the quality of M. sextelata was comprehensively evaluated through correlation analysis, principal component analysis (PCA), and cluster analysis (CA). The results showed that the total FAAs contents were 14.61-39.96 mg/g across different producing area. The amino acid TAVs of M. sextelata from different regions was the highest for bitter amino acids, followed by umami, sweet, and aromatic amino acids. Five principal components were extracted using principal components analysis, with a cumulative variance contribution rate of 85.94%, and the top five samples in comprehensive scores were ZJ, GZ4, GZ5, NX, and GZ2. 20 samples were classified into three clusters by CA: the first cluster (ZJ, NX, GZ4, GZ2) and the second cluster (GZ5, SC5) exhibited superior quality, while the third cluster (the remainder samples) showed inferior quality. The content of free amino acids in M. sextelata from different regions was rich and varied greatly, with ZJ, GZ5, NX, GZ4, and GZ2 demonstrating the highest nutritional quality. These findings provided a theoretical basis for the graded processing of M. sextelata.

Using 4 Zhenjiang aromatic vinegars stored in glass bottles more than 20 years and new vinegar as the research object, the differences of physicochemical indicators, microbial indicators, organic acids, free amino acids and volatile flavor substances were analyzed to study the quality differences. The results showed that the total acid, non-volatile acid, reducing sugar, amino acid nitrogen and total number of colonies of these 4 bottles of aged aromatic vinegar all met the requirements of the national standard GB/T 18623—2011 "product of geographical indication-Zhenjiang aromatic vinegar". The overall difference in organic acids, amino acids, and volatile flavor compounds among these 4 bottles of aged vinegar were not significant. Compared with the newly produced Zhenjiang vinegar, the proportion of acetic acid in these 4 bottles of aged aromatic vinegar reduced to less than 50%, and the taste was softer. A total of 24 free amino acids were detected, and alanine had the highest proportion, reaching 19.73%-22.19%. Compared with the newly produced Zhenjiang vinegar, the types of volatile compounds in the aged aromatic vinegar such as esters, pyrazines, aldehydes, and oxazoles increased by 23, and the total mass concentration of volatile flavor substances was 301.31-348.56 mg/L, with a more intense aroma. Therefore, Zhenjiang vinegar stored in glass bottle still had higher flavor quality, which provided a reference for glass bottle storage.

In order to explore the characteristics of volatile flavor components in strong-flavor (Nongxiangxing) Baijiu from Henan, using strong-flavor Baijiu in Sichuan as the control, the volatile flavor components in strong-flavor Baijiu samples with different brands from Henan were identified by gas chromatography-ion mobility spectrometry (GC-IMS) technology, the fingerprint was constructed, and the principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were carried out. The results showed that a total of 87 volatile flavor components were detected in control and strong-flavor Baijiu samples with different brands from Henan, including 9 alcohols, 37 esters, 12 aldehydes, 14 ketones, and 15 others. Among them, esters accounted for the largest proportion (70%). Fingerprint analysis showed that there were differences in control and strong-flavor Baijiu samples with different brands from Henan. The control and strong-flavor Baijiu with different brands from Henan could be effectively distinguished through PCA and PLS-DA. Based on the variable importance projection (VIP) value>1 and P<0.05, a total of 33 differential volatile flavor components such as butyl 3-methylbutyrate, 2,5-dimethylpyrazine, butyl valproate, and methyl acetate were identified. These substances were the main reasons for the different flavor characteristics of strong-flavor Baijiu with different brands from Henan, laying the foundation for the establishment of the flavor substance database of strong-flavor Baijiu from Henan.

A method was established for the determination of four saccharides, including glucose, fructose, maltose, and maltotriose in the fermented grains of sauce-flavor (Jiangxiangxing) Baijiu using ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry (UPLC- MS/MS). The results showed that using water as the extraction solvent, oscillation extraction 10 min, the interfering substances such as proteins were precipitated and separated with acetonitrile. The separation was achieved through a fine particle packed chromatographic column (2.1 mm×100 mm, 1.7 μm), and the mobile phase was acetonitrile-5 mmol/L ammonium acetate (0.1% ammonia water). The various carbohydrate substances were determined by the multiple reaction monitoring (MRM) mode, and were quantitatively analyzed by the external standard method with standard solutions. The linear relationships of the four saccharides were good within their respective mass concentration ranges, and the correlation coefficients (R²) were all >0.998. The average spiked recovery rates were 82%-118%, the relative standard deviation (RSD) of the precision tests results was less than 2.0%, the limit of detection (LOD) were 0.003 0-0.022 5 mg/L, and the limit of quantification (LOQ) were 0.010-0.075 mg/L. This method had the advantages of short detection time, high sensitivity, accuracy and high throughput, and could meet the accurate qualitative and quantitative requirements of saccharides in the fermented grains of sauce-flavor Baijiu.

Aiming at the limitation of traditional Abbe refractometer in determining high concentration ethyl acetate and the complicated operation of gas chromatography (GC) standard curve method, a correction factor method of internal standard for gas chromatography was established using n-propyl acetate as internal standard to detect ethyl acetate content. At the same time, it was compared with the standard curve method, and the specificity, repeatability, stability and standard recovery rate of the method were investigated. The results showed that the GC internal standard correction factor method could accurately determine ethyl acetate with the mass concentration of 0.093-45.018 g/L and mass fraction of 10.262%-97.930%. The limit of detection of the method was 7.55 mg/L, the limit of quantitation was 24.46 mg/L, the relative standard deviation (RSD) of the repeatability and stability tests results were 0.12% and 0.25%, respectively, the standard recovery rates of ethyl acetate in Baijiu samples and synthetic samples were 100.96% and 100.46%, respectively, and the RSD of the standard recovery rate test results was 0.66% and 0.31%, respectively, which showed that the method was suitable for detecting the content of ethyl acetate, with good repeatability, high stability and simple and fast operation, which significantly improved the efficiency of food analysis and quality control.

In order to quickly detect the base liquor grade of strong-flavor (Nongxiangxing) Baijiu and improve the interpretability of the prediction model, 687 near-infrared (NIR) spectra of base liquor were collected. The raw spectra were preprocessed using the Savitzky-Golay (SG) smoothing algorithm and first derivative (FD), followed by feature wavelength selection using competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA), respectively. Finally, a base liquor grade prediction model was constructed based on the extreme Gradient Boosting (GBoost) and Light Gradient Boosting Machine (LightGBM) algorithms, and the optimal model was interpreted using the Shapley Additive Explanations (SHAP) algorithm. The results showed that the LightGBM model constructed from 27 feature spectral obtained by SG preprocessing and CARS feature selection of the original spectra had the optimal prediction performance, with a prediction set accuracy of 98.54%. The SHAP interpretation results of the model showed that the characteristic spectral points with wavenumbers of 4 798 cm^-1, 6 245 cm^-1, 5 936 cm^-1 and 7 080 cm^-1 contributed significantly to the SHAP output of the model. These spectral points mainly reflected the characteristic information of hydroxyl and carbonyl compounds in the base liquor.

In the context of the digital era, big data technology has become the core driving force for innovation and development in various industries, and the sauce-flavor (Jiangxiangxing) Baijiu industry is facing the innovation opportunities and challenges brought by big data technology. The application status of big data in the market development of the sauce-flavor Baijiu industry was discussed. The problems existing in the process of big data in the market development of the sauce-flavor Baijiu industry, such as data quality issues, data privacy and security, and technical and talent bottlenecks were analyzed. Countermeasures and suggestions were put forward, such as data integration and cleaning, strengthening privacy protection measures, enhancing technical training and talent introduction, as well as implementing precise marketing strategies, etc., which could effectively enhance the market competitiveness and consumer satisfaction of the sauce-flavor Baijiu industry. The research indicated that although big data technology had brought unprecedented opportunities to the sauce-flavor Baijiu industry, it was also accompanied by multiple challenges in terms of data quality, data security and privacy protection, as well as technology and talent. Sauce-flavor Baijiu enterprises need to make efforts in terms of technology, management and ethics to ensure the effective utilization of big data resources and promote the sustainable development of the industry. The research conclusion could provide theoretical guidance and practical reference for the digital transformation of the sauce-flavor Baijiu industry and even broader traditional industries, and had certain practical significance.

In the digital age, short video marketing has become an important tool for brand promotion. The short video of intangible cultural heritage Baijiu integrates Baijiu culture and intangible cultural heritage elements, providing a new path for brand differentiation competition. Based on Stimulus- Organism-Response (SOR) theory, a total of 389 valid questionnaires were collected, and a structural equation model was established to explore the influence mechanism of intangible cultural heritage Baijiu short video on consumers' purchase intention, analyze the influences of the functionality, interactivity and hedonic characteristics of short video on purchase intention, and introduces emotional resonance as an intermediary variable and cultural identity as a moderating variable. Studies showed that the functionality, interactivity and hedonic characteristics of short videos of intangible cultural heritage Baijiu had a significant positive impact on purchase intention, emotional resonance played a mediating role in it, and cultural identity strengthened the promotion effect of emotional resonance on purchase intention. It is suggested that Baijiu enterprises should enhance content functionality, enhance interactivity, pay attention to hedonic characteristics, and accurately locate target consumer groups to optimize short video marketing strategies. The aims of this paper were to reveal the marketing effect and its functional mechanism of short videos on intangible cultural heritage Baijiu, and at the same time provide scientific basis and practical guidance for Baijiu enterprises to formulate effective marketing strategies.

In order to explore the influence mechanism of brand authenticity perception of traditional brewing process Baijiu on consumers' purchase intention, a conceptual model between brand authenticity perception and purchase intention was constructed with brand identity as the intermediary variable. The impact mechanism of each variable on consumers' purchase intentions was tested by hierarchical regression analysis method. The empirical analysis showed that the brand authenticity perception of traditional brewing technology Baijiu had a significant positive impact on purchase intention; Brand identity had a significant positive impact on purchase intention. Brand identity played a part of intermediary role between brand perception and purchase intention of traditional brewing technology Baijiu. Based on this, it is proposed: Strengthen the dissemination of traditional brewing Baijiu culture; Shape a unique brand cultural identity of traditional brewed Baijiu; Showcase the traditional brewing production process and operational skills. This article could provide theoretical support and practical guidance for the brand building of traditional brewing technology Baijiu and the marketing of the Baijiu industry.

Using 19 listed Baijiu enterprises from 2010 to 2022 as the samples, an index system reflecting the degree of enterprises digital transformation was constructed by combining Python word segmentation with manual recognition, and the enterprises servitization level was measured by the servitization rate. Based on 182 sets of valid sample data, the effect of digital transformation on the servitization level of Baijiu enterprises was empirically tested by a fixed-effects regression model, and regional difference characteristics of this influence was further analyzed. The results showed that the digital transformation of Baijiu enterprises could effectively enhance the servitization level, with a core observation coefficient of 0.411. Among them, the regression coefficient in the eastern region was 0.804 (P<0.05), which was significantly higher than that in the central and western regions, indicating that there were heterogeneous differences among regions. Countermeasures and suggestions for promoting the digital transformation of Baijiu enterprises from the levels of the government, industry and enterprises was proposed.