Mussel foot protein is renowned for its remarkable adhesive properties, outstanding biocompatibility, and biodegradability, presenting broad and unique application prospects in fields such as medicine, food, and speciality materials manufacturing.The synthesis of mussel foot protein via synthetic biology techniques, specifically through recombinant microbial expression, holds significant potential.However, inappropriate expression conditions and a mismatched expression cassette in the engineered strain are major factors contributing to the low production intensity.Therefore, this study implemented a combination of strategies to optimize the expression of the recombinant mussel foot protein Mcofp-3 in Escherichia coli, with the aim of achieving efficient fermentation preparation of Mcofp-3.Initially, it was found that recombinant Mcofp-3 expressed in inclusion bodies resulted in a higher production, with an initial yield of 158.6 mg/L, and the protein proportion exceeded 85% by centrifugation.Subsequently, through orthogonal optimization of the culture conditions for the recombinant strain, it was determined that an induction time of 1 hour, an inducer concentration of 0.4 mmol/L, and a post-induction culture temperature of 37 ℃ in TB medium resulted in an Mcofp-3 expression level of 303.3 mg/L.Building on this, by integrating strategies, such as vector selection, promoter, and RBS engineering for further optimization, the expression level of Mcofp-3 was further increased to 484.2 mg/L when employing pACYCDuet as the vector, the T7 promoter, and substituting with the higher translation rate RBS6.The final optimization results in a 5-L fermenter indicated that after 37 hours of fermentation, the expression level of Mcofp-3 reached 1 720 mg/L, with a yield of 46.49 mg/(L·h), marking the highest level reported in the recombinant expression of mussel foot proteins to date.The above study lays the foundation for the large-scale industrial production of Mcofp-3, and also provides an important reference for the optimized expression of other mussel foot proteins.

As one of the main components of human milk oligosaccharides (HMOs), 3-fucosyllactose (3-FL) constitutes approximately 5% of HMOs.It plays important roles in modulating gut microbiota, providing immune support, and promoting brain development.At present, the research on the synthesis of 3-FL mainly focuses on Escherichia coli.This study introduced lac12 from Kluyveromyces lactis, gmd and gmer from Mortierella alpina, and screened six α-1,3-fucosyltransferases (α-1,3-Fut).Among them, fut3Bc from Neobacillus cucumis was selected, enabling the synthesis of 3-FL in Yarrowia lipolytica for the first time, with a yield of 0.66 g/L.Further overexpression of related genes identified the metabolic step catalyzed by α-1,3-Fut as the rate-limiting step in 3-FL synthesis.Subsequently, by adding a small ubiquitin-related modifier (SUMO) tag to Fut3Bc and multi-copy expressing SUMO-fut3Bc, the 3-FL yield increased to 2.28 g/L.Finally, enhancing the supply of NADPH further improved the 3-FL yield to 2.84 g/L.After fed-batch fermentation in 5 L fermentor, the 3-FL yield reached 14.70 g/L.This study explores the feasibility of producing 3-FL in Yarrowia lipolytica and provides valuable insights for constructing microbial cell factories for the production of HMOs.

The effects of pretreatment with varying steam explosion (SE) pressures on the physicochemical properties, molecular structure, functional characteristics, and antioxidant activity of rice bran arabinoxylan (RAX) were systematically investigated.A constitutive relationship was established based on SE pressure as the variable.SE pretreatment significantly increased the RAX yield by 1.8-fold while markedly reducing its molecular weight from 63.1 to 9.6 kDa, with the degree of reduction positively correlated with SE pressure.Furthermore, SE altered the branching degree of RAX.At a lower pressure (0.8 MPa), SE primarily targeted the α-L-Araf residues on the side chains, whereas at a higher pressure (1.2 MPa), the main site of action shifted to the 4-Xylp units of the backbone.SE pretreatment also significantly improved RAX solubility (P<0.05) and decreased its apparent viscosity as pressure increased.Frequency sweep analysis indicated that both RAX and RAX0.8 exhibited gel-forming potential, with RAX0.8 demonstrating superior gel performance.Additionally, the hydroxyl radical scavenging activity of RAX0.8 and RAX1.2 was enhanced compared with untreated RAX.These findings offer a technical foundation for the high-value utilization of rice processing by-products and the development of RAX with targeted nutritional functions.

Taking Qinghai’s characteristic resources of Berberis dasystachya Maxim as raw material, hot water extraction, ultrasonic auxiliary hot water extraction, microwave auxiliary hot water extraction, ultrasonic synergy enzymatic, microwave synergy enzymatic, and hot water coenzyme method six methods were used to prepare Berberis dasystachya polysaccharides (BDPs).The structural characteristics of the extracted BDPs were analyzed by Fourier transform infrared spectroscopy (FT-IR), ultraviolet spectroscopy (UV), scanning electron microscope (SEM), and Congo red test.The bioactivities were evaluated through antioxidant capacity assays and in vitro hypoglycemic activity tests.Results showed that the six BDPs prepared by different extraction methods all contained the key functional groups of polysaccharides, and the polysaccharides were in the pyranose configuration linked by α and β glycosidic bonds.SEM showed that the apparent structures of the polysaccharides obtained by different extraction methods were different.Compared with other extraction methods, BDPs extracted by ultrasonic synergy enzymatic (BDPs-UEE) had the highest yield, and the polysaccharide content was as high as 75.96% (P<0.05).The determination results of the scavenging abilities of DPPH free radicals and ABTS cationic radicals, as well as the inhibitory rates of the activities of α-glucosidase and α-amylase, indicated that all six types of BDPs exhibited antioxidant and hypoglycemic activities to varying degrees.Among them, BDPs-UEE showed relatively better antioxidant and hypoglycemic activities.Therefore, the ultrasonic synergy enzymatic method could be regarded as the optimal method for extracting BDPs.This study could lay a certain foundation for the development and utilization of BDPs.

This study investigated the comparative effects of refrigerated storage at 4 ℃ and simulated transport storage conditions (0-4 days) on the physicochemical properties of myofibrillar proteins (MPs) isolated from Litopenaeus vannamei (LV) and Parapenaeopsis hardwickii (PH).Significant differences (P<0.05) in the denaturation extent of MPs between the two shrimp species were observed through analysis of total sulfhydryl content, carbonyl content, surface hydrophobicity, particle size, secondary and tertiary structures, and SDS-PAGE.Results demonstrated that during the 4-day storage period, both LV and PH MPs exhibited significant increases in surface hydrophobicity and carbonyl content, accompanied by a decrease in total sulfhydryl content.Particle size, C—H peak intensity, and intrinsic fluorescence intensity displayed a consistent trend of initial increase followed by subsequent decrease.SDS-PAGE analysis revealed the fading of actin bands and the emergence of new bands by day 4 under simulated transport conditions, indicating MP degradation and aggregation.Overall, simulated transport storage conditions exerted more deleterious effects on MPs than those at 4 ℃ refrigeration, with LV demonstrating significantly higher MPs stability than PH (P<0.05).This study elucidates the extent of molecular damage in MPs from both shrimp species under distinct storage environments, providing theoretical support for developing tailored cold storage technologies for LV and PH.

The popularity of meat analogue has surged significantly in recent years, primarily due to the increasing awareness of the adverse environmental effects of meat production and the escalating demand on protein for the rapidly growing world population.Textured soybean protein (TSP) has shown promising potential in meat analogues due to its fibrous structure, which is similar to animal meat.In this study, 100, 200, and 600 kDa oat β-glucan (OG)were added into TSP, aiming to investigate the effects of OG of different molecular weights on the textural and sensory properties of TSP.Texture profile analysis (TPA) and sensory evaluation were conducted to comprehensively evaluate the quality of TSP.Meanwhile, a texture evaluation model was established by principal component analysis (PCA) on TPA for a concise result.Results revealed that the two principal components extracted from TPA could be renamed as chewing characteristics (F1) and compression resistance characteristics (F2), respectively, which possessed a cumulative variance contribution rate reaching 80.008%.The comprehensive score (F) for TSP-OG60-1, TSP-OG60-2, and TSP-OG20-1 groups was higher than that of the control group, among which TSP-OG60-2 had the highest score, while TSP-OG10-1 and TSP-OG20-2 groups showed decreased scores.This suggested that 200 and 600 kDa OG could improve the textural properties of TSP, while the addition of 100 kDa could damage the internal fibrous structure of TSP.Results of sensory evaluation showed consistency with TPA, that 200 and 600 kDa OG could make the internal fibers of TSP full and distinct, thus resulting in a better hardness and chewiness;while 100 kDa OG would undermine the internal fiber structure, causing an undesirable mouthfeel.Generally, this study designed and developed textural and sensory evaluation methods specifically for TSP, demonstrating that OG can effectively enhance both the textural and sensory properties of TSP.

To investigate the effects of pre-harvest chitosan oligosaccharide (COS) treatment on the quality of wine, Cabernet Franc grapes were used as the test material, and chitosan oligosaccharides were sprayed during the swelling and veraison stages.The ripening grape fruits were harvested and brewed, and physical and chemical indicators, aroma substances, and sensory quality of the wine were analyzed.Results showed that the alcohol content, total acidity, total phenols, and tannin content of the treatment group increased significantly, with the most significant improvement observed in the veraison period treatment group.Chitosan oligosaccharide application to grape increased the content and variety of aroma substances of the final wine beverages.Among them, the swelling stage treatment showed the highest content of C₆/C₉, branched chain, aromatic, and isoprene substances, while the veraison stage treatment showed the highest content of terpene substances.The comprehensive analysis of aroma substances indicated a strong correlation of the treated group with phenethyl alcohol, lauric acid, β-ionone, ethyl heptanoate,trans-2-hexenal, and dodecyl aldehyde, while the control group exhibited correlation with 1-pentanol, 2-ethyl-1-hexanol, and ethyl nonanoate.Fifteen aroma compounds, including (E)-6,10-dimethyl-5,9-undecadien-2-one, ethyl laurate, and cis-3,7-dimethyl-2,6-octadienol, etc., were recognized to distinguish different treatments of wine samples.Sensory evaluation showed that the organoleptic quality of wine samples treated with chitosan oligosaccharides was higher than that of the control group, with the highest score in the swelling treatment group.This experiment could provide a theoretical basis for improving wine quality by pre-harvest chitosan oligosaccharide spraying on grapes.

This study employed high internal phase emulsion (HIPEs) curing technology to construct a novel lipid coating system, achieving physical anchoring of lipids through intermolecular forces.Taking surimi products as the research object, the effects of different HIPEs coatings on their quality characteristics during air frying were systematically evaluated to clarify their applicability as coatings and provide a theoretical basis and technical support for the development of high-quality, low-fat fried foods.By adjusting the ratio of ultrasonically treated casein-cellulose nanocrystals (U-CA-CNC, abbreviated as UCC) stabilizer (0.25∶1, 0.5∶1, 1∶1) and its composite system with 10 g/L grape seed extract (GSE) (abbreviated as UCCG), HIPEs coatings with different viscoelasticities were prepared and applied to air-fried surimi slices.Results showed that in terms of color, UCC(0.5∶1) and UCCG(0.5∶1) samples presented a uniform golden yellow.When the CA∶CNC ratio was no higher than 0.5, the hardness and chewiness of UCC/UCCG coatings were the closest to the oil-fried control group.UCC/UCCG coatings with a CA∶CNC ratio of no less than 0.5 significantly reduced the degree of lipid oxidation, and the free radical scavenging rate increased in a gradient manner with the increase of the CA ratio.Moreover, UCCG coatings showed a stronger scavenging effect due to the intervention of GSE.In terms of inhibiting harmful substances, UCCG(1∶1) coating, benefiting from the dense interface film formed by the high CA ratio and the synergistic effect of antioxidant activity of GSE, had the lowest total heterocyclic amine content.Overall, UCCG(0.5∶1) coating, with its appropriate rheological properties, optimized the color and texture characteristics of air-fried surimi products and exhibited excellent antioxidant and harmful substance inhibition effects.

Holoferritin is rich in iron and is considered as an excellent potential iron supplementation factor.However, its preparation process has problems, such as a complicated process and a high loss rate.This study optimized and established a process for the efficient preparation of holoferritin based on the system of microbial cell biosynthesis of holoferritin induced by the iron ion coercion, and explored the effect of this process on the structure and properties of holoferritin.The results of agarose gel electrophoresis, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and native polyacrylamide gel electrophoresis showed that 0.005% nuclease treatment could effectively remove the host nucleic acid residues, and the combination of heat treatment and ammonium sulfate precipitation treatment could efficiently produce high-purity holoferritin.Holoferritin was characterized by UV spectroscopy, circular dichroism, Fourier transform infrared spectroscopy, Malvern particle sizing, transmission electron microscopy, etc.It was found that the purification process maintained the natural ferritin nanocage-iron core intact conformation and the typical α-helical secondary structure of holoferritin.In addition, this process could shorten the protein purification cycle from 72 hours to 48 hours on the premise of ensuring the structural integrity of holoferritin, which provides reliable technical support for the large-scale production of holoferritin and its application in biomedicine, food, and other fields.

This study aimed to develop high-protein liquid formulations suitable for elderly individuals with dysphagia by investigating the effects of pectin from different sources-sugar beet pectin, citrus pectin, and apple pectin-on the physicochemical, rheological, and dysphagia-related properties of whey protein isolate (WPI)-pectin complexes.The particle size distribution, zeta potential, microstructure, secondary structure of proteins, rheological behavior, and international dysphagia diet standardisation initiative (IDDSI) classification were systematically evaluated.Results showed that the incorporation of pectin significantly inhibited protein aggregation and reduced the average particle size of the complexes, with citrus pectin yielding the smallest particle size.Fourier-transform infrared spectroscopy (FTIR) revealed that pectin enhanced intermolecular hydrogen bonding and mitigated protein aggregation through structural stabilization.Rheological analysis demonstrated that pectin significantly decreased the apparent viscosity of WPI-pectin systems.Among the three pectins tested, sugar beet pectin exhibited the lowest consistency coefficient (8.02 Pa·sⁿ), representing an 89.55% reduction compared to the pure WPI sample (P<0.05).Additionally, both the storage modulus (G′) and loss modulus (G″) of the complexes were significantly reduced upon pectin addition (P<0.05).IDDSI testing indicated that the pure WPI sample was classified as level 4 (pasty), exhibiting residual lumps after spoon tilt.In contrast, all pectin-containing complexes were categorized as level 3, forming a smooth, uniform film on the spoon after dripping, thereby demonstrating improved suitability for individuals with dysphagia.These findings provide a scientific basis for the formulation of texture-modified, high-protein functional foods tailored for dysphagia management.

Soy sauce, a traditional fermented condiment made from soybeans, originated in Asia and is now widely consumed around the world.To enhance its safety and quality, this study explored the use of three halotolerant microbial strains, applied individually or in combination with glutaminase, during fermentation.The effects of enzyme-microbe coupling on soy sauce quality were evaluated by analysis of physicochemical indicators, free amino acids (FAA), biogenic amines (BAs) levels, and flavor characteristics.Enzyme- microbe coupling fermentation groups reached amino acid nitrogen levels exceeding 0.8 g/100 mL, meeting the standard for premium-grade soy sauce.Additionally, volatile base nitrogen remained below 150 mg/100 mL.Notably, the group co-fermented with all three strains and glutaminase showed a 47.36% increase in free amino acids compared to the naturally fermented control.Among the strains tested, Tetragenococcus halophilus C17 was most effective in suppressing BAs formation.When combined with Zygosaccharomyces rouxii L1 and glutaminase, total BAs content decreased by 33.31 mg/kg compared to natural fermentation.Furthermore, enzyme-microbe coupling fermentation enriched favorable flavor compounds while reducing off-flavor volatiles such as cyclohexanone and 1-penten-3-ol.This study provides a theoretical basis for using the enzyme-microbe coupling strategy to inhibit BAs accumulation and improve the overall flavor quality in soy sauce.

This study aimed to explore the improvement mechanism of persimmon proanthocyanidins (PPAs) on Caco-2 cell damage induced by lipopolysaccharide (LPS).Caco-2 cells were incubated with LPS and treated with different concentrations of PPAs.The changes in cell permeability were evaluated using lactate dehydrogenase (LDH) and alkaline phosphatase (AKP) kits, while the levels of oxidative stress were assessed using superoxide dismutase (SOD), malondialdehyde (MDA), and NO kits.Cell apoptosis was also evaluated, and the expression of genes in the EGFR-ERK1/2-NF-κB signalling pathway and the tight junction protein ZO-1 was detected by real-time RT-PCR and immunofluorescence techniques, respectively.Results showed that PPAs significantly (P<0.05) reduced the leakage of LDH and AKP in a dose-dependent manner.After the intervention of PPAs, the activity of SOD was enhanced and the levels of MDA and NO notably decreased (P<0.05).The apoptosis rate was decreased to 4.13% at a concentration of 45 μg/mL.Additionally, PPAs inhibited the expression of the EGFR-ERK1/2-NF-κB signalling pathway at the transcriptional level, and upregulated the expression of ZO-1 protein, thus enhancing the integrity of the tight junction.This study demonstrated that PPAs effectively alleviated LPS-induced intestinal epithelial cell damage by regulating oxidative stress homeostasis and the EGFR signalling pathway, and provided a theoretical basis for revealing the regulated mechanism of proanthocyanidins on intestinal barrier damage.

To improve the stability of rice bran polysaccharide (RBP) and increase its utilization as a biocarrier, RBP and Zein composite nanoparticles (Z-R NPs) were prepared in this study by antisolvent precipitation.The intermolecular interactions were analyzed by fluorescence spectroscopy and Fourier infrared spectroscopy, while the microscopic morphology, crystal structure, and thermal stability of nanoparticles were evaluated by scanning electron microscopy, X-ray diffraction, and thermogravimetry.Additionally, the interfacial adsorption properties, including emulsification, foaming, and surface hydrophobicity of the composite nanoparticles, were determined.The results showed that the stable dispersion of composite nanoparticles was better when the mass ratio of Zein to RBP was 2∶1, and the average particle size of the particles was (125.26±1.88) nm, accompanied by the potential of (-16.05±1.91) mV.SEM results showed that the composite nanoparticles of Z-R NPs exhibited a small and uniform hollow spherical core-shell structure because the nanoparticles were attracted to each other via electrostatic attraction, hydrogen bonds, and hydrophobic interaction.The combination of zein and RBPs resulted in higher thermal stability, denser crystal structure, and excellent emulsification properties of composite nanoparticles.This study was conducive to improving the added value of rice bran as well as providing a theoretical basis for the development of RBPs as delivery carriers and encapsulated wall materials.

In this study, three apple cultivars (‘Fuji’, ‘Qincui’, and ‘Ruixue’) were used as raw materials to analyze their injury symptoms under high CO₂ storage conditions and change patterns of the physicochemical properties, such as sugars and acids, volatile compounds, antioxidant related enzyme activities.The results showed that the incidence rates of CO₂ injury in ‘Fuji’, ‘Qincui’, and ‘Ruixue’ apple was 1.0%, 45.00% and 12.50%, respectively, under the condition of 0 ℃, 15 kPa CO₂ after 15 d storage.The main symptom of ‘Qincui’ apple was flesh browning, whereas ‘Ruixue’ showed peel browning.After CO₂ treatment, the peel and flesh in all three apple cultivars displayed a decrease in L^* values, while an increase in a^* and b^* values.Moreover, the high concentration of CO₂ treatment significantly (P<0.05) inhibited the increase of soluble solid content and the decrease of total acid content in all three apple cultivars.Analysis of volatile aroma components indicated that esters were the main component in ‘Fuji’ apple, accounting for 60.70%, whereas aldehydes (2-hexenal) were the main component in ‘Qincui’ and ‘Ruixue’ apple, accounting for 41.50% and 50.90%, respectively.High concentration of CO₂ treatment increased the esters content and decreased the aldehydes content in ‘Qincui’ and ‘Ruixue’ apple.In addition, CO₂ treatment promoted the increase of total phenol and DPPH free radical scavenging rate in ‘Fuji’ and ‘Qincui’ apples in the early stage of storage, but inhibited the changes in the later stage of storage.High concentration of CO₂ treatment also significantly (P<0.05) inhibited the activities of PPO, CAT, SOD, APX, and GR of ‘Fuji’ and ‘Qincui’ apple, but increased the PPO activity of ‘Ruixue’ apple.In conclusion, CO₂ interfered with the antioxidant system of apples by influencing antioxidant enzymes and phenolic substances, thus affecting the sugar and acid quality and fruit flavor.This study provides a reference for further research on CO₂ tolerance mechanisms of new apple cultivars.

In the present study, a variety of Suijing 18 rice was used as raw material, moderately milled rice (MMR) with bran degrees of 2.2%, 3.6%, and 6.9% was then prepared, respectively.This study evaluated the physicochemical properties of MMR, including appearance, germ retention rate, and nutrients, as well as its edible qualities, such as cooking characteristics and sensory evaluation, with brown rice and polished rice serving as control groups.Results indicated that an optimal balance between physicochemical characteristics and edible quality was exhibited under a 3.6% bran degree of MMR, and its remained germ rate was significantly higher than that of polished rice, and broken rice rate was lower than that of polished rice (P<0.05).Under 3.6% of bran degree, its contents of protein, fat, dietary fiber, and vitamin B₁ were significantly higher than those of polished rice (P<0.05), while there was no significant difference between starch content and soup pH (P>0.05).On the basis of cooking analysis, water absorption rate, volumetric expansion rate, and soup solids of MMR with a 3.6% bran degree were intermediate between brown and polished rice, which were consistent with the trends of texture property and sensory evaluation.Among the three types of samples, MMR with a 3.6% bran degree exhibited the best edible quality.These findings provide theoretical references for practical applications in milled rice production, offering valuable insights for improving the product quality of MMR.

With the accelerating aging of the population, the demand for food thickeners among dysphagia patients has become increasingly urgent.This study investigated the konjac glucomannan (KGM) and hyaluronan (HA) composite gel system through rheological tests, gel permeation chromatography, and IDDSI framework assessment to systematically analyze the entanglement characteristics, rheological behavior, and swallowing safety of KGM-HA gels with different ratios.The aim was to provide theoretical support for developing safe and stable food thickeners for dysphagia patients.Results indicated that the ratio of KGM to HA significantly affected the micro-network structure of the sol system.When the KGM∶HA ratio was 8∶2, the sol system exhibited the maximum storage modulus, highest zero-shear viscosity, and demonstrated optimal elastic properties with a more compact network structure.Additionally, the sol displayed stable viscosity under dynamic shear conditions with no thixotropy observed, making it suitable for long-term swallowing care.Through IDDSI framework evaluation tests, all KGM-HA sol formulations met the Level 3 liquid food standard, characterized by moderate fluidity and uniform texture, thereby reducing aspiration risks.This study provides valuable insights for developing specialized food thickeners for patients with dysphagia.

To investigate the flavor characteristics and microbial community composition of Kazak cheese from Xinjiang, this study analyzed the volatile compounds and microbial community of the cheese by determining its proximate composition, organic acids, and free amino acid content, combined with headspace solid-phase microextraction-gas chromatography-mass spectrometry methodology and high-throughput sequencing technology.Results indicated that Kazak cheese was an acidic semi-hard cheese with high protein content (53.15%) and low-fat content (13.74%).The cheese contained eight organic acids, predominantly lactic acid (70.03%) and acetic acid (7.55%), as well as 16 free amino acids, among which essential amino acids accounted for 37.76%.Through volatile component analysis, a total of 89 volatile compounds were identified, with 21 of them (relative odor activity value ≥1) determined as key aroma compounds.Seven common key aroma compounds were found in Kazak cheese from different regions, including nonanal, trans-2-nonenal, trans-2-decenal, 2-nonanone, D-limonene, ethyl octanoate, and ethyl decanoate.Microbial community analysis revealed Lactobacillus, Streptococcus, and Lactococcus as the dominant bacterial genera, with Dipodascaceae, Issatchenkia, and Saccharomyces as the shared dominant fungal genera.Spearman correlation analysis showed that Achromobacter, Lactococcus, and Streptococcus were significantly positively correlated with aroma compounds such as 1-heptanol, heptanal, and ethyl heptanoate, while the dominant fungal genera were closely related to aroma compounds in the categories of alcohols, ketones, esters, and terpenes.This study provides a theoretical basis for improving the flavor quality of Kazak cheese from Xinjiang.

Canned tomato is rich in nutrition, and it is easy to be contaminated by microorganisms in the production process.To realize the identification, analysis and traceability of dominant bacteria in the process of tomato canned production, the abundance, diversity, and species differences of the operational taxa, the changes of bacterial community structure, and the differences of key species in the samples were analyzed comprehensively in this study by genomic DNA extraction from 50 samples collected at different times and at different production stages, 16S rRNA amplicon sequencing using the MGISEK-2000 high-throughput platform.Isolation and identification were performed by pure culture combined with polyphase identification techniques to determine the taxonomic status of the strains.The dominant bacteria and their source were identified by retro-inoculation assay and random amplified polymorphic DNA (RAPD) analysis.Results showed that a total of 19 756 operational taxa were recorded from 50 samples.The diversity of bacterial community structure increased with the continuous production process, and Weissella sp.played a key role in the whole production process.150 strains of bacteria were obtained by pure culture technique, among which Weissella cibaria was the dominant bacteria, accounting for 11.33%.The retro-inoculation experiment and random amplification polymorphism analysis showed that Weissella cibaria was the dominant bacteria causing bulging and spoilage of canned tomato, and it was distributed in the whole production process.

This study investigated optimization strategies for bio-inspired high-temperature Daqu production by comparing conventional rice straw (Group C) with alternative insulation materials (Group A).Physicochemical properties, microbial dynamics, and flavor evolution were systematically characterized during fermentation.Group A demonstrated superior moisture retention capacity, with middle/lower layers reaching peak temperatures and cooling phases more rapidly than Group C.Volatile profiling revealed distinct temporal patterns, including acetic acid, caproic acid, and 1-heptanol peaked at day 7, whereas 3-octanol, 3-octanone, and phenylethyl alcohol accumulated progressively to maximum levels by fermentation endpoint.Microbial community analysis showed comparable richness/diversity indices but distinct taxonomic compositions.Initial dominance by Puccinia transitioned to Aspergillus, Paecilomyces, and Rasamsonia during turning stages.Proteus were displaced by Thermoactinomyces (Group C) and Weissella (Group A) during mid-fermentation.Terminal fermentation layers exhibited dominance by Scopulibacillus (Group C upper layer) and Lentibacillus (Group A all layers/Group C lower layer).Key ester-producing genera Scopulibacillus, Scytalidium, and Alternaria were identified as critical contributors to aroma development.These findings validate the feasibility of alternative insulation materials in high-temperature Daqu production, providing mechanistic insights into microbial succession and flavor biosynthesis for process optimization.

The application of Staphylococcus carnosus in meat fermentation can effectively improve the flavor and color of the product.To prepare a highly active starter culture, the culture conditions and fermentation tank process of S.carnosus were optimized through single-factor experiments to increase the number of viable bacteria, and a bacterial growth kinetic model was constructed using a nonlinear autoregressive (NAR) neural network.It is further necessary to use vacuum freeze-drying technology to prepare the starter and determine the optimal pre-freezing temperature of the strain through a single-factor test.To evaluate the freeze-drying damage of the strain, the cell membrane integrity, fluidity, and Na⁺/K⁺-ATPase activity changes were measured, and the three-dimensional structure of the bacteria was observed by scanning electron microscopy, so that the corresponding freeze-drying protective agent could be used to reduce damage.Results indicated that the optimal culture conditions were 1% inoculation, an initial pH of 7.5, and a temperature range of 35-40 ℃, under which the viable count reached 2.53×10⁹ CFU/mL.The optimal process conditions for the fermenter included a rotation speed of 400 r/min, with ammonia water used as a neutralizer to maintain pH 7.5.Under these conditions, the viable count increased to 7.56×10¹⁰ CFU/mL, which was 40 times greater than that observed before optimization.The bacterial growth dynamics model constructed by the NAR neural network could accurately predict the bacterial proliferation trend.In addition, the single factor experiment showed that the survival rate of freeze-dried culture medium at -80 ℃ was 19.9%, and the Na⁺/K⁺-ATPase activity was reduced by 77%.Results from laser confocal microscopy and fluorescence polarization revealed significant damage to both the integrity and fluidity of the cell membrane.Additionally, scanning electron microscopy demonstrated that the three-dimensional structure of the bacteria was compromised.After confirming the freeze-drying damage, preliminary analysis suggested that potential freeze-drying protective agents included skim milk, trehalose, and mannitol.In summary, this study successfully achieved high-density cultivation of S.carnosus, which provides a reference for enhancing the freeze-drying survival rate of this bacterium and establishes a theoretical foundation for the subsequent preparation of fermentation agents.

To develop intervention or mitigating factors for non-alcoholic fatty liver disease (NAFLD) of natural origin and with low toxicity and side effects, this study prepared pea oligopeptides by enzymatic hydrolysis and tested the 3-hydroxy-3-methylglutaryl monocoenzyme A (HMG-CoA) reductase inhibitory activity of pea oligopeptides and in vitro NAFLD mitigating effect and mitigating mechanism.Results showed that the inhibition rate of 100 mg/mL oligopeptide was 56.62%.At 800 μg/mL, pea oligopeptides could reduce intracellular lipid deposition significantly, and the intracellular triglyceride and total cholesterol contents were also significantly reduced in the NAFLD model assay constructed in HepG2 cells.Western blot assay shows that pea oligopeptides inhibit acetyl-CoA carboxylase (ACC)activity and sterol-regu-latory element binding protein 2 expression by activating adenosine 5′-monophosphate (AMP)-activated protein kinase(AMPK) phosphorylation, further up-regulation of carnitine acyl transferase I expression, and down-regulation of 3-hydroxy-3-methylglutaryl-CoA reductase expression. These enhance the β-oxidation of fatty acids and attenuate the cholesterol synthesis pathway. These results ultimately reduced intracellular lipid accumulation.

To improve the quality of peanut oil body ice cream, the peanut oil body was prepared into oleogels and compounded with a small amount of hydrogenated palm kernel oil and coconut oil as fat sources to add to ice cream, and the effect on the texture characteristics of ice cream and the mechanism of quality were explored compared with milk fat ice cream.Results showed that different concentrations of oleogels could enhance the melting resistance and hardness of peanut oil body ice cream, but the expansion rate was not significantly improved, which was about 20% different from that of milk fat ice cream.To improve the expansion rate of peanut oil body ice cream, the method of compounding peanut oil body with a small amount of vegetable oils needed to be further studied.With the decrease in the proportion of peanut oil body, the expansion rate and melting resistance of ice cream increased, and the hardness decreased.Finally, the mechanism of ice cream emulsion on the quality of ice cream was studied.It was found that the viscosity and stability of the ice cream emulsion compounded with peanut oil body were the highest, and the interface protein content was closest to milk fat ice cream.When the mass ratio of peanut oil body to hydrogenated palm kernel oil to coconut oil was 6∶3∶1, the expansion rate of ice cream was 49.57%, the melting rate was 20.97%, and the hardness was 6.61 N.The properties of emulsion and ice cream were more balanced with the control group, and peanut oil ice cream with better quality could be obtained.

To analyze the effect of adding Cistanche deserticola powder on cake quality by measuring the specific gravity, nutritional components, texture, DPPH free radical scavenging capacity, Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD), the effect of adding C.deserticola powder on the aging ability of cakes during storage was analyzed.The effects of cistanche powder on cake quality and the aging ability of cake during the storage period were analyzed.Results showed that the hardness of C.deserticola cake was close to (66.13±1.8) g, the chewability was increased by 7.75%, and the cohesion was increased by 0.58%.The batter proportion was 0.472 g/cm³, slightly higher than that of ordinary cake.The DPPH free radical clearance rate of C.deserticola cake was 43.52%, which was 2.69 times that of ordinary cake.After being stored at 4 ℃ for 7 days, the hardness and chewiness of both cakes significantly increased (P<0.05), and the hardness and chewiness of the Cistanche deserticola cake were higher, while the enthalpy value and crystallinity of C.deserticola cake decreased by 3.41% and 7.95% compared with those of the ordinary cake.It is concluded that the addition of C.deserticola powder can effectively improve the quality of the cake and delay the aging of the cake.

To explore the effect of lotus seed powder on the rheological properties of wheat dough and the quality properties of fresh wet noodles, different amounts of lotus seed powder were added to wheat flour.The effects of lotus seed powder addition on the rheological properties of wheat dough and the cooking properties, texture properties, sensory properties, thermodynamic properties, starch short-range order structure, and protein secondary structure of fresh wet noodles were analyzed.Results showed that with the increase of lotus seed powder addition, the peak viscosity, final viscosity, attenuation value, and retrogradation value of the mixed powder decreased gradually.The storage modulus and loss modulus of lotus seed-wheat dough gradually increased with the increase of addition amount.The hardness, chewiness, and tensile properties of lotus seed-wheat fresh wet noodles increased gradually.In addition, the sensory properties showed that when the addition amount of lotus seed powder was 20 %, the edible quality of lotus seed fresh wet noodles was the best, and the comprehensive score was the highest.The results of Fourier transform infrared spectroscopy (FTIR) and thermodynamic properties showed that the overall stability of protein secondary structure in fresh wet noodles gradually increased with the increase of lotus seed powder addition.The short-range ordered structure and thermal stability of starch in fresh wet noodles were significantly enhanced (P<0.05).In summary, the addition of lotus seed powder to wheat flour can improve the rheological properties of wheat dough and the edible quality of fresh wet noodles.

To maximize the value utilization of broken rice, the main by-product produced in the rice processing process, japonica broken rice was used as raw material, and different mass fractions (0%, 0.1%, 0.2%, 0.3%, and 0.4%) of xanthan gum (XG) and different rice-to-water ratios (80∶100, 85∶100, 90∶100, 95∶100, 100∶100) were used to observe the rheological properties, printing formability, accuracy, and stability of the samples.Meanwhile, during the 3D printing process, different filling densities (60%, 70%, 80%, 90%, 100%), different printing speeds (10, 15, 20, 25, 30 mm/s) and different nozzle aperture sizes (0.60, 0.84, 1.20, 1.55, 2.00 mm) were used to observe the formability, accuracy, and stability of printed rice products.In addition, the texture, microstructure, and thermodynamic analysis of the printed rice products were carried out.The experimental results showed that the addition of XG and the increase of rice-water ratio could increase the G′ and G″ of the sample, and the sample had obvious elastic behavior, which was conducive to the shape stability of 3D printed rice products.When the mass fraction of XG was 0.2%, the rice-water ratio was 100∶100, the filling density was 90%, the printing speed was 20 mm/s, and the nozzle aperture was 0.84 mm, the printing formability, accuracy, and stability of rice products were the best.At the same time, the raw material ratio and printing parameters affected the texture and microstructure of the printed rice products, but had no obvious effect on the thermodynamic properties.The results of this study can provide a reference for the preparation and application of 3D printed rice products.

To investigate the high added-value of Morchella polysaccharides and elucidate their anti-aging mechanisms, this study evaluated the effects of feeding Caenorhabditis elegans with different concentrations of Morchella polysaccharides lifespan, body length, motor ability, reproductive capacity, stress resistance, activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX), contents of malondialdehyde (MDA) and reactive oxygen species (ROS), and oxidative stress survival rates in four gene-deficient strains, including DA1116 (eat-2), CF1903 (glp-1), CB1876 (clk-1), and CB1370 (daf-2).Results showed that compared with the blank control, Morchella polysaccharides significantly prolonged the average lifespan of C.elegans by up to 15.86%.On day 14, category C motor activity in Morchella polysaccharides-treated groups was reduced by 25.36% at maximum, while egg-laying capacity showed no significant changes.Body length exhibited no differences during the growth stage, but at day 14.25 mg/mL and 12.5 mg/mL Morchella polysaccharides significantly decreased body length by 5.2% and 6.6% (P<0.05), respectively.The 12.5 mg/mL Morchella polysaccharides group showed significantly enhanced heat stress resistance.Notably, treatment with Morchella polysaccharides reduced the oxidative stress survival rate of the insulin signalling-deficient strain CB1370 (daf-2), suggesting a potential role in insulin-like signalling pathways.Biochemical analyses revealed that Morchella polysaccharides modulated antioxidant enzyme activities (T-SOD, GSH-PX) and reduced ROS/MDA levels in a concentration-dependent manner, indicating their scavenging effects on reactive oxygen species.Genetic studies further demonstrated that the anti-aging effects of Morchella polysaccharides were partially mediated through pathways related to aging, such as food intake DA1116 (eat-2), germline development CF1903 (glp-1), mitochondrial function CB1876 (clk-1), and insulin signalling CB1370 (daf-2).Collectively, these findings highlight the significant anti-aging potential of Morchella polysaccharides in C.elegans, providing a mechanistic foundation for further research and development of Morchella polysaccharide-based functional foods or nutraceuticals targeting aging-related diseases.

To investigate the impact of acid reducing fermentation on the quality and flavor of sea buckthorn juice, Pichia terricola WJL-M4 was inoculated into the juice.High-performance liquid chromatography (HPLC), sensory evaluation, electronic nose, and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) were employed to analyze the changes in organic acids, sensory scores, and flavor before and after fermentation.Additionally, the key aroma compounds were identified by calculating the odor activity values (OAV).Results indicated that after acid reducing fermentation, the malic acid degradation rate reached (85.37±0.67)%, significantly improving the sensory score and reducing the sourness of the juice.Electronic nose analysis revealed that the aroma of the fermented sea buckthorn juice was more intense.A total of 109 volatile compounds were detected in both the pre- and post-fermentation samples, primarily composed of esters and alcohols.Through OAV analysis, 19 key aroma compounds (OAV > 1) were identified.Ethyl hexanoate and benzyl alcohol were found to contribute floral and fruity notes to the fermented sea buckthorn juice.Furthermore, the fermentation process effectively removed undesirable odors, such as isovaleric acid, pentanoic acid, and benzaldehyde, eliminating the sour and bitter almond-like smells.This acid reducing fermentation using Pichia terricola WJL-M4 significantly enhanced the sensory and flavor quality of sea buckthorn juice, providing a theoretical basis and technical support for the deep processing of sea buckthorn.

This study aimed to establish a rapid detection method for Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus using multiplex nested polymerase chain reaction (PCR) combined with capillary electrophoresis.Targeting the uidA gene of E.coli (β-glucuronidase), the hilA gene of S.typhimurium (virulence gene), and the nuc gene of S.aureus (thermostable nuclease gene), three pairs of nested primers were designed for two rounds of amplification.The PCR products were analyzed by capillary electrophoresis, and the annealing temperatures for the two rounds of nested PCR were optimized to establish a multiplex nested PCR-capillary electrophoresis detection method for the three foodborne pathogens.The three pairs of nested primers showed high specificity, with optimal annealing temperatures of 54 ℃ and 56 ℃ for the two rounds.The detection sensitivity reached 10¹ copies for E.coli and S.aureus, and 10³ copies for S.typhimurium.This method is rapid, accurate, and highly sensitive, making it suitable for detecting these three foodborne pathogens in food samples from which DNA can be extracted, thereby providing a new approach for foodborne pathogen detection.

In response to the issues of narrow antibacterial spectrum, insufficient biological safety and poor environmental stability of antimicrobial peptides in food preservation applications, this study adopted a molecular hybridization strategy to hybridize Cecropin A (1-8) with Aurein 1.2 (6-13), and through amino acid substitution optimization, successfully constructed a novel hybrid antimicrobial peptide CA16-L.Subsequently, the antibacterial activity, biocompatibility, and stability of CA16-L were systematically evaluated, and its mechanism of action and preservative performance were deeply explored.Results showed that the cell selectivity index (SI_all) of CA16-L was 59.26, and it exhibited a strong killing effect on common foodborne pathogenic bacteria.Even under different salt ion, high temperature, and extreme pH conditions, CA16-L can still maintained strong antibacterial activity.Mechanism studies indicated that CA16-L exerted antibacterial effects by disrupting bacterial cell membranes and interfering with DNA replication, effectively reducing the risk of drug resistance.The fresh pork preservation model confirmed that CA16-L could effectively inhibit the growth of Staphylococcus aureus ATCC29213, extend the shelf life of meat products, and had good preservative performance.This study provides a new idea for the development of efficient and safe food preservatives and is of great significance for promoting the sustainable development of the food industry.

As a geographical indication product, the quality characteristics of Koktiyerek grapes are closely related to their production environment.To achieve rapid, non-destructive quality evaluation and geographical indication protection, this study utilised hyperspectral imaging technology to develop a multi-task analysis method for predicting the quality of Koketireke grapes and identifying geographical indication products.The study collected hyperspectral data in the 400-1 000 nm from grape samples in the Koketireke geographical indication production area and surrounding non-geographical indication production areas in Xinjiang.Spectral preprocessing was performed using methods such as filtering and smoothing, first-order derivatives, second-order derivatives, baseline calibration, standard normalisation, and multi-spectral scattering correction to optimise data quality.Partial least squares regression was used to select the optimal preprocessing method and construct quality prediction models for soluble solids content (SSC) and total acidity (TA).Among these, baseline correction (BSL) preprocessing yielded the best results.The test set R-square (R²) for the SSC quality prediction model was 0.890 2, with a root mean square error (RMSE) of 0.689 8%, and the test set R² for the TA quality prediction model was 0.768 9, with a RMSE of 0.105 0%.For the task of identifying geographical indication products, partial least squares discriminant analysis was used to construct a geographical indication product identification model.The model with Savitzky-Golay smoothing (SG) pre-processing performed best, with R²_X=0.987, R²_Y=0.825, and a model prediction index (Q²) of 0.810, ultimately achieving a discrimination accuracy rate of 95%.This study combined chemometric models with hyperspectral imaging technology to simultaneously achieve quality prediction and geographical indication identification for Koktiyerk grapes, providing an active technical solution for the protection of agricultural product geographical indications and non-destructive quality detection of fruits.

To explore the effects of cell-free supernatant (CFS) from Latilactobacillus sakei of Tibetan sheep on the transcription and metabolism of Staphylococcus aureus, RNA-Seq and LC-MS/MS sequencing were used on the co-culture treatment group of CFS-S.aureus and the control group, and correlation analysis was performed on the transcriptome and non-targeted metabolome.Results showed 1 109 differentially expressed genes and 1 685 differentially expressed metabolites were identified in the treatment group.CFS was involved in regulating the expression of related genes in S.aureus, including fatty acid metabolism (fabF, fabI), amino acid metabolism (leuB, ilvC), sugar metabolism (sucA, sucB), and energy metabolism (qoxA, qtpB).Non-targeted metabolome analysis showed that key differentially expressed metabolites, such as amino acids, steroids, and steroid derivatives, were enriched in pathways such as organic acid and its derivatives metabolism, TCA cycle, and nucleotide metabolism.The correlation analysis of transcriptome and non-targeted metabolome indicated that differentially expressed genes, such as qoxA, and differentially expressed metabolites, such as succinic acid, were co-enriched in 24 biochemical and signal transduction pathways.In conclusion, L.sakei CFS can inhibit the growth of S.aureus by down-regulating key genes involved in protein synthesis, key rate-limiting enzymes in the TCA cycle, and the synthesis pathways of multiple metabolites such as arginine.

The study addressed the issue of high malic acid content, sour and astringent taste, and low market acceptance of ‘Shenqiuhong’ sea buckthorn pulp.Schizosaccharomyces pombe strain was screened for targeted degradation of malic acid based on acid reduction capacity and rate, optimizing the acid-reducing fermentation process, and investigating the impact of S.pombe biological acid reduction on the quality of sea buckthorn pulp.Results showed that the strain SP1757 exhibited the strongest acid-reducing ability, achieving a malic acid degradation rate of 68.90% under the conditions of 6% inoculum and 5 days of fermentation at 27 ℃.Compared to the control (sea buckthorn pulp), the deacidified samples showed reductions in total phenols, total flavonoids, reducing sugars, and titratable acids by 9.60%, 7.62%, 75.32%, and 49.55%, respectively (P<0.05), while the total carotenoid content increased by 19.92%.Sensory evaluation and correlation analysis indicated that the sour, bitter, and astringent tastes of the deacidified samples were significantly improved.Titratable acid content showed a significant positive correlation with astringency, bitterness, and overall acceptability (P<0.05).In conclusion, S.pombe fermentation effectively targeted the degradation of malic acid in sea buckthorn pulp, improving its sour and astringent taste while effectively maintaining the nutritional properties and aligning with the demand of modern consumers for sugar reduction in beverages.These findings provide a scientific basis and reference for the research, development and production of sea buckthorn beverages with low sugar content and good palatability.

Phellinus igniarius polysaccharides have antioxidant and anti-aging activity, but their activity varies depending on the extraction method.To study the anti-aging ability of P.igniarius polysaccharides extracted by different methods, in this study, Drosophila melanogaster was used as the model and randomly divided into male and female blank control group A, enzymatic polysaccharide group B, microwave polysaccharide group C, and ultrasound combined cellulase polysaccharide group D.The anti-aging of polysaccharides was evaluated by determining indicators such as superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (T-AOC), and malondialdehyde (MDA) content in the D.melanogaster tissues, as well as the average lifespan, half of death time, and maximum lifespan of the D.melanogaster.Results showed that at the experimental concentration, polysaccharides in groups B, C, and D could significantly increase the activities of SOD and CAT in D.melanogaster, enhance T-AOC, reduce the content of MDA, and prolong the lifespan of D.melanogaster (P<0.01).Among them, group D had the best effect.Among the female D.melanogaster, the activities of SOD and CAT and T-AOC in group D increased by 12.68%, 87.32%, and 108.12% respectively compared with group A, the content of MDA decreased by 39.71%, and the three lifespan indicators increased by 18.09%, 19.30%, and 10.27% respectively.Among the male D.melanogaster, the activities of SOD and CAT and T-AOC in group D increased by 23.46%, 49.7%, and 59.64% respectively compared with group A, the MDA content decreased by 41.04%, and the three lifespan indicators increased by 16.42%, 14.00%, and 7.19% respectively.The polysaccharides from P.igniarius obtained by the three extraction methods all have the effects of an antioxidant and delaying the aging of D.melanogaster. The ultrasound-combined cellulase method is a better extraction method.This study provides a theoretical basis for the development of P.igniarius polysaccharides.

The formation of food-borne advanced glycation end-products (AGEs) is closely related to the thermal processing conditions of food.In this study, fresh Lycium barbarum was dried at different hot-air temperatures (40, 50, 60 ℃) to explore the formation regularity of AGEs in L.barbarum during the drying process.A total of eight AGEs were identified in L.barbarum by targeted metabolomics.Nε- (carboxymethyl) lysine (CML), Nε- (carboxyethyl) lysine (CEL), N6-threonyl, N6-oxalyl, and N6-lactyl are lysine-derived AGEs.Nε- (carboxymethyl) arginine (CMA), Nε- (carboxyethyl) arginine (CEA), and methylglyoxal-hydroimidazolones (MG-H1) are arginine-derived AGEs.Therefore, the content of lysine-derived AGEs in L.barbarum was higher than that of arginine-derived AGEs.Results showed that during the drying process with different hot-air temperatures, AGEs in L.barbarum showed a general trend of first increasing and then decreasing.Both drying temperature and drying time affected the formation of AGEs, but drying temperature had a greater effect on their production.In addition, changes in the levels of amino acids, vitamins, carbohydrates and fatty acids in L.barbarum were correlated with the levels of AGEs, in which lysine and arginine were involved in the formation of AGEs as precursors of AGEs, whereas the vitamins (vitamin B₆, vitamin B₁, and niacinamide) and saturated fatty acids had an inhibitory effect on the formation of AGEs, and samples with a high content of carbohydrates had higher levels of AGEs, and the degree of unsaturation of unsaturated fatty acids was also positively correlated with the level of AGEs.This study elucidates the formation regularity of AGEs during the drying process of L.barbarum and the connection between AGEs and changes in bioactive components.

To broaden the application range of sheep tail oil, multi-stage dry fractionation technology with step-by-step temperature reduction was adopted to classify sheep tail oil into five different melting point fractions, namely, 35S, 30S, 25S, 20S, and 20L.The study analyzed the peroxide value, iodine value, acid value, fatty acid composition, thermodynamic properties, crystalline properties, and rheological properties of each component and applied the results in shortening bread production.Results showed that the physicochemical properties of the components were in accordance with the requirements of the national standard, among which the 35S component had the highest saturated fatty acid content (49.69%), the 20 L component had the highest unsaturated fatty acid content (57.45%), and the initial melting temperatures of the components were the highest at 46.6 ℃ and the lowest at 23.2 ℃.The high melting point fractions showed β′ crystal type with higher crystal content and higher viscosity.The specific volume, textural properties, and moisture content of the bread with 35S as the shortening were better than those of the commercially available lard-based shortening bread.This study provides a basis for the application of tail oil of lamb in food processing.

This study aimed to extend the shelf life of tuna fillets using composite coatings based on chitosan (CS) and sodium carboxymethyl cellulose (CMC), each supplemented with various concentrations of Floccularia luteovirens polysaccharides (FLPs), to maintain quality during storage.The effects of FLPs-based composite coatings at different concentrations on the quality of tuna fillets during storage were investigated.Quality indicators, which included drip loss rate, total bacterial count, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), lipid oxidation, and sensory deterioration, were measured to assess the preservation effect of the coatings.Compared with the CS and CMC control groups, the composite coatings significantly reduced drip loss, lipid oxidation, and sensory deterioration (P<0.05).After 10 days of storage, the CS-8 mg/L FLPs coating group exhibited enhanced sensory acceptance and showed reductions of 22.49% in total bacterial count, 4.39% in drip loss, 14.62 mg/100 g in TVB-N, and 0.46 mg MDA/kg in TBARS compared with the control.This coating formulation effectively delayed quality deterioration, with the CS-8 mg/L FLPs group demonstrating the best preservation effect, extending the refrigerated shelf life of tuna fillets by four days.This study provides new insights into the preservation of refrigerated tuna fillets and establishes a theoretical basis for the development and application of FLPs in food preservation.

To investigate the effects of heat treatment on pumpkin seed protein isolate (PSPI), the changes in function and structural properties of PSPI under conditions of 80, 90, 100, and 120 ℃ for 20 and 40 min were investigated, respectively.Results showed that appropriate heat treatment significantly improved the solubility, emulsifying activity, emulsifying stability, and foam ability of PSPI (P<0.05).These three functional characteristics showed highest value at 90 ℃(40 min), 80 ℃(40 min), 100 ℃(20 min), and 90 ℃(40 min) (P<0.05), which increased by 39.00%, 118.75%, 88.29%, and 27.67%, respectively.In terms of structural characteristics, appropriate heat treatment not only disrupted the block-like structure of PSPI proteins but also increased the particle size of soluble protein aggregates.Additionally, heat treatment reduced the surface hydrophobicity and increased the intrinsic fluorescence intensity of PSPI, possibly due to the refolding and aggregation of protein molecules.Overall, this study systematically analyzed the impact of heat modification on the structure and functional properties of pumpkin seed protein, revealing the potential of heat treatment in improving the functional properties of pumpkin seed protein and providing theoretical support for its processing and application.

This study aimed to enhance the quality of Rosa sertata×Rosa rugosa leaf tea and optimise the utilisation of its by-products.Utilising Rosa sertata×Rosa rugosa leaf tea from Huzhu county, Haidong city, Qinghai province as the raw material, this study investigated the impact of Eurotium cristatum fermentation on tea quality through three distinct fermentation methods, including unfermented, naturally fermented, and artificially inoculated with Eurotium cristatum.Results demonstrated that compared with the other two treatment groups, concentrations of polyphenols, total catechins, epigallocatechin gallate, epigallocatechin, theaflavin, free amino acids, sucrose, glucose, and fructose decreased significantly.The respective reductions were 10.51%, 70.69%, 61.85%, 89.29%, 52.57%, 9.71%, 78.65%, 56.04%, and 87.55%.Epicatechin gallate was detected across all treatments.Conversely, total flavonoids, catechin, epicatechin, and theabrownin increased significantly by 29.17%, 79.04%, 24.58%, and 83.48%, respectively.Compared with unfermented and naturally fermented Rosa sertata×Rosa rugosa leaf tea, Eurotium cristatum fermented tea exhibited enhanced DPPH free radical scavenging capacity (1.11%), ABTS cationic radical scavenging capacity (2.77%), and hydroxyl radical scavenging capacity (20.25%).Concurrently, it elevated theaflavin and catechin levels.This provides a theoretical foundation for optimising the fermentation process of Rosa sertata×Rosa rugosa leaf tea.

To explore the effects of steaming on the changes in the aroma characteristics of Chenpi and steamed Chenpi, electronic nose and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) techniques, combined with Pearson correlation analysis and relative odor activity value (ROAV) method, were employed to analyze the characteristic aroma components of Chenpi before and after steaming.Electronic nose results revealed distinct odor differences between Chenpi and steamed Chenpi, six characteristic sensors showed discriminative responses.GC-MS identified 23 and 21 volatile components in Chenpi and steamed Chenpi, respectively.Steaming reduced total compound diversity while altering chemical profiles, alcohol content decreases, terpene content increases, and sesquiterpene variety expands.Fourteen volatile compounds were screened out as the differential components before and after steaming of Chenpi, and they had a good correlation with the characteristic sensors.ROAV analysis showed that certain alcohols and phenols (such as linalool, α-terpineol, thymol, and other alcohols and phenols), and terpenes (such as α-farnesene, β-elemene, and other terpenes) were the main material basis for distinguishing the odor differences between Chenpi and steamed Chenpi, and also were the key aroma components.Linalool contributed the most to Chenpi’s aroma, while D-limonene contributed the most to the aroma of steamed Chenpi.After steaming, the decrease in alcohols like linalool was linked to the weakening of strong floral and spicy aromas in Chenpi.Terpenes gave steamed Chenpi light citrus and woody aromas.This study analyzed the changes in aroma characteristics of Chenpi before and after steaming, which can provide a scientific basis for the quality evaluation and application of Chenpi and steamed Chenpi.

In order to investigate the changes in quality and flavor of mint fried pork ribs during refrigeration, color difference, pH, centrifugal loss rate, total colony count, thiobarbituric acid value (TBA), acid value (AV), and peroxide value (POV) were systematically measured at 4 ℃ over 0, 2, 4, 6, and 8 days.Additionally, volatile flavor compounds were analyzed using an electronic nose, electronic tongue, and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS).A multidimensional aroma quality evaluation model was established to identify key flavor substances based on their relative odor activity values (ROAV), and orthogonal partial least squares-discriminant analysis (OPLS-DA) was employed for comprehensive flavor profiling.The results indicated that sensory attributes and overall quality declined with prolonged refrigeration time, with noticeable sensory deterioration starting from day 6.Water loss and lipid oxidation increased significantly during storage.Both electronic nose and electronic tongue technologies effectively distinguished flavor and taste differences across different storage periods.GC-MS analysis identified a total of 64 volatile compounds, with 35, 36, 39, 32, and 37 detected at 0, 2, 4, 6, and 8 days, respectively.Hydrocarbons, alcohols, and aldehydes were the dominant volatile components, showing peak concentrations on days 2 and 4.Through OPLS-DA, variable importance in projection analysis, and ROAV screening, 14 key flavor compounds were identified, L-carvone, DL-carvone, trans-caryophyllene, β-cocone, junine, (E)-3,7-dimethyl-2,6-octadienal, (+)-limonene, eucalyptol, camphene, α-pinene, β-paraponene, 3-carene, (Z)-dihydrocarvone, and 2-epi-trans-β-caryophyllene, all of which contribute positively to the flavor profile.This study provides valuable theoretical support for the development of related ready-to-eat or prefabricated food products.

L-Serine is an important non-essential amino acid with significant physiological functions, which has been widely applied in the food, cosmetics, and pharmaceutical industries.Microbial fermentation offers advantages such as environmental friendliness, mild reaction conditions, and renewable substrates, making it an ideal method for L-serine production and attracting considerable research interest.During the screening and engineering of L-serine-producing strains, it is necessary to evaluate a large number of microbial variants, which requires extensive L-serine analysis and detection.However, current detection methods for L-serine suffer from limitations such as low sensitivity, poor accuracy, and complicated procedures, which severely restrict the efficiency of high-throughput and rapid assessment of L-serine samples. To address these challenges, this study developed a simple, rapid, and highly specific detection method for L-serine based on the catalytic characteristics of L-serine-3-dehydrogenase.By exploring and analyzing the enzymatic properties of L-serine-3-dehydrogenase, an optimized enzymatic detection system for L-serine was established.This system consisted of 50 mmol/L sodium carbonate-sodium bicarbonate buffer (pH=9.5), 3 mmol/L NADP⁺, and AFSerDH enzyme at a concentration of 2 U/mL, with an optimal detection temperature of 40 ℃.The developed enzymatic detection method was characterized by its simplicity, rapid operation, and high detection efficiency.It demonstrated a good linear relationship within the L-serine concentration range of 1-10 mmol/L, with an R² value of 0.996 5.This enzyme-based detection method enables high-throughput detection and evaluation of L-serine samples, providing crucial technical support for the efficient screening of industrial L-serine-producing strains.

This paper aims to establish a rapid quantitative detection method for intact inactivated bacterial cells in postbiotic samples using flow cytometry with the fluorescent dyes SYTO 9 and propidium iodide (PI), enhancing the quality control technology of postbiotic products.First, different proportions of live and inactivated probiotic suspensions were prepared and counted via flow cytometry.The detected proportions were consistent with the added proportions, with linear regression coefficients of 0.997 9 and 0.996 3 for live and inactivated bacteria, respectively.Therefore, the reliability of the flow cytometry-based method was verified.A flow cytometry assay was performed on 14 strains of probiotics and compared with the traditional plate counting method.Results indicated that the live bacterial counts obtained by both methods and the inactivated bacterial counts detected by flow cytometry were highly consistent (R²=0.995 5, 0.994 3, 0.990 2), which verified the feasibility of flow cytometry for quantifying inactivated bacterial cells.Subsequently, suspensions of inactivated bacteria mixed with postbiotic sample solutions in various proportions were subjected to flow cytometry detection.The detection proportions of inactivated bacteria to postbiotic samples exhibited a strong linear correlation with the added sample proportions (R²=0.995 1), validating the feasibility of this method for quantitative detection of inactivated bacterial cells in postbiotic samples.This method was then used to count inactivated bacterial cells in eight commercial postbiotic products, with flow cytometry detection values closely aligning with the labelled values of the products.In conclusion, this study has successfully developed a rapid and reliable quantitative detection technology for intact inactivated bacterial cells in postbiotic samples, which is of great significance for the healthy development of the postbiotic industry.

To develop a visual, sensitive, and specific method for the determination of Escherichia coli O157:H7 in food, the rfbE gene, specific to the O157:H7 serotype, was selected as the target sequence.A circular probe was designed to recognize target sequences.After DNA binding, the circular probe was circularized by ligation and then hybridize with capture probes.Capture probes act as primers to initiate rolling circle amplification (RCA) catalyzed by Phi29 DNA polymerase, generating a long single-stranded DNA (ssDNA).SYBR Green Ⅱ binding to the ssDNA resulted in significantly enhanced fluorescence, with signal intensity proportional to the ssDNA concentration.This enabled real-time quantitative monitoring in laboratory settings, while on-site qualitative detection was achieved through visual fluorescence under UV light.The method demonstrated a wide linear detection range (5×10^-3 to 5×10^-1 ng/μL) for genomic DNA.The detection limits were 7.5×10^-3 ng/μL (visual mode) and 5.048×10^-3 ng/μL (real-time fluorescence mode).Excellent specificity was confirmed by the absence of cross-reactivity with non-O157:H7 E.coli strains or other bacterial species.The potential application of the method was verified by analyzing spiked food samples.The developed dual-mode detection system offers significant advantages for rapid, sensitive, and specific detection in food safety monitoring.

Foodborne bacterial infections threaten global public health.Bacteria can enter a viable but nonculturable (VBNC) state when exposed to unfavorable environments.In this state, VBNC bacteria may retain pathogenicity and antimicrobial resistance, and can resuscitate under specific conditions, which poses a risk to food safety and disease transmission.This article focuses on the causes and hazards of foodborne pathogenic bacteria in the VBNC state, reviewing the influencing factors, resuscitation mechanism, and physiological characteristics of VBNC bacteria after resuscitation.This review summarizes the factors influencing resuscitation, including physical factors, chemical factors, and biological factors.The resuscitation mechanisms are divided into active resuscitation (quorum sensing, resuscitation-promoting factor) and passive resuscitation (supplementing nutrients, adding antioxidants, co-culturing with host cells).After resuscitation, the morphology, structure, metabolic function, growth ability, virulence, and resistance of the bacteria are almost restored to normal levels.

Plant essential oils are important secondary metabolites with complex chemical compositions, including various compound types such as terpenoids, aromatic compounds, aliphatic compounds, and nitrogen/sulfur-containing compounds.These bioactive compounds possess antimicrobial, antioxidant, and insecticidal effects, making them widely applied in food preservation, healthcare, and cosmetics.In the field of food preservation, plant essential oils are widely used for the preservation of various types of foods such as fruits, vegetables, meat products, dairy products, and agricultural products.Studies have shown that active chemical components in essential oils like cinnamon essential oil, rosemary essential oil, and peppermint essential oil can significantly inhibit common foodborne pathogens by destroying the structure of microbial cell membrane, interfering with energy metabolism and damaging DNA.However, strong volatility, intense odor, and food safety concerns of plant essential oils have also limited their application.The collaborative use of effective delivery systems can significantly enhance the stability of plant essential oils and reduce their impact on the sensory characteristics of foods.This review systematically summarizes the research progress on the application of plant essential oils in food preservation, introduces the latest research advancements in this field, and aims to provide references for the further promotion and application of plant essential oils in the food preservation industry.

Non-Saccharomyces yeasts are crucial functional microorganisms in wine fermentation processes, which directly influence the fermentation rate through various metabolic activities.Non-Saccharomyces yeasts significantly enhance wine quality characteristics in different ways, including the secretion of aromatic compounds, the regulation of glycerol content, and the reduction of ethanol concentration.Moreover, most of these enological characteristics are species and strain-dependent.Therefore, the discrimination of different non-Saccharomyces yeasts is a step of primary importance to their biotechnological application.However, current molecular identification and typing tools for differentiating these yeasts have been rarely reported, and a thorough comparison and evaluation of these methods is still lacking.Therefore, this study systematically reviews the main molecular techniques of species identification and strain differentiation of non-Saccharomyces yeasts.The principles, procedures, advantages, and limitations of various technologies, and the latest research advances in this field, were summarized and reviewed.This review aimed to offer both theoretical foundations and technical references for researchers and industry professionals in selecting appropriate identification and typing methodologies.

Starch gel is a rigid structure formed by gelatinization and retrogradation of starch, and the quality of end product is determined by its physicochemical properties.However, the application of native starch gel in food processing is limited due to its low gel strength and rapid retrogradation during storage.To enhance the gel structure and functional properties of starch, polysaccharides, as a safe and efficient native additive, have been extensively investigated for modifying starch.The addition of polysaccharides can not only reinforce the gel strength and increase the content of resistant starch, but also effectively retard starch retrogradation, thereby extending the shelf life of starch gel products.In this paper, the effect of polysaccharides on the texture properties, digestion properties, and storage stability of starch gels was summarized, and the underlying mechanism of interaction was explored.Meanwhile, the applications of polysaccharides in starch-based gel foods, such as vermicelli, rice noodles, Liangpi, and Liangfen were discussed.This review provides theoretical support and technical references for the quality improvement and functional enhancement of starch-based gel products.

Whole wheat steamed bread is rich in dietary fiber, B vitamins, and phenolic acid bioactive ingredients, which have significant efficacy in regulating intestinal flora and reducing the risk of chronic diseases.However, insoluble dietary fiber (IDF) in bran interferes with the binding of starch to the gluten network through physical barrier effect, while phytic acid reduces the bioaccessibility of minerals and other minerals through chelating effect, which leads to poor palatability and low nutrient utilization of the product.In recent years, based on enzyme regulation, microbial traditional fermentation and germination, and other biotechnological means, directional degradation of phytic acid, reconfiguration of the physicochemical properties of IDF, and through the regulation of gluten protein crosslinking network to enhance the rheological characteristics of the dough and fermentation ability, thereby improving the texture and nutritional quality of whole wheat steamed bread.This review provides a comprehensive overview of the regulatory mechanisms of enzymatic hydrolysis technology, fermentation technology, and germination technology on the processing adaptability of whole wheat dough and the sensory characteristics of the final product, and clarifies their effects on improving the nutritional quality and sensory characteristics of whole wheat steamed bread.With the growth of the demand for precise nutrition, the application prospects of biomodification technology in the processing of whole wheat staple foods are broad.This study provides a theoretical basis and technical path for the development of whole wheat steamed bread with both high nutrition and excellent quality.

Food safety issues represent a global challenge.Among these, foodborne diseases caused by pathogenic bacteria occur frequently and have garnered significant attention from public health and food safety authorities worldwide.Rapid and accurate detection of foodborne pathogens is considered the most effective strategy to prevent outbreaks of foodborne diseases.However, traditional detection methods are time-consuming and heavily reliant on substantial human and material resources, highlighting the need for more sensitive and specific approaches for detecting foodborne pathogens.Nanomaterials, with their advantages of rapid response, high sensitivity, low cost, and ease of use, have drawn extensive interest in rapid pathogen detection.Therefore, the characteristics of several commonly used nanomaterials and their specific application in the foodborne pathogens are reviewed, and the development directions of nanoparticles in the foodborne pathogens field are discussed.

Sauce-flavor Daqu plays multiple roles in Baijiu brewing including saccharification, fermentation, and aroma generation, with its quality primarily relying on the synergistic effects of complex microbial communities.However, the traditional open Daqu-making process leads to insufficient functional stability, which restricts the quality improvement of sauce-flavor Baijiu.In recent years, targeted enhancement of functional microorganisms to improve Daqu characteristics has become a research hotspot.This paper systematically reviews the diversity composition of functional microorganisms in sauce-flavor Daqu, the preparation techniques for fortified Daqu, and their application effects.It also discusses the current limitations of fortification, aiming to provide theoretical support and technical references for the standardized production of sauce-flavor Daqu and the upgrading of the Baijiu industry.