Organization in Charge:
China General Chamber of Commerce Sponsored by:
China Condiment Industrial Association
Beijing Academy of Food Science Issue Code: 2-124 Oversea Code: M 1437 ISSN 0254-5071 CN 11-1818/TS
In recent years, with the growing emphasis on healthy diets and functional foods, bioactive peptides have garnered significant attention due to their potential nutritional value and physiological functions. At present, although some studies have reported the existence of bioactive peptides in Baijiu, fermented grains (Jiupei) and distiller's grains (Jiuzao), systematic research is still insufficient. In this paper, the preparation, separation, purification and identification methods of peptides were summarized, and the research progress of peptides with antioxidant, anti-inflammatory and antihypertensive activities in Baijiu, Jiupei and Jiuzao was systematically reviewed. Finally, the future research directions of bioactive peptides in Baijiu, Jiupei and Jiuzao were prospected, and corresponding suggestions were put forward. Through in-depth excavation of bioactive peptides in the Baijiu brewing process, it aimed to provide theoretical foundation for the healthy development of the brewing industry, and provide new ideas for the resource comprehensive utilization of brewing by-products and the innovative development of the Baijiu industry.
As an important component of human dietary culture, the history of traditional fermented foods can be traced to approximately 8 000 BC. The global market size of fermented foods reached $98.6 billion in 2023 and is projected to grow to $130 billion by 2032, with dairy and vegetable products dominating the market. Some functional microorganisms beneficial to human health have been found in these fermented foods, which play a core role in traditional fermentation foods and endow the foods with unique flavors, textures and nutritional values through fermentation metabolism. The short-chain fatty acids, polyphenols, and bioactive peptides and other active substances produced by metabolism have significant effects in improving intestinal health, enhancing immunity, inhibiting inflammatory responses, promoting nutrient absorption, and regulating metabolism. With the global aging population and rising incidence of chronic diseases, the demand for functional foods has significantly increased, promoting the development and market expansion of related products. In the future, research on functional microorganisms will integrate metagenomics, synthetic biology, and multi-omics technologies to further optimize strains and processes, providing a scientific basis for the development of functional foods and promoting the sustainable development of the health-focused industry.
With the continuous rise in labor costs and the increasingly serious problems such as resource shortages, more and more sauce-flavor (Jiang- xiangxing) Baijiu enterprises have started to transform from traditional brewing to mechanized, automated and intelligent production. To clarify the mechanism of intelligent brewing, as well as to ensure the production and quality of intelligent brewing of sauce-flavor Baijiu have become an industry- wide research hotspot. In this paper, the application of key technologies of intelligent brewing in the production of Jiuqu-making, steaming, cooling, fermentation and gathering liquor, as well as the effects of traditional process intelligence on the microecology, production and quality of sauce-flavor Baijiu brewing were summarized. In addition, the corresponding solutions to the problems of intelligent brewing of sauce-flavor Baijiu were put forward, aiming to provide theoretical reference for the intelligent development of sauce-flavor Baijiu.
High temperature stacking is one of the indispensable technical links in the brewing process of sauce-flavor (Jiangxiangxing) Baijiu, which has the saying that "no stacking, no liquor". It can naturally gather and enrich microorganisms in the drying environment to form a stable microbial community structure, and provide functional strains, enzymes, and aroma substances for fermentation in the pit. The analysis of dominant functional microorganisms and characteristic aroma substances in the fermentation process of stacking fermented grains can clarify the complex change rules and functional relationships of microorganisms, physiochemical factors and flavor substances, as well as the unique production process characteristics of sauce-flavor Baijiu. The enzymes and aroma producing microorganisms during the fermentation of stacking fermented grains, as well as the dynamic changes of dominant fungi and bacteria in different rounds fermentation of stacking fermented grains were systematically reviewed. The changes in physicochemical factors and flavor substances during different rounds fermentation of stacking fermented grains were expounded, and the relationships among microorganisms, physicochemical factors, and flavor substances in the fermentation process of stacking fermented grains were analyzed.
To understand and master the current development situation and direction of China's plant-derived flavor beer, better promote the iterative upgrading of China's beer industry, optimize product structure, expand market scale, and explore ways to develop and utilize local characteristic plant resources. In this study, through the combination of literature research and field investigation, a new type of beer in the market at present were defined and classified, and the future development direction and prospect were predicted on the basis of summarizing and analyzing the present situation. The results indicated that the market scale of plant-derived flavor beer has shown a steady growth trend, and has begun to enter the international market to participate in competition, which promotes the Chinese beer production enterprises to continuously improve the global operation ability. The pursuit of healthy diet and personalized experience is the main driving force for the development of new beer categories; Clean production, digital production, and international development are important directions for the industry development; Building personalized new experiences in diverse scenarios and establishing a new mechanism for harmonious coexistences between standards and traditional craft is to meet the needs of market development. The development and utilization of local characteristic plant resources, as well as the continuous establishment and improvement of industry norms and laws and regulations are the foundation for promoting the development of enterprises. Plant-derived flavor beer is expected to occupy a more important position in the future development of the beer market and become one of the important forces to promote the diversified development of the beer industry.
In this study, using the 1st to the 7th rounds of base liquor of sauce-flavor (Jiangxiangxing) Baijiu as research objects, the sensory characteristics and volatile components were analyzed by quantitative descriptive analysis (QDA), gas chromatography-mass spectrometry (GC-MS), and gas chromatography (GC), and the differences of volatile components and their correlation with sensory attributes were analyzed by orthogonal partial least squares discriminant analysis (OPLS-DA) and partial least squares regression (PLSR) analysis, respectively. The results showed that the 1st and 2nd rounds of base liquor had obvious grain, sour and fruity aroma with prominent sourness, the 3rd, 4th and 5th rounds of base liquor had floral, grassy, sauce, Daqu and pasty aroma with obvious aftertaste of sweetness and purity, while the 6th and 7th rounds of base liquor presented strong pasty and Daqu aroma, highlighted by bitterness and aftertaste. A total of 272 volatile components were identified from the base liquor of each round. In terms of categories, esters were the most abundant, and the differences in the types of substances between rounds were mainly concentrated on esters, aldehydes and ketones. In terms of content, as the number of rounds increased, the contents of alcohols, esters and acids showed a decreasing trend, while the others showed an increasing trend. Based on the variable importance in the projection (VIP)>1 and the odor activity value (OAV)>1, 13 main components contributed to content difference and 45 important components contributed to aroma difference were screened from the base liquor of each round, respectively, which were correlated with the sensory attributes of base liquor of each round.
Long-lived strains of Saccharomyces cerevisiae were screened under high-concentration glucose conditions by adaptive laboratory evolution (ALE), and the viability, growth characteristics, and glucose fermentation capacity of the selected strains were measured using wild-type S. cerevisiae BY4742 as the control. The results indicated that the viability and adaptability of the 10 strains of S. cerevisiae screened by ALE method were significantly improved under high-concentration glucose conditions, and the viability of these strains on the 5th day was 20.43 times that of the wild-type S. cerevisiae BY4742, with a maximum of 26.74 times, and still maintained an average relative viability of 1.79% on the 10th day. Concurrently, the growth characteristics and glucose fermentation capacity of the selected strains showed no significant differences compared to the wild-type S. cerevisiae BY4742, although their total biomass under high-concentration glucose conditions reached up to 1.25 times that of the wild-type S. cerevisiae BY4742. ALE was an effective method for selecting high-glucose-tolerant and long-lived S. cerevisiae strains, which provided a practical foundation for the breeding of industrial strains suitable for high-concentration sugar and high-density fermentation processes.
In this study, using Aspergillus oryzae Huniang 3.042 as the main strain for koji-making, and Aspergillus niger 3.350 and Pediococcus pentosaceus WT9 were added for multi-strain collaborative koji production. The effect on the quality of finished koji and soy sauce was explored. The results showed that the comprehensive quality of the finished koji and soy sauce prepared by A. niger 3.350, P. pentosaceus WT9 and A. oryzae Huniang 3.042 was the optimal. Compared with the finished koji prepared by A. oryzae Huniang 3.042, the activities of neutral protease, acidic protease, amylase and cellulase in the finished koji were increased by 27.73%, 27.52%, 79.53% and 7.46%, respectively, and the contents of total phenols and total flavonoids were increased by 9.65% and 11.04%, respectively. In addition, the use of compound strains for koji-making could increase the contents of total acid, amino acid nitrogen and reducing sugar in soy sauce increased by 12.50%, 19.61% and 69.23%, respectively, the contents of organic acid and free amino acid increased by 16.25% and 31.87%, respectively, and the contents of total phenol and total flavonoids increased by 8.12% and 59.09%, respectively. The DPPH radical scavenging rate and reducing power increased by 41.79% and 10.95%, respectively. In conclusion, the use of A. niger 3.350, P. pentosaceus WT9 and A. oryzae Huniang 3.042 to make koji had the potential to enhance the activity of the finished koji enzyme system, improve the quality and flavor of soy sauce, and increase the content of functional components. The research results could provide theoretical references for optimizing the soy sauce production process and improving the quality of soy sauce.
Taking the high-temperature and medium-high-temperature Daqu of a certain distillery in Yichang city as the research object, the effect of temperature on the quality of Daqu was studied by using ultra-high deep metagenomic sequencing combined with physicochemical index detection and bionics technology, etc. The results of physicochemical indicators analysis and microbial count indicated that the physicochemical indicators (density, acidity, fermentation power, liquefaction power, esterification power and saccharification power) and microbial indicators (total colony count, lactic acid bacteria, mold and yeast count) of high-temperature Daqu were significantly lower than those of medium-high-temperature Daqu (P<0.05). The results of sensory analysis indicated that the aroma, umami, abundance and L* value of high-temperature Daqu were significantly higher than those of medium-high-temperature Daqu (P<0.05), while the aftertaste intensity of bitterness was significantly lower (P<0.05). The results of ultra- high deep metagenomic sequencing indicated that there were differences in the microbial community structures of the two types of Daqu. Among them, there were significant differences in 12 dominant bacterial species (P<0.05). The number of resistance genes, oxidoreductase and carbohydrate esterase levels of microorganisms in high-temperature Daqu were significantly lower than those in medium-high-temperature Daqu (P<0.05). However, the five aspects such as amino acid transport and metabolism, energy production and conversion were significantly higher than those of medium-high- temperature Daqu (P<0.05). Correlation analysis showed that Desmospora sp. 8437 and Kroppenstedtia eburnean in Daqu were significantly positively correlated with abundance (aftertaste of umami) and W1C, while Leuconostoc citreum and Weissella sp. were significantly positively correlated with fermentation power and esterification power (P<0.05).
To clarify the inhibitory effect of Bacillus amyloliquefaciens strain HRH317 against Botrytis cinerea and the control efficacy of gray mold caused by B. cinerea, the antibacterial activity of the strain HRH317 against B. cinerea was initially determined using the Oxford cup method. Furthermore, the effects of strain HRH317 on the cellular morphology and ultrastructure of B. cinerea at the cellular and subcellular levels were analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM), as well as laser scanning confocal microscope (LSCM) techniques. The results showed that the fermentation supernatant of the strain HRH317 exhibited strong inhibitory activity against B. cinerea, with an inhibition zone diameter of 34.67 mm. SEM results revealed that the mycelia of B. cinerea were severely twisted, deformed and shriveled after 36 h of treatment with the strain HRH317 fermentation supernatant. TEM results indicated that after 72 h of treatment with the strain HRH317 fermentation supernatant, the organelles of B. cinerea were damaged, the intracellular cavity area increased, and the number of extracellular exudates increased. LSCM results showed that after 72 h of treatment with the strain HRH317 fermentation supernatant, the cell membrane of B. cinerea was severely damaged, and propidiumiodide (PI) staining area increased, further confirming that the strain HRH317 significantly inhibited the growth of B. cinerea. The results of in vitro control of gray mold of strawberry showed that the relative control effect of fermentation supernatant of strain HRH317 against strawberry gray mold was 66.18%.
In order to study the effect of two acetic acid fermentation modes in traditional handmade pottery jar (pottery jar) and large mechanical stainless- steel pool (stainless-steel pool) on quality of Shanxi aged vinegar, the temperature and physicochemical indexes during acetic acid fermentation were monitored, and the basic physicochemical indexes, organic acids, amino acids and volatile aroma components contents of new leaching vinegar were analyzed. The results showed that under the two fermentation modes, the temperature during acetic acid fermentation rose first and then fell, the total acid increased, the alcohol content decreased, the moisture decreased first and then increased and tended to be stable, while the acetic acid fermentation period of pottery jar was shorter. Compared with the new leaching vinegar in the stainless-steel pool, the soluble unsalted solids (8.63 g/100 ml), the total contents of amino acids (4.72 mg/ml), and the total contents of volatile aroma components (15.25 mg/100 ml) of new leaching vinegar in pottery jar increased by 5.79%, 20.12%, and 4.27%, respectively, and the total contents of organic acids decreased by 25.48%. The contents of oxalic acid and malic acid increased by 59.73% and 63.48%, respectively, while the contents of tartaric acid, lactic acid and citric acid decreased by 53.73%, 57.84%, and 86.55%, respectively; The total contents of essential amino acids increased by 21.19%; The contents of acids, pyrazines and other substances in volatile aroma components increased by 55.08%, 45.05%, 52.19%, respectively, while the contents of alcohols and ketones decreased by 45.11% and 95.13%, respectively. The quality and flavor of new leaching vinegar in the traditional handmade pottery jar were better than that in the large mechanical stainless-steel pool, but the large mechanical stainless-steel pool could achieve large-scale production.
Yeast strains XR, CECA, and RC212 were selected to brew fortified sweet red wines, respectively. During the aging process, wines were analyzed at three stages: post-fermentation, 6 months of aging, and 12 months of aging, to evaluate the effects of three types of yeasts on physicochemical parameters, chromatic characteristics, volatile compounds, and sensory qualities. The results demonstrated that at 12 months of aging, the type of yeast had no significant effect on the alcohol content, reducing sugar, total acid, and volatile acid content of the wine (P>0.05), Saccharomyces cerevisiae CECA was beneficial for improving color intensity and increasing astringency of taste in young wine. Yeast RC212 could better improve the color and stability of most monomeric anthocyanins in wine, while concurrently elevating tartaric acid content and reducing succinic acid content. Wine fermented with RC212 had higher levels of gallic acid, chlorogenic acid, and syringic acid, and was more conductive to generating more ester volatile compounds. Yeast strain XR was beneficial for increasing caffeic acid and vanillic acid content while improving aromatic complexity, and young and aged wines fermented by three types of yeast could be distinguished by orthogonal partial least squares-discriminant analysis (OPLS-DA). In summary, these findings suggested CECA was the preferential choice for young fortified sweet red wines, whereas RC212 could enable wine to better exert its aging potential.
The temperature, physicochemical indexes, microorganisms and tetramethylpyrazine during the fermentation process of high-temperature Daqu were monitored in different production periods (May, July, September, November 2023 and January 2024) in the hot and cold seasons (numbered ①, ②, ③, ④, ⑤, respectively, and the correlation between temperature, physicochemical indexes and tetramethylpyrazine was analyzed. The results showed that during the fermentation process, the temperature first increased and then decreased, the moisture and saccharification power decreased, the acidity increased, and the tetramethylpyrazine content increased first and then decreased, and fluctuated in a small range. At the end of fermentation, the moisture of Chucang high-temperature Daqu was 10%-12%. However, the saccharification power of high-temperature Daqu in the cold season (400-500 mg/(g·h) was higher than that of Daqu ①, ②, ③ (50-300 mg/(g·h)), the acidity (0.8-1.5 mmol/10 g) and tetramethylpyrazine contents (10-40 mg/kg) were lower than those of high-temperature Daqu in the hot season. Before the second turnover, some yeast and mold died, bacteria and Bacillus increased. After the second turnover, the mold increased. Before the second turnover, tetramethylpyrazine was positively correlated with temperature and negatively correlated with moisture. After the second turnover, tetramethylpyrazine was positively correlated with temperature, moisture and acidity, and negatively correlated with saccharification power.
To investigate the differences in volatile flavor components of sauce-flavor (Jiangxiangxing) Baijiu in Guizhou regions with different altitude, the volatile flavor components were determined by gas chromatography (GC) and electronic nose technique. The results were systematically evaluated using principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and cluster analysis (CA). The results showed that a total of 55 volatile flavor components in sauce-flavor Baijiu with different altitude regions were identified, and there were significant differences in their types and contents (P<0.05). Thirty-nine key aroma components (OAV>1) of sauce-flavor Baijiu in Guizhou regions with different altitude were screened based on odor activity values (OAV). High-altitude samples exhibited elevated levels of ester compounds such as ethyl pentanoate and ethyl nonanoate, along with alcohols including 1-propanol and 2-methyl-1-butanol, demonstrating complex aromatic profiles. Low-altitude samples were characterized by higher concentrations of ester aroma compounds (ethyl palmitate, ethyl linoleate, ethyl tetradecanoate, and ethyl octanoate) and pyrolytic compounds such as tetramethylpyrazine, contributing to intense flavor characteristics. Mid-altitude samples displayed relatively lower volatile flavor content with less pronounced aromatic complexity. Sauce-flavor Baijiu in Guizhou regions with different altitude were effectively distinguished by PCA and OPLS-DA. Using P-value of variance analysis and variable importance in the projection (VIP) values, a total of 27 key differential components (VIP>1, P<0.05) were screened. CA results indicated that there were significant differences in the content distribution of key differential substances of sauce-flavor Baijiu with different altitude regions.
To enrich probiotic lactic acid bacteria resources, the strains of lactic acid bacteria were isolated through traditional culture isolation method from the traditional naturally fermented koumiss in Xinjiang, identified through morphological observation and molecular biology techniques, and their probiotic characteristics, including the acid and bile tolerance, hydrophobicity, antibacterial ability, antioxidant activity, stress resistance, carbohydrate utilization and antibiotic sensitivity, were evaluated. The results showed that a total of 9 strains of lactic acid bacteria were isolated, 3 strains (K-1、K-5、K-6) were identified as Levilactobacillus brevis, and 6 strains (K-2、K-3、K-4、K-7、K-8、K-9) were identified as Lactiplantibacills plantarum. Among them, the counts of viable bacteria of strains K-1, K-2 and K-3 remained unchanged for 2 h under the condition of pH 2.0, and the strain K-2 could completely tolerate 0.3% bile for 4 h. The hydrophobicities of the strain K-7 to the xylene, hexadecane and chloroform were the highest, reaching over 80%. Most strains could inhibit the growth of Escherichia coli, Salmonella paratyphi and Staphylococcus aureus. The scavenging abilities of the cell-free supernatants of all strains to hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were significantly higher than 1.5 mg/ml vitamin C (P<0.05). The strains K-3 and K-8 could completely tolerate 4% NaCl, and the strain K-2 had the optimal tolerance to ethanol. It was species-specific and strains-specific for the carbohydrate utilization and antibiotic sensitivity of all lactic acid bacteria isolates. In conclusion, all the isolates of lactic acid bacteria had superior in vitro probiotic properties.
The intrinsic relationship between soybean oil components (SOC) and the flavor formation of Cantonese-style soy sauce was studied from microbial community structure and the flavor of soy sauce by constructing a soy sauce brewing model using soybean oil components with defatted soybeans. The results showed that the bacterial and fungal community structures in koji of soy sauce brewed with SOC was similar to those of traditional Cantonese-style soy sauce, significantly different from those of the koji of soy sauce brewed without SOC, and the richness was higher than that of koji of soy sauce brewed without SOC. The content of amino acids (6.38 g/100 ml) in the soy sauce brewed with SOC was the highest, the types of organic acids were rich and the content was relatively high, and the content of 16 major ester substances was the highest, aligning with type characteristic flavor profile of Cantonese-style soy sauce. The results demonstrated that the soybean oil components in the fermentation matrix positively regulated the unique microbial communities in Cantonese-style soy sauce production. Furthermore, most soybean oil components participated in the biotransformation of flavor compounds during Cantonese-style soy sauce brewing.
Taking the high-temperature Daqu samples of the sauce-flavor (Jiangxiangxing) Baijiu from the core area of Maotai town, Guizhou province (A) and the famous liquor industrial park of Renhuai city (B) as the research objects. The physiochemical indicators, enzyme activities and volatile flavor compounds were analyzed during the Daqu making process (Rucang fermentation, first Fancang, second Fancang and Chucang). The volatile flavor compounds were analyzed by partial least squares-discriminant analysis (PLS-DA). Combined with the variable importance in the projection (VIP) values, the significantly differential volatile flavor compounds (VIP>1, P<0.05) were determined, and cluster analysis (CA) was conducted based on the significantly different volatile flavor compounds. The results showed that during the high-temperature Daqu making process in region A and region B, the moisture, saccharification power and the acidic protease activity as a whole showed a gradually decreasing trend, while the acidity and esterification power gradually increased, and the liquefaction power had no significantly change. A total of 114 and 121 kinds of volatile flavor compounds were detected, respectively. There were 70 and 71 kinds of common volatile flavor compounds, respectively, and 11 and 6 kinds of unique volatile flavor compounds respectively. The contents of esters, alcohols and pyrazine substances in the Chucangqu from region A (48.73 μg/g, 6.01 μg/g and 21.17 μg/g, respectively) were significantly higher than those in region B. A total of 53 significantly differential volatile flavor compounds were obtained, such as phenyl ethyl acetate and methyl palmitate. Cluster analysis (CA) results indicated that ester substances might be the main substances causing the flavor differences of the Chucangqu in region A and B.
Taking the brine used for making stinky tofu produced by a certain company in Hunan Province as the research object, the physicochemical properties of the brine were determined, and the quality differences of the brine samples (labeled as Ⅰ to Ⅵ) with different fermentation time (454 d, 455 d, 456 d, 462 d, 463 d and 829 d) were investigated. The volatile flavor components of the brine related to the production of stinky tofu were analyzed by using solid-phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS), and the bacterial flora of the brine at different fermentation stages were analyzed by 16S rDNA sequence. The results indicated that a total of 115 volatile flavor substances were identified in the samples of stinky tofu brine, mainly including acids, esters, phenols, indoles, alcohols, ethers, ketones, etc. A total of 10 dominant bacterial genera were identified in the brine, including Sporanaerobacter, Clostridium sensu stricto 7, Clostridium sensu stricto 1, Clostridium sensu stricto 15, Caproiciproducens, Prevotella, unclassified f Clostridiaceae, Haloimpatiens, Streptococcus and Caldicoprobacter. Among them, Sporanaerobacter, Clostridium sensu stricto 1 and Caproiciproducens were the main dominant bacterial genera in the brine. The results showed that for sample No. Ⅱ (fermentation time 455 d), the salt content was 3.01%, and the nitrite content was the lowest of 0.08 mg/kg. The contents of amino acid nitrogen and total acid were relatively high, which were 0.73 g/100 ml and 14.17 g/100 ml, respectively. The relative content of the main volatile flavor substance methyl phenol was the highest of 78.20%. The research results could provide scientific basis for the quality control of brine in the production of stinky tofu.
In order to comprehensively investigate the bacterial community structure of lactic acid bacteria in traditional Luoyang sour pulp and identify valuable lactic acid bacterial strains, 9 samples of traditional sour pulp were subjected to isolation of lactic acid bacteria using the dilution plating method. The selected strains were identified by morphological and molecular biological identification. Furthermore, their growth characteristic, stress tolerance, in vitro antioxidant activity, acid production performance and safety were systematically evaluated. The results revealed that a total of 24 lactic acid bacterial strains were isolated and identified, belonging to 10 genera and 12 species. Among them, there were a total of 7 isolated strains of Limosilactobacillus fermentum, followed by 5 strains of Lactiplantibacillus plantarum and 2 strains of Lacticaseibacillus paracasei. The growth curves, osmotic tolerance, bile salt tolerance, acid tolerance, resistance to gastric juice, acid production ability, and in vitro antioxidant activity of the isolated strains were analyzed and compared, and 10 superior strains were selected. On this basis, antibiotic sensitivity and hemolysis tests were conducted, and the results revealed that a majority of the strains carried multiple antibiotic resistance genes and exhibited hemolytic characteristics. Finally, strains L62 (Levilactobacillus brevis), L64 (Leuconostoc lactis), and L82 (Staphylococcus hominis) were chosen due to their outstanding performance, minimal carriage of resistance genes, and non-hemolytic properties. The three strains have the potential to be developed into direct-inoculated fermentation starter cultures for sour pulp production, offering significant application value.
Gastrodia elata Lujiu was prepared with G. elata, American ginseng and wolfberry as raw materials, and strong-flavor (Nongxiangxing) Baijiu as base liquor. The volatile flavor components of 5 different production batches of base liquor (1#-5#) were detected. The key volatile flavor components (ROAV>1) were analyzed in combination with the relative odor activity value (ROAV) to screen the optimal base liquor. The volatile flavor components of the G. elata Lujiu prepared by the base liquor were analyzed, and its safety was evaluated. The results showed that a total of 79 volatile flavor components and 13 key volatile flavor components were detected in the 5 base liquors. Among them, base liquor 5# had the richest variety of volatile flavor components (45), including 12 key volatile flavor components. A total of 68 volatile flavor components were detected in G. elata Lujiu prepared by the base liquor 5#. Among them, there were many types of alcohols and esters (22 and 21), with relative contents of 79.33% and 11.36%, respectively. The results of the safety evaluation indicated that no poisoning symptoms or death occurred in the mice, and there was no significant difference in organ indices (P<0.05). The maximum tolerated dose (MTD) was>8 260 mg/kg body mass, and the degree of pathological damage to the liver tissue of mice was relatively mild. Therefore, G. elata Lujiu prepared by the base liquor 5# presented a harmonious and complex aroma with a distinct sauce flavor and rich and mellow taste, and it maintained a unique plant-based fortified Lujiu style, with relatively high safety.
In order to explore the effect of whey on the quality and microbial community diversity of pickled radish, radishes were soaked in salt water, unfermented whey and naturally fermented whey (numbered as C, N and F, respectively), the pH, total acid, nitrite contents and brittleness changes of pickled radish during the fermentation process were determined, and the microbial community diversity of samples N and F was analyzed by high- throughput sequencing technology. The results showed that the quality of sample F was good. At 6 h of fermentation, the pH was less than 4, the total acid content reached 1.5%, the brittleness was 28 N, and the nitrite content during the fermentation process was less than 4 mg/kg. The microbial diversity analysis indicated that the absolute dominant bacterial genera and species during the fermentation process of sample F were Lactobacillus and Lactobacillus helveticus (relative abundance>95%), respectively. The dominant fungal genera were Pichia, Candida, Trichosporon, etc. (relative abundance all>1%), and the dominant fungal species were Pichia kudriavzevii (relative abundance>40%). Naturally fermented whey could stabilize the microbial community structure of pickled radish, shorten the fermentation cycle, and produce a positive impact on its quality.
The sauce-flavor bacteria were isolated and screened from the sauce-flavor Daqu through the dilution and coating plate method, protease production and high-temperature resistance test, as well as simulated solid-state fermentation. The strains were identified through morphological observation, physiological and biochemical tests, and molecular biology techniques. The volatile flavor components in the simulated solid-state fermentation products were analyzed using headspace solid-phase microextraction (HS-SPME) and GC-MS, and superior strains were screened to prepare a composite solid microbial agent for application in the production of cellar surface liquor. The results indicated that a total of 7 strains producing sauce-flavor were successfully isolated. After identification, strains XJ-26 and XJ-47 were Bacillus amyloliquefaciens, strains XJ-98, XJ-129, and XJ-169 were all Bacillus licheniformis, and strains XJ-8 and XJ-193 were Bacillus velezensis and Bacillus subtilis, respectively. The prevalent dominant volatile flavor compounds produced by these strains included 2,3,5,6-tetramethylpyrazine, 2,3,5-trimethylpyrazine, and 2,3-butanediol. Strains XJ-8, XJ-47, XJ-98, and XJ-193 were selected to make composite solid bacterial agents for fermentation to produce pit surface liquor. Compared with the control group, the reducing sugar and moisture content of the fermented grains unloading pit in the experimental group decreased significantly (P<0.05), and the contents of esters, aldehydes, pyrazines, and acids in the liquor samples all increased significantly (P<0.05). Among them, the contents of ethyl lactate, furfural, tetramethylpyrazine and acetic acid increased by 82.60%, 54.46%, 96.28% and 98.71%, respectively.
In order to explore the effect of inoculation fermentation on the aroma and sensory characteristics of Musalais wine, Musalais wine was prepared by inoculation fermentation (MDSY) and natural fermentation (MDZR) methods, and its volatile flavor components were detected by headspace solid- phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and the sensory evaluation was conducted. Finally, the main volatile flavor components of the two types of wine were analyzed by partial least squares-discriminant analysis (PLS-DA). The results showed that the two types of wine samples had their own characteristics in sensory evaluation. The MDSY sample was slightly superior to the MDZR sample in terms of clarity, aroma intensity, taste intensity and aftertaste, and had a higher sensory score. Both of the two wine samples were mainly characterized by fruit and floral aromas, but there were certain differences in volatile flavor substances. The contents of esters and acids in the MDSY sample were significantly higher than those in the MDZR sample (P<0.05), while the contents of alcohols, phenols and other substances were significantly lower than those in the MDZR sample (P<0.05). Aldehydes, ketones and terpenes were slightly lower than those in the MDZR sample (P>0.05). According to the variable importance projection (VIP) value>1, a total of 16 differentially volatile flavor substances were screened, including isopentyl acetate, ethyl octoate, ethyl 9-decenoate, etc. In conclusion, the aroma and sensory characteristics of the Musalais wine by inoculation fermentation were relatively better.
In order to investigate the immunomodulatory effects of Pu-erh tea polysaccharides (TP) and catechins (TPC) compound, using immunosuppressive mice induced by cyclophosphamide (Cy) as the research object, the immune indexes of mice were detected by enzyme-linked immunosorbent assay (ELISA) and hematoxylin-eosin (HE) staining section, and the dose of Pu-erh tea polysaccharide with the optimal immune regulation effect was screened, and the effects of TPC compound on immune indexes and metabolite composition of immunosuppressive mice were investigated. The model was constructed by orthogonal partial least squares-discriminant analysis (OPLS-DA), the key differential metabolites was screened by variable importance in projection (VIP) and variance analysis P value, and the metabolic pathway was analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG). The results showed that the spleen index of mice in each dose of TP and TPC groups decreased extremely significantly (P<0.01), and the thymus index increased extremely significantly (P<0.01). TP and TPC significantly reduced the levels of interleukin-6 (IL-6) and interferon-γ (IFN-γ) in serum of mice (P<0.05), increased the levels of immunoglobulin G (IgG) and immunoglobulin M (IgM), and restored the spleen damage of immunosuppressed mice. The effect of high-dose TP group was the optimal, and the levels of some factors in the TPC group were better than those in the high- dose TP group. Normal control group (CK), model control group (MD) and TPC group could be effectively distinguished by OPLS-DA. With VIP≥1 and P<0.05 as the standards, a total of 130 key differential metabolites were screened between MD and TPC groups. KEGG metabolic pathway analysis showed that choline phosphate and pyridoxamine were respectively related to the metabolism of choline in cancer and metabolic pathways such as vitamin digestion and absorption.
In order to improve the production process and product quality of fermented rice milk, lactic acid bacteria strains with the ability to degrade starch were screened from Lactiplantibacillus plantarum (numbered as YB9, YB36, LP-P2), Lactococcus lactis (numbered as LLA6115), and Lactobacillus acidophilus (numbered as AD125) by the transparent circle method, and its fermentation characteristics were studied. Then the strains were inoculated into rice milk to prepare fermented rice milk beverages. The effects of different compound ratios of strains, the ratio of material to liquid, fermentation temperature and time on the quality of fermented rice milk beverages were investigated. The results showed that the strains LLA6115, LP-P2 and AD125 had a strong ability to degrade starch (the diameter of the transparent circle>13 mm). When the culture time was 24 h, their amylase activities all reached the maximum value, which were 10.98 U/ml, 9.66 U/ml and 9.25 U/ml, respectively. When cultured for 12 h, 18 h and 14 h respectively, the growth entered the stable stage and the pH value<4. There was no antagonistic effect among the three strains. The optimal technological conditions for fermented rice milk beverage were as follows: the compound ratio of strain LLA6115 to LP-P2 1∶1, the ratio of material to liquid 1∶8 (g∶ml), the fermentation temperature 37 ℃ and time 24 h. Under this optimized condition, the sensory score of the fermented rice milk beverage was 86 points, the pH value was 4.92, and the acidity was 102.6 °T.
The lactic acid bacteria in the Cupei of Zhenjiang vinegar were isolated and screened by high-throughput sequencing technology and plate method. The isolated strains were identified through morphological observation and 16S rDNA sequencing, and the suitable growth temperature, acetic acid and ethanol tolerance of the strains were studied. Then they were applied to the fermentation of liquid apple cider vinegar. The difference changes in physiochemical indicators and volatile flavor substances after the bacteria participated in the fermentation of apple cider vinegar were analyzed. The results showed that the main screened lactic acid bacterium were Lactobacillus acetotolerans L-1. The suitable growth temperature was 30 ℃. It could still grow well when the mass concentration of acetic acid was <3 g/100 ml and the volume fraction of ethanol was <9%, and had strong acid and ethanol tolerance. L. acetotolerans L-1 could increase the mass concentration of non-volatile acid in apple cider vinegar (0.39 g/100 ml). Meanwhile, gas chromatography-mass spectrometry analysis indicated that the content of volatile flavor substances in apple cider vinegar prepared by the synergistic fermentation of L. acetotolerans L-1 was higher, reaching 22.20 mg/L. Among them, the types and mass concentrations of ester substances increased significantly, especially substances with floral and fruity aroma such as isopentyl acetate, phenethyl acetate, ethyl octoate, and ethyl decanoate.
The agricultural antibiotic-producing strain was screened from soil by dilution coating plate method using Gaoshi No.1 medium supplemented with potassium dichromate, and identified by morphological observation, physiological and biochemical experiments, and molecular biological technique. The fermentation conditions of the screened strain were optimized through single factor and response surface tests based on the diameter of the inhibition zone against Fusarium chlamydosporum as the response value. The results showed that a strain of agricultural antibiotic-producing strain Ly was screened and identified as Methylobacterium oryzae, which exhibited good antibacterial activity against F. chlamydosporum, Aspergillus aculeatu and Escherichia coli with inhibition zone diameters of 23.11 mm, 12.13 mm, and 6.80 mm, respectively. The optimal fermentation conditions for producing agricultural antibiotics by M. oryzae Ly were liquid loading volume 100 ml/250 ml, soybean cake powder as nitrogen source, fermentation temperature 31 ℃, rotation speed 220 r/min, initial pH 8, and fermentation time 7 d. Under these optimal conditions, the inhibition zone diameter of M. oryzae Ly against F. chlamydosporum was 41.91 mm, which was 1.81 times larger than that before optimization.
In this study, using the yeast strain G4 without ethanol production but with high ester production as research object, the strain was identified by morphological observation and molecular biology techniques. With the strain G4 as the starting strain, a superior strain with low ethanol and high ester production was selected by atmospheric pressure and room temperature plasma (ARTP) mutagenesis combined with ultraviolet mutagenesis, and its genetic stability, tolerance and hemolysis safety were studied. The results showed that the strain G4 was identified as Rhodotorula glutinosa, and a superior mutant strain AU73 without ethanol production but with high ester production was obtained by mutation breeding, the total ester production was 1.10 g/L, which was 1.53 times that of the starting strain G4. The mutant strain AU73 had good genetic stability, tolerance and security, which could tolerate pH 2.5, ethanol volume fraction 10%, SO2 150 mg/L, and glucose 30%. In summary, the mutant strain AU73 had the characteristics of no ethanol production and high ester production, which provided a theoretical basis for improving the quality of fermented fruit juice and reducing the production cost.
Using tangerine peel and honey as the main raw materials, the tangerine peel mead was prepared by fermentation with Saccharomyces cerevisiae LA-FR. Using sensory evaluation as the main evaluation index, the fermentation process of tangerine peel mead was optimized through single factor tests and response surface methodology. And the physicochemical indicators and volatile flavor components of tangerine peel mead were detected and analyzed by conventional detection methods and gas chromatography-tandem mass spectrometry (GC-MS/MS). The results showed that the optimum fermentation process conditions for tangerine peel mead were as follows: tangerine peel addition 1.7%, initial soluble solid content 23%, yeast inoculum 0.11%, initial pH 4.0, and fermentation temperature 28 ℃. The tangerine peel mead brewed under these optimized conditions was amber in color, clear and transparent, with the fragrance of tangerine peel and honey, rich taste, and mellow flavor, and the sensory score was 92.24 points. The alcohol content was 10.60%vol, the total acid content (calculated as tartaric acid) was 4.35 g/L, and the soluble solids content was 9.50%. The total bacterial counts were 51 CFU/ml, no coliform bacteria were detected, and all indicators met the requirements of QB/T 5475-2020 "Mead". A total of 17 major volatile flavor components were detected in tangerine peel mead, including 6 alcohols, 8 esters, and 3 alkenes. Among them, the ethanol (28.36%), D-limonene (18.8%), 2-methylbutanol (16.22%) and phenylethanol (12.07%) had relatively high relative contents.
The effects of adding organic acids on the fermentation process, quality and flavor of radish Paocai were investigated, by determining the physicochemical indexes, colour, texture, organic acid composition and volatile flavor substances of fermented radish Paocai with 0.089 mol/L addition of lactic acid, acetic acid and citric acid as well as without organic acids addition as control (CK). The results showed that after 5 d of fermentation, compared with the CK group, the reducing sugar contents in the acetic acid group was significantly reduced (P<0.05), and the nitrite contents in each organic acid group was significantly reduced (P<0.05). The b* values of the lactate and acetic acid groups significantly increased (P<0.05), the hardness and chewiness of the citric acid group significantly reduced (P<0.05), the chewiness of the acetic acid group was significantly reduced (P<0.05), and the brittleness was significantly increased (P<0.05). The total acid content and organic acid composition of the citric acid group changed greatly, while the organic acid composition of the lactic acid group was more abundant. Lactic acid group and citric acid group have more similar volatile flavor compounds, which were more conducive to the production of ester volatile flavor components. In summary, the addition of lactic acid had the optimal overall effect on radish Paocai.
In this study, taking dry corn stover (DCS) as a raw material, medium-temperature Daqu were added to DCS samples, the DCS was pretreated by anaerobic fermentation, the organic acids, pH and cellulose fractions during the pretreatment process (0-35 d) were determined, the microbial community structure was analyzed by high-throughput sequencing technology, the principal coordinate analysis (PCoA) was carried out based on the results, and the enzymatic process conditions of DCS after pretreatment were optimized by single factor tests and response surface tests. The results showed that the contents of lactic acid and acetic acid during the pretreatment process of DCS showed an overall increasing trend, and the pH, contents of cellulose and hemicellulose showed a decreasing trend. When adding medium-temperature Daqu fermentation DCS for 28 d, the lactic acid and acetic acid contents, pH, cellulose and hemicellulose contents were 4.07%, 1.06%, 4.83, 30.31% and 17.02%, respectively. In addition, its dominant flora was relatively abundant, the dominant fungal genus was Alternaria (relative abundance 38.85%), and the dominant bacterial genera were Loigolactobacillus, Lactococcus and Enterococcus (relative abundance>1%). PCoA results showed that the microbial community structure remained relatively stable during the DCS pretreatment process of medium-temperature Daqu. The optimal enzymatic process conditions for DCS pretreatment of medium-temperature Daqu for 28 d were as follows: enzymatic hydrolysis time 60 h, substrate mass fraction 9%, and cellulase addition 23 FPU/g cellulose. Under the optimal conditions, the enzymatic hydrolysis rate of cellulose reached 91.87%.
To investigate the effects of different sterilization methods on the quality of Guizhou red sour soup, the red sour soup was treated by 3 kinds of different sterilization methods, including ultra high pressure sterilization, pasteurization and steam sterilization, and the effects of different sterilization methods on pH, total acid, total colonies counts, vitamin C, total phenol, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging rate, nitrite, organic acid, color and odor were determined. The results showed that the sterilization rates of 3 methods were all above 99%, and could slow down the changes of pH and total acid of red sour soup during 100 d of storage. The nitrite contents of all samples was between 1.54-1.96 mg/kg, complying with the national safety standard (<20 mg/kg). At 100 d of storage, the contents of vitamin C, total phenols, DPPH radical scavenging rate, lactic acid, and color difference ΔE value of the red sour soup treated with ultra-high pressure sterilization were 42.94 mg/kg, 348.77 mg/kg, 38.27%-96.08%, 554.63 mg/kg, and 40.69, respectively, which were superior to those treated with pasteurization and steam sterilization. The electronic nose detection results showed that the odor of red sour soup was mainly composed of nitrogen oxides, ethanol and some aromatic compounds. Pasteurization and steam sterilization changed the odor of red sour soup, resulting in the increase of sulfur compounds and alkane compounds. In conclusion, ultra high pressure sterilization was a better sterilization method for red sour soup, which could effectively retain nutrients and flavor.
In this study, Zha-chili was prepared with fresh chili as raw materials, corn flour and salt as auxiliary materials, and Lactiplantibacillus plantarum as fermented strain. With amino acid nitrogen contents and sensory score as evaluation indicators, the fermentation conditions of Zha-chili were determined by single-factor tests and Box-Benhnken response surface tests, and the volatile flavor components were detected by electron nose and headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) technology. The results showed that the optimal fermentation conditions of Zha-chili were as follows: fermentation time 5 d, salt addition 4%, bacterial powder addition 5.5%, and mass ratio of corn flour and chili 1∶1. Under these optimized conditions, the sensory score of Zha-chili was 88.9, the total acid content (in terms of lactic acid) was 1.13%, the amino acid nitrogen content was 0.17%, and the pH was 4.02. The electronic nose results showed that the main volatile components of Zha-chili included aromatic components, sulfur compounds, methyl compounds, alcohols and nitrogen oxides, etc. The HS-SPME-GC-MS results showed that 25 volatile flavor components were detected in Zha-chili, including 9 esters, 7 aldehydes, 3 alcohols, 2 ketones, 3 phenols and 1 alkane. The main volatile flavor components were 4-ethylphenol, n-hexanol and linalool, with relative concentrations of 18.55%, 17.38% and 14.04%, respectively.
To screen suitable varieties for jujube wine, fermented jujube wine was prepared using different varieties of fresh jujubes (Hama jujube, You Jujube, Fuping jujube, Jun jujube, Hui jujube, and Huping jujube) as raw materials. The basic physiochemical indicators, organic acid content and volatile flavor substances were determined. Based on the volatile flavor substances, different wine samples were analyzed by partial least squares-discriminant analysis (PLS-DA). The key volatile flavor substances were screened combined with the odor activity value (OAV), and the sensory quality of jujube wine was analyzed. The results showed that there were certain differences in the physicochemical indicators of fermented wine with different varieties of jujube. The alcohol content of Huping jujube wine was the highest (12%vol), the sugar-acid ratio was the lowest (0.24), and the citric acid and succinic acid contents were the highest (0.18 g/L, 0.99 g/L). The contents of ascorbic acid and total phenol in the Hama jujube wine were the highest (11.25 mg/L, 0.66 mg/L). Succinic acid, lactic acid and acetic acid were common organic acids in the fermented wine of fresh jujubes, and mainly lactic acid and acetic acid with contents of 1.15-5.49 g/L and 0.89-2.37 g/L, respectively. A total of 45 volatile flavor substances were detected in fermented wine with different varieties of fresh jujubes, among which there were 6 alcohols, 5 aldehydes, 26 esters, 4 alkanes and 4 other types. PLS-DA could distinguish different varieties of jujube wine samples based on volatile flavor substances. Among the 6 kinds of jujube fermented wines, there were a total of 9 key volatile flavor substances (OAV>1). In conclusion, Hama jujubes and Huping jujubes wine had distinct style and were more suitable for brewing jujube wine.
Camel milk wine was prepared using safflower, a characteristic economic crop of Xinjiang, and camel milk powder as raw materials. Through the analysis of the physiochemical indicators, antioxidant properties, volatile flavor components and sensory qualities of the wine body, the effect of adding safflower (0-2 g/L) on the quality of camel milk wine was investigated. The results showed that the color of camel milk wine with safflower addition was better than that without safflower addition. Moreover, with the safflower addition increased, the content of titrable acid decreased significantly (P<0.05), the pH value increased significantly (P<0.05), but there was no significant change in alcohol content (P>0.05). The content of hydroxysafflor yellow A and its free radical scavenging ability were significantly increased (P<0.05). When the safflower addition was 2 g/L, the color and body of camel milk wine presented a bright red-yellow tone. The content of hydroxysafflor yellow A was 2.30 mg/L, and the clearance rates of 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion and hydroxyl radicals were 18.58%, 30.01% and 47.76%, respectively. The number of volatile compounds (43 kinds) in the safflower camel milk wine with 2 g/L addition were higher than those in the camel milk wine without safflower (27 kinds). The main aroma contributing components were 9 volatile substances such as ethyl caproate, butyl acetate, and phenyl ethyl acetate. The sensory score of the safflower camel milk wine with 2 g/L addition (80.72 points) was higher than that of the camel milk wine without safflower (76.01 points), and it had better color, taste, aroma and texture characteristics.
In order to simulate aged brine, vegetable juice fermentation broth was prepared using radish, cucumber and tomato as raw materials and Lactobacillus plantarum P158, LYA31 and Pediococcus pentosaceus PP as fermentation strains. The fermentation conditions were optimized by single- factor experiments and orthogonal experiments. The volatile flavor compounds were analyzed by headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS), and the key volatile flavor compounds (OAV≥1) were determined by the odor activity value (OAV). The results showed that the optimal fermentation conditions for vegetable juice fermentation broth were as follows: glucose addition 2%, salt addition 2%, solid-liquid ratio 1.5∶1.0 (g∶ml), and fermentation temperature 37 ℃. Under this optimized condition, the total acid content of the vegetable juice fermentation broth was 0.81 g/100 ml, the pH value was 3.20, and the lactic acid bacteria counts were 8.59 lg (CFU/ml). A total of 26 volatile flavor compounds were detected in the vegetable juice fermentation broth, including 2 acids, 1 ester, 9 alcohols, 5 aldehydes, 4 ketones, 2 hydrocarbons and 3 others. Among them, the contents of ethanol and dimethyl disulfide were relatively high, which were 58.13 μg/kg and 41.15 μg/kg, respectively. The key volatile flavor substances were n-hexanol, linalool, crotonaldehyde, trans-2-octenal, dimethyl disulfide and dimethyl trisulfide.
In order to analyze the difference of volatile flavor components in strong-flavor (Nongxiangxing) Baijiu base liquor with different grades, the volatile flavor components in 4 grades of strong-flavor Baijiu base liquor were analyzed by gas chromatography-mass spectrometry (GC-MS) technology. Principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) were conducted based on the results, the key flavor components were screened based on odor activity value (OAV), the different flavor components were screened using variable importance in the projection (VIP) values, and the discriminant model was established combined with machine learning. The results showed that a total of 44 common volatile flavor components were detected in 4 grades of strong-flavor Baijiu base liquor by GC-MS, including 17 alcohols, 12 esters, 5 acids, 5 aldehydes and ketones, and 5 others. The 4 grades of strong-flavor Baijiu base liquor could be effectively distinguished by PCA and OPLS-DA. A total of 21 key flavor components (OAV>1) and 12 differential flavor components (VIP>1) were screened out. The 3 discriminative models were constructed through machine learning, among them, the random forest model had the optimal discriminative effect with an accuracy of 100%.
The volatile flavor compounds in strong-flavor (Nongxiangxing) Baijiu were detected and analyzed by four pretreatment methods including solid phase extraction (SPE), liquid-liquid microextraction (LLME), headspace-solid phase microextraction (HS-SPME) and immersion-solid phase microextraction (DI-SPME), combined with gas chromatograph mass spectrometry (GC-MS). The results showed that a total of 130 volatile flavor compounds were identified including 53 esters, 15 alcohols, 15 acids, 10 aromatics, 20 aldehydes (including 14 acetals), 8 ketones, 6 furans and 3 pyrazines. The types of volatile flavor substances measured by different pretreatment methods were similar, but the quantities and contents showed significant differences. SPE and LLME were suitable for the extraction of most substances. They had good extraction rates for hydrophilic substances with lg P<6 and hydrophobic substances with lg P<2 or >6, especially aldehyde substances. The relative contents of esters and aromatic substances measured by HS-SPME and DI-SPME were higher than those by SPE and LLME methods, and were particularly suitable for the determination of hydrophobic ester substances with 2<lg P<6. The research results provided a theoretical basis for further studies on the flavor composition of strong-flavor Baijiu.
The study established a detection method for determining the content of advantame in fermented milk by combining an enhanced lipid removal purification technology (Captiva EMR-Lipid) with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The sample was salted out by sodium chloride, ultrasonic extracted by 1% formic acid acetonitrile solution, purified by Captiva EMR-Lipid solid phase extraction column, eluted with methanol -0.1% formic acid aqueous solution as mobile phase gradient, and using external standard method of matrix matching standard curve under the mode of positive ion scanning of heated electrospray ion (HESI) source and selected ion monitoring (SRM). The results shown that the linear relationship of advantame was good within the range of 0.2-500 ng/ml, correlation coefficient R2 was 0.998 3, limit of detection (LOD) was 0.6 μg/kg, limit of quantitation (LOQ) was 2 μg/kg, and the recovery rates were 87.9%-102.5%. The method had the advantages of simple extraction, high sensitivity, and good accuracy, and was suitable for the detection of advantame in fermented milk.
This study established a method for determining the contents of four organic acids (lactic acid, acetic acid, butyric acid and caproic acid) in sauce-flavor (Jiangxiangxing) Baijiu by HPLC. An InertSustainSwift C18 chromatographic column (4.6 mm×250 mm, 5 μm) was selected. The mobile phase gradient elution was carried out with methanol-0.02 mol/L potassium dihydrogen phosphate aqueous solution (pH=2.30) at a flow rate of 1.0 ml/min, the column temperature was 35 ℃. The quantitative analysis was performed using external standard method. The results showed that all the four organic acids reached baseline separation within 20 min. The method has a good linear relationship (R2>0.997 9) for the determination of lactic acid and acetic acid, butyric acid and hexanoic acid in the mass concentration ranges of 300-4 200 mg/L and 20-400 mg/L, respectively. The detection limits of the four organic acids were 0.003 1-0.005 3 mg/ml, and the quantification limits were 0.009 3-0.016 5 mg/ml. The relative standard deviations of the precision experiments results were below 2%, and the average recovery rates were 95.48%-100.53%. The method was simple to operate, had high precision, and could accurately detect the contents of organic acids in different samples of Baijiu. It was suitable for the determination of four organic acids in Baijiu during production.
Referring to GB 5009.291—2023 "National Food Safety Standard for the Determination of Chlorate and Perchlorate in Foods" and BJS 201706 "Determination of Chlorate and Perchlorate in Foods", the chlorate and perchlorate in soy sauce were determined by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and the uncertainty introduced by various factors during the measurement process, including sample measurement repeatability, instrument analysis, sample solution preparation, series standard solutions preparation, and standard recovery rate, were analyzed. The results showed that when the mass fractions of chlorate and perchlorate in soy sauce were 75.6 μg/kg and 10.1 μg/kg, respectively, the expanded uncertainties were 11 μg/kg (k=2) and 1.7 μg/kg (k=2), respectively. The main sources of uncertainty were the repeatability of the series standard working solutions measurement, preparation of the series standard working solutions, standard substances, and instrument analysis, and the preparation of the series standard working solutions had the greatest impact. The introduced uncertainty could be reduced by improving operator skills, standardizing the preparation of series standard solutions, using certified volumetric flasks, regularly maintaining and calibrating pipettes and instruments, or choosing standard substances with higher accuracy, to improve the accuracy and credibility of the measurement results, which could effectively control the quality of the testing.
The eastern foothills of Helan Mountain in Ningxia has been recognized by the industry as one of the most suitable golden areas for grape cultivation and high-end wine production in the world. With the development of the wine industry, a large amount of business data has been accumulated. Due to the lack of effective correlation between data, it is difficult to form effective industrial knowledge. In order to make full use of these data, the knowledge graph was designed from five aspects: data layer, ontology layer construction, knowledge extraction layer, knowledge fusion, and industrial application, proposing the idea and methods of constructing a domain knowledge graph for the wine industry in the eastern foothills of Helan Mountain. Based on the knowledge graph, the data of the entire industrial chain was deeply mined and integrated, providing knowledge services in two aspects: the expert Q&A system and automatic customer service. In order to enhance the digitalization level of the wine industry in the production area and achieve the goal of making the wine industry in the eastern foothills of Helan Mountain "astonishing the world" as soon as possible.
As the key to microbial fermentation, fermented grains have a decisive influence on the quality and flavor of Baijiu. In recent years, the research on fermented grains has received extensive attention from the academic community, especially in terms of the influence of microbial populations and their metabolic activities on the quality of Baijiu. Based on the bibliometric method, from multiple dimensions such as the number of published articles, journal distribution, author and institutional cooperation network, keywords co-occurrence and cluster analysis, the 1 373 related literatures published on China National Knowledge Infrastructure (CNKI) from 2014 to 2023 were systematically sorted out and visualized using CiteSpace V6.3.R1 software. The aim was to reveal the current hotspots and development trends of fermented grains research. The results showed that the main topics of fermented grains research focus on flavor substances, microorganisms and their fermentation processes, and microorganisms and flavor substances were the hot spots in the field of fermented grains. The study provided important references and guidance for researchers in the field of fermented grains, promoted further exploration and innovation in the field, and advanced the sustainable development of China's fermented grains industry.
Short drama marketing has currently become a new weapon to capture the minds of young consumers. In this study, a mixed research was conducted, focusing on the influencing factors and internal mechanisms of short dramas on the purchase intention of alcoholic drink brands among young consumer groups. Through exploratory interviews with 28 representative young consumers and the application of the grounded theory, it was coded and found that imaginative role-taking, cognitive role-taking, plot coherence and conflict, perceived enjoyment and usefulness, and brand recognition could affect the purchase intention of alcoholic drink brands among young consumer groups. Three key configuration paths of imagination-coherence-oriented (0.901 167), cognition-conflict-oriented (0.915 392) and perceived value-oriented (0.913 781) were identified through qualitative comparative analysis, revealing the significant role of multi-factor synergy in purchase intention, and making up for the shortcomings of existing research in the in-depth analysis of alcoholic drink brand short dramas. The purpose of this study was to provide precise strategic guidance for liquor enterprises in short drama marketing, help them optimize short drama content creation, brand management, and communication and promotion strategies according to the psychological and behavioral characteristics of young consumers in a highly competitive market, strengthen the connection between brands and young groups, effectively enhance the sales and influence of alcoholic drink products in the youth market, and promote the sustainable development of alcoholic enterprises.
In this study, using Baijiu products as the research object, based on the Stimulus-Organism-Response (S-O-R) theory, a theoretical model was constructed in which short video content marketing of liquor products was treated as the independent variable, perceived value as the mediating variable, and consumers' purchase intention as the dependent variable. The model was tested through questionnaire surveys and empirical research. The results revealed that entertainment-oriented and emotion-oriented content in short video marketing positively affected consumers' purchase intention. Furthermore, functional, entertainment-oriented, and emotion-oriented content positively influenced consumers' perceived value. A positive effect of perceived value on consumers' purchase intention was also confirmed. Moreover, perceived value was found to play a mediating role between short video content marketing and purchase intention. Based on these findings, the following suggestions were proposed: precisely control short video duration and release time of short videos; enhance the entertainment value and emotional interactivity of short videos, and encourage consumers to convert perceived value into purchasing behavior through interaction.