Rhamnolipids (RLs) are a class of glycolipid biosurfactants with excellent performance, with high interfacial activity, good biodegradability and low toxicity, and their biomanufacturing prospects are broad.At present, RLs synthesis has been reported in Pseudomonas aeruginosa, Escherichia coli, Pseudomonas putida and Saccharomyces cerevisiae.In this study, we used Pichia pastoris GS115 for the first time to synthesize RLs, and first expressed synthetic gene clusters (rmlABCD, rhlAB) to study the effects of different promoters (P_GAP and P_AOX) and transformation modes (single and double transformation) on RLs.The results showed that promoter type and transformation mode had significant effects on the synthesis amount and structural diversity of RLs.Using the P_GAP promoter, the RLs of GS115/pGAPZ A-rmlABCD-rhlAB (HW001) strain reaches 30.80 mg/L, with structures including three types:Rha-C₁₀, Rha-C₁₀-C₁₀, and Rha-C₁₀-C_12∶1.The GS115/pGAPZ A-rmlABCD/pGAPZAMH-rhlAB (HW002) strain achieves a production of 38.20 mg/L, synthesizing structures of Rha-C₈-C10 and Rha-C₁₀-C_12∶1.Using the P_AOX promoter, the GS115/pPICZ A-rmlABCD-rhlAB (HW003) strain reaches a synthesis yield of 53.86 mg/L, with structures of Rha-C₁₀ and Rha-C₁₀-C₁₀.The GS115/pPICZ A-rmlABCD/pPICZAMH-rhlAB (HW004) synthesizes Rha-C₈-C₁₀ and Rha-C₁₀-C_12∶1, yielding 42.70 mg/L.This study lays the theoretical foundation for the synthesis of RLs in Pichia pastoris.This study lays a theoretical foundation for the synthesis of RLs in Pichia pastoris.

Cell-based foods promise to supply animal protein through large-scale cell culture rather than animal farming.Bovine serum albumin (BSA) is an essential nutrient supplied by the culture medium, critical for maintaining cell survival and growth in vitro.Currently, most BSA in use is extracted from bovine serum, which is plagued by batch variability and contamination risks.Here, we report an engineered Komagataella phaffii platform for efficient production of recombinant BSA (rBSA).Through systematic screening of 17 promoters and 38 signal peptides, the combination of P_AOX2m promoter and M4FI signal peptide proved optimal, achieving a 2.57-fold increase in rBSA yield compared to the starting strain.Subsequently, by screening for high-copy strains and co-expressing the molecular chaperone HRD1 and protein transcription factor HAC1, a high-yielding rBSA strain was obtained.This strain achieved a yield of 0.40 g/L rBSA in shake flask fermentation, 8 times that of the starting strain.Furthermore, the protein structure and bioactivity of purified rBSA were evaluated, confirming its natural-like secondary structure and excellent pro-proliferative effect on bovine mesenchymal stem cells.This work optimized the extracellular expression of rBSA in Komagataella phaffii and evaluated its potential application in cell-based food production.

Bifidobacterium favimelis sp.nov.IMAU50987^T is a novel species of the genus Bifidobacterium isolated from black comb honey in Yunnan, China.API 50 CHL results indicate that IMAU50987^T can utilize 11 carbon sources, including sucrose, maltose, and starch, showing a preference for polysaccharides and oligosaccharides over monosaccharides such as glucose.This carbon source utilization differs from that of closely related strains.To elucidate the genetic basis underlying these differences, comparative genomic analysis was performed on this strain and its closely related species:The core-pan-genome was constructed using Roary, and functional annotation was performed using the cluster of orthologous groups of proteins database (COG), the carbohydrate-active enzymes database (CAZy), and the kyoto encyclopedia of genes and genomes database (KEGG).COG annotation results indicate that carbohydrate transport and metabolism-related genes dominate in the B.asteroides group.CAZy analysis identifies 25 subfamilies within three major classes of carbohydrate-active enzymes, The CBM48 domain, which can specifically bind glycogen or starch granules, is unique to strain IMAU50987^T.KEGG annotation results reveal that strain IMAU50987^T possesses the largest number of genes involved in secondary carbohydrate metabolism pathways., particularly in the starch and sucrose metabolism pathway as well as the glycolysis/gluconeogenesis pathway.The strain also harbors unique genes such as sucP, cbpA_2, and pulA.Analysis of virulence and antibiotic resistance genes confirms that IMAU50987^T is genetically safe.The unique carbohydrate utilization characteristics of IMAU50987^T confer it a strong competitive advantage in complex carbohydrate-rich environments, providing a solid foundation for further investigation and potential application of this strain.

High-performance multifunctional strains are critical for innovation in the natto industry.This study aimed to screen Bacillus subtilis strains with high nattokinase productivity and systematically conduct functional analysis and application development of the selected strains.Through specific screening of Bacillus subtilis, an outstanding strain CGMCC 34222 with high nattokinase yield was identified, and the nattokinase activity reached 75 794 U/g, accompanied by excellent sensory properties, including a subtle aroma and prominent stringiness.Functional analysis revealed that this strain exhibits significant inhibitory activity against Candida albicans, with an inhibition zone diameter of approximately 25 mm, thereby demonstrating its potential for developing novel biological antimicrobial agents.Genomic characterization indicated that the single nucleotide polymorphisms of strain CGMCC 34222 were significantly different from those of known natto-related strains.Notably, the serine protease gene encoding nattokinase contains specific variations, which are hypothesized to underlie its high enzymatic activity.Subsequent optimization of fermentation conditions via response surface methodology determined the optimal parameters:2.8% inoculation, 47 ℃, and 6.6 h fermentation time.Under these optimized conditions, the nattokinase activity reached 105 157 U/g, with the highest sensory score.The strain CGMCC 34222 in this study serves as a critical basis for the industrial application of natto in functional foods, biomedicine, and green agriculture.

This study aims to develop a specific, efficient, and cost-effective PCR-based method for the accurate identification of Heyndrickxia coagulans.Existing identification techniques for this bacterium, such as 16S rRNA sequencing and physiological and biochemical tests, generally have limitations of high detection cost or long cycle.Besides, the specific PCR primers reported previously were mostly designed based on old taxonomic system;with two changes in the genus name of this bacterium, the specificity of these primers urgently needs to be revalidated under the current taxonomic framework.In this study, bioinformatics tools like Roary 3.31.0 were used to perform pan-genome analysis on 183 genomes of the genus Hendrickxia and its closely related genus Bacillus. Nine Hendrickxia coagulans-specific genes were screened out, and ten pairs of primers were designed accordingly.Validation with 35 negative bacterial strains and 25 positive bacterial strains showed that the primer SCFF-WCYW008, which targets the cold shock protein gene, exhibited 100% amplification specificity.It achieved good amplification effects within an annealing temperature range of 50-60 ℃ and a DNA template concentration of ≥ 0.96 ng/μL. In this study, the specific primers for Heyndrickxia coagulans developed through bioinformatics approaches demonstrated high specificity and sensitivity, significantly reduce its identification time and costs, which could be served as a valuable reference for developing species-specific primers for other microorganisms.

Saccharomycopsis fibuligera is an important microorganism in Chinese traditional fermentation systems, renowned for its exceptional enzyme production capabilities.This study used transcriptomics technology to systematically analyze the enzyme production mechanisms of protease, amylase, and β-glucosidase.The results revealed that 2 162 DEGs were identified in the proteasome group;373 DEGs were identified in the amylase group;293 DEGs were identified in the β-glucosidase group.GO and KEGG enrichment analysis indicated that the regulation of the three enzyme systems exhibited a “common basic characteristic branch” regulatory pattern.The MAPK signaling pathway, nitrogen metabolism, ribosomes, amino acid synthesis and longevity regulation constitute the basis of a common regulatory network.At the specific level, protease expression relies on the synergistic enhancement of protein synthesis, processing and secretion pathways;amylase expression is closely linked to the central carbon metabolism and energy metabolism network;while β-glucosidase expression emphasizes the reconstruction of cell membrane structure and transport system.The study provides theoretical foundations and molecular targets for developing industrial strains capable of degrading protein, starches, and cellulose.It contributes to improve raw material utilization, enhance product flavor quality, and promotes technological advancements within China’s traditional fermentation industry.

Enzymatic degumming technology has great potential in the oil refining industry.However, most of the existing degumming enzymes are mesophilic enzymes, which do not match the temperature requirement in the oil refining process.Therefore, mining degumming enzymes suitable for continuous degumming at high temperature is of great value to the oil refining industry.Researches have revealed that Thermomyces lanuginosus lipase (TLL) has high efficiency of oil degumming, however, the thermostability of TLL is poor.This study applied ancestral sequence reconstruction (ASR) technique for mining thermostable lipases using TLL as a template.Firstly, eight ancestral enzyme sequences were obtained through ASR;Secondly, enzymatic property analysis showed that the specific activities of ASR107 and ASR110 were 124.70 U/mg and 178.33 U/mg, respectively, and the residual enzymatic activity of them remained above 90% after treatment at 70 ℃ for 12 hours, which indicated that they possessed good thermal stability.Finally, after 8 hours of degumming at 70 ℃, ASR110 reduced the residual phosphorus content of cottonseed oil to 8.52 mg/kg, which revealed that it achieved good degumming effect.This study obtains thermostable lipases using ancestral sequence reconstruction strategy, which provides new enzyme resources for the degumming of vegetable oils.

To investigate the anti-aging activity of capsular polysaccharides (CPS) produced by lactic acid bacteria and evaluate their application potential in functional foods, this study used Limosilactobacillus fermentum S1 as the starting strain.CPS was extracted using a lysozyme-based method, purified by DEAE-52 ion-exchange column chromatography, and subsequently characterized.On this basis, the anti-aging effects of CPS were systematically evaluated using Caenorhabditis elegans as the model organism.The results showed that purification via DEAE-52 ion-exchange chromatography yielded a major polysaccharide fraction, designated CPS-3, with an average molecular weight of 4.47×10⁴ Da.This polysaccharide adopted a random coiled conformation and consisted of rhamnose, glucose, and galactose in a molar ratio of 1∶1.58∶12.39.Methylation and NMR analyses revealed that CPS-3 primarily consisted of β-D-Galp-(1→2,6), β-D-Glcp-(1→2,6), β-D-Glcp-(1→2), β-D-Galp-(1→3), α-L-Rhap-(1→2), α-D-Galp-(1→3), and β-D-Galp-(1→ residues.In C.elegans assays, 160 μg/mL CPS-3 significantly enhanced the in vivo antioxidant capacity of nematodes, while extending their lifespan under normal culture, oxidative stress, and thermal stress conditions by 19.24%, 32.91%, and 30.02%, respectively.Furthermore, this dosage reduced reactive oxygen species and lipofuscin levels by 76.02% and 59.63%, respectively, and improved reproductive capacity, pharyngeal pumping rate, and locomotion ability.In summary, CPS-3 exhibits clear anti-aging activity and shows promise as a natural anti-aging ingredient for functional foods.

To elucidate the influence of distinct workshop brewing microecologies on physicochemical factors, microbial community structures, and flavor substance compositions during the stacking and pit fermentation of Jiang-flavor Baijiu, this study investigated the environments and fermented grains across three fermentation rounds in a new workshop (operational time < 3 years) and an old workshop (operational time > 20 years). High-throughput sequencing, high-performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry (GC-MS) were employed, combined with SourceTracker and multivariate statistical analysis. Results revealed that for physicochemical characteristics, the new workshop exhibited a more drastic consumption of reducing sugars and starch in the early stage, with higher levels of total acidity and lactic acid throughout the fermentation cycle compared to the old workshop. The acidity of the middle-layer pit-out grains was 4.17 mmol/10 g in the new workshop and 3.95 mmol/10 g in the old workshop, while the old workshop featured a more gradual organic acid accumulation process and a higher enrichment of acetic acid. Microbially, the old workshop pit mud showed a higher bacterial richness (OTUs = 2 400.00±92.00) in the early phase. During the mid-stacking phase, Bacillus (35%) dominated the bacterial community in the old workshop, whereas Lactobacillus (71%) occupied an absolute dominance in the new workshop. Meanwhile, the relative abundance of Pichia in the old workshop fermented grains remained consistently stable above 70% throughout the cycle, whereas the new workshop environmental fungi showed higher richness on the surfaces of operating tools and the upper layer of empty pits. SourceTracker analysis indicated that the factory ground was the primary bacterial contributor (>50%) for both workshops during the open stacking stage; however, upon entering the sealed pit fermentation stage, the core bacteria in the old workshop mainly originated from the middle layer of empty pits, and its dominant fungi stably sourced from spatial media such as object surfaces and indoor air. In contrast, the microbial community in the new workshop exhibited a strong dependence on specific operating tools and non-pit environments, displaying spatial heterogeneity. Redundancy analysis (RDA) further confirmed that the fungal community in the new workshop was intensively driven by moisture, acidity, and lactic acid, whereas the community succession in the old workshop converged toward a homeostatic state. Driven by these microecological variations, the abundance of flavor substances in the old workshop was higher overall than that in the new workshop, where the total ester content continuously increased from 48.08 μg/g to 385.55 μg/g at the pit-out stage, whereas it peaked at 146.52 μg/g during the mid-fermentation phase and then decreased in the new workshop. Furthermore, the final contents of total alcohols and volatile fatty acids in the new workshop were lower than those in the old workshop. This study clarifies the distinct characteristics of the brewing microecological structures, source tracking functions, and flavor metabolism between the new and old workshops, providing theoretical references for the microecological replication of traditional workshops and the precise regulation of newly established workshops.

The aging in pottery jars is a crucial step in enhancing the overall quality of Baijiu.The sensory characteristics, chroma, metal ions, and volatile flavor compounds of Jiangxiangxing Baijiu aged in a pottery jar were analyzed, investigating the impact of aging in pottery jars on the sensory and flavor quality of Baijiu.Analysis revealed that the levels of aged aroma, sweet aroma, fruity aroma, floral aroma, yellow-blue hue, and most metal ions except for Se were positively correlated with aging time, while the grain aroma, sour aroma, light-dark hue, and Se content were negatively correlated with aging time.Additionally, volatile flavor compounds decreased with the increase in storage time.And 20 significant aromatic components that contribute to the aroma of Baijiu [odor activity value (OAV)>1] with value of variable importance in projection (VIP)> 1 and P<0.01, including isovaleraldehyde, acetaldehyde, ethyl butyrate, dimethyl trisulfide, and ethyl 2-methylbutyrate, were screened out.Among these, compounds like isovaleraldehyde and ethyl 2-methylbutyrate significantly contribute to the overall aroma profile, while the aromatic contributions of isobutyraldehyde and phenylacetaldehyde decreased with the increase of year.Correlation analysis revealed a significant positive correlation between Se and ethyl dodecanoate (P<0.05), while Ni, Ti, Ga, Al and other metal ions primarily showed significant negative correlations with isobutyraldehyde and phenylacetaldehyde (P<0.01).This study provides theoretical support for enhancing the quality of Jiangxiangxing Baijiu storage in a pottery jar.

Low-alcohol represents a major trend in the spirits industry, with alcohol-reduction technology being one of the core aspects of its production.The study prepared low-alcohol Jiangxiangxing Baijiu using water dilution, vacuum distillation, and dialysis.Through quantitative analysis of total acids, total esters, and 105 flavor compounds, the influence of each alcohol-reduction technique on the flavor profile and sensory characteristics was systematically investigated.A comprehensive comparison evaluated the feasibility of each alcohol-reduction method.Results showed that compared to the original liquor, samples prepared by water dilution and dialysis had lower acid and ester content.The water-diluted samples showed obvious sauce flavor, while had a little water taste.The dialysis samples had less sauce flavor but a clean aroma and prominent aldehyde aroma.Those two kinds of samples were both feasible for seasoning.Vacuum-distilled samples had good aroma and showed acid increasing and ester decreasing, which tasted sour and like a “new liquor”.Its distillate had more esters and fewer acids, which could be used as an auxiliary seasoning.Cluster analysis, principal component analysis and partial least squares-discriminant analysis revealed that water-diluted and dialyzed samples closely resembled the original liquor, while vacuum-distilled samples showed significant divergence.Comparison of variable importance for the projection values and odor activity values identified acetaldehyde dimethyl acetal, ethyl acetate, ethyl lactate, and acetic acid as the key flavor compounds responsible for sensory differences among samples.The study provided a theoretical data basis for the development of low-alcohol Jiangxiangxing Baijiu by different alcohol-reduction methods.

The traditional final-round Jiangxiangxing Baijiu has low yield and weak flavor.Sweet wine lees were added to high-temperature Daqu to improve saccharification.However, the impact of sweet wine lees enhancement on the flavor of Baijiu was still unknown.The flavor of Baijiu is closely related to the microorganisms and physicochemical environment in fermented sorghums. To investigate the effects of sweet wine lees enhancement on Daqu fermentation performance and Baijiu flavor, this experiment added sweet wine lees and sweet wine koji to traditional high-temperature Daqu, comparing biochemical indicators and microbial communities.The physicochemical indicators, microbial types, and diversity of final-round Jiangxiang liquor mash were analyzed, and the Baijiu samples were tested for physicochemical indicators, by GC-MS.The results indicated that high-temperature Daqu with sweet wine lees significantly improved the fermentation ability, saccharification ability, esterification ability, protease activity, and amino nitrogen levels compared with traditional Daqu.Furthermore, sweet wine lees enhancement increased the number and diversity of bacteria, molds, yeasts, lactic acid bacteria, etc., both in Daqu and fermented sorghums.Laboratory-distilled Baijiu samples showed that in the sweet wine lees group, the alcohol content, total acid, and total esters increased by 13.6%, 21.4%, and 21.4% respectively;aroma components such as alcohols increased, particularly ethyl acetate, ethyl butyrate, and ethyl hexanoate, which increased significantly by 39.27%, 13.54%, and 24.52%, respectively, making the liquor flavor smoother and more harmonious.Therefore, sweet wine lees enhancement can improve the production performance of traditional Daqu, enrich the number and diversity of bacteria, and enhance the flavor of the liquor.

In this study, high-throughput sequencing technology was employed to comparatively analyze the bacterial diversity and species composition of three types of pit mud (deteriorated after 2 years of use, normal after 2 years of use, and fresh), and to investigate the species and functional differences of bacterial communities among pit mud in different states.The results showed that there was no significant difference in Shannon index among the three types of pit mud (P>0.05).However, Chao1 index of fresh pit mud was significantly higher than that in both deteriorated and normal pit mud (P<0.05), while no significant difference was observed between deteriorated and normal pit mud (P>0.05).Compared with fresh pit mud, the relative abundance of Caproiciproducens decreased, whereas that of Lactobacillus increased in normal pit mud after 2 years of use.Meanwhile, in deteriorated pit mud after 2 years of use, the relative abundances of Pseudomonas and Acinetobacter increased, while that of Bacillus decreased.Additionally, the relative abundances of Petrimonas and Proteiniphilum, the dominant genera in normal pit mud, were higher than those in deteriorated pit mud.The results of PICRUSt indicated that the proportion of replication and repair functions in normal pit mud that had been used for 2 years increased, while the proportion of biosynthetic functions of other secondary metabolites decreased compared with new pit mud.Meanwhile, in the deteriorated pit mud used for 2 years, the proportions of both the biosynthetic function of other secondary metabolites and the metabolic function of terpenoids and polyketides decreased.Compared with new pit mud, the metabolic pathways related to microbial metabolism (ko00980) in deteriorated pit mud were significantly upregulated (P<0.05), while the metabolic pathways related to metabolic regulation and fermentation stability (ko03040) and ester metabolism (ko04113) were significantly downregulated (P<0.05).However, in normal pit mud, the metabolic pathways related to aroma substance synthesis (ko00943) and precursor flavor substance metabolism (ko03050) were significantly downregulated (P<0.05).This study can provide a theoretical basis for improving the quality of pit mud used in northern Strang-flavor Baijiu production.

To investigate the mechanisms underlying the influence of wheat type on the microbial incubation process of Nongxiang-flavor Daqu, this study selected hard wheat (HW) and soft wheat (SW) as raw materials for Daqu production.By dynamically monitoring the incubation process and combining microbiome and physicochemical analyses, we systematically elucidated the interrelationships among environmental factors, microbial community structure, and enzymatic activity.The results showed that, compared with SW Daqu, HW Daqu exhibited more rapid temperature fluctuations and a lower peak temperature during incubation.Although no significant differences in physicochemical parameters were observed between the two Daqu types during most of the cultivation period, by the end of incubation, HW Daqu showed significantly higher acidity and saccharification power than SW Daqu.Microbiome analysis revealed that fungal diversity in HW Daqu markedly rebounded in the later incubation stages, with Aspergillus (14.83%) and Candida (11.44%) emerging as dominant genera.In contrast, the SW Daqu showed low fungal diversity, with predominantly thermophilic fungi, including Thermoascus (55.66%) and Thermomyces (19.31%).Bacterial diversity in both Daqu types followed a similar pattern:an initial increase followed by a decline, with consistently higher diversity in HW Daqu.The final bacterial community in the HW Daqu was dominated by Weissella (55.72%) and Pantoea (19.63%), whereas the SW Daqu was primarily composed of Weissella (50.28%) and Bacillus (9.97%).Network topology analysis indicated that SW Daqu possessed a more complex microbial co-occurrence structure, suggesting potentially greater functional stability during subsequent pit fermentation.Redundancy analysis (RDA) further identified temperature and humidity as the key environmental drivers shaping microbial succession and demonstrated that the microbial assemblage in HW Daqu was more sensitive to environmental fluctuation.This study elucidates the mechanism by which wheat’s physicochemical properties influence Daqu quality by modulating microbial metabolism and community structure.The findings provide a theoretical foundation for optimizing raw material selection and fermentation parameters in Daqu production.

Red-fleshed kiwifruit serves as an excellent raw material for fruit wine processing due to its high sweetness and rich antioxidant compounds.This study systematically screened non-Saccharomyces yeasts (NSY) to enhance the aroma of red-fleshed kiwifruit wine.Durham tube assays combined with sensory evaluation selected five NSY strains,including Pichia kudriavzevii PP-7-6, Pichia occidentalis LM-1-4, Candida quercitrusa M-8-36, C.quercitrusa M-8-49, and C.quercitrusa PP-5-3.Physicochemical indices of wines fermented by these NSY strains and Saccharomyces cerevisiae (ScAQ) were then compared.Volatile compounds were finally analyzed using partial least squares-discriminant analysis (PLS-DA).Compared with ScAQ-fermented wine, NSY-fermented wines exhibited 34%-51% lower ethanol production and showed significant color differentiation from red-fleshed kiwifruit juice.Fermentation enhanced vitamin C content in all wines, with P.occidentalis LM-1-4 retaining the highest levels of total flavonoids and total phenolics post-fermentation.Sensory evaluation demonstrated that NSY-fermented wines displayed more intense fruity and floral aromas while exhibiting reduced alcoholic and herb notes.PLS-DA further revealed significant differences in 42 volatile compounds among wines, which are likely key contributors to aroma divergence.NSY effectively enhances flavor complexity and functional properties of red-fleshed kiwifruit wine, providing a novel strategy for developing indigenous microbial resources in the fruit wine industry.

Fungi can secrete various enzymes and promote fermentation, which play an important role in Baijiu brewing.Aspergillus albicans can produce high levels of glucoamylase, which contributes to liquor yield and flavor substances, and has good application prospects.The fungal community structure of 4 kinds of Daqu sample from different regions was analyzed by high-throughput sequencing.Results showed that Aspergillus was the dominant strain in 4 kinds of Daqu, and the relative abundance of Aspergillus in Q4 was higher than 60%.Eight strains of Aspergillus were screened from Q4, and screened again for saccharifying ability, among which strain J2 had higher glucoamylase activity (995.33 U/g).J2 was identified as A. albicans by colony morphology and molecular biology.J2 was applied to the production of Sichuan-style Xiaoqu Baijiu through Fuqu as the medium.Results showed that the Baijiu yield of group X2 was 46%, which was 3.5% higher than that of the control group X.The content of ethyl acetate in group X2 was 1 675.46 mg/L, which was 946.70 mg/L higher than control group X1.The content of ethyl lactate was 575.57 mg/L, which was 123.60 mg/L higher than that of the control group X1, and the content of isobutanol was 860.01 mg/L, which was 91.07 mg/L lower than that of the control group X1.Results showed that A. albicans screened from Daqu could be applied to the brewing of Sichuan-style Xiaoqu Baijiu to improve the quality of Sichuan-style Xiaoqu Baijiu, which provided a reference for the excavation and application of brewing functional bacteria in Daqu.

This study investigates the key physicochemical prperties and their correlations during the traditional fermentation of fermented bean curd, Precisely monitoring was conducted to track changes in moisture, amino acid nitrogen, protein and amino acids at different stages (0, 3, 7, 11, 15 days) of the traditional fermented bean curd fermentation process.The results show that during the 16-day fermentation process of fermented bean curd, the moisture content continuously decreased continuously from 74.99% on day 0 to 57.59% on day 15 (P<0.01), providing a suitable environment for microbial growth and metabolism.The amino acid nitrogen content increased significantly by 383.5% (from 0.194 to 0.938 g/100 g), directly characterizing the degree of protein degradation.The protein content generally decreased, with a total reduction of 7.888 g/100 g.The amino acid content increased 15.8-fold (form 0.063 to 1.061 g/100 g), and the types became more diverse, changing from 6 to 17.Essential amino acids accounted for 37.45% of the total, exceeding the FAO(Food and Agriculture Organization of the United Nations)/WHO(World Health Organization) standard of 35.38%.These changes collectively contribute to the unique quality and flavor of traditional fermented bean curd.Further correlation analysis revealed that amino acids were significantly positively correlated with amino acid nitrogen (r=0.95), significantly negatively correlated with moisture (r=-0.96), and also significantly negatively correlated with protein (r=-0.89).By elucidating the coordinated variations of multiple indicators, this study not only enhances the theoretical understanding of fermented bean curd fermentation but also provides a scientific basis for improving quality control in practical production.

Probiotic fermentation can enhance the nutritional value of black rice milk;however, its shelf life is short, and direct spray drying often leads to substantial probiotic loss.Therefore, improving the viability of probiotics and the reconstitution quality of rice milk powder is of great importance.In this study, black rice milk was prepared through co-fermentation with Aspergillus oryzae and Lacticaseibacillus casei, and microencapsulated using a gelatin-gum arabic complex coacervation method.The resulting microcapsules were spray-dried to obtain rice milk powder.The viable counts, hygroscopicity, and crystalline structure of the powders were systematically analyzed, and the stability and rheological properties of the reconstituted beverages were evaluated.The results showed that after spray drying, the rice milk powder encapsulated with gelatin-gum arabic exhibited higher crystallinity and a denser structure, maintained the highest viable counts of L.casei, and demonstrated superior storage stability.Upon reconstitution, the viable counts met national standards (6.33 lg CFU/mL), with a low centrifugal sedimentation rate and good fluidity.These findings indicate that complex coacervation using gelatin and gum arabic effectively reduces probiotic mortality during spray drying, significantly enhances the storage stability and reconstitution quality of black rice milk powder, and offers promising potential for industrial applications.

This study employed Leuconostoc mesenteroides D3, a strain with strong antifungal activity, to ferment rye bran sourdough and identified the principal antifungal metabolites and their effects on sourdough and bread quality.The antifungal activity of the D3 cell-free supernatant was predominantly attributable to organic acids.Compared with naturally fermented rye bran sourdough (RN), 24 h fermentation with D3 or D9 (a L.mesenteroides strain with weak antifungal activity) yielded sourdoughs with significantly higher viable counts and titratable acidity (P<0.05);the D3 sourdough also exhibited greater antioxidant capacity and the highest free polyphenol content (207.06 mg/100 g).Breads made from D3- or D9-fermented sourdough showed superior texture, sensory attributes, volatile flavor profile, total free amino acids, and in vitro protein digestibility relative to RN bread.Notably, D3 bread displayed the strongest antifungal efficacy, extending the mold-free shelf life by 4 days compared with RN bread.

To improve the flavor and quality of papaya fermented juice, Lactiplantibacillus plantarum LM2, LS2, and LN3 producing γ-aminobutyric acid (GABA) were individually inoculated into papaya juice.Four groups of samples were tested and analyzed for pH, total acid, reducing sugar, carotenoids, total phenols, GABA, organic acids, antioxidant capacity, volatile flavor compounds, and sensory evaluation.Results showed that compared with the control group, fermentation significantly increased the contents of total acid, total phenols, GABA, and organic acid, enhanced antioxidant capacity, and increased the number of volatile flavor compound species, all of which collectively improved the flavor of beverage.Notably, among the three fermented groups, the LS2-inoculated papaya juice exhibited the highest values in all key indices:total acid content reached 5.83 g/L, GABA content was 1.30 mg/L, total organic acid content was 3.87 mg/g, and the sensory evaluation score was 87.5.Additionally, its scavenging rates for DPPH free radicals and ABTS cationic radicals were 91.38% and 88.71%, respectively, which were the highest among all fermented groups.Furthermore, the LS2-inoculated papaya juice contained a rich variety of volatile flavor compounds, with 51 species detected in total, mainly alcohols and esters.Specifically, the contents of key flavor compounds (linalool and benzyl isothiocyanate) were 520.16 μg/g and 151.78 μg/g, respectively, effectively retaining the characteristic aroma components of papaya.In conclusion, fermentation with Lactiplantibacillus plantarum LS2 could significantly increase the GABA content of papaya fermented juice while improving its flavor and overall quality.This study provides technical support for the development of GABA-enriched papaya fermented juice products.

This study aimed to investigate the effects of Lactiplantibacillus plantarum XR4 and Pediococcus acidilactici DS9 as a composite fermentation agent on beef jerky quality.Lean beef hindquarter was used as raw material, inoculated with the composite fermentation agent (XR4∶DS9=3∶1) to produce fermented beef jerky.Comparative analysis was conducted on physicochemical indicators and flavour characteristics at different processing stages.Results indicated that compared to the naturally fermented control group, post-maturation pH in the composite fermentation group decreased to 5.03.Moisture content and water activity were reduced to 18.557% and 0.788, respectively, with a hardness measured at 6 856.999 N.Residual nitrite levels were 3.94 mg/kg, while the thiobarbituric acid value and volatile basic nitrogen content were 0.126 and 4.497, respectively, both significantly lower than those of the control group (P<0.05).The redness value was 13.16, significantly higher than the control group (P<0.05).Analysis of flavour compound evolution during fermentation stages using an electronic nose coupled with gas chromatography-mass spectrometry revealed 48 volatile flavour compounds in cured, fermented, and matured beef jerky.Post-fermentation and maturation showed significant contributions from aldehydes, ketones, and alcohols, indicating that the composite starter culture enhances both physicochemical quality and flavour characteristics of beef jerky.This provides theoretical reference for developing novel fermented beef jerky products.ketones, and alcohols contributed significantly to the flavour profile.This indicates that the addition of a composite fermentation agent helps improve the physicochemical quality and flavour characteristics of beef jerky, providing a theoretical reference for the development of novel fermented beef jerky products.

Hypercholesterolemia is a critical risk factor for cardiovascular diseases, driving the need for safe and effective natural cholesterol-lowering strategies.To address the adverse effects of chemical lipid-lowering drugs and the low gastrointestinal survival rate of probiotics, this study aimed to explore cholesterol-reducing potential and enhance digestive tolerance of lactic acid bacteria derived from traditional fermented foods.In vitro cholesterol removal assays identified four high-efficiency strains from 72 candidates.Lactiplantibacillus paraplantarum MRS1026.2 exhibited the highest cholesterol removal rate (74.65%) under optimized conditions (29 ℃, pH 6.1, and a bile salt mass fraction of 0.19%).L.plantarum MRS1026.4 demonstrated superior tolerance and adhesion capabilities, achieving a simulated gastrointestinal survival rate of 26.92%.Immobilization of MRS1026.2 using an optimized sodium alginate-konjac gum-chitosan composite system (mass fractions 1.40%-1.81%-1.80%) significantly improved its survival rate in simulated gastrointestinal environments from 0.016% to 57.39%, with 87.50% intestinal release within 4 h.For MRS1026.4, a lyoprotectant formulation (mass fractions 13.42% skim milk-14.15% trehalose-12.95% inulin) enhanced freeze-dried survival to 73.42%.These findings highlight lactic acid bacteria strains with promising cholesterol-lowering capabilities.The optimized immobilization and freeze-drying strategies markedly improved gastrointestinal tolerance, providing critical scientific and technical support for developing novel functional foods targeting hypercholesterolemia.

To evaluate the feasibility of Pichia pastoris (JR-21) on promoting the ripening of cheddar cheese, the fermentation broth of Pichia yeast (JR-21, JR-42, M-19) was evaluated, and JR-21 strain was selected as the yeast for the subsequent fermentation of Cheddar cheese, two different types of cheddar cheese were prepared without addition (control) and with auxiliary starter culture (JR-21), and the texture and flavor parameters of the two cheeses were measured during the 40-day maturation period, and the effects of Pichia pastoris on the physicochemical characteristics, texture and flavor changes of cheese during the ripening period were explored.Results showed that with the extension of the ripening period, there were no significant differences in moisture content or protein content between the two groups (P>0.05). At 0 d of cheese ripening, the pH values of the two groups showed a significant difference (P<0.05). Between 30 and 40 d of ripening, the changes in fat content between the experimental group (M) and the control group (S) differed significantly (P<0.05), in which the addition of JR-21 fermented cheese produced organic acids, polysaccharides, and protein binding to increase the compactness of the protein network structure, making its hardness and chewiness higher than that of the control group, while the elasticity, cohesion, and adhesion did not change significantly, compared with the control group, the addition (JR-21) made the cheese appear honeycomb structure, forming the iconic “eye” pores.With the extension of the ripening period, the two kinds of cheese contained acids, alcohols and esters, and the characteristic flavor compounds detected by the addition (JR-21) fermented cheese at 40 days of maturation were the most abundant, mainly including organic acids such as caprylic acid and acetic acid, alcohols such as ethanol and isoamyl alcohol, and various ester compounds such as ethyl caprate and ethyl caprylate.The control group reached a peak at 30 days and included only 6-caprylic acid, acetic acid, ethanol, ethyl caprate, ethyl caprylate, and ethyl caproate.The addition of Pichia pastoris changed the content and proportion of different organic acids in cheese, and the content and proportion of alcohols and esters synthesized with them as precursors also changed, among which ethanol, isoamyl alcohol, 1-pentanol, ethyl caprate, ethyl caprylate, ethyl heptanoate, amyl formate and ethyl acetate were significantly higher than those in the control group in the addition (JR-21) fermented cheese.Therefore, the addition of Pichia pastoris JR-21 can effectively promote protein breakdown and cheese maturation, while improving the flavor and texture of cheese.

This study investigated the effects of alkaline high-temperature steaming, snailase treatment, and their combination on the properties of wheat bran insoluble dietary fiber (WBIDF) using defatted wheat bran.The combined modification significantly increased WBIDF purity to 93.44%, raising cellulose content while reducing hemicellulose and lignin levels.Microstructural analysis revealed a more porous structure with reduced particle size and increased surface area after treatment.Structural characterization indicated decreased absorption intensity at 1 036 cm^-1, enhanced crystallinity, and improved thermal stability.The water-holding capacity, oil-holding capacity, and swelling capacity of the collaborative modified WBIDF are 1.34 times, 1.23 times, and 2.22 times that of the unmodified WBIDF, respectively.The glucose adsorption capacity has increased to 3.03 times that of before modification.The glucose dialysis retardation index has increased from 12.33% to 34.33%.These results demonstrated that combined alkaline and enzymatic modification effectively enhanced WBIDF structure and functionality, supporting its potential for high value applications.

To explore the synergistic effect of non-starch polysaccharides and proteins in quinoa, this study prepared deproteinized quinoa non-starch polysaccharides (D-QNSP) and non-starch polysaccharides without protein removal (QNSP), and conducted a comparative study on their structural characterization, physicochemical properties and antioxidant activities.The structures were analyzed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, GC-MS, and X-ray diffraction. Their antioxidant activities were investigated by DPPH and ABTS cationic radical scavenging capacity.The results showed that the uronic acid level of QNSP was lower than that of D-QNSP, and the monosaccharide composition mainly included glucose, arabinose, galacturonic acid and galactose.The galactose and arabinose content of D-QNSP was higher than that of QNSP.The molecular weight of D-QNSP (28.97±1.24) was higher than that of QNSP (15.21±0.85).FTIR showed that the absorption peak at 1 640 cm^-1 of D-QNSP was reduced but did not change the functional groups of quinoa non-starch polysaccharides.The surface of D-QNSP was denser than that of QNSP, with fewer large pores and more uniform particle distribution.The oil-holding capacity, swelling power, foaming capacity and stability, emulsifying capacity and stability of QNSP were all higher than those of D-QNSP.Both QNSP and D-QNSP had certain free radical scavenging effects, and the antioxidant activity of QNSP was higher than that of D-QNSP.In conclusion, QNSP has better functional activity, processing value and nutritional efficacy.The synergistic effect of polysaccharides and proteins is greater than that of a single component, which provides a research direction for QNSP and expands its application value.

This study aimed to optimize the stability and loading performance of menthol emulsions.Menthol-loaded chitosan-cinnamaldehyde interfacial bond emulsions were prepared using high-speed dispersion followed by high-pressure microfluidization, with chitosan and cinnamaldehyde serving as interfacial stabilizers.The effects of different chitosan-to-cinnamaldehyde mass ratios (1∶0, 1∶0.25, 1∶0.50, 1∶0.75, 1∶1.00, and 1∶1.25) on the emulsion system were systematically investigated.Key structural characteristics, including interfacial properties, droplet size distribution, zeta potential, microstructure, rheological behavior, and centrifugal stability, were analyzed to explore their influence on encapsulation efficiency and storage stability.The results indicated that the incorporation of cinnamaldehyde significantly reduced the oil-water interfacial tension, enhancing interfacial adsorption.When the mass ratio of chitosan to cinnamaldehyde is 1∶0.75, the emulsion exhibited optimal overall performance, characterized by the smallest droplet size (0.36 μm) and the highest encapsulation efficiency (78.4%), along with excellent centrifugal and storage stability.Confocal laser scanning microscopy images revealed uniform droplet distribution with no aggregation.Studies suggested that an appropriate amount of cinnamaldehyde could form a dense, stable composite interfacial film through covalent bonding with chitosan, while excessive cinnamaldehyde caused over-crosslinking of the chitosan molecules, thereby compromising the emulsion’s stability.This work provides an effective strategy and theoretical foundation for the development of high-performance menthol delivery systems.

The Maillard reaction yields a variety of heterocyclic compounds, yet current research predominantly focuses on their flavor contributions, while systematic analyses of their product species, structures, and toxicological properties are insufficient.In this study, heterocyclic products formed in serine/methionine-glucose Maillard reaction systems were investigated.Q-Exactive Orbitrap high-resolution mass spectrometry (HRMS) was used to screen and identify heterocyclic products in the reaction systems.Product distributions were visualized using the Van Krevelen diagram, and the potential toxicity of the heterocyclic products was evaluated using Discovery Studio software.The results showed that the serine/methionine-glucose system produced 198 and 159 heterocyclic products, respectively.The serine-glucose products mainly consisted of CHON and CHON_1+x types, while methionine-glucose products mainly consisted of CHON, CHON_1+x, CHONS and CHON_1+xS types.Visualization analysis revealed that both systems were primarily characterized by CHON_1+x type products, which were further classified into pyrrole, imidazole, and pyrazine derivatives based on their structural profiles.Among all heterocyclic compounds, 16 exhibited high mutagenicity, potential developmental toxicity, and skin sensitization potential.This study elucidated the relationship between amino acid structures and the quantity and composition of heterocyclic compounds, and performed preliminary toxicity assessments.These findings provide data and methodological support for further elucidating the formation mechanisms and safety evaluation of heterocyclic hazards in heat-processed foods.

This study used goat milk as the raw material to investigate the effects of different heat treatments on the structure, functionality, and interactions of whey proteins.The degree of denaturation increased with the heating intensity.A treatment of 75 ℃ for 10 min served as the critical threshold for maintaining protein activity.Multiscale analyses showed that the absolute zeta potential decreased from 20.9 mV to 11 mV as heating intensity increased.Scanning electron microscopy revealed a transition from uniform distribution to sheet-like aggregation.Circular dichroism indicated that the proportion of random coil structure rose to 35.6% after treatment at 100 ℃ for 120 s.Fluorescence spectroscopy confirmed that unfolding of tertiary structure exposed large numbers of hydrophobic groups.Differential scanning calorimetry demonstrated that lactoferrin(LF) was completely denatured at 121 ℃.SDS-PAGE verified that β-lactoglobulin(β-Lg) formed covalent disulfide crosslinks with LF through free sulfhydryl groups, directly masking the LF active sites.Although α-lactalbumin(α-La) did not directly crosslink with LF, its aggregation further limited LF activity through steric hindrance.These results reveal that formation of whey protein heat aggregates contributes to LF thermal inactivation at the molecular level.This study provides a theoretical basis for optimizing processing conditions of high-activity goat milk products.

To address issues such as significant variations in water samples from different regions and unstable product quality, this study focused on the ion concentration of soaking water used in the natto production process as a variable.Municipal water supply was blended with reverse osmosis water at a specific ratio to prepare soaking water samples with different ion concentrations.Parameters including pH value, electrical conductivity, hardness, and concentrations of major metal ions were measured.Natto quality was analyzed using indicators such as texture profile analysis, color, stringiness, nattokinase activity, amino acid nitrogen content, and total volatile basic nitrogen (TVB-N) content.The results showed that variations in soaking water had no effect on the water absorption rate and swelling rate of soybeans.The ion concentration of water samples was positively correlated with the hardness, elasticity, chewiness, cohesiveness, and color of natto.When the electrical conductivity of soaking water was 73.2 μS/cm and 61.8 μS/cm,respectively, compared with the high-conductivity group (484 μS/cm), the nattokinase activity and amino acid nitrogen content increased by 32.4% and 24.9%, respectively, while the TVB-N content decreased by 10%.By adjusting the ion concentration of soaking water, this study effectively improved the sensory score, nattokinase activity, and amino acid nitrogen content of natto, while inhibiting the formation of TVB-N.It provides technical support for the process optimization of natto production.

To investigate the taste properties of diverse yeast extracts (YE) and their application in spicy strips, this study first analyzed the taste characteristics of free amino acids, flavor nucleotides, and organic acids in eight commercially available YEs, which were categorized into pure YEs (1, 3, 5, 6) and nucleic acid-treated YEs (2, 4, 7, 8).Subsequently, by integrating analyses of taste activity value (TAV), equivalent umami concentration, sensory evaluation, and saltiness-enhancing effect, the salt reduction effect of different YE addition levels in spicy strips was evaluated.Results revealed significant variations in taste characteristics and salt reduction efficacy among different types of YEs.YE8 exhibited the highest total content of free amino acids, umami amino acids (Asp, Glu), TAV values of 5′-inosine monophosphate (5′-IMP) and 5′-guanosine monophosphate (5′-GMP), succinic acid content, and equivalent umami concentration value.YEs could enhance saltiness perception and lower the salt threshold through synergistic and additive effects.Specifically, when YE8 replaced 0.25 g/mL of salt, the saltiness intensity was approximately 8 points.Flavor substances in YEs, including glutamic acid, aspartic acid, citric acid, succinic acid, 5′-GMP, and 5′-IMP, demonstrated significant saltiness-enhancing effects.These findings confirm that the synergistic action of multiple flavor components in YE8 enables the application effect of “reducing salt without compromising saltiness” in spicy strips.

The growing emphasis on healthy lifestyles has accelerated the development of high dietary fiber foods.However, increased fiber content often significantly impairs the marination quality of dried tofu.Pulsed vacuum marination (PVM) employs an alternating cycle of “hot marination under slight pressure at medium temperature” and “low-temperature vacuum impregnation”, which drives the rapid penetration of color and flavor compounds from the brine into the product, thereby markedly improving marination efficiency.This study aimed to investigate the effect of PVM on improving the quality of high-fiber dried tofu (HT).The results showed that response surface methodology combined with artificial neural network optimization established the optimal PVM parameters for high-fiber dried tofu:a vacuum pressure of 40 kPa, hot marination temperature of 85 ℃, hot marination time of 19 min, and processing cycles of 3.Under the synergistic effect of alternating pressure and temperature, the hot marination temperature had the greatest influence on marination quality.Moreover, PVM significantly promoted the formation of fruity, floral, fatty, and spicy aroma notes, contributing to an improved olfactory profile.Compared with the other three treatment groups, the PVM-HT group exhibited higher protein and fat content, seasoning absorption rate, and water-holding capacity, although moisture and total soybean isoflavone levels were lower.In terms of sensory characteristics, the PVM-HT samples displayed a more uniform and brighter red color, significantly increased elasticity (P<0.05), and enhanced hardness and chewiness, leading to an overall acceptable texture.GC-MS analysis identified a total of 92 volatile compounds across all samples, with the PVM-HT group showing the highest diversity and total concentration (66 compounds, 2 427.16 mg/kg).Key aroma-active compounds such as nonanal, octanal, E-2-decenal, and α-terpineol were notably elevated in this group.These findings demonstrate that PVM effectively improves both the quality and flavor of high-fiber dried tofu, offering a valuable reference for innovating legume product processing.

To establish an objective method for evaluating the quality of fermented tofu, this study selected 30 commercially available fermented tofu products from Yunnan, Guizhou and Sichuan provinces as the research subjects.Fifteen quality indicators including the yield rate, color, texture, water activity and protein content were measured.Through difference analysis, correlation analysis, principal component analysis and cluster analysis, the core evaluation indicators were screened out.The reliability of the evaluation model was verified by sensory scores.The results showed that five indicators, namely the yield rate, crispness, protein content, pH and a^*, were selected as the characteristic quality evaluation indicators of fermented tofu by combining correlation analysis with principal component analysis and cluster analysis.The weights of these indicators were determined by the analytic hierarchy process and a quality evaluation model of fermented tofu was established as Y=0.35×coating yield + 0.25×crispness + 0.20×protein content + 0.12×pH + 0.08×a^*.The model validation showed that the linear regression fitting degree R² between the score of the model and the sensory score was 0.98.This model achieved the quantitative evaluation of the quality of fermented tofu and provided practical reference for the research of fermented tofu.

The coffee extract prepared by the traditional extraction methods has some problems, such as time and energy consumption, low extraction rate and resolution loss.This paper used propylene glycol as the main solvent and medium roasted coffee beans as the raw material to prepare the coffee extract.On the basis of a single-factor experiment, the Box-Behnken Design model was used to optimize the process conditions for increasing the caffeine content in the propylene glycol coffee extract.Its antioxidant activity was evaluated by DPPH radical scavenging activity assay and FRAP activity assay.The flavor components were analyzed by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS).Results showed that the optimum conditions for the preparation of coffee extract were propylene glycol volume fraction of 75%, liquid-to-material ratio of 15∶1 (mL∶g), reflux time of 87 min, reflux temperature of 100 ℃, ultrasonic power of 200 W, ultrasonic time of 25 min.Under this condition, the caffeine extraction amount was 9.28 mg/g coffee powder, which was close to the predicted value.The free radical scavenging capacity of DPPH was 12.99 mmol Trolox/mL (calculated by Trolox equivalent), and the iron ion reduction capacity measured by the FRAP method was 34.04 mmol FeSO₄/mL (calculated by FeSO₄ equivalent).26 volatile substances were separated and identified by GC-MS, including 2-methylbutyric acid, guaiacol, 5-methylfuranone, etc.

To clarify the main active components of dietary fiber in Lipu taro (medium glycemic index, GI), this study explores its probiotic effects and lays a theoretical foundation for its development and application in functional foods.It adopted a high-temperature enzymatic method to extract soluble dietary fiber (SDF) and insoluble dietary fiber (IDF).The study evaluated the probiotic effects of Lipu taro dietary fiber via mouse experiments and in vitro monobacterial fermentation assays.It analyzed the main active components of SDF using monobacterial fermentation experiments, molecular weight determination, and monosaccharide composition analysis.The results showed that SDF contains 85.61% total sugar, 16.90% uronic acid, and 29.89% reducing sugar.Both SDF and IDF improved the abundance and diversity of intestinal microorganisms, and significantly increase the relative abundance of Lactobacillus spp., Firmicutes, and Actinobacteria.In monobacterial fermentation experiments, all four probiotics effectively utilized SDF and its SDF-0.3 fraction as carbon sources, but did not significantly promote Escherichia coli growth.The SDF-0.3 fraction mainly consisted of carbohydrates with a molecular weight of (0.832-29.086) kDa, primarily galacturonic acid, galactose, and glucose.In summary, SDF is a pectin-rich dietary fiber with significant probiotic effects.It protects intestinal health by regulating intestinal microorganisms structure, and its main active component is the SDF-0.3 fraction.

After adding modified corn flour to corn flour to form a mixed flour, the peak viscosity, minimum viscosity, final viscosity, setback value, and breakdown value of the corn mixed flour all significantly decreased with the increase in the amount of modified corn flour added.Except for the gelatinization temperature of extruded expanded corn flour, which decreased with the increase of the addition amount, the gelatinization temperatures of the other three modified corn flours increased with the increase of the addition amount.The relaxation time, weakly bound water content, free water content, L^*value, and hardness of the modified corn dough decreased with the increase of the addition amount, while the bound water content, elasticity, cohesiveness, and b^* value increased.Among all the modified doughs, the dough with 60% extruded expanded corn flour had the most uniform structure, the best formability, and the best dough quality.The hardness, adhesiveness, frozen water content, and L^* value of the dumpling wrappers and steamed corn dumplings made from extruded expanded corn flour significantly increased with the extension of the frozen storage time, while the elasticity and cohesiveness significantly decreased.The freeze cracking rate and water loss rate of the steamed corn dumplings significantly increased.The frozen water content increased by 5.58 percentage points, and the freeze cracking rate increased to 62.2% after 20 days of frozen storage, and the water loss rate increased to 7.99%.According to the sensory evaluation results, the steamed corn dumplings had better eating quality when consumed within 0-5 days of frozen storage.With the extension of the frozen storage time, due to the growth and recrystallization of ice crystals, the internal structure of the steamed corn dumpling wrappers was severely damaged, and the quality deteriorated.

To overcome the limitations of traditional natural fermentation relying on empirical control, this study systematically extracted and characterised key indicators affecting the quality of fresh wet rice noodles, elucidating their dynamic changes during the fermentation process and their correlation with quality improvement mechanisms.Through a 10-day natural fermentation, biochemical indicators such as fermentation liquid pH, total acid, extracellular polysaccharides (EPS), and amylase activity were monitored.Starch at different stages was extracted and systematically characterised for molecular weight, amylose content, crystallinity, pasting and retrogradation properties, and freeze-thaw stability.Subsequently, fresh wet rice noodles were prepared, and their cooking indicators such as noodle breakage rate, cooking loss, and iodine blue value, texture indicators such as hardness and elasticity, and changes in hardness increase and moisture migration (T₂ relaxation time) during storage were comprehensively evaluated.The results showed that the fermentation process exhibited two stages:a degradation-dominated stage (0-4 days) and a reorganisation-stable stage (4-10 days).During the degradation stage, key indicators included a 61.4% decrease in starch weight-average molecular weight, reduced amylose content, and significantly lowered retrogradation value;the reorganisation stage was characterised by significant EPS accumulation and partial recovery of molecular weight.Rice noodles made from starch fermented for 4 days showed an 80% reduction in noodle breakage rate, reduced cooking loss, improved sensory scores, and a significantly lower hardness growth rate than the control after storage at 4 ℃ for 3 days.This study identified the key indicators regulating the quality of fresh wet rice noodles (such as molecular weight, amylose content, retrogradation value, EPS content, noodle breakage rate, storage hardness, etc.) and their changing trends, establishing a fermentation process control framework based on indicator characterisation, providing a scientific basis for transforming natural fermentation processes from empirically driven to precisely regulated.

The purpose of the study is to clarify the dynamic patterns of the sensory quality formation of millet porridge during cooking.Sensory evaluation, physicochemical analysis, free amino acid analysis, and non-targeted metabolomics were employed to systematically investigate the quality changes in millet porridge at different cooking times (5, 10, 15, 20, and 25 minutes).The results showed that cooking time significantly affected the sensory quality of millet porridge.As cooking progressed, carotenoid migration and starch gelatinization led to a yellowing colour and increased viscosity of the porridge.Aspartic acid was identified as the key compound contributing to umami, while sweetness was mainly attributed to reducing sugars, alanine, and serine;bitterness and astringency were respectively associated with total flavonoids and γ-linolenic acid.Thirteen volatile compounds, including hexanal and methyl valerate, were identified as key contributors to aroma optimization.Correlation analysis between differential flavor compounds and sensory characteristics revealed that taste compounds such as total phenols, serine, arginine, pantothenic acid, and volatile components such as heptane and phenylacetaldehyde were significantly correlated with the overall sensory score, highlighting them as key compounds influencing the flavor quality of millet porridge.This study clarified the dynamic patterns of quality formation during the cooking of millet porridge from a multi-omics perspective, establishing the intrinsic relationship between key flavor components and sensory attributes.

Microbial contamination is a primary cause of food spoilage.Photodynamic technology has garnered widespread attention due to its high sterilization efficiency and its low tendency to induce bacterial resistance.This study utilized light-responsive Chinese artichoke carbon dots as photosensitizers and biodegradable polyvinyl alcohol (PVA) as the matrix to prepare photodynamic antibacterial films via the solution casting method.The films were comprehensively characterized for their microstructure, chemical structure, surface hydrophobicity, mechanical properties, and antibacterial performance.Furthermore, their preservation efficacy was evaluated on tray-packaged fresh mutton.Scanning electron microscopy and Fourier transform infrared spectroscopy confirmed the successful formation of the composite films.Mechanical tests indicated that films containing a low concentration of CDs (3 mL) exhibited higher tensile strength and elongation at break compared to pure PVA films.Antibacterial experiments validated the light-responsive activity of the films, achieving a 99.99% inhibition rate against both Staphylococcus aureus and Escherichia coli under visible light irradiation.In the fresh mutton storage experiment, the active films effectively inhibited microbial proliferation and delayed quality deterioration, extending the shelf life of the fresh mutton from 36 hours to 60 hours.This research provides a theoretical basis and technical support for the application of photodynamic antibacterial packaging in meat preservation.

Krebs cycle substrates show potential in regulating postmortem muscle metabolism and color stability, but their effects on the color stability of frozen beef remain unclear.This study systematically evaluated the effects of four substrates (sodium pyruvate, sodium citrate, sodium succinate, and sodium malate) on the color of beef patties during repeated freeze-thaw cycles, which served as an accelerated model for long-term frozen storage.Based on the optimization of concentrations for color improvement, freeze-thaw cycles (1-7 times) were applied to assess long-term effects.Measurements including color parameters, myoglobin composition, metmyoglobin reducing activity (MRA), oxygen consumption rate (OCR), NADH content, succinate dehydrogenase (SDH) activity, pH, and TBARS values were conducted.Results showed that 2% sodium succinate performed best in maintaining color stability during repeated freeze-thaw cycles, followed by 2% sodium citrate, while 2% sodium pyruvate and 3% sodium malate exhibited limited long-term color enhancement.After 7 cycles, the 2% sodium succinate group maintained significantly higher a^* (14.17), C^* (17.34), and R630/R580 (2.82) values, along with increased oxymyoglobin content (up to 66.37%), enhanced MRA, and elevated OCR (P＜0.05).These improvements were associated with increased NADH levels and SDH activity.In contrast, 2% sodium pyruvate significantly inhibited lipid oxidation but reduced NADH content and suppressed SDH activity (P＜0.05), failing to promote mitochondrial-mediated metmyoglobin reduction.This study demonstrates the potential of sodium succinate as a color-preserving agent in long-term frozen meat products and provides a theoretical and experimental basis for developing color stabilization technologies for frozen meat products.

To systematically analyze the quality characteristics of largemouth bass under different farming systems, this study selected specimens from three production models:pond intensive farming, recirculating aquaculture systems, and traditional pond farming.A comprehensive assessment was conducted on their nutritional composition, textural properties, freshness, volatile flavor compounds, and safety profile.Results indicated that bass from all farming systems exhibited typical aquatic fatty acid profiles, though with distinct distributions:high-density pond-raised bass contained higher docosahexaenoic acid and eicosapentaenoic acid levels;recirculating aquaculture system-raised bass displayed notably elevated oleic acid content;while pond-raised largemouth bass exhibited higher total polyunsaturated fatty acids (PUFA).Texturally, recirculating aquaculture system-raised largemouth bass demonstrated superior hardness, elasticity, and chewiness, yielding the firmest and most resilient flesh.Furthermore, recirculating aquaculture system-raised largemouth bass showed distinct advantages in organic acid composition and oxidative stability;while pond-raised largemouth bass exhibit greater PUFA content and higher mineral levels of zinc and selenium.Volatile flavor fingerprint analysis indicates pond-raised sea bass contains notable levels of diallyl sulfide, phellandrene, and isoamyl alcohol in raw flesh, with lower responses observed in both recirculating aquaculture and pond-raised sea bass.Following cooking, farmed sea bass from recirculating aquaculture systems exhibited the richest flavor profile, with significantly increased levels of n-pentanol, 3-pentanol, 2-hexanol, and 2-butanone.These compounds constitute key aromatic components of cooked fish meat, masking undesirable raw odors.Furthermore, heavy metal levels in samples from all three farming systems remained within regulatory limits, confirming their edible safety.The findings provide scientific basis for bass quality control, product grading, and consumer guidance.

In this study, ‘Crimson’ grapes were fumigated with 500 μL/L SO₂ to investigate the effect of SO₂ on the postharvest quality of table grapes.The quality and reactive oxygen species metabolism of the fruit were analyzed during storage at room temperature.The results showed that SO₂ effectively delayed the decline of fruit firmness, total soluble solids, and titratable acidity, while reducing increases in shattering rate, weight loss, and decay incidence.At the end of storage, the firmness, total soluble solids, and titratable acidity in SO₂-treated grapes were 18.22%, 7.12% and 9.20%, higher than in the control, respectively.Meanwhile, the fruit shedding rate, weight loss, and decay incidence in SO₂-treated grapes were 62.39%, 35.79% and 84.23%, lower than in the control, respectively.SO₂inhibited the accumulation of superoxide anion, hydrogen peroxide, and malondialdehyde.Mechanistically, SO₂ down-regulated VvNOX expression, reduced NADPH oxidase activity, and up-regulated the expression and activity of antioxidant enzymes.Simultaneously, SO₂ treatment promoted the accumulation of ascorbic acid and reduced glutathione, while inhibiting the formation of dehydroascorbic acid and oxidized glutathione, thereby maintaining ascorbic acid/dehydroascorbic acid and reduced glutathione/oxidized glutathione ratios.Correlation analysis revealed that superoxide anion, hydrogen peroxide, and malondialdehyde contents were negatively associated with firmness, total soluble solids, and titratable acidity, and positively correlated with weight loss, shattering rate, and decay incidence.Overall, SO₂ delayed reactive oxygen species accumulation and fruit senescence by modulating the NADPH oxidase/superoxide dismutase system and the ascorbate-glutathione cycle, thereby effectively preserving postharvest grape quality and extending shelf life.

The regulatory effects and associated physiological mechanisms of propyl gallate (PG) treatment on postharvest cold-storage browning of ‘Hongyedongtao’ peach fruit were investigated.Peaches were immersed in a 0.05 mmol/L solution of PG, with distilled water treatment used as the control.The fruit was stored at 1 ℃ for 35 days, and samples were collected regularly.The preservative effects of PG were determined by calculation of the browning index and examination of fruit firmness, relative electrolyte leakage, levels of reactive oxygen species (ROS), and antioxidant enzyme activities.The results showed that PG treatment delayed fruit browning, seen in a significant reduction in the browning index, while maintaining fruit firmness.The treatment also significantly reduced H₂O₂ contents and ·O₂^- production, slowed the depletion of reduced glutathione, and enhanced the activities of antioxidant enzymes, including superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase.These findings indicate that PG treatment is effective in scavenging ROS and maintaining cell membrane integrity by enhancing both enzymatic and non-enzymatic antioxidant systems, thereby delaying postharvest browning of ‘Hongyedongtao’ peach fruit.

To investigate the effects of different processing methods on the flavor substances of quinoa, the volatile components of steamed, roasted, and stir-fried white quinoa were qualitatively and quantitatively analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry method (HS-SPME-GC-MS/MS).Principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to screen the differential volatile components, and the relative odor activity value (rOAV) analysis was conducted to determine the key aroma components.The results showed that a total of 265 volatile components (15 types) were detected, among which esters had the largest number, 46, accounting for 17.36%.The PCA and HCA results indicated that the volatile components of white quinoa under the three processing methods were significantly different.From the 265 volatile components, 233 (87.92%) differential volatile components were screened out, and 11 core differential volatile components were selected by Venn diagram analysis. Through the relative odor activity value (rOAV>1) analysis, 49 key aroma components were determined.This study provides theoretical support and data reference for the development of quinoa food.

To improve the poor flavor quality in black tea produced from summer-autumn tea leaves, this study examined the effects of freezing fresh leaves and withered leaves for 2, 4, 6, and 12 hours.The influence of these treatments on the quality of summer-autumn black tea was evaluated.The results showed that freezing reduced green notes, increased taste smoothness, and enhanced sweet aroma.Theaflavins and thearubigins increased significantly (P<0.05), while water-extractable substances decreased.Freezing fresh leaves increased soluble sugars and reduced free amino acids, whereas freezing withered leaves caused the opposite trend.Aroma analysis indicated that freezing fresh leaves promoted the formation of floral linalool oxides.Freezing withered leaves facilitated the accumulation of aldehydes such as nonanal, trans-2-octenal, and citral, which contribute fatty, floral, and fruity notes.Both treatments reached optimal overall quality after 6 hours of freezing.Tea made from frozen fresh leaves presented a richer taste, while tea made from frozen withered leaves showed a more pronounced sweet aroma.Both treatments significantly increased theaflavin content and improved flavor quality.This study suggests that appropriate freezing treatment can effectively enhance the overall quality of summer-autumn black tea, providing a reference for optimizing its processing technology.

Short-chain fatty acids (SCFAs) are sourced primarily from gut microbial fermentation of indigestible dietary fiber.They possess diverse physiological properties that mediate the health benefits of probiotics and prebiotics for the host.However, the bio-efficacy and health-promoting potential of SCFAs are fundamentally governed by their bioavailability in vivo.A thorough understanding of the absorption and metabolism of both endogenous and exogenous SCFAs is therefore crucial for assessing clinical implications.Starting with an overview of SCFAs bioactivities, this review principally examines the metabolic processes of endogenous SCFAs and the bioavailability of their oral forms.Building on current evidence, it further discusses key factors influencing their bioavailability and highlights challenges associated with oral supplementation.This provides valuable insights into dietetic strategies to optimize SCFAs bio-efficacy from a bioavailability perspective.

The walnut industry in China is vital for economic development in mountainous regions and for increasing farmers’ income.As a key preparatory step in walnut processing, shell-breaking and kernel extraction technologies directly influence both kernel quality and production profitability.This review systematically summarizes recent advances in walnut shell-breaking and kernel-extraction technologies.The intrinsic connection between the material properties of walnuts and their shell-breaking effect is summarized.Mainstream shell-breaking methods, including extrusion-based and impact-based techniques, are discussed.The influence of key parameters (e.g., extrusion gap, impact velocity, and loading rate) on shell-breaking performance is analyzed.Subsequently, performance-enhancement strategies based on pretreatment and orientation techniques are presented.Finally, current challenges and future perspectives are outlined.Adaptive shell-breaking technology that integrates machine vision and artificial intelligence is expected to enable parameter adjustment tailored to walnut variety and size, thereby providing critical support for intelligent and efficient walnut processing.

Fresh noodles are highly favored by consumers due to their chewy and smooth texture, rich wheat aroma, and high nutritional value.However, their high moisture content and rich nutrient profile make them highly susceptible to microbial contamination during storage, leading to a significantly shortened shelf life.This greatly limits their large-scale production.Therefore, analyzing the key factors affecting the shelf life of fresh noodles and the corresponding preservation technologies is crucial for their processing and production.This review first summarizes the main factors influencing the shelf life of fresh noodles.Subsequently, it systematically summarizes and analyzes the effects of existing preservation techniques on the quality characteristics and shelf life of fresh noodles, including physical, chemical, biological, and packaging methods.Finally, prospects for the application of various preservation technologies in fresh noodles are discussed, aiming to provide theoretical insights for advancing preservation techniques and industrial development in this field.

Theaflavins are key components responsible for the quality and health benefits of black tea.However, the mechanisms underlying their formation and oxidation during the fermentation process remain incompletely understood.A systematic review of recent research advances in this field is presented.First, regarding the formation mechanism, various controversies and consensus concerning multiple biosynthetic pathways of theaflavins are summarized and compared, with the critical role of the bicyclo[3.2.1]octane intermediate clarified.Second, in terms of the oxidation mechanism, the key intermediate theanaphthoquinone and its transformation pathways, which have attracted significant attention in recent years, are comprehensively reviewed, and multiple branching routes leading to thearubigins and theabrownins are elucidated.Finally, regarding research methodologies, various approaches, such as enzymatic oxidation, chemical oxidation, and computational chemistry are emphasized, with the unique advantages of computational chemistry in analyzing unstable reaction intermediates and pathways highlighted.This review provides a theoretical foundation for the precise regulation of black tea fermentation and for the development of theaflavin-based functional products.

To investigate the current status, development trends, and management optimization pathways for dosage forms of health food in China, current regulatory requirements for health food dosage forms were systematically reviewed.The dosage form distribution of registered and filed products was statistically analyzed, domestic and international regulatory practices and demands of Chinese consumers were summarized and compared with the status of registered/filed products status.Existing problems with health food forms were identified.The dosage forms of registered and filed health food in China are highly concentrated in drug-like forms, accounting for nearly 90%.This leads to issues including incomplete alignment with market demands, misalignment with food attributes and standards, and impacts on consumers’ accurate perception and rational use.Significant differences exist compared to dosage form proportions in countries/regions with mature health food management.Developing health food in conventional food formats offers expandable institutional and technical space.This approach will help bridge the gap between health functionality and consumer experience, addressing diverse health needs.Specific suggestions for quality control and oversight were proposed.

Near-infrared spectroscopy (NIR) has been widely adopted in food quality and safety assessment owing to its inherent advantages—including rapid analysis, non-destructive measurement, and operational simplicity—that enable high-throughput, real-time, and on-site monitoring without sample preparation.However, NIR measurements are inherently susceptible to experimental interferences—such as ambient temperature fluctuations, optical path variations, and inconsistencies in solid sample mass—leading to spectral instability.Moreover, the technique suffers from intrinsic limitations, including a low signal-to-noise ratio, broad and overlapping absorption bands, and poorly resolved characteristic peaks.In recent years, the rapid advancement of artificial intelligence (AI) has offered robust, data-driven solutions to enhance the accuracy, sensitivity, and robustness of NIR-based analysis.The integration of AI algorithms with NIR enables efficient extraction of latent patterns from complex, high-dimensional spectral data—thereby substantially improving predictive performance and analytical reliability.This AI-enhanced NIR paradigm has emerged as a prominent and rapidly expanding research frontier.This review first articulates the foundational methodological framework underpinning NIR-AI integration, then provides a critical synthesis of representative applications in non-destructive food quality and safety assessment—spanning meat and poultry products, cereal- and oil-based foods, and liquid beverages—with explicit attention to algorithmic rationale, validation rigor, and quantitative performance metrics.It further critically examines key methodological challenges and practical constraints in real-world implementation—such as spectral variability across heterogeneous food matrices, limited generalizability of AI models to unseen production batches, and the scarcity of standardized, publicly accessible NIR-AI benchmark datasets—and concludes with a forward-looking perspective on translational pathways toward routine deployment, including instrument-algorithm co-design, regulatory validation frameworks, and edge-AI-enabled portable systems.Collectively, this synthesis aims to inform evidence-based research prioritization and accelerate the adoption of NIR-AI solutions in food safety governance and quality control practice.