Streptomyces mobaraensis transglutaminase (TGase), with its ability to catalyze protein cross-linking, is widely applied in food processing.Previously, a thermostable variant FRAPD-TGm2 of S.mobaraensis TGase was constructed to improve its application performance under high temperatures.This study identified a TGase variant with further improved thermostability based on dynamic cross-correlation analysis.Firstly, based on molecular dynamics simulation and dynamic cross-correlation analysis, this study identified 48 residues exhibiting dynamic cross-correlation with the flexible region of the FRAPD-TGm2 substrate-binding pocket.Subsequently, virtual saturation mutagenesis on these residues employing Rosetta Cartesian_ddg resulted in 20 variants with a folding free energy change of less than -1 kcal/mol.These mutants were then expressed, purified, and subjected to enzymatic property characterization.Among them, the 60 ℃ half-life and 65 ℃ specific enzyme activity of the variant FRAPD-TGm2-Y34 W reached 100.5 min and 134.2 U/mg, respectively, which were 89.1% and 28.5% higher than that of FRAPD-TGm2.Furthermore, this study observed significant effects on enzyme activity and thermostability in FRAPD-TGm2 due to distal residues His201 and Asn32.The above results indicate that enzyme molecular redesign, based on dynamic cross-correlation and folding free energy analysis, can effectively enhance the thermostability of TGase.

Utilisation of alkali to eliminate lactic acid (LA) stress during lactic acid bacteria (LAB) culturing is an important way to achieve a high-density culture of LAB, but excess alkali also causes cell death due to osmotic pressure.Hence, in situ isolation of LA during cultivation is a promising method without salt stress.In this study, the feasibility of using supported liquid membrane in situ extraction of LA to achieve a high-density culture of Lactobacillus delbrueckii ssp.bulgaricus sp1.1 was evaluated.Firstly, a supported liquid membrane extraction culture system was constructed using a polyvinylidene difluoride (PVDF) membrane as a solid support membrane, natural deep eutectic solvents (NADES) composed of food source components as a carrier, and NaOH as the receiving phase.Results showed that the 30% oleic acid/menthol (2∶1) supported liquid membrane had the best growth promotion effect of L.bulgaricus sp1.1, and produced 4.62-fold live bacteria numbers than that without extraction.Extraction of LA was achieved by the strong hydrogen bonds between the carboxyl groups of oleic acid and the hydroxyl or carboxyl groups of LA, while menthol was responsible for the stabilisation of NADES.SLM extraction cultures allow continuous growth of L.bulgaricus sp1.1 by maintaining a stable pH above 4.3 (fully inhibited pH of 4.2) compared to normal cultures.However, membrane stability issues prevented the long-term growth of L.bulgaricus sp1.1.The NADES solvent extraction system has the potential to be used in the development of high-density cultures of LAB.

To ensure that high-protein ice cream can achieve the texture stability of current ice cream with ordinary protein content, the study investigated the performance of ice cream prepared with skimmed milk powder, whey protein concentrate, and soy protein isolate at ordinary protein content (3%) and high protein content (5%), and used different animal- and plant-based proteins (skimmed milk powder and soy protein isolate, whey protein concentrate, and soy protein isolate) to overcome the negative impacts of high protein content on texture properties.Results showed that at high protein concentrations, the overall melting resistance of skimmed milk powder and whey protein concentrate ice cream decreased and the anti-collapse ability weakened.The melting rate of soy protein isolate ice cream increased, but the dripping time was extended and the anti-collapse ability was relatively stable.Increasing the proportion of soy protein isolate in the compound system could improve the melt resistance and obtain relatively good and stable collapse resistance, but the hardness and adhesion would increase significantly.Among samples, when the mass ratio of whey protein concentrates and soy protein isolate was 1∶1, each texture property was relatively balanced, and better texture quality of high-protein ice cream could be obtained.

In response to the existing quality gap between butter-based whipping cream and traditional whipping cream, this study investigated the effects of thermal pretreatment of skim milk powder on the piping quality and whipping performance of butter-based whipping cream using skim milk powder as raw material, without thermal pretreatment and with thermal pretreatment at 60, 75, 90, and 105 ℃ for 30 minutes.The study also analyzed the reasons for the differences in the apparent properties and interfacial properties of emulsion.Results showed that as the thermal pretreatment temperature increased from 60 ℃ to 105 ℃, the proportion of protein aggregates increased from 31.8% to 45.3%, while the proportion of whey proteins decreased from 17.5% to 6.6%.When the thermal pretreatment temperature was 105 ℃, the piping performance and foam stability of the whipping cream were weaker than those of the untreated group.However, when the thermal pretreatment temperature was between 60 ℃ and 90 ℃, the piping performance and foam stability of the whipping cream were improved compared to the untreated group.The collapse rate decreased from 23.37% to 17.33%, hardness increased from 7.20 g to 9.91 g, and the whey leakage rate decreased from 12.8% to 7.4%.Among these, at the thermal pretreatment temperature of 90 ℃, the emulsion exhibited the highest viscosity (0.61 Pa·s), smallest average particle size (4.39 μm), lowest interfacial protein content (5.58 mg/m²), and lowest interfacial modulus (3.93 Pa), demonstrating the best piping performance and foam stability.

Higher alcohols are aroma components and health risk factors in alcoholic drinks.Although the control of higher alcohols is a widely concerned issue, so far there are few reports on the key enzymes related to the formation of higher alcohols.In this paper, bioinformatics analysis of two key enzymes, pyruvate decarboxylases (PDCs) and alcohol dehydrogenases (ADHs), involved in the formation pathways of three main higher alcohols (isoamyl alcohol, isobutanol, and n-propanol) was performed.The control of higher alcohols in brewing was discussed from the perspective of key enzymes from four aspects, including substrate, microbial source, enzyme gene expression, and enzyme activity.Results showed that the PDCs and ADHs sequences in the UniProt database were all from fungi, mainly saccharomyces.The theoretical isoelectric points of different microbial PDCs were between 5.51 and 5.80, while those of ADHs were between 5.76 and 6.60.Subcellular localization prediction results suggested that both PDCs and ADHs were intracellular enzymes.Molecular docking analysis revealed that most of the components in Poria, Astragalus, Ginseng, Liquorice, white tricks, and mulberry leaves, which could reduce higher alcohol production in brewing, had relatively low binding energy with PDCs and ADHs.This study can provide a reference for the control of higher alcohols in brewing.

This study aimed to investigate novel β-lactam resistance genes in soil and elucidate the underlying mechanisms of resistance, thus providing valuable clinical alerts, and insights that contribute to the development of new β-lactam drugs.The positive clone was screened from soil metagenomic library, and resistance gene sequence was obtained by subclone construction and sequencing.Sequence alignment, phylogenetic tree and three-dimensional structure modeling were used to analyze the drug resistance gene.Microbroth dilution method was used to evaluate drug resistance.The gene was expressed heterologously, and the hydrolysis ability of the purified protein was tested.Sequence analysis of the subclone revealed that pZF700 contained one novel β-lactamase gene, gob-54, exhibiting 52.3% amino acid sequence identity with the known β-lactamase genes.This gene encodes the broad-spectrum β-lactam enzyme GOB-54.The three-dimensional modeling of GOB-54 generated using SWISS-MODEL, revealed striking structural similarities with GOB-18 from clinical sources.The kinetic parameters indicated that GOB-54 had the highest affinity and catalytic activity for piperacillin among the β-lactam antibiotics tested.The K_m and K_cat/K_m values were found to be 121.82 μmol/L and 49.15 L/(mmol·s), respectively.In this study, the novel β-lactam resistance gene gob-54 was discovered from soil by functional metagenomics serves as a valuable reference for clinical monitoring and prevention of the dissemination of β-lactam antibiotic resistance genes.

Structural and rheological properties of pectins from tomato pomace were investigated compared to commercial citrus pectin and apple pectin.Results showed that the galacturonic acid content and degree of esterification from tomato pectin were 56.25% and 47.40%, respectively.Among all neutral sugars, galactose had the highest content in tomato pectin, followed by rhamnose, mannose, glucose, arabinose, and fucose.Compared to commercial pectins, tomato pectin had a higher proportion of the RG-I region, but its RG-I region had a lower degree of branching.Tomato pectin belonged to non-Newtonian fluid, specifically pseudoplastic fluid, and exhibited shear-thinning property.It had a higher apparent viscosity and lower activation energy than citrus pectin, indicating that tomato pectin had a higher viscosity and better stability.The storage modulus of tomato pectin was greater than the loss modulus, indicating that it was more elastic.The storage and loss modulus of tomato pectin were higher than those of citrus pectin and apple pectin, indicating tomato pectin was more viscoelastic.It could be concluded that tomato pectin had better thickening and gelling properties, and could be developed as a thickening and gelling agent.This research provided a theoretical foundation for the development of tomato pectin.

Benzothiadiazole (BTH) induces disease resistance and affects secondary metabolism in grapes.This study aimed to evaluate the impact of BTH on the aroma compounds of Chardonnay grapes and wines.Chardonnay grapevines were treated with 50 mg/L BTH at veraison to investigate its impact on physicochemical parameters, phenolics, and free and bound aroma in ripe grapes and wines.Results showed that BTH treatment increased reducing sugars, pH, total soluble solids, and skin/berry ratio of ripe grapes.BTH treatment increased glycerol, pH, dry extract, and alcohol, and decreased the content of titratable acidity, volatile acid, and residual sugar in Chardonnay wine.BTH-treated grapes and wines had higher concentrations of total phenolics, total flavonoids, total flavanols, and total flavonols than CK.Moreover, BTH treatment increased the types and concentrations of straight-chain aliphatic, aromatic, branched-chain aliphatic, terpenoids, and norisoprenoids and decreased the concentration of C₆/C₉ compounds in grapes and wines.Exogenous BTH application significantly enhanced the floral and fruity aroma of wines by increasing the concentrations of isoamyl acetate and β-damascenone, and attenuated the vegetal flavor.The findings of this study may offer scientific evidence to support the implementation of BTH modulation in vineyard management practices for enhancing aroma compounds in Chardonnay grapes and wines.

To investigate the effect of yeast on the quality of fermented radish, the dynamic changes and the differences in the microbial count, pH value, total acid, reducing sugar, organic acids, and volatile flavor compounds between the aged brine and the yeast-free aged brine during the fermentation process were analyzed.Results showed that the consumption rate of reducing sugar in the aged brine was faster than that in the yeast-free aged brine, while the total acid and organic acid contents were lower.The compositions of the organic acids were altered by yeast, in which the lactic acid content in the aged brine being 5.67 mg/mL lower than that in the yeast-free aged brine;however, the acetic acid content being 0.33 mg/mL higher at the end of fermentation.In addition, the relative contents of alcohols, esters, and acids in the aged brine were higher than that in the yeast-free aged brine, while amines and phenols were lower.There were 19 differential compounds calculated by analysis (variable importance in projection value>1, P<0.05), which included 6 alcohols, 5 hydrocarbons, 4 esters and 2 amines, 1 phenolic, and 1 acid.In particular, more floral compounds were identified in the aged brine among these differential compounds.Overall, the study demonstrated the pivotal role of yeast on the quality and provided a basis for quality stability control of the fermented radish.

γ-Glutamyl transpeptidase is an enzyme that can catalyze glutamine to generate a γ-glutamyl-enzyme complex.Then the complex can be nucleophilically substituted by an acceptor substrate such as an amino acid or a short peptide, resulting in a transpeptidation reaction that forms a γ-glutamyl peptide.This enzyme has significant application value in the fields of food and medicine.In this research, Bacillus subtilis SCK6 was used as the expression host, based on 173 signal peptides of Bacillus subtilis, a signal peptide screening library was constructed, and the optimal signal peptide (SP_cotC) was identified.Promoter screening was then carried out to obtain the optimal promoter (P_aprE).Finally, with the optimal signal peptide and prompter, a recombinant strain BS-gts3 was constructed which could express and secrete γ-glutamyl transpeptidase.The maximum extracellular enzyme activity reached 5.04 U/mL in shake flask fermentation.The optimal medium was further determined through one-way and response surface tests.The optimal composition of the medium was 31.73 g/L of lactose, 50.26 g/L of FM802, 1.24 g/L of MgSO₄, 1.25 g/L of KH₂PO₄, and 0.75 g/L of K₂HPO₄.The culture was then scaled up in a 5 L fermenter, and the maximum extracellular enzyme activity reached 28.26 U/mL after 38 h fermentation, which was the highest reported level.This study provides a foundation for the development and application of γ-glutamyl transpeptidase.

Neomycin is an aminoglycoside antibiotic mainly produced by Streptomyces fradiae.It is widely used in medicine, animal husbandry and other fields.It can effectively control and treat diseases caused by bacteria, and improve the growth speed and production performance of livestock and poultry.To improve the production of neomycin, the transcriptome data of the original Streptomyces fradiae SF-1 and the mutagenic high-yield strain SF-2 were analyzed by comparative transcriptomics, and the transcription factors with significant differences in transcription levels were mined, and then the recombinant plasmids were constructed by overexpression, and then the engineered strains were constructed by conjugation transfer.The engineering strain with significant effect on neomycin synthesis was screened by shake flask fermentation, and the high-yield neomycin producing engineering strain SF-2/pP-NeyR was finally obtained by promoter optimization.Then the components of fermentation medium were orthogonal optimized, and the final titer of neomycin B was 11 843 U/mL.After comprehensive optimization, the titer of neomycin B increased by 29.6% compared with the initial one.The experimental results laid a foundation for the follow-up study of metabolic mechanism, the study of its interaction with Streptomyces fradiae neomycin synthesis gene cluster, the analysis and regulation of neomycin synthesis mechanism, and provided ideas for further improving the potency of neomycin.

This study aimed to investigate the preparation and functional properties of polypeptides derived from Ziziphi Spinosae Semen with varying molecular weights.This study screened suitable hydrolysis conditions for Ziziphi Spinosae Semen and isolated polypeptides with different molecular weights (ZSSPP-I, ZSSPP-Ⅱ, ZSSPP-Ⅲ, and ZSSPP-Ⅳ) through the use of ultrafiltration.Various functional characteristics of each polypeptide component were examined, including the solubility, oil absorption, foaming ability, foaming stability, emulsification ability, and emulsification stability of each polypeptide component were studied.The relationship between these functional characteristics and molecular weight, as well as temperature and pH, were analyzed.The polypeptides prepared by acid hydrolysis were mainly composed of components with a molecular weight of less than 3 kDa, while those produced through enzymatic hydrolysis displayed more balanced molecular weight distributions.The study showed that the functional characteristics of Ziziphi Spinosae Semen polypeptides with different molecular weights exhibited distinct functional characteristics.ZSSPP-I (molecular weight greater than 10 kDa) demonstrated superior solubility, oil absorption, foaming and emulsification properties, while ZSSPP-Ⅳ (molecular weight less than 3 kDa) showed the best foam stability and emulsification stability.Results indicated that polypeptides with different molecular weights could be efficiently prepared from Ziziphi Spinosae Semen using either or acid hydrolysis.ZSSPP-I and ZSSPP-Ⅳ possess substantial potential for development, which can provide a reference for further research and application of Ziziphi Spinosae Semen polypeptides.

In the recycling process of food contact polypropylene, some chemicals will inevitably remain due to incomplete cleaning or degradation, which may threaten food safety.In this paper, gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-mass spectrometry (HPLC-MS) were used to develop analytical methods for determining the residual of 4 processing additives [bis(2-ethylhexyl) phthalate, Irgafos 168, bis(3,4-dimethylbenzylidene) sorbitol, 2,2′-(octadecylimino)diethanol], degradation products (2,4-di-tert-butylpheno), and 3 volatile compounds (D-limonene, α-terpineol, galaxolide) in recycled polypropylen (rPP).The analytical method was used to analyze 9 market rPP samples, and the results showed that the residue of Irgafos 168 was the highest (998.36 mg/kg).To further study its migration to food in films with different rPP contents, 7 types of films with different contents of rPP (0%, 10%, 25%, 50%, 75%, 90%, 100%, mass fraction) were prepared and then immersed in isooctane, 95% (volume fraction) ethanol, 50% ethanol, and 4% acetic acid at 70 ℃ for 2 hours, respectively.The principal component analysis and the classification and regression tree algorithm were used to analyze the residues.Results indicated that there was no significant difference from virgin polypropylene when the rPP content was less than 25%.This study offers data and protocol support for the safe utilization of rPP for food contact, which is essential for promoting resource recycling and ensuring food safety.

Achieving high-density fermentation and increased sporulation rates are critical challenges in the fermentation of Clostridium butyricum.To address this issue, the present study optimized the fermentation and sporulation conditions of C.butyricum through single factor and response surface experiments, combined with a segmented pH control strategy.Results indicated that the optimal composition of the C.butyricum triangular flask scale fermentation medium was as follows:10.34 g/L of soluble starch, 30.96 g/L of yeast extract, 5.12 g/L of dipotassium hydrogen phosphate, 4.00 g/L of sodium acetate, 0.50 g/L of cysteine hydrochloride, 0.80 g/L of calcium chloride, 0.60 g/L of magnesium sulfate, and 0.20 g/L of manganese sulfate.The optimal fermentation conditions included a temperature of 37 ℃, an initial pH of 7.0, and an inoculum of 1%.The experiment conducted on the 5 L fermentation tank showed that the maximum biomass level was achieved when the pH was maintained at 5.5.On the other hand, the optimal pH for sporulation was found to be 6.0.Therefore, a staged pH control strategy was employed.As the pH was decreased from an initial 7.0 to 5.5, ammonia solution was continuously added to maintain the pH level at 5.5 until the microbial culture entered the stable phase.The pH was then adjusted to 6.0 and maintained until the fermentation process was completed.Following this strategy, the biomass of C.butyricum cultured in a 5 L fermentation tank at 37 ℃ for 20 h, reached its maximum level of 3.3×10⁹ cells/mL, which was 3.23 times higher than that before optimization, with a sporulation rate of over 90%.

Fresh-cut broccoli was soaked with 5 mL/L diacetyl treatment for 10 min to study the effects of diacetyl treatment on the quality and antioxidant capacity of fresh-cut broccoli during storage at 10 ℃.Results showed that 5 mL/L diacetyl treatment could significantly reduce the weight loss rate of fresh-cut broccoli during storage, maintain good color, chlorophyll, hardness, soluble solids, and soluble protein content.At the same time, diacetyl treatment maintained higher superoxide dismutase, catalase and peroxidase activities, effectively maintained the scavenging ability of DPPH free radical and hydroxyl radical, significantly inhibited the accumulation of malondialdehyde and the generation of hydrogen peroxide, and then better maintained the metabolic balance of reactive oxygen species.Diacetyl treatment also could significantly inhibit polyphenol oxidase activity and maintain phenylalanine ammonia lyase activity, and maintain a high total phenol content.In summary, diacetyl treatment could maintain the storage quality and antioxidant capacity of fresh-cut broccoli, delay the yellowing of fresh-cut broccoli during storage, and prolong the storage period.This study provides a reference and theoretical basis for the effect of diacetyl treatment on postharvest storage and preservation of broccoli.

Trapa acornis Nakano is a unique aquatic economic plant in Jiaxing city, Zhejiang province.It has a sweet and delicious taste and is nutritionally rich.However, it is highly susceptible to rot and deterioration after harvesting.To investigate the preservation effect of the coating of Porphyridium cruentum polysaccharide on Trapa acornis Nakano during storage, this study used Trapa acornis Nakano fruits as the test material.Coating treatments with Porphyridium cruentum polysaccharide at concentrations of 5 mg/mL and 10 mg/mL were applied, and 11 quality and physiological indicators were meticulously measured and analyzed at different storage periods.Results indicated that the Porphyridium cruentum polysaccharide coating reduced the weight loss of Trapa acornis Nakano fruits, delayed the decline in key components such as soluble sugars, soluble proteins, total phenols, and vitamin C, maintained a higher titratable acid content, and inhibited the accumulation of malondialdehyde and antioxidant enzyme activity during fruit storage.Principal component analysis simplified various indicators into two principal components, with a cumulative variance contribution rate of 86.364%.A comprehensive evaluation model was established, which revealed a strong correlation among soluble sugar content, polyphenol oxidase activity, peroxidase activity, malondialdehyde content, and weight loss rate.The group with a 5 mg/mL polysaccharide coating showed the best comprehensive score, contributing to the preservation of Trapa acornis Nakano fruits during storage.This study provides data and theoretical support for the application of Porphyridium cruentum polysaccharide in food storage and preservation, laying the theoretical foundation for the transportation and industrialization of Trapa acornis Nakano.

As a characteristic milk resource of the Qinghai-Tibet Plateau, yak milk was less researched and transformed into functional products, which was not conducive to the development of the local economy.To investigate the antioxidant activity of Gannan yak milk, hydroxyl radicals, superoxide anions, and DPPH radicals were selected to evaluate the antioxidant effect of yak milk in vitro, and zebrafish with 3 dpf after fertilization were exposed to yak milk with different additions (12.5, 25.0, 50.0 μL/mL) for 24 h.The production rate of reactive oxygen species (ROS) and the activity of superoxide dismutase in zebrafish were detected by fluorescent staining, and the antioxidant effect in yak milk was evaluated.Results showed that yak milk had the ability to scavenge hydroxyl free radicals, DPPH free radicals, and superoxide anions.12.5 μL/mL, 25.0 μL/mL, and 50.0 μL/mL addition of yak milk could reduce ROS production rate and increase antioxidant oxidase activity in zebrafish, which indicated that yak milk has antioxidant activity, and the antioxidant effect in yak milk was positively correlated with its mass concentration.When the addition of yak milk was 50.0 μL/mL, the antioxidant effect on zebrafish reached 43.25%.Results showed that Gannan yak milk had antioxidant activity and could be used as a raw material for antioxidant functional food.

Two methods of hot dip (sample W) and hot dip after baking (sample H) were used to pretreat hemp seed and prepare hemp milk beverages.The effects of two heat treatment methods on the stability, sensory quality, nutrients, and volatile flavor substances of hemp milk beverages were compared.Results showed that the fat floatation rate (0.84%), centrifugal precipitation rate (9.37%), soluble solid content (12.57%), and lipid oxidation degree (OD_532nm=0.127) of sample W were lower, and the color of sample W was light brown, while the color of sample H was milky white and the sensory score was higher.The contents of amino acids in the two groups were abundant (about 2.60 g/100 g).The essential amino acids in sample W accounted for 42.1% of the total amino acids, which was 7.13% higher than that in sample H.The relative content of unsaturated fatty acids in the two groups was higher (about 80%), among which the relative content of oleic acid was the highest (over 50%).The content of polyunsaturated fatty acids in sample W was higher than that in sample H, indicating that hot soaking was more beneficial to the retention of nutrients in hemp milk beverages.25 and 21 volatile flavor compounds were detected in sample H and sample W, respectively, which were mainly aldehydes and alcohols.The three flavor compounds with the highest contents were furfural, 1-octene-3-alcohol, and hexaldehyde.In contrast, the relative contents of alcohol, heterocyclic, and sulfur compounds in sample H were higher.In general, the two groups of samples had higher nutritional value.Sample W had better stability, higher essential amino acid content and unsaturated fatty acid content, and lower fat oxidation degree, while sample H had more flavor substances and a higher sensory score.

In this study, we analyzed the effects of liquid nitrogen immersion freezing (LF), quick freezer freezing (QF), package immersion freezing (PF), ultra-low-temperature freezer freezing (UF), and storage time (0, 15, 30, and 60 days) on the freezable water of frozen dough, sulfhydryl disulfide bonding, secondary structure of proteins, microstructure, and quality of steamed bread.Results showed that the free sulfhydryl content was PF>UF>QF>LF, and the protein secondary structure was determined, with the least decrease in α-helix content and a relatively high increase in β-folding in LF-treated frozen dough, which indicated that LF was beneficial in maintaining the stability of frozen dough proteins.More interestingly, scanning electron microscopy results showed that the QF- and LF-treated frozen dough displayed a compact and continuous honeycomb structure with a smoother and less porous surface during 15 days of frozen storage.In addition, the steamed bread stored in PF had the largest difference in color change between L^* and a^* values and aged faster, while the steamed bread treated with LF had less color change than those treated with QF, UF and PF and the steamed bread treated with LF had a larger specific volume.Overall, the LF-treated frozen dough was better and was effective in maintaining the quality of the frozen dough during the 15-day storage period.These results provide information to guide the application of freezing methods and storage time in frozen foods.

Solid saccharification and semi-solid fermentation are the main ways to brew rice-flavor Baijiu.To reveal the microbial community characteristics in this process, this study analyzed the structure and succession of the microbial community of rice-flavor Baijiu by high throughput sequencing technology, the fungal genera of Saccharomyces, Saccharomycopsis, and Rhizopus, the bacterial genera of Lactobacillus, Pediococcus, and Weissella were the dominant microbial genus during saccharification and fermentation stage.In this stage, bacterial diversity was higher than fungal diversity and microorganisms were rapidly accumulated.The characterization of microbial dynamics through succession distance indicated that fungus is rapidly changed in saccharification, while bacteria are in fermentation.This study used the PICURSt2 to predict the function of bacterial community during saccharification and fermentation to explore the potential metabolic function characteristics of rice flavor Baijiu brewing process, the metabolic functions mainly included carbohydrate metabolism, amino acid metabolism, nucleotide metabolism, membrane transport, replication and repair, translation and so on.Correlation analysis showed that Lactobacillus was the microbial genus that contributed the most to the metabolic function of rice-flavor Baijiu which participated in 11 kinds of metabolism.The carbohydrate metabolism of the bacterial genera became active during fermentation, glucose, ethanol, and lactic acid were important indicators to judge the brewing process of rice flavor Baijiu, which were mainly produced by glycolysis/gluconeogenesis.Therefore, this study tracked this pathway and found that the relative abundance of functional enzymes involved in the conversion of pyruvate to acetyl-CoA and lactate, and acetaldehyde to ethanol increased during fermentation.Saccharification provided appropriate functional microbial community structure and functions for fermentation to ensure the fermentation process was more smoothly.This study contributes to analyzing the brewing mechanism of rice flavor Baijiu and provides a theoretical basis for further controlling and improving the quality of rice flavor Baijiu.

Differences in phenolic structure and concentration between grape skins and seeds affect the sensory characteristics and aging potential of wines.To investigate the effects of adjusting the skin-to-seed ratio at different stages of the alcoholic fermentation maceration process on the color and sensory characteristics of the wines, ‘Cabernet Sauvignon’ grapes were used as the test material, the wines were de-seeded at 10%, 20%, and 30% at the specific gravity of 1.060 and 1.030, the basic physicochemical, CIELab color parameters, phenolic content, and antioxidant activity of the wines were measured, the sensory quality of the wines was comprehensively evaluated by fuzzy mathematical method, the results were subjected to variance and partial least squares-discriminant analysis.Results showed that different treatments with different percentages of seed removal did not significantly affect the basic physicochemical properties of the wines.As the percentage of seed removal increased, the wine tended to have a yellowish hue, and contents of total phenol, total flavan-3-ols, total flavonoids, and tannins and antioxidant capacity were significantly reduced.From the results of the sensory evaluation, it was concluded that the treatment with 10% seed removal at a specific gravity of 1.030 yielded a 9.29% improvement in the overall tasting score compared to the control group, the wines showed a purplish-red color, a fruity taste and less bitterness.In conclusion, 10% seed removal at a specific gravity of 1.030 could help produce wines with higher overall quality.The results of the study can lay a theoretical foundation for improving the color stability and drinking comfort of wines from Xinjiang appellation.

Limosilactobacillus fermentum FUA033, a strain capable of converting ellagic acid to urolithin A in vitro, has the potential to be developed as a next-generation probiotic.In the present study, the genome of the strain was sequenced with the PacBio Sequel and Illumina platform to have a comprehensive understanding of the genetic architecture of L.fermentum FUA033.The whole genome sequence was analyzed to evaluate the safety and probiotic potential of the strain.The chromosome size of this strain was 2 150 545 bp with a GC content of 51.34% and 2 215 protein-coding genes.No plasmid was identified.VFDB database and ARDB database annotation results showed that L.fermentum FUA033 contained 81 virulence genes and 9 resistance genes.Due to the absence of plasmids and transposons, it was tentatively concluded that the virulence factors and resistance genes would not transfer.19 acid tolerance genes (arcA, argH, napA, etc.), 16 bile salt tolerance genes (ldhA、ykpA、pstB1, etc.), 11 antioxidant genes (msrA, Trxs, ahpC, etc.), and 3 cell adhesion genes were mined from the genome sequence of L.fermentum FUA033.The results preliminarily revealed the safety and probiotic properties of L.fermentum FUA033 and laid a theoretical foundation for the development and further application of the strain.

To investigate the effect of high-energy electron beam irradiation on the total bacterial count and microbial community diversity of shredded beef, vacuum-packed shredded beef was irradiated with electron beams at different doses (0, 2, 5, 8 kGy).This study measured the total bacterial count during storage and analyzed the community structure using Illumina MiSeq high-throughput sequencing technology.Results demonstrated that as the irradiation dose increased, the total bacterial count decreased, consequently extending the shelf life of the product.The increase in irradiation dose reduced the richness of microbial species, and the extension of storage time also led to a decrease in richness.At the phylum level, Firmicutes and Proteobacteria were the dominant microbial communities during storage across all groups.At the genus level, increasing the irradiation dose resulted in an increased abundance of Bacillus and Acinetobacter, while the abundance of Enterobacterium decreased.The control (CK) and the 2 kGy group exhibited a significant increase in the abundance of Weissella during storage (P<0.05).In the 5 kGy and 8 kGy groups, the relative abundance of Bacillus significantly increased with storage time (P<0.05).This study provides a preliminary exploration of the changes in microbial diversity during the storage of shredded beef after irradiation and offers a theoretical foundation for the application of irradiation sterilization technology in the preservation of meat products and the prediction of shelf life.

A Nosphingobium sp.strain D6 that could produce extracellular polysaccharide (EPS) was isolated from Fujian white koji.The fermentation conditions were optimized through single-factor tests and the response surface method.Under the optimal fermentation conditions, which were sucrose at 39.0 g/L, soybean meal at 3.6 g/L, manganese sulfate at 0.4 g/L, fermentation temperature at 30 ℃, rotation speed at 250 r/min, liquid loading volume at 100 mL/500 mL, seed age at 24 h, inoculation ratio at 5% (v/v), the EPS yield reached (22.38±0.43) g/L, making an increase of 5.87 times.The EPS of D6 comprised of four types of monosaccharide, including mannose, galacturonic acid, glucose and galactose, and was modified with acetyl groups.Additionally, the EPS aqueous solution demonstrated pseudoplastic fluid characteristics, and exhibited good emulsifying properties and thermal stability.

Damage to the intestinal barrier is associated with many diseases.Preventing and improving impaired intestinal barrier function through dietary interventions, especially probiotics, may be a promising therapeutic strategy.This study utilized lipopolysaccharide to induce damage in the Caco-2 cell monolayer barrier model to investigate the protective effect of Lacticaseibacillus rhamnosus KF7 fermented milk supernatant on the intestinal barrier in vitro. Cell Counting Kit-8(CCK-8) assay was used to detect the effects of KF7 fermented milk supernatant on cell viability.A resistivity meter and fluorescein isothiocyanate-dextrose were used to examine the structural integrity and permeability of the intestinal epithelial barrier.Fluorescent probe and colorimetric assay were used to detect the intracellular levels of reactive oxygen species and malondialdehyde (MDA), and qRT-PCR was used to analyze the gene expression levels of tight junction proteins, pro-inflammatory cytokines, anti-inflammatory cytokines, and markers of oxidative stress and inflammation-related pathways.Results revealed that 1%-5% Lacticaseibacillus rhamnosus KF7 fermented milk supernatant did not impair Caco-2 cell viability, but protected the Caco-2 cell monolayer barrier, decreasing lipopolysaccharides-induced inflammatory response (down-regulation of gene expression of TNF-α, IL-1β, and IL-6, and up-regulation of IL-10) and oxidative stress (reduction of MDA content), increasing the expression of intercellular tight junction protein-related genes (Claudin-1 and Occludin), improving cell monolayer trans-epithelial electrical resistance, and reducing the permeability, thus recovered the integrity of Caco-2 cell monolayer barrier.Mechanistically, Lacticaseibacillus rhamnosus KF7 fermented milk supernatant may antagonize oxidative stress by promoting the Nrf2/NQO1 signaling pathway, and decrease the inflammatory response and intestinal epithelial inter-cellular permeability by inhibiting the TLR/MyD88/NF-κB signaling pathway and downstream myosin lightchain kinase(MLCK) gene expression.The results of this study may provide some theoretical basis for Lacticaseibacillus rhamnosus KF7 fermented dairy products as a promising functional probiotic dietary supplement for protecting intestinal health.

The emergence of culturomics, with rich media (RM) as a crucial component, provides a significant foundation for studying the mechanisms of interaction between the gut microbiota and the host.To explore the in vitro cultivation effects of different RMs on the human gut microbiota, the plate counting method and high-throughput 16S rDNA sequencing technology were employed to analyze the cultivation effects of Yeast extract-casein hydrolysate-fatty acid medium (YCFA medium), Gifu anaerobic medium (GAM medium), and a patented ZJ medium on the human gut microbiota.Plate counting results showed that the total colony count of gut microbiota exhibited a trend of initially increasing and then decreasing after cultivation for different durations (0-7 days) in various culture media.The highest colony count values for the gut microbiota after cultivation in three different media were as follows:ZJ (9.88 lg CFU/mL) > GAM (9.79 lg CFU/mL) > YCFA (9.68 lg CFU/mL).The high-throughput sequencing results revealed a decrease in bacterial diversity after in vitro cultivation, with each culture medium selectively enriching different strains.Among them, the ZJ medium exhibited the most significant decrease in community diversity after cultivation.The β-diversity analysis indicated that the gut microbiota’s composition after cultivation in the GAM medium was closer to the composition observed in the uncultivated state.Therefore, compared to YCFA and ZJ media, GAM medium is a more optimal RM medium for the in vitro cultivation of the gut microbiota.

This study aimed to promote the development of high-value-added chestnut deep processing products and to explore the effect of polyphenols on weight reduction and fat decrease.In this paper, a new chestnut vinegar with a soft taste and unique flavor was brewed using chestnut as raw material.The polyphenols in chestnut vinegar were extracted and purified, and the structure identification of the purified polyphenols was carried out by ultraviolet absorption spectroscopy, infrared spectroscopy, and high-performance liquid chromatography-mass spectrometry (HPLC-MS).Animal studies were conducted to investigate the weight loss and lipid-lowering effects of chestnut vinegar polyphenols.Results showed that the ultraviolet absorption spectrum of chestnut vinegar polyphenols had the typical absorption peaks of polyphenols, which contained flavonoids and phenolic acids, its infrared spectra had phenolic hydroxyls and the skeletal vibration of aryl rings, which were in line with the typical characteristics of phenolic functional groups.The high-performance liquid chromatography-mass spectrometry identified 12 phenolic compounds under positive and negative ions, which demonstrated that chestnut vinegar polyphenols were a kind of structurally complex substance.Animal studies showed that different doses of chestnut vinegar polyphenols reduced body weight, affected organs and adiposity coefficients, affected biochemical indices, ameliorated hepatic steatosis, and affected leptin, lipocalin, and hepatic lipase levels to varying degrees.Therefore, chestnut vinegar polyphenols have good weight loss and lipid-lowering and hepatoprotective effects with dose-dependence.The results of this experiment provide new ideas for the development of chestnut deep-processed products and the functional research and utilization of novel chestnut vinegar polyphenols.

In this paper, the myofibrillar proteins (MPs) of Tibetan mutton were used as the research object.MPs systems with different ionic strengths were prepared by Na⁺, Mg²⁺, Ca²⁺, and K⁺, and heating and control treatment groups were set up to study the effects of different ionic strengths and heating on the solubility and structure of MPs and five characteristic flavor substances of Tibetan mutton were selected.Headspace gas chromatography-mass spectrometry (HS-GC-MS) was used to determine the ability of treated MPs to bind flavor substances.Results showed that different ionic strengths and heating treatments could aggravate the oxidation of MPs in Tibetan mutton, resulting in a decrease in total sulfhydryl content and an increase in total carbonyl content.The hydrogen bond interaction between protein molecules was induced, resulting in an increase in hydrogen bond content.The hydrophobic groups were exposed to the surface of the protein, the endogenous fluorescence intensity decreased, and the adsorption capacity of the flavor substances was enhanced.Among them, Ca²⁺ treatment had the most significant effect on the structure and binding flavor ability of Tibetan mutton MPs.Therefore, it is speculated that the different ionic strengths and content in water will affect the structure and flavor substances of MPs in Tibetan mutton.

Oat germination is a process of physiological change and material transformation from static dormancy to dynamic activity, and it is the best way to change macromolecules into small molecules that can be easily absorbed by the human body.This study optimized the germination conditions of oats and determined the content of dietary fiber (ODF) in oats germinated for 4-8 days under optimum conditions.The structural and functional changes of ODF before and after germination were explored.Results showed that the germination rate of oats was the highest at 25 ℃, soaked for 60 min, and sprayed with 3∶2 (g∶mL) water every 8 h, The ODF content increased first and then decreased, reaching the highest on the 7th day after germination, which was 7.41%.Scanning electron microscopy observed that the ODF after germination showed a spiral loose structure.X-ray diffraction results showed that the intensity of the diffraction peak and crystallinity of ODF decreased after germination treatment.The infrared spectrum confirmed that the intensity of the characteristic absorption peak of ODF changed before and after germination, but the shape and position of the whole peak did not change significantly.Compared with before germination, the water-holding capacity, oil-holding capacity, and cholesterol adsorption capacity of ODF increased by 3.6, 10.4, and 1.6 times respectively.The solubility and cholate adsorption capacity are reduced by 2.1 and 1.3 times respectively, while the adsorption of glucose and nitrite changed little.It is proved that germination can change the structural and functional properties of ODF.This paper can provide a theoretical basis for the physiological health effects of ODF on weight loss and cholesterol adsorption.

Purple rice cake is rich in nutrients and has a unique flavor, but its short shelf life limits its circulation and sales.To extend its shelf-life, this study isolated and identified dominant spoilage bacteria and fungi from purple rice cake, and investigated the efficacy of bacteriostatic agents on spoilage bacteria and fungi by measuring diameters of inhibition zones, the minimum inhibitory concentration value, fractional inhibitory concentration index, and growth curves.The formula of the compound preservative was optimized by the response surface method and studied the changes in the anthocyanin content and the volatile flavor of purple rice cake during the storage period.Results showed that the spoilage purple rice cake contained two strains of dominant spoilage bacteria and three strains of spoilage fungi, namely Bacillus amyloliquefaciens, Bacillus licheniformis, Cladosporium sp., Aspergillus versicolor, and Penicillium glabrum.The antibacterial effect of four preservatives against five dominant spoilage bacteria and fungi was evaluated and it was found that the inhibition zone diameters of ε-polylysine and potassium sorbate were > 20 mm, which indicated good antibacterial effects.The fractional inhibitory concentration index of ε-polylysine and potassium sorbate on 5 dominant spoilage strains were <1 and could inhibit the growth of bacteria and fungi better and delayed the logarithmic phase, which indicated a strong synergistic effect.Besides, the study found that lowering the pH could improve the inhibitory effectiveness of bacteriostatic agents.The optimum formula of compound preservative was ε-polylysine 0.045 g/kg, potassium sorbate 0.93 g/kg and citric acid 4.67 g/kg, which the shelf life of the purple rice cake could be extended to 30 days at room temperature, and maintained the content of anthocyanin and a good volatile flavor.This study is of great significance in prolonging the shelf life and circulation of purple rice cake.

To investigate the relationship between magnetic field (MF) and pork quality during the freezing process, this study used the effects of different magnetic field strengths (0, 1, 3, 5 mT) on the freezing curve, physicochemical properties, moisture content and distribution, and microstructure of pork.Results showed that MF could significantly shorten the freezing time of pork samples, reduce the loss of juice after thawing as well as cooking loss, and improve the water holding capacity.The tenderness of meat of MF-3 treated samples (2 754.63 g) was significantly higher compared to other treatment groups and there was no significant change with the control group.The MF-3 treatment group had more water that was not readily mobile, reduced mobility and loss of fixed to free water, and a denser density of red protons representing water content.In the microstructure, the MF-3 tissue fibers had smaller gaps and more uniform fibers, indicating that MF-3 produced finer and more uniform ice crystals.Overall, MF is effective in minimizing the quality deterioration of pork after freezing, reducing ice crystal size and moisture migration losses during freezing.

Controlling postharvest fruit diseases by inducing fruit disease resistance is an important means to reduce postharvest fruit losses.To investigate the inhibitory effect of arabinogalactan (AG) treatment on postharvest brown rot of Qingcui plum and its relationship with fruit disease resistance, the direct inhibitory effect of AG on Monilinia fructicola, the control effect of wound inoculation and AG soaking treatment on brown rot of plum fruits, the contents of phenolic acid, activities of enzymes, and expression level of genes related to disease resistance were determined after AG treatment.Results showed that AG did not inhibit the growth of M.fructicola, and the incidence, spot diameter, and natural incidence of M.fructicola were significantly lower than those of the control (P＜0.05).In addition, AG treatment significantly increased the content of phenolic acid and the activity of peroxidase, polyphenol oxidase, β-1,3-glucanase, and chitinase, and the expression levels of genes related to peroxidase, chitinase, and disease-related proteins in plum fruit.In conclusion, AG treatment regulates the activity of disease-related enzymes and the accumulation of phenolic acids by increasing the expression level of disease-related genes, thereby improving the disease resistance of Qingcui plum and inhibiting the occurrence of postharvest diseases.

The interaction of polyphenols with proteins can change the structural and functional properties of proteins.This study aimed to study the effect of preheating treatment on the interaction between pine nut kernel protein (PKP) and epigallocatechin gallate (EGCG) and to obtain a complex with good functional properties.In this study, under different pH values (pH 3.0, 7.0, and 9.0), the interaction between PKP and EGCG and the structural changes of proteins were characterized by ultraviolet spectroscopy, fluorescence spectroscopy, infrared spectroscopy, and SDS-PAGE gel electrophoresis.The effects of preheating treatment on particle size, Zeta- potential, surface hydrophobicity, emulsification, and foamability of PKP and its complex with EGCG were further analyzed.Results showed that the maximum absorption intensity of the UV-visible spectrum of preheating pine nut kernel protein (HPKP) increased, exposing more hydrophobic groups, increasing random curl content, and improving molecular flexibility, thus enhancing the binding affinity between preheating pine kernel protein and EGCG.The quenching type of EGCG on PKP/HPKP was static quenching, and the preheating treatment did not change the interaction force type under the same pH value.Compared with the PKP-EGCG complex, the surface hydrophobicity of the HPKP-EGCG complex decreased by 19.76%, 36.24%, and 43.12% at three pH values, respectively, and the random crimp content further increased (P<0.05).At pH 7.0 and pH 9.0, HPKP interacted with EGCG to form smaller complexes with emulsifying properties (11.71±0.31) m²/g comparable to commercial soybean protein isolate (SPI) at pH 9.0.Emulsifying stability (103.6±1.76) min and foamability (137.2±1.2)% were much higher than SPI.Under pH 3.0 conditions, EGCG may bind to the surface of HPKP, resulting in an increase in the size of the complex and a decrease in emulsification (P<0.05).The results showed that the preheating treatment could change the structure of PKP and enhance its binding affinity with polyphenols, which further improved the functional properties of the complex.

This experiment focused on the investigation of the drying and rehydration kinetics of green peppers.Different hot air drying temperatures (40, 50, 60 ℃) were used to dry green peppers with varying sizes (10 mm×10 mm, 20 mm×20 mm, 30 mm×30 mm, 40 mm×40 mm, 50 mm×50 mm) until they reached a safe moisture content.Eight common thin-layer drying mathematical models were adopted in the analysis and fitting of the drying characteristics of green peppers.Moreover, the Weibull distribution function mathematical model was used to emulate the rehydration characteristics of dried green pepper products.Results showed that when the hot air drying temperature was set at 60 ℃, it took the shortest time (7.5 h) for 10 mm×10 mm green pepper cuts to reach a safe moisture content, exhibiting the highest average rate of drying.On the other hand, at a drying temperature of 40 ℃, it took the longest time (39.5 h) to complete the drying process for 50 mm×50 mm green pepper cuts, exhibiting the lowest average rate of drying.The fitting analysis of the eight mathematical models suggested that the Page, Modified Page, and Two-term Exponential models were the most appropriate for illustrating the moisture ratio of green peppers during drying changes.Additionally, the Weibull distribution function fitting demonstrated high accuracy in simulating the rehydration process of dried green pepper products, with a coefficient of determination R² ranging from 0.968 8 to 0.996 0, χ² ranging from 0.020 5 to 0.291 2, and root mean square error ranging from 0.004 1 to 0.058 2.Moreover, at a temperature of 60 ℃, the shrinking rate of 40 mm×40 mm green peppers was the highest at 58.06%, whereas, at a temperature of 40 ℃, the shrinkage rate of 10 mm×10 mm green peppers was the lowest at 21.25%.

Plant-based fermented foods have attracted considerable attention because of their potential health benefits.This study compared the characteristics of loquat juice fermented with Lactiplantibacillus plantarum, Lacticaseibacillus paracasei, and Lactobacillus brevis, respectively.Results demonstrated that during fermentation with different lactic acid bacteria, the pH, total acid content, total phenolic content, reducing sugar content, and antioxidant activity of loquat juice exhibited noteworthy variations.Upon completion of fermentation, the cell number of all three lactic acid bacteria stabilized at over 8.0 lg CFU/g, with a total acid content exceeding 2.6 g/100 mL.Notably, the fermentation of Lactiplantibacillus plantarum M2 yielded the highest total phenol content, which was 126.79% of that on Day 0.Non-targeted metabolomics analysis revealed 409 metabolites in 14 categories within three fermented loquat juices.The predominant constituents were organic acids and their derivatives, as well as lipids and lipid-like molecules.Substantial variations existed in the metabolite composition of the three fermented loquat juices, particularly concerning amino acids, fatty acids, and organoheterocyclic compounds.The findings serve as a valuable reference for the analysis of metabolites in lactic acid bacteria-fermented juices and the development of functional foods utilizing loquat juice.

In this study, a Raman immunoprobe with a gold-core silver-shell as the enhanced substrate was prepared, and the simultaneous detection of spiramycin and tilmicosin was achieved through optimizing the key factors, including antibody addition, coagulant type and dosage, concentration of encapsulated antigen, and probe addition.In the method, both spiramycin and tilmicosin exhibited a good linear relationship between the logarithmic values of concentration and inhibition rate within the range of 0.000 1 ng/mL to 10 ng/mL.The detection limits for spiramycin and tilmicosin were determined to be 0.57 pg/mL and 0.25 pg/mL, respectively.The feasibility of the method was validated by conducting spiked experiments in milk, and it was found that the recoveries and relative standard deviations of spiramycin and tilmicosin complied with the requirements of the method.Furthermore, cross-reactivity studies demonstrated specificity, showing no cross-reactivity between spiramycin, tilmicosin, and other antibiotics such as erythromycin, oleandomycin, clarithromycin, or roxithromycin.Overall, the method is rapid, convenient and sensitive, and can meet the requirement of simultaneous determination of spiramycin and tilmicosin.

Huajiao (Zanthoxylum bungeanum), known for its strong pungency and unique aroma, is widely employed in regional cuisines and food processing.However, its development is hindered by its obvious bitter taste.Red huajiao (Zanthoxylum bungeanum Maxim.) has extensive cultivation and production.To compare the bitterness difference in red huajiao peels from different regions, this study focused on 20 distinct regions of red huajiao peels and used HPLC and amino acid autoanalyzer to analyze bitter compounds contents.Results showed that bitter substances were distributed in the red huajiao peels from 20 regions, and the content was different.Quercetin and arbutin were the main bitter substances in most areas, with the contents of 0.127-1.200 mg/g and 0.451-1.918 mg/g, respectively.Hierarchical cluster analysis (HCA) categorized 20 regions into five distinct classes based on bitter compounds composition and contents.Isoquercitrin, quercetin, and isorhamnetin were important bitter compounds influencing the classification of red huajiao peels into different clusters, and they were screened through combined partial least squares discrimination anlysis (PLS-DA) with variable importance in project (VIP).This study establishes a foundational data set for quality control purposes of red huajiao peels.

This study aimed to screen for selective antibiotic combinations through antimicrobial susceptibility tests, establishing selective media that can quantify the absolute abundance of any strain in a synthetic broad bean paste microbial community.The antimicrobial activity of 42 antibiotics against Staphylococcus carnosus, Bacillus subtilis, Bacillus amyloliquefaciens, Tetragenococcus halophilus, and Weissella confusa was analyzed using microdilution method, and antibiotics that could effectively distinguish these specific bacteria through cultivation were screened.Selective media were designed by combining ampicillin sodium, nafcillin sodium, chlortetracycline hydrochloride, oxolinic acid, lincomycin, and antifungal nystatin.The CFU number of the target strain on selective plates inoculated with the target strain and mixed microbial suspension did not show a significant difference (P>0.05).These selective media could accurately quantify the absolute abundance of any strain in the synthetic microbial community composed of Zygosaccharomyces rouxii, Staphylococcus carnosus, Bacillus subtilis, Bacillus amyloliquefaciens, Tetragenococcus halophilus, and Weissella confusa.By applying this method, the composition of a synthetic broad bean paste microbial community and the interactions between community members were successfully analyzed.This study provides a simple, accurate and low-cost solution for the development of methods for quantifying the composition of synthetic microbial communities with fewer members.

To improve the accuracy of fish freshness detection, electronic nose, machine vision, and multi-data fusion techniques were used to rapidly detect the freshness of refrigerated fish.Total volatile base nitrogen (TVB-N), which is closely related to freshness and is easy to measure, was selected as an indicator of fish freshness.Machine vision and electronic nose-acquired images as well as odor information were collected from samples.Three models, namely, the backpropagation neural network (BPNN), convolutional neural network (CNN), and convolutional neural network-gated recurrent unit-attention (CNN-GRU-Attention), were applied to fish freshness for 3-classification and 7-classification prediction.Results showed that the classification effect of the three models using the electronic nose data was better than that of the machine vision method, regardless of whether the application was 3-classification or 7-classification.In addition, the classification accuracy of the three models improved after the fusion of the original data.In particular, the multisensory data fusion method based on the CNN-GRU-Attention model performed the best in this study, with its accuracies on the test set reaching 97.61% and 90.48%, respectively.The results showed that multi-perception detection technology combined with the CNN-GRU-Attention prediction model could effectively improve the accuracy of fish freshness detection.

To investigate the high throughput detection method of veterinary drug residues, ultra performance liquid chromatography-quadrupole time of flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) was used to detect livestock and poultry matrix samples and 21 standard veterinary drugs.The retention time and characteristic fragment ion mass spectra of each standard veterinary drug were obtained.The linear equation, correlation coefficient, linear range, and limit of detection were obtained.Based on the GNPS (global natural products social molecular networking) website, the secondary mass spectrometry cleavage of veterinary drugs was further explored, and the structure of the compound was analyzed and confirmed.Results showed that the cleavage pattern of the same type of veterinary drug molecule was similar, and the rapid high throughput screening of veterinary drug residues in livestock and poultry meat could be realized based on the secondary mass spectrometry lysis fragments of veterinary drug molecule.According to UPLC-Q-TOF MS/MS and GNPS molecular network technology, 10 drugs were detected positive in 24 matrix samples of pork and fish, and 3 positive drugs were not included in the established standard veterinary drug information database.Indicating that compared with the conventional detection methods, UPLC-Q-TOF MS/MS combined with GNPS molecular network technology can realize the identification of veterinary drug residues in livestock and poultry meat quickly and accurately, and it can also find unknown veterinary drugs.

This study aimed to analyze the quality difference of seabuckthorn leaf tea from different producing areas and evaluate it comprehensively.The physicochemical components including water content, water-soluble extracts, tea polyphenols, and sensory evaluation of seabuckthorn leaf tea from different origins were determined.Cluster analysis, correlation analysis, difference analysis, principal component analysis, and comprehensive score model were used to comprehensively evaluate seabuckthorn leaf tea from six different production areas.The sensory comprehensive score of Xinjiang seabuckthorn leaf tea was higher than that of seabuckthorn leaf tea from other regions, and in terms of aroma and leaf base tenderness, it was significantly better than that of seabuckthorn leaf tea from other regions (P<0.05).There were significant differences in physicochemical indexes of sea-buckthorn leaf tea from different producing areas (P<0.05), especially caffeine, phenol-ammonia ratio, total flavonoids, and tea polysaccharides.There was a certain correlation between physicochemical indexes and sensory quality, including a significant positive correlation between appearance and water extract content (P<0.05), a highly significant positive correlation between phenol-ammonia ratio and dry matter content (P<0.01), and a significant negative correlation with free amino acid content (P<0.05).Three principal components were extracted by principal component analysis, with a cumulative contribution rate of 88.623%.The comprehensive scores are ranked from high to low as follows:Xinjiang seabuckthorn leaf tea, Yangquan seabuckthorn leaf tea, Lvliang seabuckthorn leaf tea, Gansu seabuckthorn leaf tea, Xinzhou seabuckthorn leaf tea, and Northeast seabuckthorn leaf tea.The research results can provide assistance for the breeding of high-quality seabuckthorn leaf tea resources and promote the further development and utilization of seabuckthorn resources.

A method for the simultaneous determination of 33 mycotoxins in edible plant source Jiaosu by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed.The samples were extracted by acetonitrile-water-formic acid (79∶20∶1, by volume), and cleaned up by matrix dispersion solid phase extraction (QuEChERS).The analytes were separated by BEH C18 column (2.1 mm×100 mm,1.7 μm) using acetonitrile and 0.1% formic acid solution as mobile phase by gradient elution, analyzed in positive and negative electrospray ionization (ESI) mode by multiple reaction monitoring (MRM) mode, and quantified by matrix matching external standard method.Results showed that the linearities of 33 mycotoxins were good in respective ranges, with correlation coefficient (R²) greater than 0.980.The method recoveries were 60.9%-119.4%, and relative standard deviations (n=8) were 6.9%-14.9%.The method is simple and efficient for analysis of 33 mycotoxins in edible plant source Jiaosu.

To clarify the impact of aging time on the aroma components of brandy, volatile compounds of different nine brandy samples with different aging times were analyzed by headspace solid-phase microextraction with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (HS-SPME-GC×GC-TOFMS).Results showed that among all the samples, 495 volatile compounds were identified, with the sample aged for 0 years having the fewest types of volatile compounds (275), and the sample aged for 18 years having the most (318), the species of volatile compounds indicated an increasing trend with longer aging time.The contents of different categories of aroma components varies with the duration of aging, the contents of alcohols, aldehydes, terpenes and sulfur-containing compounds decreased with aging time, while the contents of acid compounds increased gradually.The result of principal component analysis showed that the samples of different vintages showed trend changes with the age of the brandy, and the aroma changes were greater in the pre-aging period (0-1 years).Based on one-way ANOVA, a total of 268 aroma components with significant differences were screened.Among them, some compounds were more prominent, like compounds with fruit, spice and baking aroma characteristics and so on, while the compounds with floral and herbaceous aroma characteristics generally decreased with storage time.This research systematically analyzed the impact of aging time on the aroma components of brandy.The research not only enriches the theoretical system of flavor chemistry of brandy, but also furnishes a data basis and theoretical foundation for the regulation of flavor profiles in the production of brandy.

In recent years, the food industry has undergone significant changes.Globalization, technological advancements, and evolving consumer demands have driven continuous development and innovation within the sector.As an advanced emerging technology, machine learning and big data play an increasingly critical role in the food industry.The application of machine learning and big data in the food sector is closely intertwined.Machine learning utilizes pattern recognition and data analysis to extract key information from food production and supply chains, while big data technologies support the processing of large-scale datasets, providing a more comprehensive decision-making perspective.Together, these technologies propel innovation in food research and industrial development.In-depth analysis of large datasets using machine learning can predict food trends, improve production processes, and optimize supply chains.This paper presents the current state of application of machine learning and big data in the food industry, covering machine learning and deep learning technologies, adaptive neuro-fuzzy inference systems, and the multidimensional applications of machine learning in food detection, such as food detection techniques that combine machine learning algorithms with near-infrared spectroscopy, applications of computer vision in the food sector, and real-time food detection technologies that integrate machine learning algorithms with smart sensors.It analyzes the technical challenges faced by big data (such as issues with data authenticity, completeness, and difficulties in data labelling), proposes potential solutions (including blockchain technology and data augmentation and preprocessing techniques), and anticipates future development trends of machine learning technologies in food research.Furthermore, with the advent of “Food Industry 4.0,” the food sector is poised for rapid growth, and cutting-edge technologies derived from machine learning—such as smart agriculture, robotic farming, drones, 3D printing, and digital twins—will further emerge.In light of these numerous opportunities for innovation and improvement, the food industry will also need to address challenges related to intelligent production and sustainability.Finally, the paper discusses potential challenges and future directions for development within the food industry.

Aquatic products possess various characteristics, including high moisture content, elevated endogenous enzyme activity, abundant protein content, and delicate muscle tissue.However, these attributes render them susceptible to diminished freshness or even spoilage shortly after being captured.Freezing is a prevalent technique utilized to preserve the freshness of aquatic products.Nevertheless, the formation of ice crystals during the freezing process can harm the cell structure of aquatic products, resulting in quality deterioration, such as protein and lipid oxidation, muscle texture softening, and discoloration.Currently, with the continuous development of ultra-low temperature freezing technology, the size of ice crystals in frozen aquatic products can be effectively controlled, thereby effectively delaying the quality deterioration of frozen aquatic products.This review mainly summarizes the principle and influencing factors of ice crystal formation in the ultra-low temperature freezing process of aquatic products, the impact of ice crystals on the quality of aquatic products, and the detection methods and control technologies of ice crystals, providing a reference for the development of new freezing technologies for frozen aquatic products.

Aquatic products are favored by many consumers because of their rich nutrition and convenient acquisition.In recent years, quality and safety problems of aquatic products have been frequent in the process of breeding, transportation, and preservation, among which the use of illegal drugs (chloramphenicol, malachite green, nitrofurans, etc.) and excessive use of conventional drugs (enrofloxacin, etc.) are an important reason that affects the quality and safety of aquatic products.There are low drug residues, complex matrices, and many interfering substances in aquatic product samples, so it is necessary to develop sample pretreatment methods and detection technologies with strong selectivity, good separation, and high sensitivity.This paper mainly expounded on the pretreatment technology, detection methods, and advantages and disadvantages of drug residues in aquatic products at home and abroad in recent years and looked forward to the development prospect of drug residue detection technology, providing a technical basis and methodological basis for drug residues detection in aquatic products.

Efficient collection of food quality and safety data is the foundation for implementing online food inspection and intelligent sorting.Hyperspectral imaging (HSI), as a rapid and non-destructive detection method, plays a crucial role in the food industry.Microscopy can provide detailed information about the microstructure of food products, making it a classic yet effective means of detection as well.Hyperspectral microscope imaging (HMI) combines the benefits of HSI with microscopy to extract spectral, spatial, and microstructural data from samples at the same time.HMI can acquire rich information on food samples in real-time and realize multi-dimensional analysis, providing a more comprehensive, accurate, and efficient means for food testing.Thus, HMI has great potential in food quality analysis and safety inspections.Researchers are constantly conducting relevant studies.This study introduces the principle and system components of HMI, summarize the research progress, and discusses the existing application bottlenecks.This study also proposes further development prospects, such as expanding the adaptability of detection and enhancing compatibility with other technologies.The goal of this paper is to provide a reference for the further study and application of HMI in the field of food science.

Ultrasound is a type of energy produced by sound waves whose frequency is above the threshold of human ear hearing.Its mechanical and physical effects can enhance the mass transfer process and facilitate the removal of strongly attached water.As an emerging non-thermal pretreatment technology, ultrasonic pretreatment has been applied to fruit and vegetable drying.Its application effectively reduces the drying time of fruits and vegetables, improves the drying rate of fruits and vegetables, and improves the quality of products.The mechanism of ultrasonic pretreatment technology and the application of ultrasonic pretreatment in fruit and vegetable drying technology were introduced.Compared with the untreated group, it significantly improved the mass transfer rate and drying efficiency. Because it is a non-thermal pretreatment technology, the color, rehydration characteristics, and ascorbic acid content will not change much after ultrasonic treatment, which helps to maintain the quality and nutritional value of the food.In addition, the effects of ultrasonic power, ultrasonic temperature, ultrasonic time, and other parameters on fruit and vegetable drying efficiency, drying time, and product quality were also discussed, which provided a reference for future application in fruit and vegetable drying technology.

The development of detection technologies that can rapidly and efficiently detect potentially harmful substances in food is of great significance for ensuring food safety and safeguarding human health.Hydrogels with three-dimensional polymer network structures have the advantages of large specific surface area, easy structural functionalization, good biocompatibility, good flexibility, good mechanical stability, etc.Among them, composite hydrogels have attracted wide attention in the field of food safety detection.This paper reviews the synthesis and classification of composite DNA hydrogels and their application in the detection of mycotoxins in food.The different synthesis strategies are divided into physical and chemical cross-linking methods, and according to the composite type, composite DNA hydrogels can be divided into polymer composite DNA hydrogels and nanoparticle composite DNA hydrogels.This study summarizes the research progress of composite DNA hydrogel in the detection of various mycotoxins in food.Research progress and suggestions are put forward to improve the sensitivity and accuracy of food safety detection through further functionalization and intelligent design, and its development prospects are prospected.

Hyperuricemia (HUA) is a prevalent metabolic disorder that can precipitate gout along with other severe complications.Ampelopsis grossedentata, a traditional medicinal plant, has long been utilized in traditional Chinese medicine to treat HUA and its related ailments.This review seeks to unravel the operational pathways of Ampelopsis grossedentata in mitigating HUA, spotlighting research milestones achieved to date.Initially, the article reviews the pathophysiology of HUA, focusing primarily on abnormalities in purine metabolism and uric acid excretion.An overview of current medications for the treatment of HUA, their pharmacological effects, and side effects is then provided.Then the discussion extends to assimilate findings from investigations on Ampelopsis grossedentata and its active components, indicating their roles in curtailing uric acid production, facilitating its expulsion, and fostering antioxidant and anti-inflammatory actions.Additionally, the review explores the potential mechanisms by which Ampelopsis grossedentata combats HUA, suggesting its involvement in regulating gut homeostasis and insulin resistance.Conclusively, while Ampelopsis grossedentata emerges as a formidable natural candidate for HUA management, it beckons a thorough clinical and experimental inquiry to affirm its therapeutic promise and carve its niche in clinical practice.