Abstract:Highland barley,valued for its high nutritional value and health benefits,is a major cereal crop cultivated in the Tibetan Plateau region.However,its low gluten protein content makes it difficult to process.The addition of vital wheat gluten(VWG),a natural source of gluten protein,can improve the rheological properties of dough.The effect of VWG addition on the network structure of highland barley flour(HBF)–wheat flour mixed dough was investigated using infrared spectroscopy,Raman spectroscopy,scanning electron microscopy(SEM),and confocal scanning laser microscope(CSLM).The molecular structure of the dough,changes in disulfide bonds,and the microstructures of the gluten proteins were also analyzed.The results indicate that the addition of VWG markedly enhances the number of hydrogen and disulfide bonds within the dough and promotes the ordering of the protein secondary structure,with the highest disulfide bond content(7.49 μmol/g)observed in the group containing 40%HBF and 8%VWG.Furthermore,the inclusion of VWG effectively mitigated the disruption of the gluten network structure caused by HBF,enhancing the overall structural stability of the dough.The results provide a scientific basis for the application and development of HBF in baked products and demonstrate that VWG addition can improve the quality of highland barley dough.

Abstract:To explore the impacts of different stabilization treatments on the flavor components of rice bran,this study employed an electronic nose and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry(GC×GC-TOFMS),combined with partial least squares discriminant analysis(PLS-DA)and relative odor activity value(ROAV)evaluation to systematically analyze the changes in volatile flavor compounds of rice bran.The results indicated that there were significant differences in the effects of different stabilization methods on the flavor of rice bran.A total of 99 volatile aroma compounds were detected,including 6 aldehydes,10 ketones,22 alkanes,12 alcohols,28 terpenes,8 esters,and 13 other compounds.Among them,infrared treatment had minimal impact on rice bran flavor,while high-pressure steam treatment effectively reduced the off-flavor(indole)in rice bran.Variable Importance in Projection(VIP)identified 23 potential differential substances,with significant decreases being found in the relative contents of potential differential substances such as geranylacetone and(-)-limonene in the rice bran after four different stabilization treatments.The ROAV values revealed that the key flavor substances(ROAV>1)in rice bran decreased after the stabilization treatments like baking,microwaving,and high-pressure steaming.Eight substances,including 2-n-pentylfuran,methylheptenone,and citronellene,were identified as the key flavor compounds contributing to the differences in flavor among the rice bran samples subjected to different stabilization methods.This study conducted a differential analysis of volatile flavor substances in rice bran subjected to different stabilization methods,providing a theoretical basis for enhancing the added value and quality of rice bran products.

Abstract:To explore the impacts of different carbon dioxide concentrations on the quality of fresh highly processed pork products,fresh processed pork tenderloin,pork belly slices,and pork rib pieces were selected as research subjects.The changing trends of color difference,shear force,total volatile base nitrogen(TVB-N)value,pH value,water content,and total bacterial count(CFU)of the three products were investigated during storage under modified atmosphere packaging conditions of 70%O2/15%CO2/15%N2 or 70%O2/30%CO2.The experimental results showed that after 8 days of storage under the 70%O2/30%CO2 treatment,the TVB-N and lg CFU/g values were 14.63 mg/100 g and 5.55 for the pork tenderloin,and were 14.95 mg/100 g and 5.78 for pork belly slices.However,under the 70%O2/15%CO2/15%N2 treatment,the TVB-N and lg CFU/g values of the same pork products exceeded the national standard limits.Both treatments showed little correlation with the pork products'water contents,and under the same modified atmosphere packaging conditions,the differences in all the indicators among the three products were insignificant.Comprehensive analysis revealed that the 70%O2/30%CO2 treatment can significantly(P<0.05)control the changes in the total bacterial count and TVB-N value,slow down the increase in pH value,and influence significantly(P<0.05)the redness value,which is more conducive to maintaining the quality of modified atmosphere highly processed pork products.

Abstract:Through detecting the differences in the contents of 10 main antioxidant substances,including caffeine and epigallocatechin gallate,using high-performance liquid chromatography(HPLC),and evaluating their antioxidant capacities comprehensively based on DPPH radical scavenging rate,hydroxyl radical scavenging rate,and total antioxidant capacity,this study explored the relationship between the chemical composition and antioxidant capacity of the green teas from different origins in Guangxi.The results showed that that the green teas had a content of caffeine between 17.08 and 37.16 mg/g,content of theobromine around 5 mg/g,low content of theophylline between 0 and 0.47 mg/g,content of epigallocatechin gallate between 10 and 20 mg/g,high content of epigallocatechin gallate around 50 mg/g,varying content of epicatechin gallate in the range of 2.14～21.2 mg/g,content of epicatechin around 5 mg/g,contents of gallic acid and epigallocatechin gallate not higher than 5 mg/g,and content of epigallocatechin gallate essentially below 2 mg/g.Combining the results of similarity evaluation and clustering analysis,the green teas from the high-and mid-latitude regions of Guangxi were highly similar,and could be distinctly distinguished from those of the low-latitude regions.The DPPH radical scavenging rates of all teas were above 60%;the hydroxyl radical scavenging rates ranged from 1.68%to 85.38%;the total antioxidant capacities were between 1.644 and 3.608 mmol/g.Overall,the green teas from Guangxi possess good antioxidant activities on average,and there was a positive correlation between the content of polyphenols and antioxidant activity.This study provides a data foundation for the quality evaluation and differential analysis of Guangxi green teas.

Abstract:In this study,the nutritional value of 12 micronutrients in lyophilized sweet stem broccoli powder was evaluated by the INQ value,and the effects of the sweet stem broccoli powder on the growth of four probiotics and metabolism of SCFAs were studied based on an in vitro simulated gastrointestinal digestion and fermentation system.The results showed that the lyophilized powder prepared in this study was rich in 6 vitamins and 6 mineral elements,and the INQ value of each nutrient was greater than 1.In the in vitro simulated intestinal environment,the growth levels of B.lactis B420,B.lactis HN019,L.acidophilus NCFM and L.paracasei Lpc-37 were increased by a factor of about 2.The contents of acetic acid and butyric acid in the fermented products increased significantly upon the fermentation of broccoli powder with one of the four probiotics,though the yield of propionic acid increased insignificantly.Among which,the highest acetic acid content of B.lactis B420(about 600 μg/mL)occurred during co-fermentation.The butyric acid content was the highest during co-fermentation with B.lactis HN019,reaching 2 199.39 μg/mL.The sweet stem broccoli powder in this study was rich in 12 kinds of trace elements,and can promote the growth and metabolic SCFAs level of four probiotics in the simulated intestine,which makes up for the research gap of sweet stem broccoli in intestinal probiotic function.This research provides a theoretical basis for the development of sweet stem broccoli and its derived functional foods.

Abstract:With the development of the modern food industry and the advancement of globalization,food quality and safety have emerged as major concerns for the public.In the context of expanding global trade and supply chains,fresh agricultural products,including fruits and vegetables,meat,and aquatic products,encounter considerable challenges related to perishability and the preservation.It is imperative to develop accurate and rapid quality and safety testing to improve monitoring and provide consumer protection.Traditional detection methods,such as gas chromatography,high-performance liquid chromatography,and polymerase chain reaction,are often limited by stringent detection requirements,long detection cycles,and potential sample damage,hindering their large-scale application in the food industry.With the rapid development of artificial intelligence and computer technology,machine learning models with strong predictive abilities and high accuracy have been widely used in quality and safety inspections of fresh agricultural products,effectively addressing the limitations related to data redundancy and the processing of large datasets.This article provides a systematic overview of machine learning technology and deep learning algorithms and analyzes their applications in quality and safety inspections of fresh agricultural products.It also introduces the principles of several emerging non-destructive testing technologies,and discusses current research progress and potential application prospects for machine learning and non-destructive testing technologies in the food industry.

Abstract:In order to explore the bacteria-reducing effect and quality changes of dehydrated garlic slices treated by cold plasma,with bacterial reduction rate as the main index and color difference as the reference index,single-factor experiments were carried out on three factors:treatment time(min),treatment height(cm)and loading amount(kg/m2),respectively.The response surface test design was further carried out with sterilization rate as the response variable,to obtain the optimal process for bacteria-reducing treatment.The contents of allicin and volatile flavor components before and after the cold plasma treatment were determined.The results showed the order of influencing factors as treatment time>treatment height>loading amount;After the response surface optimization and considering the practical production,the optimal cold plasma process for bacteria-reducingtreatment of garlic slices was:treatment time,3 min;treatment height,3 cm;loading amount,1 kg/m2.Under these conditions,the bacteria reduction rate was 98.11%,the color difference was 3.14,and the color difference underwent insignificant change(within the acceptable range).After the treatment,the allicin content of the dehydrated garlic slices increased by 31.68%;The volatile flavor components were partially decomposed and the overall content decreased.It is concluded that the cold plasma technology exerts a significant bacteria-reducing effect while causing minimal damage to quality,which provides a new idea and method for bacteria-reducing treatment of garlic slices.

Abstract:Nitric Oxide(NO)has demonstrated excellent preservation function in the food field due to its outstanding anti-microbial,anti-biofilm and anti-pest properties.In order to further improve its stability,extend its service life,and reduce its toxic side effects,many researchers are dedicated to the development of NO donor sustained-release carriers and systems that are more stable,efficient,and safe.Different sustained-release strategies have facilitated the modulation of NO release rates within a range of 0.1 to 10 μmol/h,while extending the release duration from several hours to several tens of days.This enhanced release profile has enabled the widespread application of NO donor sustained-release systems in the biomedical field.In this paper,the production and signaling pathways of NO are reviewed.The design and development of various types of NO donor sustained-release systems,as well as their practical effectiveness and application potential in food preservation across categories such as meat,seafood,fruits and vegetables,are analyzed and summarized.The development of NO donor sustained-release system can provide new ideas and solutions to enhance the bioavailability of NO,improve the food quality and extend its shelf life,which shows great application prospects in the food sector.

Abstract:Coffee is one of the most important and widely used economic crops in the world,and is ranked as the first of the world's top three beverages due to its unique flavor and biological functions.Roasting is the key step in developing coffee flavor.Raw coffee beans are roasted,ground,andbrewed before being presented to consumers.During roasting,reactions such as the Maillard and caramelization reactions give coffee its unique flavor,while hazardous substances such as acrylamide,5-hydroxymethylfurfural and furans are also generated,which not only affect coffee quality but also pose a threat to consumers' health.Inthis paper,the toxicity,formation mechanisms,and reduction measures of these hazardous substances in the coffee roasting process are discussed,and prospects on new research directions related to the inhibition and reduction of hazardous substances are provided,aiming to deepen people's understanding of the hazardous substances generated during coffee roasting,and provide theoretical references to green processing of coffee and the control of hazardous substances during roasting.

Abstract:The effects of vacuum concentration,membrane concentration,freezing concentration and thermal concentration on the nutrient composition and antioxidant components of crystal pears were investigated using polyphenol oxidase(PPO),5-hydroxymethylfurfural(5-HFM),total phenol content,titratable acidity,vitamin C(Vc)content and antioxidant activity as the indicators.The results showed that all four concentration methods increased the total phenolic content,total antioxidant activity,and ABTS+and DPPH radical scavenging capacities of pear juice,with insignificant difference in reducing sugar content.Vacuum-concentrated pear juice had the highest sugar content(60 °Bx)and showed the greatest antioxidant effect,althoughhaving a higher PPO activity.Thermal-concentrated pear juice had the highest total phenolic content and the lowest soluble protein content(0.015 mg/mL),while causing the generation of 5-HMF(which was not detected otherwise in the juices treated by other methods).Freeze-concentration and membrane-concentration affected the titratable acid and Vc contents of pear juice to different extents.Correlation analysis showed that there were different degrees of correlation between the indicators,and the cumulative contribution of the three characteristic factors extracted from the principal component analysis reached 94.53%,reflecting the comprehensive influence of multiple indicators on the quality of pear juice.The comprehensive analysis showed that the pear juice obtained via vacuum concentration had the highest comprehensive score(1.95)and significant advantages in concentration efficiency and antioxidant activity;thermal concentration had certain advantages in improving the nutrient content of pear juice,but due to the generation of 5-HFM,its comprehensive score was the second highest.This study provides a theoretical basis for pear juice concentration and fruit deep processing.

Abstract:The relationship between the citrus pectin extraction process,its structural characteristics,and performance remain poorly understood.To address this gap in knowledge and enhance the value of citrus processing by-products,precise application scenarios for pectin with varying properties were analyzed.An acid extraction method was used to extract pectin from the citrus processing by-product pomace.Pectin yield,degree of esterification,and gel strength were evaluated as key indicators to optimize the application quality of citrus pectin.The optimal extraction conditions were as follows:72.00℃,pH of 1.75,and an extraction time of 4.50 h.Under these conditions,the average pectin yield was 25.70%,the average esterification degree was 71.97%,and the average gel strength was 253.00 g/cm2.The textural relationship analysis of pectin indicated that when the molecular weight of the pomace was>30.0×104 g/mol,viscosity was>7.0 dL/g,and the galacturonic acid content was 82%～88%,the pectin exhibited a favorable degree of esterification and gel performance(degree of esterification>70.00%and gel strength>230.00 g/cm²),which were associated with a complete molecular chain structure,a higher number of esterification and crystallization sites,and a higher galacturonic acid content.The low protein precipitation rate of the pectin(<0.50%)was related to its molecular weight,side chain structure,and degree of esterification.Variations in the extraction processes and raw materials lead to changes in the structural characteristics of pectin,thereby affecting its application performance and functional activity.Elucidating the influence of extraction processes and raw material properties on pectin products is crucial for developing high-quality pectin products and selecting suitable pectin raw materials.

Abstract:The formulation of restructured goose livers was developed using goose liver,chicken,tapioca starch,and soy protein as the primary ingredients.The cross-linking effect of transglutaminase(TGase)was used to enhance the gel properties of the restructured goose livers product.Single-factor experiments,orthogonal tests,and fuzzy mathematics methods were applied to optimize the restructured goose liver formulation,with sensory evaluation,cooking loss rate,and textural characteristics serving as evaluation indicators.The results revealed that,based on the combined weight of goose liver and chicken meat,the optimal formulation for the restructured goose liver product was as follows:25wt.%goose liver,75wt.%chicken,1.75wt.%TGase,10wt.%tapioca starch,and 2.75wt.%soy protein.Under these conditions,the restructured goose liver product exhibited a cooking loss rate of 0.13%,whiteness of 54.87,hardness of 27.77 N,elasticity of 4.56 mm,and chewiness of 83.32 mj.The product surface was smooth,with good chewiness and elasticity,a compact structure,rich flavor,and an overall quality score of 89.60 points,which did not differ markedly from the model-predicted score of 87.15 points.The findings of this research provide a theoretical basis for the comprehensive processing and diversification of conventional goose liver products.

Abstract:Lactic acid bacteria with broad-spectrum antibacterial activities were isolated from fermented foods.These specific strains of lactic acid bacteria were capable of producing antimicrobial peptides,which were effective food preservatives.The main antibacterial substances present in the fermentation supernatant were analyzed for their properties,including heat,acid,and alkali tolerances;cell wall integrity;membrane permeability;and glucose availability.The fermentation conditions were optimized using single-factor analysis and response surface experiments.The effects of the resulting product on the preservation of pork and fish were examined.Lactobacillus delbrueckii(L.delbrueckii)M2 and L.delbrueckii subsp.bulgaricus M6 were isolated from sour bean and fermented milk,respectively,which exhibited broad-spectrum antibacterial activities.Their main antimicrobial components consisted of proteins or peptides with high thermal and acid-base stability.Moreover,the alkali tolerance of the antimicrobial substances from M2 was higher than those from M6.The optimal fermentation conditions for the two Lactobacillus strains were a 2.00%mass fraction of glucose,3.00%mass fraction of soybean peptone,and 3.00%inoculation volume fraction.The antibacterial effects of L.delbrueckii M2 and L.delbrueckii subsp.bulgaricus M6 were 25.47%and 22.64%stronger under these conditions than under the baseline conditions,respectively.The supernatant of the two strains disrupted cell wall integrity and membrane permeability,leading to alterations in glucose utilization and ultimately producing the observed antibacterial effects.Their fermentation supernatants reduced the total viable bacteria counts and prolonged the shelf life of chilled pork and fish by 2～4 days.This study provides theoretical insights for the development and application of new broad-spectrum biological preservatives.

Abstract:The shell breaking process of Camellia oleifera fruit relies on drying stress to separate the seeds from the shells.Shell-breaking experiments were performed to analyze the moisture loss characteristics during shell-breaking caused by drying stress at different drying temperatures(50,60,70,and 80℃)and the influence of the shell-breaking process on the quality of cold-pressed oils.A model for moisture loss characteristics during shell-breaking caused by drying stress was established,and a variable temperature shell-breaking process was developed.The moisture loss curves of C.oleifera fruit during shell-breaking demonstrated a decreasing trend,and the moisture loss rate showed a decreasing trend with a ladder pattern,exhibiting an initial acceleration stage,followed by several nearly constant-rate stages.With the increase in drying temperature,moisture loss curves became steeper,and the time to reach the endpoint moisture content of 32.00%(w.b.)for C.oleifera was significantly reduced.The newly established mathematical model with R2≥0.999 7 and RMSE≤0.428 6%can accurately describe the moisture loss process during the shell-breaking of C.oleifera fruit caused by drying stress.With increasing shell-breaking temperature,the acid value of the cold-pressing oil prepared using C.oleifera seeds increased from 0.08 mg/g to 0.39 mg/g.The total color difference value increased from 76.27 to 83.63,and the crude oil yield decreased from 23.43%to 18.84%.Shell-breaking caused by drying stress at low temperature improved the quality and crude oil yield of cold-pressed oil from C.oleifera seeds.After variable temperature shell-breaking caused by drying stress,the shell-breaking and seed-breaking ratios of the C.oleifera fruits were 98.35%and 0%,respectively.The acid(based on KOH)and peroxide values of the cold-pressing crude oil were 1.00 mg/g and 0.009 9 g/100 g,respectively.The moisture and volatile matter content was 0.35%,and the crude oil yield was 21.08%.The results of this study will provide reference data for the optimization of shell-breaking technology.

Abstract:Diabetes mellitus is a common metabolic and endocrine disorder that can result in serious complications,affecting an individual's quality of life.Although multiple hypoglycemic drugs are available for clinical use,they are all associated with varying degrees of adverse reactions.In recent years,research on edible fungal proteins has increased,and their potential for lowering blood sugar has garnered considerable attention from the scientific community.This review discusses the mechanisms by which edible fungal proteins regulate glucose metabolism,including the modulation of immunity,regulation of glucose utilization,modulation of insulin signaling pathways,and alleviation of oxidative inflammatory responses.This review findings provide guidance for the development of safer and more effective treatment options for patients with diabetes.

Abstract:In order to non-destructively determine mango ripeness,this study focused on exploring the combined use of visible near-infrared hyperspectral imaging and deep learning methods.The hyperspectral data of unripe,ripe and overripe mangoes were collected in the wavelength range of 400~1 000 nm using a diffuse reflectance hyperspectral imaging system.The SPXY algorithm was used to divide the data into training,validation and testing sets in a ratio ofo 6:2:2.After the spectral pre-processing such as Wavelet Threshold Denoising(WTD)and Multiplicative Scatter Correction(MSC),a 1-Dimensional Convolutional Neural Network(1DCNN)model was constructed.Meanwhile,Principal Component Analysis(PCA)and Bootstrapping Soft Shrinkage(BOSS)were used to extract the feature bands,and the classification models of Partial Least Squares-Discriminant Analysis(PLS-DS)and Extreme learning machine(ELM)were constructed.Comparative analysis shows that the 1DCNN model based on multiple scatter correction preprocessing performed the best,with a classification accuracy of 98.30%and a Kappa coefficient of 0.97 on the test set.The study concludes that the combination of hyperspectral imaging technology and neural network algorithm can reliably and accurately determine mango ripeness,providing a theoretical basis for the practical application of automated mango sorting.

Abstract:In this study,the antioxidant activity and protective effect against AAPH-induced oxidative damage in human erythrocytes of the polysaccharides from Broussonetia papyrifera panicle were studied.Broussonetia papyrifera panicle was taken as the raw material,single factor experiments were designed for a hot water extraction method and the extraction process of Broussonetia papyrifera panicle crude polysaccharide was optimized by the response surface method.The evaluation indicators included the scavenging rate of ABTS+∙,DPPH∙ and ∙OH,the reducing ability of Fe3+,and the protective effect against the AAPH-induced human red blood cell oxidative damage,to study the in vitro antioxidant activity and hemolysis inhibition of the polysaccharides.The results showed that the optimal conditions were:solid-to-liquid ratio 1:32.33(g/mL),extraction temperature 89.89℃,extraction time 116.53 min,under which the yield of crude polysaccharide was 23.67%.In the antioxidant experiments,the scavenging rates of ABTS+∙,DPPH∙ and ∙OH of the polysaccharide were 76.92%,57.81%and 80.76%,respectively.The absorbance of the polysaccharide corresponding to the reducing ability against Fe3+was 1.66 at a polysaccharide mass concentration of 8 mg/mL and the wavelength of 700 nm.Erythrocyte hemolysis experiments showed that the polysaccharide could effectively inhibit the production of ROS and MDA in the erythrocytes treated by AAPH,reduce the conversion rate of GSH to GSSG,and regulate the enzyme activities of CAT,GSH-PX and SOD to restore normal red blood cell levels.The study confirmed that the polysaccharide from Broussonetia papyrifera panicle possessed good antioxidant capacity and can protect erythrocytes from oxidative damage caused by AAPH.This research aimed to provide a scientific foundation for the study on the bioactive material basis of Broussonetia papyrifera panicle polysaccharides,which is of great significance for the research and development of health food products derived from Broussonetia papyrifera panicle.

Abstract:In order to explore the status of adding artificial and natural sweeteners to beverages,an ultra-high performance liquid chromatography-quadrupole/electrostatic orbitrap high-resolution mass spectrometry(UPLC-Q/Orbitrap HRMS)method was established for the screening and determination of 11 types of artificial and natural sweeteners in beverages,and the MS fragmentation pathways of the sweeteners were profiled.The beverage samples were diluted with a methanol-water solution in a volume ratio of 1:1,and after filtration through a membrane,the filtrate was separated using an HSS T3 column then detected by UPLC-Q/Orbitrap HRMS.Mass spectrometry simultaneously collected primary parent ions and secondary fragment ions for qualitative confirmation based on the retention time,parent ion and secondary fragment ions,while the peak areas of the parent ions were used for quantification.Through profiling of the MS fragment pathways,it was found that the steviol glycosides had common fragment ions m/z 641.316 3,479.265 0 and 317.211 9,allowing for qualitative identification of the unknown steviol glycoside compounds in the samples using the parent ion and common fragment ions.The method validation results showed a good linear relationship for the 11 sweeteners within the corresponding concentration ranges,with average recoveries of 77.29%～98.82%and relative standard deviations(RSDs)in the range of 1.5%～9.6%(n=6),limit of detection of aloin being 150.0 μg/L,and limits of detection of other 10 sweeteners in the range of 1.0~15.0 μg/L.The testing of real samples revealed that sodium cyclamate was detected in two fruit beverages(at concentrations of 0.8 mg/L and 190.9 mg/L,respectively),and stevioside and rebaudioside A were detected in one tea beverage(at concentrations of 94.2 μg/L and 62.1 μg/L,respectively),with no other unknown steviol glycoside sweeteners being detected.The results showed that although the contents of the sweeteners in the tested beverages did not exceed the maximum allowable limit specified in the standards,there were instances of incomplete labeling contents,suggesting a need for stronger supervision and management of food labeling.

Abstract:To develop the deer meat industry,it is vital to elucidate the quality characteristics of prepared venison after reheating.Mass texture analysis,gas chromatography-ion mobility spectrometry(GC-IMS),and three additional techniques,including an electronic nose,were used for a comprehensive analysis of reheated deer meat.The texture parameters of prepared venison after heat treatment in an air fryer were as follows:hardness 14.25 N,elasticity 4.82 mm,and chewability 44.78 mJ.The GC-IMS test revealed 41 main volatile components in the precast braised venison after reheating.Based on orthogonal partial least squares discriminant analysis(OPLS-DA),12 flavors were selected to distinguish the relative content of key characteristic flavors among different reheating samples.The electronic nose results revealed that braised venison contains five primary aromas,including benzenaldehyde,alcohol,and aromatic compounds,consistent with the GC-IMS detection characteristics.The results of this study provide a scientific basis for the development and popularization of venison and serve as reference data for the reheating of prefabricated meat dishes.

Abstract:The changes in the flavor characteristics of different grades of Pixian Douban after stir-frying were evaluated using a quantitative sensory descriptive method(QDA)and gas chromatography-ion mobility spectrometry(GC-IMS).The QDA analysis revealed that premium Douban possesses a low moisture content and a fruity,winey,malty,and burnt aroma after stir-frying.The higher water content of the first and second grade Douban led to greater differences in sensory scores compared with extra-grade Douban,but exerted less influence on the main sauce flavor.The GC-IMS detected 45 compounds,comprising 11 alcohols,9 aldehydes,8 esters,6 ketones,5 alkenes,2 acids,2 heptane,1 pyridine,and 1 furan;however,many compounds remain unidentified.After stir-frying,the proportion of alcohols in the Douban increased from 14%to 37%,and the proportion of esters substantially increased from 2%to 11%.This indicates that stir-frying converts and concentrates the alcohols in the dal in a Maillard reaction.The resulting aroma is fruity,alcoholic,malty,and sour.High-temperature stir-frying results in the conversion of certain aldehydes into esters and ketones,altering the soy sauce flavor of the Douban to a burnt,fatty aroma.This study reveals the remarkable influence of the moisture content of different grades of Pixian bean paste on the flavor characteristics of stir-fried bean paste,providing crucial technical support and guidance for the advanced processing and innovative development of Douban.