Kefir is a kind of probiotic fermented foods with a long history, which is fermented by kefir grains (KG). KG are divided into milk kefir grains (MKG) and water kefir grains (WKG) according to different substrates, which are mainly composed of lactic acid bacterium and yeast, and is the main source for screening probiotic strains. In this paper, the fermentation strains and methods of milk kefir (MK) and water kefir (WK) were introduced, and their effects on the prevention and adjuvant therapy of intestinal dysfunction, liver protection and metabolic syndrome were summarized, providing theoretical basis for the discovery of probiotic strains and the research and development of functional fermented foods.

Baijiu is a distilled liquor made by steaming, saccharifying, fermentation and distillation with grain as raw material, Daqu, Xiaoqu and Fuqu as saccharifying starter culture. The quality and flavor of Baijiu are closely related to the microbial community structure. With the progress of microbial culture and isolation, metagenomics, metatranscriptomics and other technologies, more and more microbial functions in Baijiu brewing were analyzed, explored and applied. The main microbial composition in Baijiu brewing process, functional characteristics of important microorganisms, and the research progress on the application of functional microorganisms in the improvement of Baijiu quality, the strengthening of Jiuqu, the maintenance of pits and pit mud, and the resource utilization of brewing by-products were reviewed, in order to provide a reference for the microbial research in Baijiu brewing process, the application of functional microorganisms, and the improvement of Baijiu quality.

Sulfur dioxide is widely used in wine production because of its good antibacterial and antioxidant effects, but excessive use of sulfur dioxide affects the sensory quality of wine and be detrimental to the health of consumers. At present, the market demand for wine products with low sulfur dioxide content has increased significantly, and "green" and "healthy" have become the development trend of the world wine industry. Therefore, many wine industries in the developed countries have taken sulfur dioxide substitutes and new non-thermal sterilization technology as the key support direction for the sustainable development of the industry. At present, there have been relevant studies on the substitution of sulfur dioxide by lysozyme, chitosan, dimethyl dicarbonate, glutathione and tannin can replace sulfur dioxide in wine. New non-thermal sterilization technologies such as ultrasonic wave, ultra-high pressure, pulsed electric field in wine. Based on this, the characteristics and functions of sulfur dioxide were introduced and the sulfur dioxide substitutes and new non-thermal sterilization technologies were summarized, in order to provide ideas for reducing the use of sulfur dioxide in wine production.

Zaopei (fermented grains) fermentation is the key link in the production of strong-flavor (Nongxiangxing) Baijiu, which plays a decisive role in the flavor and quality of the final product. In recent years, with the progress of science and technology, researchers had a deeper understanding of the dynamic changes of microbial communities during Zaopei fermentation. The spatial and temporal heterogeneity of microbial community succession in fermented Zaopei of strong-flavor Baijiu and its dynamic changes under different seasons, raw materials and pit age were reviewed. The fluctuation of temperature and humidity caused by seasonal changes, the change of nutrient composition caused by the difference of raw materials, and the microbial ecological maturity affected by pit age all proved to have significant effects on the composition and function of the microbial community during Zaopei fermentation. In addition, the innovative research results on microbial community assembly mechanism, abundance classification and flavor components synthesis mechanism in the fermentation process of Zaopei in recent years were summarized in order to provide a new perspective and method for the optimization and control of the fermentation process of strong-flavor Baijiu, and to promote the development of strong-flavor Baijiu industry to a more efficient and sustainable direction.

Alcoholism is a disease resulting from excessive ethanol intake and inadequate metabolism within a short period of time. Acute alcoholism can lead to brain dysfunction and even fatality, while chronic alcoholism is closely associated with metabolic disorders such as cardiovascular and cerebrovascular diseases, as well as liver diseases. The intervention of ethanol metabolism through microorganisms presents a potentially safe, cost- effective, and efficient approach. Ethanol-degrading microorganisms have the ability to metabolize ethanol by producing enzymes and enhancing enzyme expression in the body, or they can inhibit ethanol absorption by restoring intestinal flora homeostasis, reducing intestinal permeability, and promoting antioxidant activity to mitigate alcoholic liver injury. The ways, characteristics of microbial degradation of ethanol and the function and characteristics of related anti-alcohol products were reviewed, aiming to establish a theoretical foundation for future research.

In this study, the ester aroma-producing yeast strains were isolated and screened from medium- and high-temperature Daqu samples by traditional culture isolation method combined with the olfactory method, and identified by molecular biology techniques, and their growth characteristics and aroma-producing characteristics were analyzed. The results showed that 5 representative strains of ester aroma-producing yeasts, numbered G-8, Z-3, G-1, G-2 and G-3, were screened and identified as Saccharomycopsis fibuligera, Wickerhamomyces anomalus, Pichia kudriavzevii, Meyerozyma caribbica and Naganishia diffluens, respectively. Among them, the strain Z-3 grew ripidly and had better tolerance and the optimal effect on increasing the content of volatile flavor substances, which could tolerate 13% (V/V) ethanol, 70% glucose and 1.0% (V/V) acetic acid. A total of 21 volatile flavor compounds were detected from the solid-state fermentation product of strain Z-3, and the total content was 197.13 μg/g. Among them, 8 key volatile flavor compounds were screened according to odor activity value (OAV)>1, including ethyl acetate, isoamyl acetate and so on, indicating that the strain Z-3 had good application potential in improving Baijiu flavor.

Using 8 different varieties of sorghum (numbered as JZG, JZ12, CZ5, JZB, LZ1, JZ218, JZ109, LZ2) as the research objects, their physicochemical indexes were detected, and their effects on the physicochemical indexes of fermented grains of strong-flavor (Nongxiangxing) Baijiu and the volatile flavor components of the Baijiu were investigated. Based on the detection results, partial least squares-discriminant analysis (PLS-DA) and correlation analysis were carried out. The results showed that the moisture of different varieties of sorghum had little difference, while the contents of tannin, amylopectin, crude protein and crude fat had great differences. There were certain differences in the acidity, moisture, starch content and alcohol content of the fermented grains for Baijiu brewed from different varieties of sorghum. A total of 38 volatile flavor components were detected in strong-flavor Baijiu brewed from different varieties of sorghum, including 12 esters, 12 alcohols, 10 acids, and 4 aldehydes. The contents of ester substances were the highest (1 636.75-5 677.69 mg/L). According to variable importance in the projection (VIP) value and odor activity value (OAV), 14 different volatile flavor components (VIP value≥1) such as ethyl caproate and acetal, and 23 key volatile flavor components (OAV>1), such as ethyl acetate and isoamyl acetate, were screened. Correlation analysis showed that the amylopectin in sorghum was beneficial to alcohol production, and the contents of crude fat and tannin in sorghum were negatively correlated with the contents of main volatile flavor substances such as ethyl butyrate, ethyl caproate and caproic acid.

Based on the traditional sensory evaluation, the effects of different temperature on sensory quality of sauce-flavor (Jiangxiangxing) Baijiu were studied by means of Check-All-That-Apply (CATA) and electroencephalogram (EEG) signal extraction and analysis technology. The results of the professional sensory evaluation analysis showed that the optimal tasting temperature of the liquor body was between 10 ℃ and 25 ℃. According to the results of consumer evaluation CATA method, the optimal tasting temperature should be higher than 15 ℃, and the taste was better at 15-20 ℃, and the aroma was better at 20-25 ℃. The EEG signal analysis results showed that the index of alcohol-drinking analysis (IAA) was the highest at 20 ℃ when drinking at 10-25 ℃. Through the frequency screening method, the optimal tasting temperature was 16-17 ℃, and consumers had the highest preference for sauce-flavor Baijiu.

In this study, the physiochemical indicators of fermented grains during low-salt solid-state fermentation of Deyang soy sauce were analyzed, the microbial community composition and succession laws during the fermentation process were analyzed by high-throughput sequencing technology, and the physiochemical indicators and microbial genera were analyzed by Spearman correlation. The results indicated that the dominant bacterial genera of fermented grains during low-salt solid-state fermentation process of Deyang soy sauce were Bacillus (41.2%), Unclassified Enterobacteriaceae (19.5%), Klebsiella (13.6%), Enterobacter (12.4%), and Enterococcus (3.4%). The dominant fungal genera was Aspergillus (99.3%). As fermentation progressed, the relative abundances of Bacillus (34.4%-46.7%) and Enterococcus (1.0%-4.1%) significantly increased (P<0.05), while the relative abundances of Unclassified Enterobacteriaceae (21.9%-17.8%) and Klebsiella (23.6%-8.8%) significantly decreased (P<0.05). The correlation analysis results showed that Cronobacter, Aerococcus, Staphylococcus, Enterococcus, Bacillus and Enterobacter were positively correlated with reducing sugars, neutral protease, and amino acid nitrogen. Aspergillus was positively correlated with neutral protease, alkaline protease, and total acid, while it was negatively correlated with amino acid nitrogen and reducing sugars.

In order to explore the differences in flavor and quality of sauce-flavor (Jiangxiangxing) Baijiu produced in different ecological environments, the environmental soil and air fungal community structure of the representative sauce-flavor Baijiu production enterprises factory area of Gulin and Jian'ou were analyzed by high-throughput sequencing technology. The results showed that the fungal species richness and community diversity in the environmental soil of Gulin factory area were higher than that in Jian'ou factory area, while the air fungal species richness and community diversity were lower than those in Jian' ou factory area. The structure of environmental dominant fungal communities in the two factory areas was roughly similar at phyla and genus level, and the soil and air fungal genera shared by the two factory areas were 69 and 45, respectively, which accounted for 14.98% of the total fungi genera of soil and air. When the linear discriminant analysis (LDA) threshold was>3.5, the two sauce-flavor Baijiu producing areas contain 41 significantly differential fungi genera, including Eurotium, Thermomyces and Saccharomycopsis. Therefore, it could be seen that there were obvious differences in the environmental fungal community structure between Gulin and Jian'ou, which further proved that different producing areas have a unique wine microbial ecological environment.

In order to optimize the fermentation process and enhance the quality of fermented Allium chinense, the bacterial diversity and dominant microbiota of traditional natural fermented A. chinense and its fermentation broth was analyzed using high-throughput sequencing. Lactic acid bacteria with excellent acid production, aroma generation, and amino nitrogen production capabilities were screened, the multi-bacterial complex fermentation system was constructed, and their antibacterial effects were investigated. The results showed that Firmicutes was the predominant phylum in traditional fermented A. chinense and its fermentation broth, with Leuconostoc and Lactobacillus as the dominant genera. A total of 25 lactic acid bacteria strains were initially screened, among which strains D1-9, D2-3 and D1 with strong acid production, acetoin production, and amino nitrogen production abilities were selected, respectively. These strains were identified as Lactiplantibacillus plantarum (D1-9), Pediococcus pentosaceus (D2-3), Lactobacillus pentosus (D1). After 24 h of cultivation, the total acidity, acetoin, and amino acid nitrogen contents of strain D1-9, D2-3, D1 reached 18.60 g/L, 47.16 mg/L, and 0.32 g/100 ml, respectively. The three strains had no antagonistic effect and mutualism when cultured together, and had significant antibacterial effect on foodborne pathogenic bacteria. When the mixture culture ratio of strains D1, D1-9 and D2-3 was 1∶1∶2, the fermented A. chinense achieved the highest levels of total acidity (0.92 g/100 g), amino acid nitrogen (0.202 g/100 g), acetoin concentration (52.08 mg/L) and sensory evaluation score (88.40).

In order to investigate the composition changes of ginseng powder before and after fermentation and the alleviating effect of exercise fatigue, the contents changes of total saponins, rare saponins (Rg3, Rg3R, Rg5), polysaccharide, protein, amino acid and short-chain fatty acid in ginseng powder before and after fermentation were analyzed, and a mouse experimental model to verify the alleviating effect of ginseng powder on exercise fatigue was established. The results showed that the total saponins contents of ginseng powder after fermentation were increased by 44.4%, and the rare saponins Rg3, Rg3R and Rg5 contents were 86 times, 9.3 times and 120 times of ginseng powder before fermentation, respectively. The types of free amino acids increased from 16 to 20, the total contents increased from 4.04% to 5.76%, and the lactic acid contents increased from (35.89±3.59) mg/kg to (19 702.20±1 970.22) mg/kg. Compared with the model control group, fermented ginseng powder could significantly prolong the exhaustive time of mice, reduce the lactic acid contents, malondialdehyde (MDA), urea nitrogen (BUN) and creatine kinase (CK) levels in serum of mice, increase the liver glycogen contents, lactate dehydrogenase (LDH), antioxidant enzyme levels, and adenosine triphosphate (ATP) enzyme activity, which showed that it had the effect of relieving exercise fatigue to some extent.

The physicochemical indexes, active microbial community structure, metabolic function, and correlation between virus groups and microbes of radish Paocai during the fermentation were studied by relevant national standard method, macrotranscriptome sequencing technology, Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and Spearman correlation analysis. The results indicated that in the fermentation process of radish Paocai, the pH value increased slightly at the beginning of fermentation, the reducing sugar content decreased rapidly, the salt content showed a non-monotonic increasing trend, the total acid content increased first and then decreased, the malic acid and succinic acid were rapidly consumed, and the lactic acid and acetic acid became the main organic acids. The predominant active microflora underwent a gradual transition to Lactobacillus (7.91%-22.68%) with fermentation, with Lactobacillus pentosus, Lactobacillus parafarraginis, Lactobacillus plantarum and so on being the dominant species among the 62 species of Lactobacillus. The major metabolic pathways of the active microflora were metabolism and genetic information processing. Additionally, the pathway associated with the immune system was active during the initial fermentation phase. The main virus groups were Siphoviridae, Myoviridae and so on in the radish Paocai, among which Lactobacillus phage, especially LP65, ATCC8014-B2 and so on were extremely active during the initial fermentation phase. A total of 30 significant positive and 14 significant negative correlations between 6 Lactobacillus phages and 62 Lactobacillus were found (|r |>0.8, P<0.05). The results of this study laid a foundation for revealing the regulatory mechanism of virus groups on microflora in the radish Paocai system.

In this study, the volatile aroma components of distilled Huaniu apple spirits at different distillation stages (distillation fraction Ⅰ with alcohol content 90%vol, distillation fraction Ⅱ with alcohol content 75%vol, distillation fraction Ⅲ with alcohol content 53%vol, distillation fraction Ⅳ with alcohol content 30%vol) were analyzed using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME- GC-MS). The results showed that a total of 108 aroma compounds in distilled Huaniu apple spirits were identified, including 61 esters, 33 alcohols, 5 acids, and 9 aldehydes and ketones. In the distillation process, the content of ester substances gradually decreased, the content of acid substances continuously increased, while the content of alcohols, aldehydes and ketones increased first and then decreased. Among them, the content of esters was the highest in distillation fraction Ⅰ, reaching 9 971.19 mg/L, the content of alcohols was the highest in distillation fraction II, reaching 2 328.92 mg/L, the content of acids was the highest in distillation fraction Ⅳ, reaching 1 363.42 mg/L, whereas the content of aldehydes and ketones was the highest in distillation fraction II, reaching 22.47 mg/L. Different distillation fractions of distilled Huaniu apple spirit were classified into three categories by hierarchical cluster analysis (HCA), distillation fraction Ⅰ with high types and contents of esters was a class, distillation fraction Ⅱ with high types and contents of alcohols was a class, distillation fraction Ⅲ and Ⅳ with high types and contents of acids, aldehydes and ketones were classified as a class. These study results provided a key basis for the in-depth understanding of the aroma formation mechanism of distilled Huaniu apple spirit, and provided theoretical support for optimizing production technology and improving product quality.

The volatile flavor components of 'Marselan' dry red and rose wines from Shacheng and Changli producing areas were analyzed by headspace solid-phase microextraction (HS-SPME)-gas chromatography-mass spectrometry (GC-MS), the key aroma substances of the wine samples were analyzed with odor activity value (OAV), and principal component analysis (PCA) based on the test results was carried out. The results showed that a total of 50 volatile flavor components were identified in the dry red wines from both producing areas, 47 and 49 kinds of volatile flavor components and 22 key aroma components（OAV>1） were detected in rose wine from Shacheng and Changli, respectively. The contents of volatile flavor components in rose and dry red wines from Shacheng producing area (0.74g /L and 1.46g /L) were higher than those in Changli producing area (0.59 g/L and 1.00 g/L), respectively. There were obvious differences in aroma profiles between 'Marselan' dry red and rose wines. The fruit aroma and cheese aroma of rose wine were prominent, and the contribution of linear fatty acid ethyl ester, fatty acid and isoamyl acetate was significant. Fruity, floral and mellow flavor of dry red wines were prominent, and the contribution of branched-chain fatty acid ethyl ester, β-ionone, 2-phenylethanol and higher alcohol was significant. Changli 'Matheran' dry red wines had significant floral aroma, and the contribution of phenylethanol, phenylacetaldehyde and β-ionone was significant. Shacheng 'Matheran' dry red wines had obvious mellow, plant aroma, and the contribution of 2,3-butanediol, 1-hexanol was significant. PCA could distinguish wine samples with different producing areas.

In order to efficiently prepare baicalein using synthetic biology techniques, a synthesis pathway of baicalein was constructed based on the synthetic chassis cell Ch-9 from Saccharomyces cerevisiae, which synthesizes chrysin. The coenzyme A ligase (4CL) mutant 4AT and the homologous enzyme CLL-7 gene from the Arabidopsis thaliana were integrated into the PAD1 gene site of the cinnamic acid decarboxylase. Gene substitution knockout was achieved through homologous recombination, and the yield of chrysin in shake flask fermentation of strain BA-C2-1 was 40.21 mg/L. The alkenyl reductase gene MdECR from apples was integrated and replaced into DBR gene site in S. cerevisiae, and enhance the expression of the ACS gene for acetyl CoA synthase to increase the supply of acetyl CoA. The results showed that the yield of chrysin by shake flask fermentation of recombinant yeast strain BA-C3-4 was 70.25 mg/L, which was 7.2 times higher than that of the original chassis cell Ch-9; After enhancing the expression of ACS gene and acetyl CoA, the yeast strain BA-C4-22 produced chrysin 125.04 mg/L in shake flask fermentation, which was 1.78 times higher than the experimental group without enhanced expression of ACS gene; Finally, the BA-C4-22 strain was integrated with the SbaiCYP82D4 gene and ART2 gene, to extend the synthesis endpoint to baicalein, the yield of baicalein in fermentation broth of strain BA-B1-5 was 70.94 mg/L.

In this study, the diversity of fungal flora in the fermentation process of Musalesi was analyzed by high-throughput sequencing technology, and yeast was isolated and screened by traditional culture separation method combined with morphological observation. Superior Saccharomyces cerevisiae were screened by physiological and biochemical tests, ethanol production, ester production capacity and acid tolerance analysis, and strains were identified by molecular biology technology. The results showed that the richness, uniformity and diversity of fungal flora increased first and then decreased, and a total of 25 fungi genera were identified during the fermentation process of Musalesi. The main fungal genera were Saccharomyces, Aspergillus, Talaromyces, Aureobasidium, Rhodotorula, Filobasidium, Morchella, Fusarium. The dominant fungi genera (relative abundance>1%) at the early stage of fermentation were Rhodotorula, Morchella, Fusarium and Filobasidium, at the middle stage of fermentation, there were Saccharomyces, Aureobasidium, Coriolopsis, Talaromyces, Penicillium, Aspergillus, and at the later stage of fermentation, there were Saccharomyces, Aspergillus, Talaromyces, Filobasidium, Penicillium. A total of two dominant yeast strains (numbered as J-1 and J-6) were isolated and screened in the fermentation process of Musalesi. They were both identified as S. cerevisiae, and their acid resistance and growth performance were superior to commercial S. cerevisiae SY.

In this study, the fermented grains was fermented using Miaojia Jiuqu (MJ), Anqi Jiuqu (AQ), Wuquxiang Jiuqu (WQ), and Guangxi Chinese herbal Jiuqu (ZY). The fungal flora diversity of different fermented grains was analyzed and compared with high-throughput sequencing technology, and the effect of different Jiuqu on fungal flora of fermented grains was investigated. The results showed that fungal flora in 4 fermented grains were assigned to 5 phyla and 24 genera. The dominant fungal phylum (relative abundance>1%) was both Mucoromycota and Ascomycota, and the common dominant fungal genera were Rhizopus and unidentified. In addition, the dominant fungal genera in AQ fermented grains included unclassified_Saccharomycetales, Candida, Aspergillus, Pichia. The dominant fungal genera in MJ fermented grains included Cyberlindnera, Aspergillus and Saccharomyces. The dominant fungal genera in WQ fermented grains included Aspergillus, Monascus, and Lichtheima. The dominant fungal genera in ZY fermented grains included Lichtheimia, Aspergillus and Candida. Principal coordinates analysis (PCoA) results showed that the fungal structure of MJ and WQ fermented grains was similar, but greatly different from AQ and ZY fermented grains. The correlation analysis showed that unclassified- Fungi, unidentified, Rhizopus and Cyberlindnera were closely linked with other species.

Alginate lyases are mostly derived from marine bacteria with unique living environments. Using sodium alginate as the sole carbon source, a strain with high-yield alginate lyase from 56 strains of marine bacteria was screened using primary screening by transparent circle method and rescreening for enzyme activity determination by 3,5-dinitrosalicylic acid (DNS) method. The screened strain was identified by morphological observation, physiological and biochemical tests and 16S rDNA gene sequence analysis, and using alginate lyase activity as the response value, the fermentation conditions for the screened strain for alginate lyase production was optimized by Plackett-Burman experiment combined with Box-Behnken response surface method. The results showed that the strain I14 with high-yield alginate lyase was obtained, and it was identified as Bacillus velezensis, and the optimum fermentation conditions for alginate lyase production by the strain I14 were determined as follows: sodium alginate addition 5 g/L, soluble starch addition 5 g/L, yeast powder addition 4.30 g/L, peptone addition 10 g/L, NaCl addition 30 g/L, CaCl₂ addition 0.30 g/L, initial pH 6.0, fermentation temperature 35 ℃, time 24 h, and liquid loading volume 30 ml/100 ml. Under these optimal conditions, the activity of alginate lyase reached 81.29 U/ml, which was 4.76 times that of before optimization. This study provided a new strain option for the development and utilization of alginate lyases, and expanded the application of strain I14 in food and biological fields such as degradation of alginate and production of polysaccharide lyases.

In order to obtain special yeast strains for sourdough, yeasts were isolated from traditional sourdough in Zhengzhou, Nanyang, Anyang, Zhoukou, Shangqiu and Sanmenxia by the method of traditional cultivation and separation methods. These tested strains were identified by molecular biology techniques and their fermentability were researched. The results showed that 9 strains were isolated and purified. 1 strain was identified as Saccharomycopsis fibuligera and 8 strains were identified as Saccharomyces cerevisiae. The 9 strains had different acid and ethanol tolerance. Strain Y2-1 had better tolerance, which could tolerate pH 1.5 and ethanol 16%. With the extension of fermentation time, the titration acidity of dough with different yeast addition showed an overall upward trend, while the pH value showed an overall downward trend. The volumes of the doughs increased gradually. Strains Y2-1 could increase the volume of dough by 1.23 times after fermentation for 3 h. To sum up, S. cerevisiae Y2-1 had better tolerance and the fermentation ability was the strongest, which could be used as an excellent strain to provide theoretical support for the development of direct delivery starter.

Using the sauce-flavor (Jiangxiangxing) Baijiu samples (Y5-Y17) aged for 5 to 17 years as the research object, the volatile flavor components and organic acid contents were detected using gas chromatography-flame ionization detector (GC-FID) and ion chromatography (IC). The characteristic differential volatile flavor components of Baijiu samples in different aging years were screened using partial least squares-discriminant analysis (PLS-DA). The results showed that 51 kinds of volatile flavor components were detected, including 13 alcohols, 6 acids, 18 esters, 7 aldehydes and ketones, 4 aromatics and 3 others. The volatile flavor components in 13 samples of sauce-flavor Baijiu were mainly esters (2 863.85-5 366.10 mg/L), alcohols (1 279.77-4 695.78 mg/L) and acids (2 191.60-3 053.50 mg/L). Among them, the contents of esters, alcohols and acids were the highest in Y5 sample, and the total contents of other components were the highest in Y6 sample. After that, as the storage year increased, the contents showed a downward trend, while the total contents of aldehydes and ketones and aromatic components had no change significantly with the storage year increase. PLS-DA result showed that the sauce-flavor Baijiu aged for less than 10 years and more than 10 years could be distinguished. Based on the variable importance projection (VIP) value, 13 characteristic differential volatile flavor components (VIP value>1), including para-butanol, ethyl lactate and isoamyl caproate, were screened. Among them, para-butanol and ethyl lactate were important characteristic differential volatile flavor components.

In order to investigate the effects of different production processes on the quality of commercial Doubanjiang, using the traditionally fermented Doubanjiang (TFD) and industrially fermented Doubanjiang (IFD) with consistent production cycles as research objects, the microbial community composition of them was analyzed using Illumina NovaSeq sequencing technology. The contents of free amino acid, volatile flavor substances and biogenic amine were detected by HPLC and GC-MS. The results showed that amino acid composition of two kinds of Doubanjiang was identical, but the content of 16 kinds of free amino acids were significantly different (P<0.05), and the proportion of fresh and sweet amino acid in TFD was higher. There were significant differences in the volatile flavor substances, and ethyl 3-methylbutyrate, ethyl 4-methyl-valerate, linalsol and β-ionone were the distinguishing differential aroma components in the two kinds of Doubanjiang. There were some differences in the dominant communities of the two kinds of Doubanjiang. The dominant communities (relative abundance>0.5%) in TFD were 16 bacterial genera including Virgibacillus and Lentibacillus, and 4 fungi genera including Starmerella and Wickerhamiella. The dominant communities in IFD were 7 bacterial genera, including Bacillus and Staphylococcus, and 5 fungal genera, including Aspergillus and Starmerella. The total biogenic amine content of TFD (299.85 mg/kg) was higher than that of IFD (272.37 mg/kg), and the contents of histamine, β-phenylethylamine and spermine were significantly different between them. Overall, IFD was better in terms of flavor and safety.

In this study, lactic acid bacteria were isolated and purified from Tongxian fish in Shangcheng county of Xinyang fermented for 5 d, 10 d and 15 d by dilution plate method and streak separation method, and lactic acid bacteria with excellent fermentation characteristics were screened by morphological observation and physiological and biochemical tests. The screened strains were identified by molecular biology techniques, and their growth and acid-producing properties were analyzed. The results showed that 19 strains were isolated and purified from fresh fish, 12 of them were lactic acid bacteria, all of which produced no viscosity, fermented glucose, maltose, lactose and sucrose, produced acid without gas, amino acid decarboxylase test results were negative, and could hydrolyze starch, among which strain L15-9 had the strongest starch hydrolysis ability, NaCl tolerance, nitrite tolerance and bacteriostasis ability. The results showed that a total of 19 strains were isolated and purified from Tongxian fish, of which 12 were lactic acid bacteria. All 12 strains did not produce viscosity, fermented glucose, maltose, lactose and sucrose produced acid but no gas. The results of amino acid decarboxylase test were negative, and all strains could hydrolyze starch. Among them, strain L15-9 had the strongest capacity of starch hydrolysis, NaCl resistance, nitrite resistance and antibacterial ability. Strain L15-9 was identified as Lactiplantibacillus plantarum. It rapidly entered a logarithmic growth phase after 2 h and a stable growth phase after 12 h, and its pH decreased to below 4.0 at 12 h.

Using Aspergillus oryzae 3.042 as the research object, the effects of different carbon sources, nitrogen sources, and inorganic salts on the quality of soy sauce seed koji were investigated by using spore production, hydrophobicity, trehalose content, and spore germination rate as the evaluation indicators. The results showed that glucose could increase the spore production, hydrophobicity and trehalose content of A. oryzae. Adding 5 g/kg of glucose (calculated by carbon element) could increase the spore numbers in seed koji by 34%. Ammonium sulfate, potassium dihydrogen phosphate and sodium dihydrogen phosphate could increase the spore number, hydrophobicity and germination rate of seed koji. Adding 3 g/kg of ammonium sulfate, the spore numbers of seed koji increased by 23% and the germination rate increased by 15 times. Adding 3 g/kg of potassium dihydrogen phosphate, the spore numbers of seed koji increased by 15% and the germination rate increased by 2 times. Adding 3 g/kg of sodium dihydrogen phosphate, the spore numbers of seed koji increased by 13% and the germination rate increased by 1.5-2.0 times.

In this study, using Musalais wine as base wine, and medicinal and edible homology plants such as black wolfberry, Cistanche deserticola, jujube and sea buckthorn as auxiliary materials, the Musalais wine with new formula was prepared by soaking the base wine with auxiliary materials. Using total flavonoids content and sensory score as response values, the formula of Musalais wine was optimized by single factor combined with response surface tests. The basic physicochemical indexes were analyzed, and the effects of different auxiliary materials on the physicochemical indexes and sensory evaluation of Musalese wine were investigated. The results showed that the optimal formula of Musalais wine was black wolfberry 8.8 g/L, C. deserticola 8.3 g/L, jujube 10.4 g/L, sea buckthorn 4.2 g/L. The total flavonoids content in the Musalais wine with new formula reached 0.61 g/L under these optimal conditions, with a sensory score of 91, and the contents of total phenols, total flavonoids, fructose and glucose were increased by 0.45 g/L, 0.29 g/L, 5.15 g/L, 7.13 g/L, respectively. All 4 auxiliary materials could increase the malic acid, fructose and glucose contents of the wine, and the addition of jujube and C. deserticola significantly increased the lactic acid content of the wine, while the addition of sea buckthorn significantly increased the total flavonoids content of the wine. The addition of auxiliary materials enhanced the organoleptic complexity of Musalais wine, and the finished wine had a good overall performance in terms of comprehensive, appearance, aroma, taste and balance.

Pineapple fruit wine was prepared by constant temperature (22±1) ℃ fermentation process using fresh pineapple as the test material in this study. Using pineapple wine fermented with the unbleached pulp as the control, the effects of blanching treatment (95 ℃, 120 s) of fruit pulp on the quality indexes, antioxidant activity and volatile flavor compounds of pineapple fruit wine was investigated by measuring the sugar, acid, total polyphenol contents, and the antioxidant activities during pineapple fermentation process. The results showed that the sugar content of pineapple fruit wine decreased to less than 4.0 g/L during the fermentation, the total acid, total polyphenol contents, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rates and Ferric ion reducing/antioxidant power (FRAP) value increased first and then tended to be stable. Blanching treatment caused a lag in the glucose reduction rate of pineapple fruit wine, extended fermentation time for 4 d, and the contents of total phenol and ascorbic acid, DPPH scavenging rates and FRAP value during the fermentation were significantly lower than those of control group (P<0.05). A total of 24 volatile flavor components (11 alcohols, 5 esters, 5 acids, 2 aldehydes and 1 ketone) were detected in the pineapple fruit wine samples, among which no ethyl formate and ethyl caproate were detected in the control group, and no furfural and 3-hydroxy-2-butanone were detected in the blanching treatment group. The types of esters in pineapple fruit wine were increased by blanching, but the contents of ethyl acetate and ethyl lactate were decreased by 26.1% and 91.8%, respectively. Blanching of pineapple pulp made pineapple fruit wine more harmonious and mellow in taste.

In order to compare the quality of Zhejiang traditional semi-solid naturally fermented vinegar (M1 and M3) and submerged fermented vinegar (M2 and M4), the physicochemical properties, active components, volatile flavor compounds, and antioxidant activities of M1-M4 were measured, sensory properties were evaluated, and the correlation analysis based on the results was conducted. The results showed that the contents of reducing sugar, amino acid nitrogen, total phenols, and total flavonoids in M1 and M3 were significantly higher than those in M2 and M4 (P<0.05), a total of 8 organic acids and 17 free amino acids (including 8 essential amino acids) were identified in M1-M4, the contents of sweet and bitter amino acids in M1 and M3 were significantly higher than those in M2 and M4 (P<0.05), while the acetic acid contents in M2 and M4 (5.64 g/100 ml, 6.43 g/100 ml) were significantly higher than those in M1 and M3 (3.87 g/100 ml, 3.42 g/100 ml) (P<0.05). Compared to submerged fermented vinegar, traditional semi-solid naturally fermented vinegar had stronger antioxidant activity and better sensory quality. A total of 112 volatile flavor compounds were identified in M1-M4, and the total contents of volatile flavor compounds in the 4 vinegar samples were M4 (801.21 mg/L)>M3 (615.16 mg/L)>M1 (562.37 mg/L)>M2 (241.03 mg/L). Correlation analysis results showed that acetone and 3-acetyl-2-butanone could improve the ester aroma and sweetness, while amino acid nitrogen showed a significant positive correlation with sweetness (P<0.05). In conclusion, traditional semi-solid naturally fermented vinegar was superior in quality and sensory properties.

In order to establish a fast, efficient and accurate technology based on gathering distillate according to the quality, the volatile flavor components in different grades of original liquor (initial distillate, middle distillate, last distillate) were analyzed by gas chromatography-mass spectrometry (GC-MS), the principal components were selected by principal component analysis (PCA). The spectrum was obtained by Fourier transform near-infrared spectroscopy (FT-NIR), and the spectrum pretreatment and wavelength screening were performed, the regression prediction model was established based on the principal components, and the model of gathering distillate according to the quality was constructed by random forest (RF). Results showed that 17 principal components were selected by PCA. Multiplicative scatter correction (MSC), competitive adaptive reweighting algorithms sampling (CARS) and support vector regression (SVR) were better methods to construct the regression prediction model, with coefficient of determination R² and root mean square error (RMSE) mean values of 0.8951 and 0.03, respectively. The model of combining with RF was the optimal, and the accuracy rate, precision and recall rates of the model were 99.10%, 99.62% and 99.78%.

In order to explore the efficient and appropriate aging method for wine, the effect of microwave-ultrasonic synergistic aging treatment on volatile flavor compounds of wine was investigated. Using fresh wine sample (S₁) without aging as a control, the volatile flavor components of wine samples (No. S₂-S₄) with different aging treatment were detected by gas chromatography-mass spectrometry (GC-MS), and the key flavor components were screened based on the relative odor activity value (ROAV) (1<ROAV<100), and the results were analyzed by principal component analysis (PCA). The results showed that a total of 205 volatile flavor substances were detected in wines with different aging treatments, and a total of 108, 134, 137 and 141 volatile flavor substances were detected in the samples from S₁ to S₄ , and the key flavor substances were 14, 4, 18 and 14, respectively, among which esters, acids and alcohols were the main flavor substances in wines, and the types of volatile flavor substances increased after the synergistic aging of the wines with microwave-ultrasonic aging. The results of PCA showed that the difference between S₃ samples and fresh wine sample (S₁) was minimal, and PCA could effectively distinguish wine samples with different aging treatment based on volatile flavor substances. Under the conditions of ultrasonic power 260 W and microwave power 100 W, the optimal microwave-ultrasonic synergistic aging treatment for wine was aging at 40 ℃ for 20 min, and then at 15 ℃ for 20 min after 7 d.

In order to investigate the effects of different SO₂ addition on the quality of 'Beibinghong' dry red wine, using 'Beibinghong' picked in 2019 as the test material, dry red wine was brewed by adding SO₂ with different mass concentrations. The contents of residual sugar, total acid, organic acid, anthocyanin content, color and sensory evaluation of dry red wine samples were determined, and the quality was evaluated comprehensively by principal component analysis (PCA). The results showed that the 'Beibinghong' dry red wine brewed with 50 mg/kg SO₂ addition had the lowest residual sugar content (4.74 g/L), and the highest anthocyanoside content (279.43 mg/L) and better color with 40 mg/kg SO₂ addition. The content of total acid (5.45 g/L), total organic acid (5.44 g/L), malic acid (0.15 g/L) and citric acid (0.18 g/L) in 'Beibinghong' dry red wine brewed with 30 mg/kg SO₂ addition was the lowest, and the content of lactic acid (0.89 g/L) and succinic acid (0.61 g/L) was the highest, which could effectively reduce the acidity of 'Beibinghong' dry red wine. The wine was mellow, moderate acidity, soft taste, and the sensory score (96.01) was the highest. Combined with PCA, the overall quality of 'Beibinghong' dry red wine was the optimal when the SO₂ addition was 30 mg/kg.

In order to improve the comprehensive utilization rate of passion fruit and roselle, increase the variety diversity of fruit wine, using Yunnan purple skin passion fruit as raw material with addition of aqueous roselle extracts, the passion fruit-roselle complex fruit wine was prepared by immobilized Saccharomyces cerevisiae. The sensory, physicochemical, microbial quality indexes and antioxidant activity were evaluated. The fermentation process of the passion fruit-roselle complex fruit wine was optimized by single factor tests and response surface tests using sensory score and alcohol content as evaluation indexes. The results showed that the optimal fermentation conditions for passion fruit-roselle complex fruit wine were initial sugar 20 °Bx, yeast inoculum 0.6%, fermentation temperature 28 ℃ and roselle aqueous extract addition 10%. Under these optimal conditions, the complex fruit wine exhibited a clear color, rich fruit aroma, and unique fermented flavor, with a sensory score of 87.8 points and alcohol content of 10.0%vol, and all quality indicators met the relevant regulations specified in NY/T 1508—2017 "Green Food-Fruit Wine." The scavenging rates of the complex fruit wine on 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), 2,2'-biazobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), hydroxyl and superoxide anion radicals were 73.7%, 100%, 89.2%, and 58.4%, respectively. The results showed that passion fruit-roselle complex fruit wine had better antioxidant activities.

By measuring the CO₂ mass loss during the alcohol fermentation stage of bran vinegar, the alcohol content, reducing sugar, total acid content, volatile aroma substances, and sensory quality of the fermented liquor samples, the effects of Saccharomyces cerevisiae and Lactiplantibacillus plantarum inoculated at different time (numbered as S4L, S2L, SL, L2S, L4S, S) on the quality of bran vinegar during the alcohol fermentation stage were studied. The results showed that the CO₂ mass loss of the sample was the largest on the first day of fermentation, and then decreased slowly and tended to be stable. The earlier the inoculation time of L. plantarum, the smaller the CO₂ mass loss. The inoculation of L. plantarum inhibited the formation of alcohol, and the alcohol content of the samples except for the S4L group was significantly lower (P<0.05), but there was no significant difference among the groups (P>0.05). The total acid content increased gradually with the advance of inoculation time of L. plantarum. The inoculation of L. plantarum significantly improved the utilization rate of reducing sugar in the fermentation system (P<0.05). The main volatile flavor components in fermented liquor samples were esters, alcohols and acids. The inoculation of L. plantarum affected the flavor of the fermented liquor samples, and the earlier the inoculation time of L. plantarum, the higher the total content of esters and alcohols, the more prominent the fruit, grass and sour aroma of liquor sample, but it had a certain inhibitory effect on sweet and grain aroma. Except for L2S group, the content of acetic acid increased with the advance of inoculation time of L. plantarum. In conclusion, the inoculation of L. plantarum could improve the quality of bran vinegar during the alcohol fermentation stage.

In order to deeply explore the value of pomegranate peel, a total of nine strains of yeasts, lactic acid bacteria and molds were selected for the liquid fermentation of pomegranate peels, respectively, and the contents of tannin, ellagic acid, total phenols, total flavonoids, total sugar and total fiber, antioxidant activity, color and volatile flavor substances in pomegranate peel were compared after 5 d of fermentation by different strains. The results showed that the contents of tannin (hydrolyzed tannin 0.16 mg/g, condensed tannin 6.23 mg/g) and total fiber (20%) were the lowest after fermentation by Aspergillus oryzae, the total sugar contents (3.5%) were the lowest after fermentation by Mucor sp., the contents of total flavonoids (6.45 mg/g) were the highest after fermentation by Monascus sp., and the contents of total phenols (98.54 mg/g) and ellagic acid (98.53 mg/g) were the highest after fermentation by Streptococcus thermophilus. After fermentation with Lactobacillus acidophilus, the scavenging rates of DPPH radical (90.98%), ABTS radical (85.03%), hydroxyl radical (36.60%) and superoxide anion radical (49.22%) were the highest, and the antioxidant capacity was the optimal. The color of pomegranate peel after fermentation by 5 strains of lactic acid bacteria was closer to that of fresh pomegranate peel, it was reddish brown after fermentation by Monascus sp., ginger after fermentation by A. oryzae and Mucor sp., and light yellow after fermentation by angel yeast. 4 strains of lactic acid bacteria and angel yeast had similar effects on the volatile components of pomegranate peel to a certain extent, and the components of pomegranate peel after fermentation by 3 strains of molds and Lactiplantibacillus plantarum were unique.

Stachys affinis craft beer was brewed using malt and S. affinis as the primary ingredients. The effects of S. affinis addition time, S. affinis addition and original wort concentration on sensory score and alcohol content of S. affinis craft beer were investigated by single factor experiment. On this basis, using the sensory score as response value, the optimal brewing process of S. affinis craft beer was optimized by response surface test, and its physicochemical properties and antioxidant activity were studied. The results showed that the optimal fermentation conditions of S. affinis craft beer were original wort concentration 11 °P and S. affinis pulp addition 2.5% at 43 min after the boiling. Under these conditions, the S. affinis craft beer exhibited a clear body, mellow taste, fine foam, and sensory score 90.6 points, diacetyl content 0.043 mg/L, chroma 12.85 EBC, total acid content 1.92 mg/100 ml, bitterness value 15.26 IBU, and alcohol content 4.87%vol. Its physiochemical indexes met the requirements of relevant national standards. The S. affinis craft beer had certain antioxidant activity, and the scavenging rates of 2,2'-diazo-bis (3-ethyl-benzothiazole-6-sulfonic acid) diamiammonium salts (ABTS) and 1, 1-diphenyl-2-phenylhydrazyl (DPPH) free radicals were 94.28% and 85.51%, respectively.

In order to investigate the effects of different lactic acid bacteria on the fermentation components and antioxidant activity of black chokeberry juice, six strains of lactic acid bacteria (Lactiplantibacillus plantarum LP-G18, Lactobacillus acidophilus LA-G80, Lactobacillus casei LC-G11, Lactobacillus rhamnosus LR-G14, Lactobacillus reuteri JYLB-291, and Lactobacillus paracasei JLPF-176) were selected to ferment black chokeberry juice. The lactic acid bacteria counts, physicochemical indexes, color characteristics, bioactive substances and in vitro antioxidant activities of the fermented black chokeberry juice were analyzed, and the correlation analysis of its quality indexes was carried out. The results showed that compared with the control group, lactic acid bacteria fermentation could improve the physicochemical properties (all higher than 8.50 lg CFU/ml), reduce pH, increase the contents of total acid, total flavonoids, total polyphenols, total anthocyanins and main flavonoids, phenols and anthocyanins, reduce the content of reducing sugar and soluble solids, and improve color and enhance antioxidant activity in vitro. In summary, the antioxidant activity of strains LR-G14, LC-G11 and JLPF-176 was better. Correlation analysis showed that total flavonoids, total polyphenols, syringic acid and cinnamic acid were significantly positively correlated with antioxidant activities in vitro (P<0.05).

Chilli was fermented using stainless-steel tank and ceramic tank as containers. The quality characteristics and microbial changes of fermented chilli were explored through analyzing physicochemical properties, lactic acid bacteria count, etc. The results indicated that the pH value of the stainless-steel tank group (ST group) first decreased to 4.0 than the ceramic tank group (CK group) during the fermentation process. After 12 d of fermentation, the lactic acid content (3.65 g/L) and total acid content (4.61 g/kg) of the ST group were significantly higher than those of the CK group (3.11 g/L, 3.60 g/kg) (P<0.05). During the fermentation process, the nitrite peak in the ST group was earlier than that in the CK group, and the nitrite content in both groups was less than 0.89 mg/kg after 12 d. There was no significant difference in hardness and chewability between the two groups after fermentation (P>0.05). The number of lactic acid bacteria in the ST group showed a stable increase during the fermentation process, reaching a peak of 7.55 lg (CFU/ml), which was higher than the CK group [7.11 lg (CFU/ml)]. The results of electronic nose analysis showed that the response values of nitrogen oxides and alcohol, some aromatic compounds in the ST group during the fermentation process were significantly higher than those of the CK group (P<0.05). The study indicated that it was feasible to ferment Paocai in stainless-steel tank, which could improve the quality of Paocai and replace traditional ceramic tank fermented Paocai in industrial production in the future.

Using blueberries, Chinese yam, and milk as raw materials, blueberry and Chinese yam flavored fermented milk was prepared. Using sensory evaluation score as the evaluation index, the fermentation process was optimized by single factor experiments, fuzzy mathematical comprehensive evaluation, and response surface methodology. The physiochemical indicators, microbial indicators, and antioxidant activity of the fermented milk were detected and analyzed. The results showed that the optimal fermentation conditions for blueberry and Chinese yam flavored fermented milk were as follows: milk 77.4%, blueberry juice 10.5%, Chinese yam pulp 5.9%, sugar 6%, bacterial starter addition 0.2%, and fermentation time 6.1 h. Under these optimized conditions, the sensory score of blueberry Chinese yam flavored fermented milk reached 93.28 points, and its acidity, protein content, soluble solids content were 93 °T, 3.67 g/100 g and 15.1%, respectively. The total number of bacterial colony was 1.73×10⁵ CFU/ml, and the lactic acid bacteria counts was 1.82×10⁶ CFU/ml. Escherichia coli and Staphylococcus aureus were not detected. All indicators met the requirements of relevant national standards. The antioxidant activity results showed that the scavenging rates of 1,1-diphenyl-2-phenylhydrazyl (DPPH) free radicals, hydroxyl free radicals and the reduction/antioxidant capacity of Fe³⁺ were 79.0%, 72.6% and 1.396, respectively, indicating that the fermented milk had certain antioxidant capacity.

Using Panax quinquefolius and fig as raw materials, yeast as fermentation strain, and P. quinquefolius-fig compound fruit wine was prepared. Based on the single factor test, the fermentation conditions of P. quinquefolius-fig compound fruit wine was optimized by response surface test with total ginsenosides and sensory scores as response values. The physicochemical, microbial indexes and antioxidant capacity were determined. The results showed that the optimal fermentation technology conditions were as follows: inoculum 0.05%, fermentation temperature 22 ℃, time 8 d, soak time of P. quinquefolius 24 h. Under these optimization conditions, P. quinquefolius-fig compound fruit wine had orange color, sweet and mellow, with a unique typical of P. Quinquefolius and fig, and sensory score was 83.7 points. The total ginsenosides content was 1.58 mg/ml, alcohol content was 11.52%vol, total acid was 6.09 g/L, total sugar was 43.20 g/L, total bacterial colony was 10 CFU/ml, and no Escherichia coli and pathogenic bacteria were detected. Its physicochemical and microbiological indexes were in line with the relevant standards. In addition, the free radical scavenging rate of 1,1-diphenyl-2-trinitrophenylhydrazide (DPPH) in P. quinquefolius-fig compound fruit wine was 93.25%, indicating that it had certain antioxidant capacity.

A method for the determination of trace volatile aroma components in sauce-flavor (Jiangxiangxing) Baijiu was developed by dispersed liquid- liquid microextraction (DLLME) combined with gas chromatography-mass spectrometry (GC-MS). The trace volatile aroma components in the sauce- flavor Baijiu samples from Renhuai and Xishui producing areas were detected, and cluster analysis and partial least squares-discriminant analysis (PLS-DA) were carried out based on the detection results. The results showed that the DB-FFAP capillary column (60 m×0.25 mm×0.25 μm) was adopted, and extraction for 2 min with ether/n-hexane (1∶1) as the extractant. Under these conditions, 59 trace volatile aroma components in sauce-flavor Baijiu could be qualitatively and quantitatively determined effectively, and each component showed a good linear relationship within the detection range. The correlation coefficient (R²) of this method was 0.996 3-0.999 9, the detection limit was 0.15-2.43 μg/L, the quantification limit was 0.28-6.07 μg/L, the spiked recovery rates were 93.00%-103.94%, and the relative standard deviation (RSD) of precision tests (n=6) was 0.34%-6.30%, which indicated that the precision and recovery rates of this method were good and could meet the detection requirements of 59 trace volatile aroma components in sauce-flavor Baijiu. The sauce-flavor Baijiu samples from Renhuai and Xishui producing areas could be effectively distinguished according to 59 trace volatile aroma components. 8 kinds of main difference trace aroma components such as dimethyl disulfide and trimethyl pyrazine, could be screened according to variable importance in the projection (VIP) value>1.

In order to establish an efficient and accurate method for detecting various trace components in strong-flavor (Nongxiangxing) Baijiu, a gas chromatography (GC) method for the detection of 53 volatile flavor components in strong-flavor Baijiu was established by optimizing the column types, split ratio and programmed temperature conditions. The results showed that the optimal GC conditions were as follows: CP-WAX 57 CB capillary column (50 m×0.25 mm×0.2 μm), a split ratio of 40:1, and a programmed temperature (initial temperature 35 ℃ for 5 min, increased at 4 ℃/min to 45 ℃ for 3 min, increased at 8 ℃/min to 140 ℃ for 2 min, then increased at 20 ℃/min to 205 ℃ for 16 min). This method could detect 53 volatile flavor substances in strong-flavor Baijiu within 44 min, achieving good linearity for each component within their respective concentration ranges (R²≥0.998 6). The limits of detection was 0.26-5.09 mg/L, limits of quantification was 0.87-18.97 mg/L, spiked recovery rate was 80.10%-113.21%, and the relative standard deviation for precision tests was 0.25%-2.75%. The results indicated that the method was simple to perform, with a short detection time and good separation performance, and could meet the requirements for detecting main flavor components in strong-flavor Baijiu.

Using 129 whiskies from different regions such as Scotland, Ireland, America and Japan as research samples, the differences in carbon stable isotope ratios (δ¹³C) of isobutanol, n-propanol, amyl alcohol, ethyl acetate, acetaldehyde and ethanol among the volatile flavor components was detected, and a method for the identification of exogenous alcohol in whiskey was established by gas chromatography-combustion-stable isotope mass spectrometry (GC-C-IRMS). Results showed that the δ¹³C of ethanol in Scottish single malt whisky ranged from -27.84‰ to -25.04‰, the δ¹³C of ethanol in Scottish blended whisky ranged from -28.21‰ to -20.72‰, the δ¹³C of ethanol in whisky containing corn raw material ranged from -26.66‰ to -12.83‰, the δ¹³C of ethanol in whisky without corn raw material ranged from -28.86‰ to -24.04‰. Based on the fitted linear intercept deviation range (2SD) to discriminating adulteration, the δ¹³C of ethanol showed good linear relationship with that of n-propanol, isobutanol and acetaldehyde in whisky. The correlation coefficients (R²) was 0.876, 0.832, and 0.868, respectively. By combining the linear intercept deviation range with the δ¹³C distribution range of ethanol, the identification of whisky exogenous alcohol is more sensitive.

A gas chromatography-tandem mass spectrometry (GC-MS/MS) method was established for the simultaneous determination of 9 succinate dehydrogenase inhibitor (SDHIs) compounds in vegetables. Samples were extracted with 10 ml acetonitrile, then salted out to separate the layers. The supernatant was purified using 30 mg N-primary secondary amine (PSA) and 30 mg octadecylsilane chemically bonded silica (C18) solid phase extraction agent, concentrated under nitrogen and dissolved with ethyl acetate. 9 SDHIs were separated by gas chromatography and ionized by electron ionization (EI) source, while the ion pairs were collected by multiple reaction monitoring (MRM) mode. The results showed that 9 SDHIs showed good linear relationships within their respective concentration ranges. The correlation coefficient R²>0.994, the limits of detection (LODs) of method ranged 1.00-6.00 μg/kg, while the limits of quantification (LOQs) of method ranged 3.00-20.0 μg/kg. The results of different levels of spiked experiments for 9 SDHIs showed a good recovery rate of 80.4%-98.2% and the relative standard deviations (RSDs) were 3.0%-7.9%. The method was efficient, fast, easy to operate, with low detection cost, high recovery rate, high sensitivity, and good reproducibility, which was suitable for batch determination of 9 SDHIs in daily vegetables.

With the rapid development of the digital economy, the digital content marketing of Baijiu enterprises has become a critical strategy for enhancing the brand competitiveness. The operational logic and optimization paths of digital content marketing models were explored by an empirical analysis of the digital marketing practices of Kweichow Moutai Group. The study revealed that consumers' brand identity, purchase intention and word-of-mouth willingness were significantly enhanced by five dimensions of content marketing, including functional information, entertaining information, self-concept, social interaction, and brand interaction. Brand identity served as a mediating factor between content marketing and consumer behavior, while consumers' status motivation moderated this relationship. The optimization suggestions for digital content marketing were made, helping Baijiu enterprises overcome traditional marketing bottlenecks, achieve brand rejuvenation, and expand market reach.

Using managers of craft beer enterprises, operators of social e-commerce platforms, and consumers of craft beer as research samples, an innovative marketing model of social e-commerce for craft beer was constructed by applying grounded theory. The results showed that the social e-commerce marketing innovation model of craft beer included four types: immersive experience and virtual community operation, gamified interaction and co-creation of social e-commerce, intelligent shopping guide and subscription social mode, and social responsibility oriented social communication. Immersive experience enhanced consumers' sense of participation and belonging to the brand through virtual technology and community activities; gamification mechanisms and co-creation activities enhanced users' emotional identification with the brand, and expanded brand influence through social communication; smart guide and subscription model and the socially responsible communication model promoted consumers' trust and continuous identification through accurate recommendation and responsible communication. Based on the above results, it was recommended that craft beer companies should utilize digital tools for market segmentation and precision marketing to improve marketing efficiency; strengthen the dissemination of brand stories and cultural connotations to attract consumers through content marketing; actively build and manage virtual communities to enhance consumers' sense of belonging to the brand; and incorporate social responsibility into their corporate strategies to enhance their brand image through environmental protection and social welfare activities.

The rapid development of the Internet and mobile communication technology has given rise to the explosive growth of data volume. Guizhou province has made remarkable achievements in the construction of big data infrastructure, and as a pioneer in the big data industry, the Internet market in Guizhou province has shown diversified development. However, the core value of big data lies in its ability to serve socio-economic development, not just data storage. Relying on its unique natural geography and ecological environment, Guizhou province has developed a sauce-flavor (Jiangxiangxing) Baijiu industry represented by Moutai Baijiu, which has become one of the key pillars of the province's economy. Although big data is regarded as an important tool to enhance the competitiveness of enterprises, there are few successful cases in the practical application of Baijiu enterprises in Moutai town. In this paper, the current situation and challenges of Moutai town Baijiu enterprises in big data application was analyzed, the constraints on big data application caused by insufficient technical infrastructure, shortage of talents, data security and privacy protection, corporate culture and management mode were discussed, and suggestions on big data application strategy for Moutai town Baijiu enterprises were put forward. It not only provided theoretical guidance and practical suggestions for Baijiu enterprises in Moutai town, but also provided reference for small and medium-sized enterprises in other regions on big data application, which had certain theoretical and practical significance.