336 samples were prepared by double enzyme hydrolysis of 8 kinds of marine organisms.The target hydrolysate with the best comprehensive effect was screened out, which was Stichopus japonicus peptides (SJPs).It was the product of enzymatic hydrolysis of sea cucumber by alkaline protease and flavourzyme.SJPs had a high in vitro ethanol dehydrogenase activation rate (118.86%), hydrophobic amino acid content (45.97%), small peptide content (81.04%), and gastrointestinal digestive stability.The acute alcoholism model and early alcoholic liver disease model of mice were established to evaluate the anti-alcoholic and hepatoprotective activities of SJPs.Results showed that oral administration of SJPs before drinking significantly prolonged the drunken latency and shortened the sleep period of mice, enhancing the tolerance to acute alcohol toxicity.In addition, SJPs accelerated the clearance of alcohol and its metabolites by activating the alcohol metabolic enzyme system, reducing liver oxidative stress and fat accumulation, and had a significant protective effect on early liver injury.In summary, SJPs may played a potential role as a functional food ingredient to alleviate alcoholism and protect the liver.

Milk's primary protein component is casein, with κ-casein (κ-CN) comprising roughly 13% of the total casein content in bovine skim milk.κ-CN offers the nutritional benefits typical of milk proteins and holds potential for future applications in total milk synthesis.Moreover, peptides derived from κ-CN hydrolysis exhibit anticoagulant and antithrombotic properties. Corynebacterium glutamicum, a safely produced strain, served as an advantageous platform for edible protein production.This study leveraged C.glutamicum's capability to express heterologous proteins, focusing on the exogenous expression of κ-CN.The κ-CN gene was codon-optimized and synthesized, and the C.glutamicum ATCC13032 strain was utilized to express κ-CN-6×His protein.Optimization efforts targeted the N-terminal solubilization tag, signal peptide, expression host, and fermentation conditions.Results showed that structural analysis revealed fixed disordered regions within κ-CN.Expression of κ-CN was confirmed via SDS-PAGE and western blotting, indicating successful expression in C.glutamicum ATCC13032 strains.Soluble expression was enhanced by incorporating SUMO and FH8 solubilization tags at the N-terminus, with further improvements in protein yield achieved through signal peptide and host screening.This study demonstrates the successful expression of κ-CN in Corynebacterium glutamicum, with optimization strategies enhancing yield and laying the groundwork for future advancements in total milk synthesis.

Lactobacillus species have been recognized for their potential to modulate the antioxidant signalling pathway, thereby upregulating the expression of antioxidant enzymes and mitigating oxidative damage.The study was undertaken to explore the enhancement of host antioxidant capacity by specific probiotics and their role in modulating oxidative stress induced by Gardnerella vaginalis (GV) infection.An inflammatory model was developed by treating VK2/E6E7 cells with 1.25 μg/mL lipopolysaccharide (LPS) for 24 hours.The Cell Counting Kit-8 (CCK-8) assay was then employed to identify Lactobacilli with antioxidant potential.An animal infection model was established via subcutaneous injection of 5 mg/mL estradiol valerate in the neck and vaginal injection of 20 μL containing 10¹⁰ CFU/mL GV solution.Subsequently, a 100 μL Lactobacillus suspension at a concentration of 10⁹ CFU/mL was gavaged to the mice daily for 10 days.At the end of the experiment, GV load, histopathological assessments, and expression levels of the antioxidant signalling pathway proteins Kelch-like ECH-associated protein 1 (Keap1) and nuclear factor erythroid 2-related factor 2 (Nrf2) in vaginal tissue of various group were evaluated.Results showed that Lactobacillus paracasei CCFM1317 significantly enhanced cell viability to 109.0% in vitro.In the animal trial, oral administration of CCFM1317 led to a reduction in the GV load by 40.6%.Histopathological examination of vaginal tissue revealed epithelial continuity restoration and a decrease in the severity of inflammatory cell infiltration.Furthermore, investigation of Keap1/Nrf2 signalling pathway expression in vaginal tissue revealed that CCFM1317 markedly decreased Keap1 mRNA expression by 48.6% and significantly increased Nrf2 mRNA expression (P<0.000 1), with a 1.9-fold increase in Nrf2 content.These findings demonstrated that L.paracasei CCFM1317 possesses characteristics that enhance vaginal antioxidant defenses and may potentially alleviate oxidative stress-related symptoms during vaginitis.

It is a feasible way to effectively control the content of ethyl carbamate in Huangjiu (Chinese rice wine) by using new immobilized neutral ureases to degrade urea in Huangjiu.In recent years, in-situ synthesis of immobilized enzymes based on metal-organic frameworks (MOFs) has attracted researchers' attention.In this study, by comparing the two MOF materials, ZIF-8 and MIL-100(Fe), MIL-100(Fe) was selected as the carrier according to the characteristics of Huangjiu to synthesize in-situ the immobilized neutral urease [NU@MIL-100(Fe)] at room temperature and in water environment.It was characterized by X-ray diffractometer (XRD) and scanning electron microscopy (SEM), and its enzymatic properties were investigated.The results showed that the crystal structure and morphology of MIL-100(Fe) were not affected by the immobilization of the enzyme when it was used as the carrier with good acid stability and alcohol tolerance.Compared with free neutral urease, the optimal pH, optimal temperature and the effect of alcohol on activity of NU@MIL-100(Fe) did not change significantly, but NU@MIL-100(Fe) showed higher acid activity and better alcohol tolerance, and its acid stability was also improved.When NU@MIL-100(Fe) was used to degrade urea in Huangjiu, the urea degradation reached to 79.96% after 4 h treatment and 93.83% after 24 h treatment, even 48.29% after 4 h treatment in the 3rd reuse, which showed a good urea degradation effect and reusability.The results provide a new reference for the practical application of immobilized neutral urease in Huangjiu.

Cathartic colon is a type of intractable constipation caused by prolonged use of stimulant laxatives.Studies have shown that long-term laxative stimulation can lead to severe intestinal nerve and intestinal barrier damage.At present, there is a lack of effective treatment for cathartic colon, and the application of probiotics to alleviate gastrointestinal diseases is a current research focus.Previous studies have shown that B.longum HuNan2016 2810 has an alleviating effect on cathartic colon, but the mechanism is not yet clear.Based on this, this study aims to analyze the possible mechanism of B.longum HuNan2016 2810 in relieving cathartic colon from the perspective of intestinal nerve and intestinal barrier.It was shown that B.longum HuNan2016 2810 had a relieving effect on the cathartic colon by the measurement of constipation indicators.Further analysis of intestinal barrier and intestinal nerve indexes and their correlation with constipation relief indexes and short chain fatty acids (SCFAs) was conducted.The results showed that B.longum HuNan2016 2810 up-regulated the relative abundance of SCFAs in the intestinal tract.Increase the content of SCFAs in feces, regulate the secretion of neurotransmitters, increase the number of intestinal glial cells, repair intestinal nerves, reduce the level of inflammation in the body, regulate intestinal barrier homeostasis, and finally relieve the laxative colon.This study provides a new idea for the relief of cathartic colon.

Pseudomonas putida KT2440 demonstrates robust tolerance under both endogenous and exogenous pressures.Cold shock proteins maintain cellular structure and function stability under extreme conditions.To delve deeper into the cells tolerance under the presence of organic compound, this study engineered strains of Pseudomonas putida KT2440 with knockout and overexpression of cold shock proteins CspAⅠand CspAⅡ.Under perilla alcohol stress, this study assessed cell growth status, half-maximal inhibitory concentration, and thymol production using a spectrophotometer and HPLC.Experimental results revealed that, under perilla alcohol stress, cells overexpressing CspAⅠshowed improved growth with an OD₆₀₀ of 2.57.The half-maximal inhibitory concentration for the complemented CspAⅠstrain was 1.88 times that of the knockout strain.Furthermore, in experiments where exogenous addition of limonene catalyzed the production of perilla alcohol, cells overexpressing CspAⅠdisplayed optimal growth status, producing perilla alcohol at a level of 156.49 mg/L.This suggested that the overexpression of cold shock proteins contributes to enhancing the cells survival capability against organic compounds and stabilizing cellular metabolic levels.

Clinical drug treatment for hyperuricemia (HUA) has significant side effects.Probiotics, as natural and safe food supplements, can assist in treating HUA.This study aimed to explore the mechanisms by which probiotics alleviate HUA and provide kidney protection.Lactobacillus gasseri CCFM1346 (5×10⁹ CFU/g) was administered to HUA model mice via oral gavage for 3 weeks.Physiological and biochemical parameters of mice, kidney histopathological sections, liver xanthine oxidase (XOD), and uricase (UOX) activities, as well as expression levels of kidney uric acid transporters, inflammasomes, and inflammatory factors, were examined.Results showed that both live and dead cells of L. gasseri CCFM1346 significantly decreased the serum uric acid levels in mice, inhibited liver XOD activity, and promoted liver UOX activity (P<0.01).Both live and dead cells significantly increased uric acid levels in the urine of HUA mice, downregulated expression of kidney reabsorption transporters, and upregulated expression of excretion transporters (P<0.001).Both live and dead cells reduced mRNA expression of NLRP3, ASC, and Caspase-1, and inflammatory factors TNF-α, IL-6, and IL-1β in kidney (P<0.01).L.gasseri CCFM1346 alleviates HUA by regulating uric acid metabolism and improving kidney inflammation.

Heavy metal lead ingestion can have detrimental effects on organisms, leading to irreversible damage to the kidneys and liver.Lactiplantibacillus plantarum is considered an important probiotic and has been recognized for its various advantages for organisms.This study aimed to investigate the protective effect of L. plantarum CCFM8661 against lead toxicity in mice.Using BALB/c mice, a lead poisoning mouse model was established by orally administering lead acetate solution.Enzyme-linked immunosorbent assay and histopathology were employed to evaluate the mitigating effect of L. plantarum CCFM8661 on lead toxicity in mice.Results revealed significant negative changes in body weight, antioxidant capacity, kidney tissue pathology, and tissue lead content in the model group compared to the control group, indicating the successful establishment of the model.However, supplementation with L. plantarum CCFM8661 reversed the deterioration observed in the model group, including body weight, antioxidant capacity, histopathology, and tissue lead content.Consequently, this study provides a theoretical foundation for developing probiotic treatment methods targeting chronic lead poisoning.

Listeria monocytogenes is a common foodborne pathogen.Active substances of lactic acid bacteria have potential abilities to control L.monocytogenes through quenching quorum sensing (QS) systems and inhibiting biofilm formation.In this study, the minimum inhibitory concentration (MIC) of ethyl acetate extract of Lactiplantibacillus pentosus Z097 (Z097-E) against L.monocytogenes was determined, and the effects of sub-MIC of Z097-E on the growth, auto-aggregation, hydrophobicity, motility, biofilm formation, exopolysaccharide, extracellular protein, and QS signal AI-2 of L.monocytogenes were explored.The elimination effects of different concentrations of Z097-E on mature biofilm were also measured.Results showed that the MIC of Z097-E was 6.4 mg/mL.At 3.2 mg/mL of Z097-E, the auto-aggregation rate and hydrophobicity of L.monocytogenes were decreased by 73.58% and 89.62%, respectively.Meanwhile, the inhibition rates on exopolysaccharide, extracellular proteins, and AI-2 of L.monocytogenes were 80.03%, 34.23%, and 84.43%, respectively.When treated with 3.2 mg/mL of Z097-E for 24 and 48 hours, the biofilm biomass was decreased by 52.76% and 53.77%, respectively.The elimination rates of 12.8 mg/mL of Z097-E on mature biofilm for 24 h and 48 h were 30.08% and 62.07%, respectively.Results showed that the Z097-E could inhibit the biofilm and quorum sensing of L.monocytogenes, providing a reference for the control of L.monocytogenes biofilm in food processing, transportation, and preservation processes.

The research team isolated Bifidobacterium bifidum B1628 with good acid and bile salt tolerance from the intestine of healthy infants.Heat-killed organisms from this strain can relieve colonic inflammatory edema in inflammatory bowel disease (IBD) mice, which has potential applications.To explore the genetic background of B.bifidum B1628 and the genes with potential probiotic properties, the complete genome of B.bifidum B1628 was sequenced and assembled by combining Illumina and Oxford Nanopore.The genomes of B.bifidum were compared with those of 119 B.bifidum isolates from different countries and regions published by NCBI.The study found that B.bifidum B1628 had only one circular chromosome of 2 234 414 bp and contained no plasmid, with a GC content of 62.4% and 1 769 protein-coding regions.120 strains of B.bifidum contained a total of 6 554 pan genes in an open pattern.A phylogenetic tree was constructed based on the 987 core genes, and the 120 B.bifidum strains were clustered into eight clads with regional aggregation, and B.bifidum B1628 belonged to clade 1, which was isolated from China.Functional annotation showed that B.bifidum B1628 contained genes for folate, tryptophan, and lactate synthesis, genes for acid tolerance, bile salt tolerance, oxidative stress-related genes, and environmental stress-related genes, as well as CRISPR-Cas adaptive immune system.This study presents the genome-wide characterization of B.bifidum B1628 and identifies potential beneficial genes, providing data reference for the development, utilization, and industrialization of this strain.

In this study, high-throughput sequencing technology was used to investigate the correlation between the physicochemical indexes and microbiota of Baoning vinegar herb Daqu in different seasons.The results of high-throughput sequencing showed that the dominant bacterial genera of Daqu were Streptomyces, Scopulibacillus, Pantoea, Saccharopolyspora, Staphylococcus and Kroppenstedtia, the dominant fungal genera were Aspergillus, Thermomyces, Rhizomucor, and Hyphopichia.Significant differences were found in the physicochemical indexes of the matured Daqu in different seasons, with moisture content around 15%, higher than the industry standard;pH around 7.0;starch content around 70 g/100 g, with the highest starch content in summer;Reducing sugar content was highest in spring;Saccharification power levels was highest in spring;Esterification and liquefaction power levels were highest in winter.Among the microbial flora, Pantoea, Saccharopolyspora, Kroppenstedtia and Rhizomucor were closely related to the saccharification power and liquefaction power of vinegar Daqu, while Pantoea, Streptomyces, Rhizomucor and Hyphopichia could enhance its esterification power.Rhizomucor and Hyphopichia were strongly correlated.This experiment reveals the correlation between physicochemical indexes and microbiota of herb Daqu in different seasons, and lays a theoretical foundation for improving the quality of it.

3-Phosphoglycerate dehydrogenase (PGDH) is the rate-limiting enzyme in the biosynthetic pathway of L-serine, playing a crucial role in efficient L-serine synthesis.In this study, the enzymatic characteristics of PGDH from Corynebacterium.glutamicum was investigated.The results indicated that the enzyme activity of Cg-PGDH was only 1.98 U/mg with poor thermal stability, which significantly hindered the high-efficiency biosynthesis of L-serine.To address this issue, directed evolution and high-throughput screening were employed to enhance the catalytic activity and thermal stability of Cg-PGDH.Through multiple rounds of screening, five mutants with significantly improved catalytic activity were obtained, including P85Q, D365Y, A389T, A183V, and I231V.Notably, the P85Q mutant exhibited a 1.55-fold increase in enzyme activity and significantly improved temperature stability, demonstrating an optimum catalytic temperature of 60 ℃.Subsequently, the combined mutations on the mutation sites of five mutants including P85Q, D365Y, A389T, A183V, and I231V were conducted, leading to the mutant P85Q-D365Y with enhanced temperature stability.Structural analysis and molecular dynamics simulations of the mutated sites within Cg-PGDH revealed that, despite P85Q and D365Y not being located in the catalytic center, they enhanced the stability of the loop in the 130-140 region, thereby increasing substrate affinity and catalytic activity.These research findings provided a significant foundation and direction for further elucidating the catalytic mechanism of Cg-PGDH and enhancing its catalytic activity.

To investigate the bacteriostatic effect of crude lipopeptide extracts of Paenibacillus polymyxa HL11 and Bacillus cabrialesii ST-1 on Phytophthora infestans, the lipopeptide crude extracts of HL11 and ST-1 were extracted by acid precipitation method, and the antibacterial effect of the lipopeptide crude extracts of the two Bacillus strains on Phytophthora infesfans was determined by Oxford cup method.The results showed that the inhibition rates of HL11 and ST-1 against P.infestans were (74.79 ±0.52)% and (79.5±0.54)%, respectively, when the concentration of lipopeptide crude extract was 10 mg/mL. The EC₅₀of the two strains of Bacillus were 0.56 and 0.021 mg/mL, respectively, as derived from the software fitting.Further observation by scanning electron microscopy showed that after treatment with lipopeptide crude extract, the surface of P.infestans showed depression, deformation or protrusions.Fluorescence microscopy showed that the structural integrity of P.infestans was destroyed to a certain extent after treatment with lipopeptide crude extract, and chromatin condensation and ROS surge occurred in the cells.By MALDI-TOF-MS analysis and data comparison, lipopeptides were mainly Iturin A, Surfactin and Fengycin.In this study, the crude lipopeptide extracts of two Bacillus strains had obvious inhibitory effect on Phytophthora infestans, and had the potential for further research and development.

To study the effects of different leucine supplemental levels on the quality of fermented sausage, different concentrations of leucine (0.1 g/kg, 0.5 g/kg, 5.0 g/kg) were added to sausage and Lactobacillus fermentum YZU-06 (L6) and Lactobacillus plant CGMCC18217 (L10) were selected as the starter culture of sausage (the inoculum volume was 10⁷ CFU/g), which have the effect of improving the flavor of fermented sausage.The effects of different contents of leucine supplementation on texture, color, free amino acids, volatile flavor substances, and sensory quality of fermented sausage were compared.Results showed that the 5.0 Leu+L6 treatment group significantly increased the hardness and chewability of fermented sausage (P<0.05), 5.0 Leu+L10 treatment group significantly increased the redness value of fermented sausage (a^*) (P<0.05).The content of 3-methylbutyric aldehyde produced in 5.0 Leu+L6 and 5.0 Leu+L10 groups was notably higher than that in other groups (P<0.05).Among them, the 5.0 Leu+L10 group had the highest efficiency of converting leucine to 3-methylbutyraldehyde (P<0.05).Principal component analysis showed that 5.0 Leu+L6 and 5.0 Leu+L10 treatment groups had a greater impact on the overall flavor characteristics of fermented sausages compared with bacteria-only groups (L6 and L10).In addition, the 5.0 Leu+L10 treatment group was shown to have the highest taste score (13.33) on the sensory evaluation.In conclusion, the 5.0 Leu+L10 treatment group can effectively improve the quality of fermented sausage.

In order to improve the expression level of nattokinase, the N-terminal coding sequences (NCSs) of the aprN were synonymously mutated without changing the amino acid sequence encoding nattokinase.Four mutant strains, NK1, NK2, NK3 and NK4, were constructed by transforming recombinant pHY-P43 plasmid which containing the mutated sequences into Bacillus subtilis.The enzyme activity of nattokinase was detected by fibrin plate.The expression of recombinant protein was verified by SDS-PAGE.The fermentation conditions of mutant strains were optimized by response surface.The results showed that the nattokinase activity of NK1, NK2, NK3 and NK4 strains were 94.8 IU/mL, 101.9 IU/mL, 124.2 IU/mL and 69.4 IU/mL, respectively.The NK3 strain had the highest enzyme activity, which was 50% higher than that of the original strain.The NK3 strain had the lowest enzyme activity, which was 83% of that of the original strain.The results of SDS-PAGE showed that the molecular weight of recombinant nattokinase was about 28 kDa, which was consistent with the theoretical molecular weight of 27 kDa.Response surface analysis showed that initial pH 7.56, fermentation temperature 35 ℃, and fermentation time 38 h were the optimal conditions for production of nattokinase in NK3 strain.The enzyme activity of nattokinase was 138.1 IU/mL, which was 11.2% higher than before the optimization.This study provides a new strategy to enhance the activity of nattokinase without altering the properties of nattokinase itself.

A study was conducted to optimize the solid-state fermentation process of tartary buckwheat using Monascus purpureus.This process converted insoluble flavonoids into soluble flavonoids and produced monacolin K, which had lipid-lowering effects.The aim was to improve the biological activity of the fermentation product and its development prospects.High-yielding strains of M. purpureus were screened for the production of Monacolin K.The solid-state fermentation process was optimized to enhance the yield of Monacolin K and soluble flavonoids.The yield of Monacolin K was the primary indicator, while soluble flavonoids, color value, and antioxidant activity served as reference indicators.Optimization was achieved through single-factor experiments and response surface experiments using the strain HQ-1.The optimal fermentation conditions were determined as follows:25 grams of tartary buckwheat mixed with 21 milliliters of nutrient solution containing 2.77 g/L NH₄NO₃, 1.82 g/L ZnSO₄, 1 g/L MgSO₄·7H₂O, 1 g/L KH₂PO₄, with a pH adjustment to 2.58 and 11 days fermentation duration. Under these conditions, the yield of Monacolin K reached 162.26 mg/100 g.Furthermore, the extraction amounts of specific flavonoids, including rutin, quercetin, kaempferol, chlorogenic acid, and ferulic acid, increased by 63%, 110%, 593%, 192%, and 57%, respectively.Additionally, the DPPH and ABTS antioxidant activities increased by 232% and 44%, respectively.These findings provide valuable insights into the key factors affecting the fermentation process and offer a practical basis for the development of tartary buckwheat tea technology.

Ethanol, a renewable energy, relies predominantly on yeast metabolism for its production.Selecting strains exhibiting high tolerance and productivity in ethanol fermentation is the key to achieve enhanced ethanol yields.In order to select and breed high-tolerant and high-yielding ethanol yeast strains, with six existing haploid brewing yeast strains, a mutant library was constructed through atmospheric and room temperature plasma mutagenesis, which were colorimetrically screened by triphenyl tetrazolium chloride, re-screened by pressure growth at 40, 41 ℃, and quantitatively analyzed by fermentation screening medium.Subsequently, nine dominant mutant haploid strains were obtained and hybridized through different mating types, resulting in a diploid brewing yeast strain, C6.with superior fermentation efficiency, better temperature resilience, acidity tolerance, and ethanol resistance than parental strains.The results exhibited that in a 35 ℃ composite sugar water fermentation medium, the C6 strain achieved an ethanol content of 14.6%, whereas parental strains AE2 and M reached 12.82% and 13.72%, respectively.Notably, the ethanol content increased by 13.8% and 6.4%, while at 30 ℃, the ethanol content for C6 came to 17.9%.It was evident that the stable OD₆₈₀ values period of the improved temperature tolerance of C6, AE2, and M strains were 4.12, 0.35, 1.15, respectively, under 40 ℃ conditions, showing a biomass increase ranging from 1.2 to 12 times.Thus, the C6 strain exhibits promising industrial applications in the field of ethanol production

Three strains of Aspergillus oryzae were selected for high-salt liquid-state fermentation to study their differences in fermentation performance.The main indicators of comparative analysis included morphological analysis, enzyme activity determination of koji, physicochemical indiced of fermented soy sauce, molecular weight of peptides, sensory evaluation, content of free amino acids and organic acids, etc.Results showed that A. oryzae D3 had better protease secretion ability, and the activity of five protease enzymes was higher than that of A. oryzae D1 and D2, especially neutral protease, aminopeptidase, and carboxypeptidase.The high-salt liquid-state soy sauce brewed by A. oryzae D3 reached the standard for superfine soy sauce through analysis of changes in physicochemical parameters.In addition, A. oryzae D3 could better hydrolyze proteins and produce more small molecule peptides of 500-3 000 Da based on the distribution analysis of peptide molecular weight.In terms of organic acids, the concentration of lactic acid and acetic acid in soy sauce brewed by A. oryzae D3 showed a suitable proportion, which was conducive to the formation of a good flavor in soy sauce.Not only that, the high-salt liquid-state soy sauce brewed by A. oryzae D3 had the highest sensory evaluation and was more popular among consumers.In summary, A. oryzae D3 has better fermentation performance, and this study provides a data basis for selecting strains more suitable for producing high-salt liquid-state soy sauce.

With the rapid growth of population, the global demand for high-quality protein is increasing day by day.To alleviate the problem of protein shortage, mycelium can be used as a new source of protein through the cultivation of high-quality strains of edible fungi breeding.In this study, Pleurotus djamor GXGD-13-1 was used as the original strain, protoplasmic cell fusion technique was used to increase its protein yield.First mycelium cell walls were enzymolysised in M2 composite for 3 hours, then released protoplast was fused with polyethylene glycol (PEG) in which 250 g/L of PEG was used as the fusion agent.A high fusion rate of 53% was achieved after the process, removing the breeding barrier of low compatibility of the tetrpolarity mating system.Primary screening and re-screening of fusion strain R-1 were carried out to select a high mycelial protein yield, 23% higher than that of the original strain GXGD-13-1.The work in this paper proved the efficiency of protoplasmic somatic cell fusion breeding technology in the selection of high-yield mycelium protein strains and provided an alternative way to meet the increasing demand for protein.

In this study, to improve the physicochemical and functional properties of elastin peptide (EP), elastin peptide was prepared by enzymolysis combined with microbial fermentation (Lactobacillus paracasei YYS-K1) (EMEP) and the physicochemical and functional properties of EMEP were compared with those of EP prepared by single protease hydrolysis.The results showed that the glycosaminoglycan content of EMEP was approximately 1.73 times higher than that of EP.The composition of amino acids and the proportion of essential amino acids was not significantly different between the two EP types;However, the proportions of Gly and Leu in EMEP were significantly higher than those in EP.The molecular weight distribution showed that the proportion of <1 000 Da peptides in EMEP and EP prepared by single enzymatic hydrolysis were 89.37% and 89.19%, respectively.The results showed that the two types of EP had a certain antioxidant capacity.When the mass concentration was 40 mg/mL, the DPPH free radical, ABTS cation free radical, and superoxide anion radical scavenging rates of EMEP increased by 29.59%, 2.74%, and 8.45%, respectively, compared to those of EP.Both EP and EMEP showed good functional properties;40 mg/mL EMEP effectively inhibited albumin degeneration, AGEs generation and pancreatic lipase and elastase activities, by 92.11%, 70.14%, 81.14%, and 83.33%, respectively, which were 20.25%, 12.66%, 81.14% and 20.85% higher than that of single protease.In conclusion, enzymatic hydrolysis combined with microbial fermentation is beneficial for further improving the physical, chemical, and functional properties of EP, and provides a theoretical basis for the development of high-quality elastin peptide products.

At present, as a potential packaging material, the properties of edible film need to be improved.To improve the antimicrobial activity and application potential of pullulan-soluble soybean polysaccharide (PS) heat-sealable film, the PS antimicrobial films loaded with ε-polylysine hydrochloride (ε-PL) were prepared.The effects of the addition of ε-PL on the structure, physics properties and antimicrobial activity of PS antimicrobial film were explored, and the application of PS antimicrobial film for packaging peptide powder was further evaluated.The results indicated that ε-PL interact with the film-forming matrix by hydrogen bonds.After adding ε-PL to PS film, the moisture content, elongation at break, barrier property and antimicrobial activity increased, and the water contact angle, tensile strength, dissolution time and transmittance decreased, while had no significant effect on the heat seal strength and thickness.When 0.4% ε-PL was added, the PS antimicrobial film (PS-0.4) had a uniform and dense surface, short dissolution time, the best antimicrobial activity and barrier properties.The results of packaging peptide powder showed that PS-0.4 film could effectively inhibit the moisture absorption rate and the total plate count of peptide powder packaging, allowing for the packaged peptide powder to dissolve within 25 s.In summary, a heat-sealable and instantly dissolvable antimicrobial film with good application potential is prepared to provide packaging material support for portable instant hot and instantly dissolvable convenience foods.

Pork is rich in dietary protein, vitamins, minerals and other nutrients.It has a long history of consumption and plays a pivotal role in Chinese food culture.High-protein foods are prone to produce heterocyclic aromatic amines risk factors during high-temperature thermal processing.There have been extensive studies at home and abroad on the production of heterocyclic aromatic amines in poultry and beef.However, there is a lack of research on the variation patterns of heterocyclic aromatic amines in pork tenderloin under high-temperature frying conditions.This article studied the effects of different frying temperatures (150, 160, 170, 180 and 190 ℃) and frying times (1, 2, 3, 4 and 5 min) on the pH, cooking loss, moisture, color, effects of texture, moisture distribution, frying temperature, sensory evaluation, and heterocyclic aromatic amines (HAA) content.The results showed that as the frying temperature and frying time increase, the moisture content, free water content, b^* and L^* in the pork tenderloin significantly decrease, and the surface center temperature, cooking loss, a^*, hardness, and cohesiveness decrease significantly, oil content and HAA content increased.The doneness and texture quality of fried food at 170 ℃ for 3 minutes were relatively good, and the HAA content was relatively low.At relatively high frying temperature (180~190 ℃) and long frying time (4~5 min), the HAA content in pork tenderloin was relatively high.Correlation analysis showed that the formation of heterocyclic aromatic amines was significantly related to frying temperature, time and pork tenderloin quality.Comprehensive analysis of the effects of different frying parameters on the quality of pork tenderloin and HAA content showed that frying at 160~170 ℃ for 2~3 minutes is the optimal condition for preparing fried pork tenderloin.This paper provides consumers and restaurant establishments with recommendations regarding meat frying times and temperatures to ensure the high quality and safety of fried pork tenderloin products.

Fresh wet noodles (FWNs) tastes smooth and tough, and have a huge market.But they are highly susceptible to corrupt and have a short shelf life.Since the low safety of synthetic antimicrobials, it is necessary to explore new types of natural antimicrobials for FWNs.This study investigated the types of spoilage microorganisms and the composition of bacterial species of FWNs in simulated market storage conditions, and studied the effects of 4 types of natural plant-derived antimicrobials (carvacrol, cinnamaldehyde, eugenol, and thymol) on the shelf life and quality of FWNs.The results of 16S rRNA sequencing showed that Panaea accounted for the largest proportion (76.19%) in corruption.These antimicrobials could inhibited all bacterial species in FWNs to varying degrees,and the inhibitory effect of FWNs with thymol was the best, followed by cinnamaldehyde and carvacrol, while FWNs with eugenol was the worst.Significant intracellular leakage was observed when bacteria were treated with the antimicrobials.The shelf life of FWNs with antimicrobials was significantly increased, and the FWNs with thymol and cinnamaldehyde had the longest shelf life of more than 48 h, longer than that of noodles with carvacrol and eugenol (36 h).Antimicrobials could also influence the quality of the FWNs.With the addition of antimicrobials, the gluten network was improved and cooking loss of FWNs was reduced.Also, the texture and sensory evaluation were affected, but still within the consumer-acceptable limits.This study suggested that natural plant-derived antimicrobial could produce FWNs with extended shelf life and high quality.

To address the issue of high glycemic index resulting from the inclusion of maltodextrin in butter tea powder and to ensure the quality of the product, various improvement strategies were implemented, including substituting maltodextrin with resistant dextrin, as well as employing secondary homogenization and spray drying techniques to produce butter tea powder with low glycemic index.Following orthogonal experiments to determine the tea liquid, salt, and butter portions, this research focused on analyzing the impact of resistant dextrin and inulin on the reconstitution characteristics of butter tea powder obtained through spray drying.Then, the product quality was evaluated by measuring particle size, reconstitution characteristics, volatile components, thermal stability and estimated glycemic index.According to the results, the optimal formula was as follows:14% of tea liquid (dry basis), 10% of salt, 20% of butter, 40% of resistant dextrin, 5% of D-mannitol, 10% of inulin and 1% of sucrose ester.The average particle size of low-glycemic butter tea powder was 500 nm, and its dispersibility, caking rate, angle of repose and stability were not significantly different from butter tea powder prepared with maltodextrin.However, the dissolution time of the low-glycemic butter tea powder was shorter (P<0.05).Furthermore, compared with the butter tea powder prepared by maltodextrin, the low-glycemic butter tea powder had higher thermal stability, richer volatile components, and a significant reduction in eGI, which had a good market development prospect.

In order to explore the different proportions of α-amylase (0.005%, 0.01%, 0.015%), sodium alginate (0.15%, 0.2%, 0.25%), sucrose fatty acid esters (0.02%, 0.03%, 0.04%) delayed the aging effect of multigrain porridge, effects of the three additives on texture properties, rheological properties, aging properties, crystal structure, amylopectin content, regeneration degree and sensory scores of multigrain porridge were compared by physical properties analysis, dynamic rheological properties analysis, differential scanning calorimetry analysis, infrared spectroscopy analysis and X-ray diffraction analysis.The results showed that the three additives could effectively delay the aging of multigrain porridge. Comparing the retrogradation degree and sensory scores of mixed grain porridge treated with three additives after 14 days of storage, it was found that the multigrain porridge added with α-amylase had the lowest regeneration degree and the best effect on delaying starch aging, but the sensory score was lower than that of the multigrain porridge added with sodium alginate and sucrose fatty acid ester. Therefore, considering the retrogradation degree and sensory scores results, 0.2% sodium alginate was selected as the best additive.After 14 days of storage, the hardness of the multigrain porridge was 497.87 g, the enthalpy of aging was 0.65 J/g, the R_1047/1022 was 1.05, the relative crystallinity was 16.49%, the amylose content was 77%, the recovery degree was 1.76, and the highest sensory score was 88 points.The investigate can provide theoretical basis for the quality improvement and practical production of ready-to-eat porridge food.

Germination is a natural and efficient method of starch modification.This study aimed to investigate the changes in adlay starch during the germination process.The structural and functional properties of the starch of the adlay were analyzed after the starch was extracted from the adlay at different time of germination.The findings revealed the emergence of noticeable holes and pores on the surface of adlay starch after germination, accompanied by a decrease in starch particle size.Moreover, solubility and swelling power of adlay starch were found to decrease.Amylose content first increased and then decreased and the ratio of A chain decreased.All adlay starch displayed A-type crystallinity.Furthermore, the water absorption, oil absorption, rapid digestion starch, and adhesiveness of adlay starch increased after germination, while enthalpy of gelati-nization, slow digestion starch, and resistant starch decreased and the hardness, cohesiveness, and gumminess of the starch gel decreased.This study highlights the ability of germination to regulate the edible quality of adlay and enhance the characteristics of adlay starch products.

To investigate the effects of different storage methods on the essential oil content, composition, and antioxidant activity of Pericarpium Citri Reticulatae (PCR), this study selected the essential oil of PCR aged for 0-9 years under the two storage methods of standard dry storage and natural aging as the object of study, extracted the essential oil of PCR by the improved Clevenger method, analyzed and compared the yield of essential oil, compared the difference of antioxidant activity by the ABTS and DPPH methods, and analyzed and compared the essential oil composition of PCR by gas chromatography-mass spectrometry.Results showed that the yield of essential oil decreased with the aging time, while the antioxidant activity showed an increasing trend.Compared with the essential oil of naturally aged PCR, the yield of the essential oil of standard dry storage PCR was higher, and the antioxidant activity was stronger.A total of 65 common aroma components were detected in the two storage methods, mainly terpenes, esters and acids.The relative contents of acids, alcohols, and aldehydes in the naturally aged essential oil were significantly higher than those in the standard dry storage essential oil, while the relative contents of phenols were significantly lower.The 10 different aroma substances could be used for the differentiation of the storage methods of the essential oil of PCR.Correlation analysis showed that γ-pinene and terpinolene were positively and significantly correlated with the antioxidant activity of the essential oils.This study analyzed and compared the differences between the storage methods of standard dry storage and natural aging, which could provide a reference for elucidating the quality and volatile composition of the two kinds of essential oils of PCR.

Vacuum pre-cooling technology can effectively eliminate the field heat and respiratory heat of fresh wolfberry after picking.However, the damage mechanism of fresh wolfberry induced by vacuum pre-cooling pressure is not clear.In order to deeply investigate the effect of vacuum pressure on the mechanical properties of fresh wolfberry, this paper explores and simulates the mechanical behavior of fresh wolfberry under different vacuum pre-cooling final pressures.Different vacuum pre-cooling final pressure conditions (500-800, 800-1 100, 1 100-1 400 Pa) were set up, and the fresh wolfberry was compressed longitudinally and transversely by using a mass spectrometer, and the stress-strain curves were linearly fitted to obtain the rupture force, modulus of elasticity, rupture energy, and stiffness of the fresh wolfberry during compression rupture, and the transverse compression of the four groups of samples was subjected to finite element simulation, and a finite element model.The results showed that the final pressure of vacuum pre-cooling had a significant effect on the mechanical properties of fresh wolfberry.Compared with the longitudinal compression and transverse compression of the blank control group, the modulus of elasticity of fresh wolfberry in the other three groups under different pre-cooling final compression conditions decreased.Among which the decrease was the smallest in the group of 800-1 100 Pa in transverse compression, and the decrease was the smallest in the group of 1 100-1 400 Pa in longitudinal compression.After finite element simulation, it was found that the stress-strain at the stress position and equatorial plane was the largest and spread outward along the equatorial plane.The errors between simulated and experimental values for all four groups of simulation tests were within 20%.This study will provide theoretical guidance for the upgrading of pre-cooling and preservation technology and equipment.

In the present study, the polysaccharides were extracted from the pulp of wampee [Clausena lansium (Lour.) Skeels] by hot water, hot acid, and hot alkaline methods (WPP-W, WPP-A, and WPP-AL), respectively, and the structures of the polysaccharides were characterized by gel permeation chromatography, ion chromatography, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy.The antioxidant activity in vitro and beneficial activity were also carried out.Results showed that the highest extraction rate (13.2%) was achieved by the hot acid method, and the average molecular weights of three polysaccharides ranged from 1 455.69 kDa to 2 111.67 kDa with arabinose, galactose, and galacturonic acid being the main components, followed by rhamnose, glucose, xylose, and glucuronic acid.Structurally, the wampee polysaccharide was an uncrystallized cyclic pyranoside containing β-D glycosidic linkage.The results of thermogravimetric analysis showed that the temperature range of the maximum thermal decomposition rate of the wampee polysaccharide was from 246.4 ℃ to 251.6 ℃.It was suggested that the polysaccharides had thermal stability.In addition, the emulsification activity index and emulsion stability index of WPP-W were significantly better than those of WPP-A and WPP-AL.Antioxidant activity test found that there were significant differences in the scavenging rate of the three polysaccharides against DPPH radicals and ABTS cation radicals, and WPP-A had the strongest antioxidant activity.The beneficial activity test found that the three polysaccharides had a certain degree of pro-proliferative effect on Lactiplantibacillus plantarum, Lactobacillus fermentum, Leuconostoc mesenteroides and Lactobacillus rhamnosus.This study could provide a reference basis for the deep processing of wampee, and the application of wampee polysaccharides in functional food and food ingredients.

Early harvesting has become one of the main factors restricting the improvement of economic benefits in the kiwifruit industry.This article analyzes the quality evolution of early harvested kiwifruit from multiple dimensions, including appearance quality, physicochemical properties, and storage characteristics.The results showed that the shape of fruits harvested 3 and 4 weeks early had not stopped growing, with higher fruit shape index and lower single fruit weight, resulting in severe yield losses.Secondly, the soluble solids content of early harvested kiwifruit was significantly lower than that of the normal harvest group, both at harvest (AH), room temperature maturation (RTM), and low temperature maturation (LTM).After matured at room temperature, kiwifruit harvested 4 weeks early had lower sugar content and higher acid content;when matured at low temperature, kiwifruit harvested 4 weeks early lost 73% of sugar and 29.76% of acid content compared to the normal harvest group, resulting in a serious imbalance of sugar-acid ratio.The weight loss and decay rate of kiwifruit harvested 2-4 weeks early increased significantly with earlier harvesting after the RTM and LTM treatments.With LTM treatment, kiwifruit harvested 2-4 weeks early experienced more serious cold damage symptoms, and the chilling injury rate, chilling injury index, as well as cell membrane permeability were all significantly higher than the normal harvesting period.This study investigated the effects of early harvest on the appearance, physicochemical quality and storage characteristics of kiwifruit, which provides a theoretical support for the timely harvesting of kiwifruit.

The purpose of this study was to explore the anti-inflammatory active ingredients of Chaenomeles and their chemical structure.Ethanol extraction, water extraction and ethanol precipitation were used to obtain different extracts of Chaenomeles.To investigate the anti-inflammatory capacity, the xylene-induced mouse ear swelling test was conducted.Using column chromatography to fractionate and purify the extracts, two active compounds were isolated from different extracts.Compound N was separated by MCI, Sephadex LX-20 and ODS-AQ columns from the ethanol extraction.Polysaccharide PCC-1 was separated by DEAE-cellulose column, HW-55F gel column and SephacryI S-400 column from the water-extracted alcohol precipitate.The anti-inflammatory capacity of these two pure compounds was further evaluated using an ear swelling model.And the degree of swelling and inflammatory factors in serum were used as evaluation indicators.The result demonstrated that component N and polysaccharide PCC-1 are anti-inflammatory active compounds of Chaenomeles.Polysaccharide PCC-1 played a key role in anti-inflammation, and component N was only an auxiliary.According to the results of NMR spectrum analysis, component N was a dimer proanthocyanidin firstly separated from Chaneomeles. Polysaccharide PCC-1 was composed of glucose and glucuronic acid.The main chain of the polysaccharide was connected by β1→4 bonds.The C₃ and C₂ positions on the main chain were connected by side chains, part of the C₆ site was formed into glucuronic acid, and part of the C₆ site was methylated.The glucuronic acid structure of the polysaccharide played a key role in the anti-inflammatory mechanism.

To investigate the control effect of oxalic acid treatment on browning of postharvest Stachys flordana Schuttl.ex Benth and to explore the relationship between browning and energy metabolism, Stachys flordana Schuttl.ex Benth was dipped in 10 mmol/L oxalic acid solution for 20 min, and then stored at 10 ℃ for 30 days.The related indexes of browning and energy metabolism of Stachys flordana Schuttl.ex Benth were measured, which was used to analyze the effect of oxalic acid treatment on browning and reveal the relationship between browning and energy metabolism.Results showed that, compared with the control, oxalic acid treatment could effectively inhibit the increase of the browning index and the decrease of the L^* value, which showed a significant difference during 15-30 days of storage.Oxalic acid treatment remarkably reduced the increase of respiration, inhibited the increase of malondialdehyde (MDA) and relative conductivity, and better maintained the integrity of the cell membrane of Stachys flordana Schuttl.ex Benth.The activities of polyphenol oxidase (PPO), peroxidase (POD), and phenylalanine aminolyase (PAL) were reduced, and total phenolic content was also significantly decreased, which could reduce the browning of Stachys flordana Schuttl.ex Benth.Meanwhile, oxalic acid treatment could improve the activities of succinate dehydrogenase (SDH), cytochrome oxidase (CCO), H⁺-ATPase, and Ca²⁺-ATPase, inhibit the decrease of ATP, ADP, and energy charge (EC), and maintain a high energy level in late storage of Stachys flordana Schuttl.ex Benth, which could delay the browning of Stachys flordana Schuttl.ex Benth.Correlation analysis showed that the browning index of Stachys flordana Schuttl.ex Benth was negatively correlated with ATP, ADP, EC, H⁺-ATPase, and Ca²⁺-ATPase, while positively correlated with total phenolic, PPO, POD, PAL, and AMP content.In conclusion, the inhibition of oxalic acid treatment on the browning of Stachys flordana Schuttl.ex Benth was related to the improvement of energy metabolism and energy levels, as well as the reduction of total phenolic content and the activity of enzymes related to browning.

In order to investigate the effect of peel addition on the quality of ultra-fine mango powder, the physicochemical and powdery characteristics of ultra-fine mango powder with different peel addition (8%, 16%, 24%) were studied.The results showed that there were significant differences in the physicochemical and powdery properties between pure mango pulp powder and pure mango peel powder.With the increase of peel addition, the particle size (D₅₀) of ultra-fine mango powder increased gradually, while the span of powder decreased, coupling with particle size distribution more uniformly.In terms of physicochemical indicators, with the increase of peel addition, the L^*, water holding capacity, oil holding capacity, glass transition temperature, total phenol, total flavone, ascorbic acid, antioxidant activity and carotenoid content increased, while the a^*, b^*, moisture content, water activity, bulk density, angle of repose, solubility and water absorption decreased.Infrared spectroscopy indicated that the addition of peel did not lead to significant changes of main functional groups of ultra-fine mango powders.The highest sensory evaluation score was obtained in 16% peel addition sample with 87.04 points, while the lowest was obtained in peel powder with 84.14 points.In general, physicochemical and powdery characteristics of ultra-fine mango powder could be significantly altered through peel addition, and the highest comprehensive quality of the ultra-fine mango powder was 16% peel addition sample.

To explore the mechanism of how high hydrostatic pressure (HHP) pretreatment affects textural characteristics of the hot-air dehydrated carrot slice, the textural properties of dehydrated carrot pretreated with different high hydrostatic pressure (100, 300, and 500 MPa) were measured, the microstructure, polygalacturonase (PG), and pectin methylesterase (PME) of the carrots before and after dehydration were detected, the water-soluble pectin (WSP), chelator-soluble pectin (CSP), and sodium carbonate soluble pectin (NSP) extracted from dehydrated samples were further characterized.Hardness of dried carrot slices pretreated with 300 and 500 MPa were 11.55% and 12.25% higher, respectively, when compared with the unpretreated carrot sample.When the pressure was over 300 MPa, tissue morphology of HHP pretreated samples was collapsed and microstructure of the dried sample became densely.Both PG and PME enzyme activities were stimulated during the selected 100~500 MPa, and the highest enzyme activities 118.76% and 128.36% were obtained at 300 MPa pretreated sample, respectively.When the pressure was over 300 MPa, CSP was tend converted to NSP, the pectin fraction ratio changed, and the degree of branching and methoxylation of pectin fractions were reduced.Moreover, molar mass of WSP, CSP, and NSP was decreased with the increasing pressure, accompanied with the pectin chains depolymerized.In summary, the changes of carrot tissue morphology and characteristics of pectin fractions induced by HHP were confirmed to be substantial factors that significantly affected the hardness of hot-air dehydrated carrot slices, which providing a mechanistic insight of HHP induced textural changes of dehydrated fruit and vegetable.

To fully exploit the quality differences and flavor specificities among different lemon varieties, this study employed fuzzy mathematical sensory scores as indicators to investigate the blending ratios of various lemon juices.The aim was to determine the optimal compounding scheme for sensory evaluation.The whole fruit juicing process of lemon juice can induce alterations in its storage stability due to the inclusion of pectin, fiber, and essential oils.Based on the optimal formulation, this study conducted single-factor experiments using the centrifugal sedimentation rate, particle size distribution, and stability coefficient of lemon juice as response variables.The stabilizer and emulsifier ratios were optimized through the response surface Box-Behnken design to enhance the stability of the blended lemon juice.The results indicated that the blend with the highest sensory score consisted of 40.0% green eulic lemon juice, 27.8% perfumed lemon juice, 25.0% tahitian lemon juice, and 7.2% small lime juice.Additionally, optimal stability was achieved with 0.100% sodium carboxymethyl cellulose (CMC), 0.075% xanthan gum, 0.820% soy lecithin, 0.600% sucralose ester, and the centrifugal sedimentation rate of 1.195% for lemon juice.Furthermore, the study revealed that the particle size distribution of the mixed lemon juice with stabilizers and emulsifiers ranged from 0.3 to 134.5 μm, while that of the original mixture ranged from 3.9 to 406.9 μm.The addition of stabilizers and emulsifiers resulted in smaller particle sizes, uniform state, even color, and higher sensory scores compared to the original mixture.This study offers theoretical support for the industrial application of lemon juice, aiding in its production and holding significant practical implications.

In this study, white kidney bean polypeptides (WKBPs) were prepared by complex fermentation of Bacillus subtilis and Aspergillus oryzae.The amino acid composition and the comparative molecular weight of WKBPs were analyzed.Meanwhile, the alteration of WKBPs' hypoglycemic activity (α-glucosidase and α-amylase inhibition rate) during gastrointestinal digestion were investigated using in vitro simulated digestion system, which assessed the biological activity stability of WKBPs.The results showed that the contents of essential amino acids in WKBPs increased from 6.47 g to 10.66 g, hydrophobic amino acids increased from 7.36 g to 13.81 g, and the basic amino acids increaed from 2.49 g to 3.65 g.The relative molecular weight distribution of WKBPs was mainly below 1 000 Da.The IC₅₀ values of WKBPs on α-glucosidase and α-amylase inhibition were 0.64 mg/mL and 0.53 mg/mL, respectively.The inhibition rate of α-glucosidase and α-amylase by WKBPs showed an increasing and then decreasing trend along with the digestion time.Meanwhile, the addition of WKBPs was able to reduce the starch digestibility in vitro.These results may provide the scientific data support for the further exploration and industrial application of WKBPs in the fields of nutrition, health food and medicine.

The purpose of this paper was to study the effect of different packaging methods on the quality changes of apricot and rose paste composite peel during storage, and to predict its shelf life by quality changes.Firstly, the composite fruit peel was packaged in four packaging methods:candy paper packaging (CW), vacuum packaging (VP), storage bag packaging (WPB) and aluminum foil bag packaging (ABP), and stored at room temperature for 180 days to determine the change value of the quality index during storage.A chemical kinetics model was established with water content, soluble sugar content, hardness and total number of colonies as characterization indexes to predict the shelf life of composite fruit peel.The results showed that VP method could effectively delay the degradation of soluble sugar, vitamin C, active ingredients and other nutrients in complex fruit peel, and inhibit the microbial contamination during storage.The changes of soluble sugar and total number of colonies were consistent with the zero-order kinetic model, and the changes of water content and hardness were consistent with the first-order kinetic model.The verification results showed that the prediction model established with four characterization indexes under VP mode had high accuracy, and the relative error between the predicted value and the measured value was small, and the Arrhenius equation had a good fit.Therefore, the application of VP method will provide a theoretical basis for the packaging and storage of composite fruit peel.

The volatile components of Tianlongquan Mixiangxing Baijiu were characterized by liquid-liquid extraction (LLE) and headspace solid-phase microextraction (SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS).In Tianlongquan Mixiangxing Baijiu, 339 potential aroma-active compounds were identified through various search and comparison strategies.These compounds include 86 esters, 50 aromatic compounds, 42 alcohols, 40 aldehydes, 32 oxygen heterocyclic compounds, 30 ketones, 25 terpenes, 19 organic acids, 11 sulfur compounds, and 4 nitrogenous heterocyclic compounds.The above results indicated the diversity and complexity of aroma components in Mixiangxing Baijiu.From the perspective of volatile aroma compounds, the samples of Mixiangxing Baijiu with different storage periods exhibited significant differences, and a certain pattern emerged as time progressed.Among them, the compounds that undergo significant changes were alcohols, esters, and aldehydes.These changes may result from adjustments in the company's production process and the chemical reactions that occur during the aging process.This study provides a deeper understanding of the trace aroma compounds in Mixiangxing Baijiu and enriches the research system of flavor chemistry in Mixiangxing Baijiu.

This article aims at investigating the influences of spontaneous fermentation and inoculated fermentation on the aroma components and sensory quality of Chardonnay white wine in Minqin region of Gansu Province.Locally planted Chardonnay grapes as test materials were fermented respectively under spontaneous and commercial-VL1-yeast inoculated conditions.GC-MS and GC-O were performed for the analysis of volatile aroma components and PLRS for the relationship of key volatile components and trait aroma, whose data provided crucial support for sensory evaluation.Results have showed that the VL1-inoculation fermented wine samples were better in terms of basic physicochemical index and taste evaluation.Total 57 aroma compounds, from which 27 important aroma compounds were detected, and the content of alcohols and esters played a crucial role in shaping different flavors.Both test samples exhibited strong scents of tropical fruit and citrus and certain scents of stone fruits and flowers.The differences were that the spontaneous fermentation tended to emit stronger pineapple and melon aromas, whereas VL1-inoculation fermentation led to more obvious banana and lychee aromas.Furthermore, among which diethyl succinate, geranyl acetate and citronellol contributed greatly to the aroma of banana and lychee, whereas farnesol, linalool, ethyl butyrate, ethyl acetate and propanol to the aroma of pineapple and melon.The research results can provide assistance for guiding the production of wine and the selection of yeast in Minqin region.

To improve the quality of pomegranate wine, which can be kept stable for a long time while ensuring the good taste of pomegranate wine, the present study was carried out to investigate the effects of saponin, polyvinylpyrrolidone, gelatin, and chitosan on anthocyanosides, total phenolics, total flavonoids, basic physicochemical indices, aroma compositions, and organoleptic qualities in the clarification of pomegranate wine, gelatin and chitosan on anthocyanosides, total phenolics, total flavonoids, basic physicochemical indices, aroma composition, and organoleptic qualities in the clarification of pomegranate wine using home-made laboratory pomegranate wine as the test material.Results showed that the basic physicochemical indices of pomegranate wine such as volatile acid and pH did not change significantly after the clarification treatment, but the total phenol (12.81%), total flavonoid (8.58%), anthocyanoside (10.99%), protein (6.58%-8.69%), and dry leachate content (5.27%) were all significantly reduced.Headspace solid phase microextraction-gas chromatography-mass spectrometry was used to detect the aroma components, and a total of 60 aroma components were detected, including 8 alcohols, 39 esters, 5 acids, 5 terpenes, 2 aldehydes, and 1 phenol.The external standard method was used to accurately quantify some of the compounds analysed by GC-MS and to evaluate the aroma in combination with the relative odour activity value and sensory analysis, and it was found that the main aroma compounds remained unchanged in pomegranate wines treated with clarifiers, which were phenylethanol, isoamyl acetate, ethyl laureate, ethyl caprylate, and ethyl caprate, which together gave the pomegranate wine its rich aroma.Together they gave the pomegranate wine a strong floral and fruity aroma.The wine samples treated with egg white powder (0.25 g/L) were placed in the same category as the original pomegranate wine and had the highest sensory score (85.6).Egg white powder (0.25 g/L) was found to be the most suitable clarifying agent for pomegranate wine.This study provides data support and technical reference for the clarification and production of pomegranate wine.

To investigate the efficacy of Prinsepia utilis Royle rennet in cheese processing, this study started with color difference, texture, free fatty acids and free amino acids to ascertain the impact of Prinsepia utilis Royle rennet on texture characteristics and main flavor substances of fermented cheese while comparing with cheese by calf rennet and papaya rennet.The results showed that the value of color difference of cheese processed by Prinsepia Utilis Royle rennet was significantly different from those of control groups (P<0.05).The hardness, cohesiveness, viscosity, chewiness and restoring ability of the cheese were significantly higher than those of control groups (P<0.05).However, the elasticity of the cheese was not significantly different from cheese by papaya rennet(P>0.05), but was significantly higher than cheese by calf rennet(P<0.05).These results indicated that the processing of cheese by Prinsepia utilis Royle rennet can improve the texture characteristics.There was no significant difference in total free fatty acids content among the groups (P>0.05), but the total free amino acids content of the cheese by Prinsepia Utilis Royle rennet was significantly lower than those of the control groups (P<0.05).By partial least squares discriminant analysis, the experiment screened out 14 important flavor substances.By analyzing the interactive heat map, it was found that 6 free amino acids and 3 free fatty acids have interaction effect.This paper provides a reference for the application of Prinsepia utilis Royle rennet in cheese processing.

A method for the determination of taurine content in formula powder for special medical by HPLC with ortho phthalaldehyde (OPA) as a pre-column derivatization reagent was established.The resulting extract was separated on a C18 column, and the addition amount of derivatization reagent, flow phase ratio, flow rate, mixing times, and waiting time after derivatization were optimized.The results of the tests showed that the peak area and pattern were optimal when the volume of the derivatization reagent dosage was 30 μL, the flow phase volume ratio was 20∶80, the flow rate was 0.6 mL/min, the mixing times was 6 times, and the waiting time after derivatization was 0 min.Under the experimental conditions, the relative standard deviation (RSD) of the peak area of the three different concentrations of taurine standards was 0.08%-0.75% and the precision was high.The content of taurine in two kinds of formula powder for special medical was detected and the RSD of the repeatability experiments were 0.67% and 0.37%, the repeatability was good.The test results of the spiked recovery were nice with the average recoveries of the samples were 97.6%-104.5% and 106.0%-110.3%, respectively.Therefore, the results showed that this analysis method had the advantages of mild reaction conditions and easy preparation for the determination of taurine content in formula powder for special medical.

An analytical approach was developed for the rapid determination of tetraniliprole hydrochloride residues in aquatic products.This method involved a modified QuEChERS extraction combined with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and multi-walled carbon nanotubes (MWCNTs).The samples were extracted using acetonitrile, and then partitioned into aqueous and organic phases by adding 4 g of anhydrous sodium sulfate and 4 g of anhydrous magnesium sulfate.The purification process involved the use of MWCNTs-improved QuEChERS, which included the addition of 3 mg of MWCNTs, 60 mg of C18, and 50 mg of PSA to each milliliter of extraction solution.Subsequently, the samples were separated on Agilent Venusil MP C18 (100 mm×2.1 mm, 3 μm) column, eluted with a methanol-water mixture, ionized via electrospray ionization in negative ion mode, and quantified using multiple reaction monitoring (MRM) with matrix matching external standard calibration.The results showed that the relationship coefficient (R²) of tetraniliprole in different aquatic product matrices at 0.1-20 μg/L was greater than 0.999.The quantitative limit of method (S/N≥10) was 0.80 μg/kg.The recovery rates at 2.0 μg/kg, 4.0 μg/kg, and 20 μg/kg for carp, yellowtail, crayfish, grass shrimp, hairy crab, swimming crab, and clam as matrix were between 82% and 97% with relative standard deviation (RSD) of 0.66%-4.02% (n=6) for intra-batch and RSD of 0.88%-2.95% (n=6) for inter-batch.The method is convenient and efficient, and can meet the requirements for the detection of tetraniliprole residues in aquatic products.

Rapeseed oil-based chili oil was prepared through high-temperature frying.Both rapeseed oil and chili powder underwent the same heating treatment.The volatile components in chili oil, rapeseed oil, heated rapeseed oil, chili powder, and heated chili powder were identified and differentiated using headspace solid-phase microextraction gas chromatography-mass spectrometry.The study compared the volatile components of five samples, as well as rapeseed oil and chili powder before and after heating individually, and to resolve the contribution of rapeseed oil and chili powder to the volatile components in chili oil.The results showed that 213 volatile components were identified in the five samples with 71 of them found in chili oil.Those components mainly included heterocycles, aldehydes, ketones, nitriles and acids.The results of principal component analysis indicated that the composition of volatile components in chili oil is more similar to that of rapeseed oil and heated rapeseed oil.The mixed frying of rapeseed oil and chili powder produced additional heterocyclic substances that provided a roasted aroma to the chili oil.Aldehydes and nitriles in rapeseed oil and heated rapeseed oil give chili oil its nutty and fruity aroma, as well as the pungent and sulfurous aroma characteristic of rapeseed oil.The ketones and acids found in chili powder and heated chili powder were important additions to the flavor of chili oil.This study serves as a reference for better comprehension of the flavor profile of rapeseed oil-based chili oil using the high-temperature frying method, as well as its underlying formation mechanism.

Enzymes of Daqu are one of the key factors affecting the quality of Daqu and Baijiu.Understanding the enzymes is of great significance for optimizing the Daqu-making technology and revealing the mechanism of Baijiu fermentation.In this study, advanced technologies for investigating the enzymes of Daqu were introduced, and their advantages and disadvantages were discussed.Additionally, known functional enzymes in typical Daqu were summarized.High-throughput sequencing and metaproteomics could be used to analyze the composition and function of enzymes in Daqu from the perspective of genome, transcriptome, and proteome.Currently, the key functional enzymes involved in the pathways of saccharification and ethanol fermentation in low-temperature Daqu, medium-temperature Daqu, and high-temperature Daqu have been identified by using the above technologies.However, because the above technologies have difficulties in detecting enzymes with lower content in Daqu, the functional enzymes involved in the pathways of flavor compound metabolism in Daqu cannot be fully identified at present.There is an urgent need to upgrade relevant technologies to promote the research on the enzymes in Daqu.

Lacticaseibacillus rhamnosus is probiotic bacteria that can regulate microecological balance and enhance host intestinal resistance.It can be used to ferment fruits and vegetables, producing organic acids, amino acids, and other metabolites, causing changes in alcohols, aldehydes, esters and terpenes, improving their flavor and nutritional value significantly.The application of L.rhamnosus in fruit and vegetable juice/puree and its by-products is elaborated in this paper, as well as the changes of metabolites and volatile flavor compounds in fermented fruits and vegetables.The application prospects and potential health benefits in the fermentation of fruits and vegetables are discussed, and suggestions for the future research priorities are put forward, to provide references for the research and standardized technology of fermented fruits and vegetables products by L.rhamnosus.

Isomaltulose, as a novel type of functional sugar, possesses characteristics such as low calorie content, anti-caries properties, easy absorption, and slow digestion.It is a sugar substitute suitable for diabetics and obese individuals, and it has broad applications in the food, pharmaceutical, and cosmetic industries.At present, the main preparation methods of isomaltulose include chemical synthesis, plant transgenic techniques, microbial conversion, and enzyme conversion.Among these methods, enzyme conversion has emerged as a new research focus in recent years, primarily utilized for sucrose isomerase (SIase).This paper reviews the mutation breeding of enzyme-producing strains of sucrose isomerase, heterologous expression, molecular modification, and chemical modification of SIase in the preparation of isomaltulose.The aim is to offer guidance for the development of related research work and industrial production.

“Caifu”, also known as preserved radish, has a folk saying in the Chaoshan region that it can promote appetite and aid digestion, and its effects become more significant over time.The traditional production techniques of Chaoshan preserved radish have been included in the list of intangible cultural heritage protection projects in Guangdong Province.However, there is relatively little research on the specific components and effects of Chaoshan preserved radish, which is not conducive to the protection and dissemination of intangible cultural heritage.Therefore, exploring the basic material foundation and mechanism of Chaoshan preserved radish is of great significance for the promotion of this intangible cultural heritage.By reviewing the research progress on the substances and mechanisms of foods and drugs that promote gastrointestinal health, such as promoting digestion and absorption, maintaining the effective structure and function of the gastrointestinal barrier, promoting gastrointestinal immune status, and regulating gastrointestinal microbiota, also by comparing and analyzing the traditional edible value of preserved radish in promoting appetite, aiding digestion, and other aspects of gastrointestinal health, it provides direction for scientific explanation of the material basis and mechanism of preserved radish in promoting gastrointestinal health, and scientific ideas for the protection and dissemination of intangible cultural heritage.

Chimonobambusa utilis shoots is a unique type of bamboo shoots in southwest China, which has the characteristics of “fresh, tender, fragrant, and crisp”.It is known as “the crown of bamboo shoots” and deeply loved by people.Drying, boiling, and freezing are common processing methods for Chimonobambusa utilis shoots.During the processing, the nutritional composition and bioactive substances of Chimonobambusa utilis shoots will be affected, and its flavor and color will also change.This paper described the nutritional ingredients and bioactive substances in Chimonobambusa utilis shoots and summarized the changes in the content of basic nutrients such as proteins, amino acids, and vitamins, as well as bioactive substances such as polysaccharides and polyphenols, during food processing.In addition, the effects of different processing methods on the physicochemical and functional properties of dietary fiber in Chimonobambusa utilis shoots were investigated, and changes in flavor and color quality during processing were overviewed.Finally, the future research direction of Chimonobambusa utilis shoots was prospected, aiming to provide a reference for the development and high-value utilization of Chimonobambusa utilis shoots.

The color of red wine is one of the important indicators for judging the quality of wine.During the process of wine making and storage, various factors such as light, temperature, and pH can cause the color of wine to fade and the quality of wine tend to decline.Polysaccharides are a large class of complex macromolecules present in wine, derived from the fragmentation of grape cell walls and autolysis of yeast cell walls.Research has found that polysaccharides have potential application value in stabilizing the color of wine.It is meaningful to utilize polysaccharides to improve the color stability of wine without reducing the quality of wine.This article provides a review of the research progress on the impact of polysaccharides utilizing on the color stability of wine.It elaborates on the types, structures, and mechanisms of polysaccharides in wine that affect wine color.Finally, future research focuses are discussed, aiming to provide reference for the development of color stabilization processes for red wine using polysaccharides.