6-α-glucosyltransferase has catalytic activities of exo-hydrolysis towards α-1,4-glucan and transglycosylation, and can produce the α-glucan which links α-1,6 glycosidic bonds on the nonreducing end through transglycosylation activity.Therefore, it can be used to produce cyclic alternating sugars and their branched derivatives, as well as cycloisomaltooligosaccharide, which can be used as new functional sugar.To expand the application of 6-α-glucosyltransferase in the food industry, the 6-α-glucosyltransferase from Bacillus globisporus N75 was expressed heterologously in the food safety strain Bacillus subtilis, and the expression level of recombinant protein increased by selecting the host strain and optimizing fermentation condition.These results indicated that the host WHS9 was more beneficial for the recombinant expression of 6-α-glucosyltransferase and the total soluble enzyme activity could achieve 2.11 U/mL at 20 ℃, including intracellular and extracellular.After adding 20 mmol/L trehalose, the total enzyme activity could reach 2.21 U/mL at 25 ℃ for 48 h.Then the fermentation period was optimized, and it was found that the highest enzyme activity could reach 3.14 U/mL at 36 h, which was 196 times higher than in WHS9 before optimization.This study firstly achieves recombinant expression of 6-α-glucosyltransferase in B.subtilis.

To effectively solve the problem that the cream top of milk tea is easy to combine with the tea broth quickly within a short period after production, this paper used corn starch as the film-forming matrix, citric acid as the cross-linking agent, and zein nanoparticles (ZNP) as the hydrophobicity enhancer, to prepare a kind of citric acid-ZNP composite thin film with good water-blocking properties and mechanical properties.The structure of the composite film was characterized by Fourier infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and X-ray diffraction to explore the physical parameters of the film, such as mechanical, water resistance, and optical properties.In addition, the water resistance test of the composite films under different tea broths (Jasmine green tea, Four Seasons Spring, Dahongpao, and Ceylon black tea), different temperatures (4 ℃, 37 ℃, and 45 ℃), and different retention time (0.5, 1.0, 1.5, 2, 4, 24 h) was explored, and the application of the composite films in milk tea creamer tops was verified.Results showed that starch could be used as an excellent carrier for ZNP, and the composite films had good thermal stability, mechanical properties, and barrier properties.Among them, the tensile strength reached 4.35 MPa, the elongation at break reached 44.21%, and the water vapor permeability was 3.07×10^-12 g·cm/(cm²·s·Pa).In the application verification of different tea bases, the water solubility was highest in Dahongpao tea broth, and the composite film reached the lowest value of water solubility and dissolution at 1.5 h.The milk tea with ZNP-citric acid starch composite film was placed at 60 min before the cream started to fuse with the tea base.In summary, the ZNP-citric acid composite film can effectively preserve milk tea with a cream topping, which tends to collapse in a short period of time, thereby preventing the problem of rapid mixing with the tea broth.This film can serve as a novel, food-specific material.

‘Cuixiang’ kiwifruit are usually hard when purchased and need to be stored to soften before they can be eaten.However, kiwifruit are respiratory leaps that are prone to concentrated ripening, and the uncontrollable evolution of kiwifruit fruit quality during home storage can lead to a poor consumer experience and a reduced desire to buy.In this paper, the evolution of fruit quality of ‘Cuixiang’ kiwifruit under home storage conditions was systematically analyzed based on the dimensions of physicochemical characteristics, organoleptic quality, and aroma characteristics.In terms of physicochemical characteristics, titratable acid content and hardness of kiwifruit decreased significantly during home storage, while the content of total soluble solids, sugar-acid ratio, and weight loss tended to increase significantly.Based on the correlation of the above indexes, hardness was chosen to establish a zero-level kinetic shelf-life prediction model, and the model had good accuracy and reliability.Meanwhile, the artificial sensory evaluation showed that, except for the appearance score, which continued to decrease during the storage period, the scores of other sensory indexes, such as color, aroma, taste, texture, etc., increased significantly and peaked on the 11th day.Therefore, the total artificial sensory scores of ‘Cuixiang’ kiwifruit were the highest on the 11th day of home storage, which was the most suitable for consumption at this time.Gas chromatography-mass spectrometry was used to evaluate the aroma profile of kiwifruit, and a total of 513 volatile organic compounds were detected, with ester concentrations accounting for the highest percentage of kiwifruit samples at different stages of home storage, and terpenes showing the highest percentage of species.On the 1st day and the 7th day, the volatiles were more abundant and the aroma was more complex, with the highest content of aldehydes and a prominent herbaceous note.On the 11th day, the proportion of esters in the total volatiles was significantly higher than that on the 1st day and the 7th day, and the fruity and sweet flavors were more intense.

Euglena gracilis polysaccharide (EGP), as a new natural functional food, has attracted more and more attention.This study investigated the extraction yield, structural characterization, and in vitro antioxidant activity of EGP.The extraction yield EGP was optimized with ultrasonic-alkali extraction by Plackett-Burman and response surface design.The molecular weight, monosaccharide composition, group composition, microstructure, and antioxidant activity of EGP were analyzed using gel permeation chromatography (GPC), ion chromatography (IC), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and free radical scavenging tests.The optimum process conditions were as follows:the liquid-to-material ratio of 1∶40 (g∶mL), water bath temperature of 41 ℃, water bath time of 0.9 h, NaOH solution concentration of 1 mol/L, ultrasonic power of 120 W, and ultrasonic time of 3 min.Under these conditions, the extraction yield was (62.84±0.49)%.Results indicated that EGP was composed of 100% glucose and connected by β-glycosidic bonds, and the molecular weight were 2.13×10⁴ Da.Antioxidant experiments demonstrated that EGP showed good antioxidant activity against ·OH, DPPH free radicals, ABTS cationic radicals, and ·O^-₂.The structural study of EGP provides a scientific theoretical basis for the continued development and utilization of Euglena gracilis.

The oily by-product is produced after extracting curcumin from turmeric, which is rich in functional active ingredients and has broad application prospects in food and drug fields.The main components of oily by-product after curcumin extraction (OBP) and the antioxidant activities were analyzed, and the stability of the main components was also investigated.The results of composition analysis showed that the total contents of three curcumin compounds and volatile components in OBP were 28.90% and 23.9% of OBP, respectively, with demethoxycurcumin (12.28%) > demethoxycurcumin (8.52%) > curcumin (8.12%).The main volatile characteristic components were α-curcumene, β-sequisilene, ar-turmerone, turmerone, β-turmerone, and atlantone.During OBP storage, it was found that curcumin compounds in the OBP were stable but the loss of main volatile components was up to 73.44%.Stability experiments showed that high temperature, light, alkaline environment, and oxidized metal ions all caused the loss of curcumin compounds.Especially in the presence of light and at pH=10, the loss rate of curcumin was 57.80% and 57.99%.The stability of curcumin compounds under different conditions was as follows:Dimethoxycurcumin > desmethoxycurcumin > curcumin.The antioxidant activity of OBP increased with its concentration, in which OBP could effectively scavenge free radicals and reduce iron ions.This study provides a theoretical basis for the further development and utilization of OBP in food and drug fields.

In the pursuit of developing high-quality preservation-enhancing composite films, this study introduced Ginkgo biloba leaf extract (GBLE) as a preservative in chitosan/polyvinyl alcohol (CS/PVA) films.The investigation aimed to explore the impact of varied levels of Ginkgo biloba leaf extract addition (2%, 6%, and 10%) on film performance and its application in preserving chilled beef.Results indicated that Ginkgo biloba leaf extract significantly enhanced the tensile strength, opacity, and antioxidant activity of the composite films (P<0.05), while significantly reducing its elongation at break and water vapor permeability (P<0.05).In a preservation experiment over 12 days, compared to the control group, the GBLE-CS/PVA composite films exhibited higher sensory scores for chilled beef, effectively delayed the rise in pH value, total bacterial count, volatile basic nitrogen content, and thiobarbituric acid reactive substances.Therefore, the GBLE-CS/PVA composite films have shown promising applications in the storage and preservation of chilled beef.

The combination of meal and wine has always been one of people’s pursuits for a better life.The academic community’s interest in the study of meal and wine pairing is rapidly growing, but there is still a lack of scientific empirical evidence.For the first time, this study adopted a within-subjects design and used correlation analysis, ANOVA and other methods to explore consumer preferences for taste and Baijiu pairings.Results showed that four typical Baijiu (elegant-flavor Baijiu, chi-flavor Baijiu, strong-flavor Baijiu, and sauce-flavor Baijiu) could significantly weaken sweet and sour taste.In addition, strong-flavor Baijiu could weaken bitter taste, while sauce-flavor Baijiu could weaken umami taste.Consumer preferences for different types of Baijiu and taste pairings were significantly different, and preferences were significantly related to taste intensity changes, purchase intention, and recommendation.Four types of Baijiu had the highest preference for pairing with a sour taste, but there were differences in other tastes suitable for different types of Baijiu.In addition to the sour taste, the combinations of chi-flavor Baijiu and elegant-flavor Baijiu with sweet and salty taste were more satisfactory, while strong-flavor Baijiu and sauce-flavor Baijiu were more suitable for sweet and umami taste.In this study, a taste solution was used to induce a basic taste experience and to explore the matching preference between it and different types of Baijiu, which laid the foundation for further research on meal and wine pairing.

As an important component of hemoglobin, heme is a porphyrin derivative which involved in the transport and combination of oxygen and other metabolic pathways.In this study, a Pichia pastoris strain with high heme productivity was used as the starting strain. The fermentation conditions were optimized to enhance the heme production in a 5 L fermenter, from the factors of pH, ferrous ion concentration, temperature, and dissolved oxygen level.Then the growth kinetics and production kinetics of the optimal fermentation condition were simulated.It was determined that controlling pH at 4 was the most favorable for heme production.The daily addition of 2 mL of FeSO₄·7H₂O solution (100 mg/L) adequately could satisfy the ferrous ion requirements for heme production, resulting in a heme production of 160.1 mg/L.The strategy of reducing temperature to enhance expression levels employed in the methanol supplementation fermentation process did not obtain the anticipated outcome in the glycerol supplementation fermentation process.Conversely, it resulted in a decline in heme production.In addition, by comparing different dissolved oxygen levels, it was found that increasing dissolved oxygen had no obvious effect on the accumulation of heme, but could effectively improve the cell growth.Finally, result of kinetic model fitting presented that the accumulation of heme was coupled with the cell growth.The obtained results could serve as references for the industrial fermentation production of heme.

The function of fish protein gel is strongly influenced by pH.Under different pH conditions (9.0-4.0), the physical properties, moisture state, and structure characteristics of heat-induced gelation of myofibrillar proteins (MP) from mandarin fish (Siniperca chuatsi) have been studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), low-field nuclear magnetic resonance (LF-NMR), Raman spectroscopy, scanning electron microscope (SEM), and other technologies, focusing on indicators such as gel strength, texture, and sulfhydryl group content.Results showed that pH had a significant effect on the properties of the fish protein gel.With the decrease of pH value, the strength and texture of MP gel of mandarin fish firstly increased and then decreased, reached the maximum value at pH 5.0, and the properties of heat-induced MP gel achieved the best at the same time.SDS-PAGE results showed that myofibril protein and actin were degraded when pH was decreased from 5.0 to 4.0, but the surface of MP gel at pH 6.0 was smoother and more uniform from the gel appearance diagram.The secondary structure results showed that the polypeptide chains of MP were hindered from unfolding and transforming by the acidic enhancement when pH was lowered from 7.0 to 4.0, thus the MP gel matrix gradually turned into a disordered structure during the formation of gel.The structure tended to be ordered at pH 6.0, forming a detailed structure with porous and uniform pore size.The hydrophobic interaction and thiol content reached maximum at pH 6.0 as well.In conclusion, the state of heat-induced MP gel achieved the best at pH 6.0.Therefore, the MP gel of mandarin fish has great potential to the development of functional fish products.

As an alternative of traditional mercury lamps, LED deep ultraviolet lamps have a wide application prospect in the food sterilization field.Firstly, by taking took Escherichia coli as the experimental object, an appropriate combination scheme of deep ultraviolet lamp was explored.Secondly, using the combination of LED deep ultraviolet lamp to sterilize E.coli, Staphylococcus aureus and Pseudomonas aeruginosa with different duration of deep ultraviolet light, the effect of deep ultraviolet irradiation time on the bactericide rate of different pathogenic bacteria was studied.Finally, the effect of LED deep ultraviolet radiation on strawberry preservation was explored by regular investigation of their bad fruit rate, decay index, weight loss rate and sensory changes.In the study, it was found that the sterilizing effect was best when there were three LED deep ultraviolet lamps on the top and the side of the plate, and the bactericide rate increased with the extension of irradiation time.The sensitivity to LED deep ultraviolet light showed:S.aureus<P.aeruginosa<E.coli.After strawberries were picked, LED deep ultraviolet treatment for a proper duration had a good effect on disease control and quality assurance.In addition, LED deep ultraviolet treatment and sealed refrigeration had a synergistic effect on improving strawberry freshness preservation effect.

During the storage and processing of lily bulbs, the phenomenon of the violet-red color change of the scales often occurs.To investigate the effect of temperature on the violet-red color change of fresh-cut lily bulb scales, Lilium davidii var.unicolor bulb scales were stored at different temperatures (4, 20, 35 ℃), and the surface color, total phenolic content, total anthocyanin content, the activities of anthocyanin synthesis-related enzymes, polyphenol oxidase (PPO), and peroxidase (POD) were determined.Results indicated that higher temperatures increased the total phenolic content of lily bulb scales during storage.In the middle of the storage period, temperature promoted the activity of polyphenol oxidase (PPO) and peroxidase (POD), leading to an increase in the browning degree of lily bulb scales and a decrease in surface quality.At the same time, higher temperatures promoted the activity of anthocyanin synthesis-related enzymes, such as phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), dihydroflavonol reductase (DFR), and anthocyanin synthase (ANS), and a storage temperature of 20 ℃ could significantly increase the accumulation of anthocyanins in lily scales, but it was not enough to cause a violet-red color on the surface of lily bulb scales.Overall, the temperature is not the main factor affecting the violet-red color change of fresh-cut lily bulb scales.

To enhance the high-temperature resistance of fermentation strains for simultaneous saccharification and fermentation, this study utilized Kluyveromyces marxianus GX-UN120, a strain known for its high ethanol yield, as the starting point.The atmospheric and room temperature plasma (ARTP) mutagenesis technology was employed to obtain a mutant strain, GX-UN127, which exhibited robust high-temperature resistance and ethanol production capabilities.This was achieved through a screening test for high-temperature resistance and subsequent rescreening for high-temperature growth ability.The findings of this study revealed that after 72 hours of cultivation at 48 ℃, the OD₆₀₀ of GX-UN127 reached 1.27.Moreover, when using 100 g/L bran as the raw material, the ethanol yield reached 7.6 g/L after 12 h of simultaneous saccharification and fermentation at 45 ℃.This represented a 15.2% increase compared to the parent strain building upon these results, the study further investigated the physiological mechanism underlying the high-temperature tolerance of the mutant strain.By combining physiological indicators and metabolomics, it was determined that the metabolism of arginine and proline, as well as cysteine and methionine, were associated with the high-temperature tolerance of GX-UN127.Additionally, glycerophospholipid metabolism, glutathione metabolism, and other metabolic pathways were found to be closely related to the enhanced high-temperature tolerance observed in the mutant strain.Overall, this research demonstrates the feasibility of breeding high-temperature resistant Kluyveromyces marxianus strains through mutation.The findings provide valuable theoretical support for the simultaneous saccharification and fermentation of this strain for ethanol production.

Soy protein isolate (SPI) and rice flour (RF) were mixed in an appropriate proportion and then heated in the water bath to prepare SPI-RF composite gel.SPI 100% was used as the control to investigate the effects of different concentrations of RF on the gel properties, the gelatinization mechanisms of SPI-RF composite gel was revealed.Results showed that the water holding capacity and viscosity coefficient of the composite gel were higher than those of the control sample (P<0.05).The hardness, elasticity, viscosity, and chewiness of the gel raised initially and then reduced (P<0.05) as the amount of RF increased.The water holding capacity, hardness, elasticity, adhesiveness, and chewiness of SPI-RF 40% gel reached the maximum values, which were 87.33%, 1 739.491 g, 0.230, 1 104.656, and 1 084.008, respectively.Molecular docking indicated that the main interaction force of protein-starch in the gel were the hydrogen bond and hydrophobic interaction.The microstructure was examined by atomic force microscopy (AFM), the single chain, multiple chains, and chain aggregates were showed.Obviously, the addition of RF improved significantly the gel properties of SPI, that would be potential for application in plant-based products.

Proteases are considered as clean alternatives to replace chemicals to use in the leather dehairing process to avoid serious pollution. This study aimed to optimize the condition for protease production by Bacillus amyloliquefaciens BS5582 strain, to characterize the enzymatic properties and to evaluate its application in cattle hide dehairing.Results showed that the optimal enzyme production media by BS5582 strain were corn powder 50.0 g/L, soybean powder 40.0 g/L, Na₂HPO₄·12H₂O 6.0 g/L, KH₂PO₄ 3.0 g/L, MgSO₄ 1.8 g/L, and CaCl₂ 0.75 g/L, with the initial pH 6.The optimal fermentation condition was as follows:The fermentation temperature was 35 ℃, the inoculation volume was 10%, and the loading volume was 15 mL.Under this condition, the crude enzyme activity of the enzyme solution reached (5 270.59±19.61) U/mL, which was 21 folds higher than that before optimization.The optimum temperature and pH of the proteases produced by the BS5582 strain were 40 ℃ and 8.5, respectively.Mn²⁺ had a significant activation effect on protease activity while Fe²⁺, Fe³⁺, and PMSF significantly inhibited the enzyme activity.The protease showed good cattle skin hair removal ability with little collagen damage.Compared with traditional chemical dehairing, the application of proteases had no hair root remaining in the pores of cattle skin with the falling of intact hairs.The pollution indexes of the dehairing wastewater, such as total suspended solids, chemical oxygen demand, and five-day biochemical oxygen demand, were reduced by 87%, 39%, and 45%, respectively.This indicated that the proteases produced by B.amyloliquefaciens BS5582 were of great potential for application in the leather industry.

This study aimed to investigate the effects of amino acid categories and their additive amounts on the quality characteristics of yak minced meat products and to obtain the optimal amino acid categories and additive amounts that can improve the quality of yak minced meat products.In this paper, the edible quality, emulsification characteristics, rheology, and microstructure of yak minced meat were measured and analyzed by using yak minced meat with different ratios of L-lysine (Lys), L-arginine (Arg), and L-histidine (His).Results showed that 0.60% of Lys, Arg, and His increased the color, water retention, textural properties, and organoleptic qualities (tissue state and mouthfeel), as well as the emulsification stability and rheology [storage modulus (G′) and loss modulus (G″)] of minced yak meat (P<0.05).The results of low-field NMR showed that Lys, Arg, and His could transform the free water of yak mince to not easily flowable water or bound water, among which Lys had the best effect.Scanning electron microscopy showed that Lys, Arg, and His could change the microstructure of yak mince from a loose structure with large voids to a dense structure with smaller voids, and the effect of Lys and Arg was better.Taken together, 0.60% Lys had the best effect on improving the quality of yak mince.

Gelling properties are important functional characteristics of fish gelatin, which directly affects its application range and commercial value.Fish gelatin was modified with hyaluronic acid in different molecular weights in this work.The effect of hyaluronic acid on gelling properties and structural characteristics of fish gelatin was studied by rheometer, texture analyzer, infrared spectroscopy, and scanning electron microscope.The findings suggested that hyaluronic acid with different molecular weights decreased gel strength of fish gelatin, but significantly increased gelling temperature, melting temperature, and apparent viscosity of fish gelatin.Moreover, the higher molecular weight of hyaluronic acid, the greater changes in gelling properties of fish gelatin.When the molecular weight of hyaluronic acid was more than 1 800 kDa, gelling temperature, melting temperature, and apparent viscosity (η₅₀) reached respectively 22.32 ℃, 32.48 ℃, and 153 mPa·s, respectively.Hyaluronic acid slightly reduced gel strength of fish gelatin by less than 8.1%.The gelation dynamics analysis showed that regardless of molecular weight, hyaluronic acid could decrease the gel rate of fish gelatin and stabilize the gel network structure of fish gelatin.Infrared spectroscopy showed the FG-HA complex formation was mainly driven by electrostatic interaction, and the complex hindered the formation of hydrogen bond between molecular chains in fish gelatin.The scanning electron microscopy analysis showed that hyaluronic acid could effectively improve gel network structure in the composite colloid.Moreover, the FG-HA_>180W complex showed the most compact microstructure.This paper will provide a theoretical basis for improving functional properties and expanding the application of fish gelatin.

With the in-depth study of probiotics, researchers have found that some inactivated bacteria and their metabolites also have certain application potential.In this study, ultra high performance liquid chromatography orbitrap exploris mass spectrometry (UHPLC-OE-MS) combined with orthogonal partial least squares discriminant analysis (OPLS-DA) were used to evaluate the metabolite composition of Lactiplantibacillus plantarum suspension with and without inactivation.Results showed that 24 potential differential metabolites were identified (variable importance in projection>1,P<0.05, fold change>1.2 or <0.8), in which 19 metabolites were up-regulated in inactivation group.Further, those differential metabolites were enriched in 6 metabolic pathways by analysis of Kyoto Encyclopedia of Genes and Genomes.L-arginine and proline metabolism pathways were extremely significant differences (P<0.01) between two groups, and L-arginine and 4-acetamidobutanoate were enriched in those two metabolic pathways.The application of these metabolites had important prospects for promoting host health, improving animal production performance, and clinical medical field.This study preliminarily revealed the differences in metabolites of Lactiplantibacillus plantarum before and after inactivation by metabolomics, and provided a theoretical basis for the subsequent application of Lactiplantibacillus plantarum.

Arbutin is a glycoside compound with various pharmacological activities such as anti-inflammatory, antibacterial, antitussive, and whitening, but its poor lipid solubility and low bioavailability limit its application range.The arbutin derivatives obtained by whole-cell catalysis have better bioactivity and bioavailability.However, the cell biomass from the original medium formula was low.In this paper, the effects of whole-cell culture conditions on cell biomass and catalytic efficiency were investigated by using arbutin caproylation as the reaction model and Aspergillus oryzae as the strain to obtain whole-cell catalysts with more biomass and higher catalytic activity.The biomass reached 6.28 g/L in the medium containing 6.0 g/L soybean oil, 7.0 g/L tryptone, 5.0 g/L (NH₄)₂SO₄, and 0.2 g/L CaCl₂ at 180 r/min and 30 ℃ for 48 h, which was 4.39-folds higher than that in the initial conditions, and the arbutin conversion reached 99.55%.The new microbial whole-cell culture system that can catalyze arbutin acylation reaction has advantages including low cost, high efficiency, and high selectivity.This study provides an effective strategy for the industrial preparation of arbutin ester derivatives.

To develop new high-quality plant protein products with health benefits, this study dynamically analyzed the alteration of nutritional components of soymilk during the fermentation process with Bacillus subtilis BSNK-5.These results indicated that B. subtilis BSNK-5 grew vigorously in the substrate of soymilk with an exponential growth trend.After 84 h fermentation, the crude protein content decreased by 23.50%, generating small molecules such as peptides and amino acids, but the total content of hydrolyzed amino acids decreased by 42.90% due to the excessive degradation of amino acids in the later fermentation.In terms of amino acid composition, the percentage of essential amino acids increased by 13.34%, and the content of methionine and lysine increased by 106.90% and 18.50%, respectively, indicating that B. subtilis BSNK-5 fermentation balanced the composition and proportion of amino acids in soymilk.During the fermentation process, the fat content increased, and the content of fatty acids peaked at 24 h fermentation, in which linoleic acid accounted for 49.28%.In addition, the conformation of soybean isoflavones was obviously transformed from glucosides into their corresponding aglycones, and the content of isoflavone aglycones peaked at 48 h fermentation.The conversion rate of daidzin was the highest, and the proportion of daidzein reached about 52.15%.Therefore, B. subtilis BSNK-5 fermentation effectively contributed to the improvement of the nutritional value and the bioavailability of soymilk, whereas the fermentation time directly affected the enrichment of each nutrient component.These results provided a theoretical basis for the control of soymilk quality, the development of functional fermented soybean products and the supplementation of plant protein resources.

Fermented wine was brewed with four mulberry varieties respectively, including Da 10, Zhongsang 5801, Jialing 30, and Zijin 6.The antioxidant, hypoglycemic, and hypolipidemic activities in vitro of mulberry fermented wine were studied.Furthermore, the physicochemical indexes (e.g., total phenol and anthocyanin contents, etc.) of different mulberry varieties and their fermented wine were comparatively analyzed.Results showed that the contents of total phenol (2.44 mg GAE/mL) and anthocyanin (410.79 mg CGE/L) in Da 10 mulberry fermented wine were significantly higher than those in the other three varieties.In terms of antioxidant activity, the DPPH radical scavenging rate (99.70%) and ferric reduction capacity of Da 10 mulberry fermented wine were the highest, and the ABTS cationic radical scavenging rates of Jialing 30, Zhongsang 5801, and Da 10 mulberry fermented wine were over 95%, which was significantly higher than that of Zijin 6 (81.29%).The ·OH scavenging rates of Da 10 and Zijin 6 mulberry fermented wine were relatively high (> 85%).In terms of hypoglycemic activity, Da 10 mulberry fermented wine showed a better effect, and its inhibition rate of α-glucosidase and α-amylase activity was 96.45% and 68.13%, respectively.In terms of hypolipidemic activity, Da 10 mulberry fermented wine also had a better binding ability to sodium glycocholate and sodium taurocholate.In summary, all four mulberry fermented wines had good antioxidant activity, inhibition activity of α-glucosidase and α-amylase as well as hypolipidemic activity in vitro.On the whole, Da 10 mulberry fermented wine showed better functional activity.The results of correlation analysis showed that the content of total phenol in mulberry fermented wine was significantly positively correlated with its hypoglycemic activity (P<0.001), anthocyanin content was significantly positively correlated with DPPH radical scavenging ability and hypolipidemic activity, and total acid content was significantly positively correlated with ·OH scavenging ability.

Fermentation of Grateloupia livida has the potential to produce bioethanol because it is rich in polysaccharides and low price.In this study, G.livida was used as raw material for bioethanol production.The optimal pretreatment condition for hydrolysis of G.livida by dilute sulfuric acid was obtained through the single factor and response surface test, including the solid-liquid ratio of 1∶20 (g∶mL), hydrolysis time of 1.8 h, hydrolysis temperature of 100 ℃, and sulfuric acid mass fraction of 3%, in which condition the reducing sugar content reached the maximum (37.64%).The compositions and contents of monosaccharides in the hydrolysate of G.livida pretreated with dilute sulfuric acid were analyzed.Results showed that dilute sulfuric acid pretreatment could significantly increase the content of monosaccharides, among which galactose and glucose possessed the highest contents.The hydrolysate of G.livida was further fermented by Pichia kudriavzevii.This yeast exhibited good growth and ethanol production ability, and the increase of inoculation could significantly enhance its biomass and ethanol fermentation characteristics.Pearson correlation analysis showed that the contents of monosaccharides in the hydrolysate of G.livida were significantly negatively correlated with biomass and various ethanol fermentation parameters, while the biomass was significantly positively correlated with various ethanol fermentation parameters.It indicated that the consumption of monosaccharides played an important role in the growth and ethanol production of P.kudriavzevii, and the growth of yeast was directly related to the production of ethanol fermentation.The correlation network showed that the consumption of glucose and galactose had the greatest influence on the biomass increase and ethanol production of P.kudriavzevii.These results suggest that the use of G.livida as raw material through dilute acid pretreatment combined with P.kudriavzevii fermentation has an application potential to produce bioethanol, which also provides an important technical reference for the fermentation of other algae to produce bioethanol.

Xylan (Xyl) were used as raw materials to prepare xylan-mineral complexes by chemical synthesis modified by metal elements, and their physical and chemical properties were determined by the determination of metal element content, ash content, basic chemical composition, molecular weight, monosaccharide composition, particle size and viscosity, and their synergistic probiotics were studied by response surface optimization method.Results showed that the Ca content of the xylan-calcium complex (Xyl-Ca) was (7.57±0.03) mg/g, the Fe content of the xylan-iron complex (Xyl-Fe) was (6.26±0.06) mg/g, and the Zn content of the xylan-zinc complex (Xyl-Zn) was (3.21±0.02) mg/g.Metal complexation could reduce the sugar content of Xyl and cause differences in the composition of monosaccharides.The ash content, molecular weight, particle size, and viscosity of xylan and its metal complexes were in the following order:Xyl-Fe> Xyl-Ca> Xyl-Zn>Xyl.The optimal weight ratio of the composite xylan metal complex on the proliferation promotion of triple probiotics was Xyl-Ca∶Xyl-Fe∶Xyl-Zn=8.9∶9.8∶11.3, and the OD value of the culture medium was 1.125 5.Results suggested that Xyl-Ca, Xyl-Fe, and Xyl-Zn could be used as potential calcium-iron-zinc supplements for functional food and pharmaceutical applications, and were alternative derivatives of prebiotics for improving intestinal health or treating intestinal diseases.

Aiming at the current situation of low comprehensive utilization of citrus peel pomace, three varieties of citrus peel pomace (lemon, orah, and navel orange) were taken as raw materials, and three physical modification techniques, including high-speed shear, ultrasonic, and high temperature-high pressure, were utilized to modify the citrus peel pomace.The effect of each modification on the fibre structural and physicochemical functional properties of the different citrus peel pomace samples was investigated.Results showed that the three modifications reduced the particle size of citrus pomace fibres, increased the specific surface area, decreased the relative crystallinity, and improved the thermal stability, while the main functional structures were not significantly altered.Among them, the effect of high-speed shear modification was better than that of the other two modifications, and the soluble dietary fiber (SDF) content, water-holding capacity, oil-holding capacity, swelling capacity, total flavonoids and phenols content, and adsorption of cholesterol and nitrite capacity of citrus peel pomace fibers after high-speed shear had the most significant enhancement effects (P<0.05).Lemon peel pomace fiber had the best performance among the three citrus varieties.In conclusion, high-speed shear was the best way to modify citrus pomace fiber.The structural and physicochemical functional properties of lemon peel pomace modified by high-speed shear were better than those of orah and navel orange, which were more conducive to their application in food products, and the results could provide some references for expanding the utilisation of citrus processing by-products.

To obtain lactic acid bacteria for the degradation of biogenic amines (BAs) in soy sauce, lactic acid bacteria strains were isolated from soy sauce and soy sauce mash, and their growth characteristics including growth curves, salt tolerance, acid resistance, other growth characteristics, and degradation characteristics were identified.Results showed that five strains with high BAs-degrading capacity were screened using the dilution separation method, double color method, oxidase test, and liquid chromatography-tandem mass spectrometry quantitative analysis.The five strains with high BAs-degrading capacity were identified as Lactobacillus fermentum by morphology, physiology, biochemistry, and 16 S rDNA molecular biology.Among the five strains, L2112, L31B2, and L41B had degradation rates of the main biogenic amines in soy sauce-tyramine, histamine, spermidine, and phenylethylamine, reaching 63.76%, 59.09%, 43.38%, and 35.12%, respectively.Moreover, L2112 and L41B had good acid and salt resistance.Strain L2112 had the best biogenic amine degradation rates at 37 ℃, 4% of salt content, and 300 mg/L of biogenic amine concentration, and strain L41B had the best biogenic amine degradation rates at 37 ℃, 13% of salt content, and 500 mg/L of biogenic amine concentration.This study was expected to provide excellent strains for the regulation of biogenic amines in the soy sauce fermentation system.

Acid stress restricts the viability and probiotic functions of lactic acid bacteria during production applications.Therefore, studying the potential acid tolerance mechanisms of a specific strain is crucial for its further application.This study first examined the influence of decreasing acidity on the growth of Lentilactobacillus kefiri IMAU10804, a slow-growing milk rod bacterium.Subsequently, this study used liquid chromatography-mass spectrometry (LC-MS) to analyze the metabolomics differences in L.kefiri IMAU10804 before and after acid stress.Results showed that the growth of L.kefiri IMAU10804 was inhibited with decreasing pH.When L.kefiri IMAU10804 was treated under pH 3.0 for 60 min, 796 and 615 metabolites were detected in positive and negative ion modes, respectively.Multivariate statistical analysis was performed using SIMCA 14.1 software combined with Metaboanalyst 5.0, revealing that a large number of metabolites were enriched in metabolic pathways, such as ABC transporter, arginine and proline metabolism, and purine metabolism.Based on the criteria of P<0.05, variable importance in projection score ≥ 1, and fold change ≥ 1.5, 24 major differential metabolites were found, including L-proline, aspartic acid, and trehalose.This study demonstrated significant changes in the growth and metabolism of L.kefiri IMAU10804 under acid stress environment, providing data support for the subsequent development and application of lactic acid bacteria products.

This study aimed to conduct a feasibility analysis on the traceability in the leg meat of Qianbei brown goat origin using elementomic, and compared with four major mutton-producing regions in China based on multi-element determined through stoichiometric methods.In total 65 foreleg cases of lamb were collected from Guizhou, Inner Mongolia, Ningxia, Xinjiang, and Gansu.The contents of 17 mineral elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometer (ICP-OES) after the mutton samples were pretreated by microwave digestion procedure.Combined with analysis of variance (ANOVA), principal component analysis (PCA), and orthogonal partial least squares discriminant (OPLS-DA), the Qianbei brown goat origins were distinguished.The discriminant model of mutton origin was established based on different elements.8 kinds of elements (Mg, Al, K, Fe, P, Rb, Cr, and Sn) in mutton were selected had significant differences between Guizhou Qianbei brown goat and four main mutton producing areas in China with OPLS-DA model.The Fisher discriminant function was established, and the cross-discrimination accuracy of samples in areas was 95.0%.The results showed that the 8 elements were feasible for the identification of the region Qianbei brown goat, thus providing a reference for traceability analysis.

To investigate the effects of three preservatives (lysozyme, tea polyphenols, and licorice antioxidants) at different concentrations on the shelf life of vacuum-packaged cooked Tibetan sheep meat, Tibetan sheep cooked products were treated with lysozyme, tea polyphenols, and licorice antioxidants, respectively, and stored at 4 ℃.The edible quality, physicochemical properties, nutritional quality, and volatile flavor substances of the Tibetan sheep cooked products were measured during storage to determine the optimal preservative.Results showed that as the refrigeration time increased (63 days), the total bacterial count of Tibetan sheep cooked products preserved with 0.4% lysozyme increased the least (P<0.05), with the least loss of soluble protein content and moisture content (P<0.05).The color was well maintained, and the amino acid and fatty acid contents were abundant (P<0.05), with low levels of undesirable flavor substances (P<0.05).Tibetan sheep cooked products preserved with 0.25% tea polyphenols had a relatively abundant amino acid content and high umami amino acid content (P<0.05).Tibetan sheep cooked products preserved with 0.15% licorice antioxidants had a high content of polyunsaturated fatty acids (P<0.05).Based on comprehensive analysis, all three natural preservatives can extend the shelf life of Tibetan sheep cooked products to more than 63 days.Among them, the 0.4% lysozyme preserved products exhibited the best preservation effect, effectively delaying the decay and deterioration of cooked sheep meat.

The aim of the study was to isolate lactic acid bacteria with the ability to alleviate hyperuricemia from Tibetan kefir grains.Based on high-performance liquid chromatography (HPLC), the degradation ability of inosine, guanosine, and adenosine was investigated in 28 selected strains.Among them, Lactobacillus ZD103 had the highest ability to degrade inosine, guanosine, and adenosine.To further analyse the potential uric acid-lowering effect of strain ZD103, the inhibition of xanthine oxidase (XOD) by metabolites of strain ZD103 was determined by the HPLC method.Results showed that metabolites from strain ZD103 significantly inhibited XOD activity and that the inhibitory effect was exerted by acids present in the extracellular metabolites.Based on molecular docking, the acids in the metabolites were docked to XOD and the three substances with the highest scores were selected to test their inhibitory effects on XOD.Results showed that the three substances, 1-hydroxy-2-naphthylcarboxylic acid, 3-indoleacrylic acid, and indolepyruvic acid, all had different degrees of inhibitory effects on XOD, among which 1-hydroxy-2-naphthylcarboxylic acid had the best inhibitory effect, with the inhibition rate of XOD reaching (98.66±1.63)%.This study provides a theoretical basis and high-quality strain resources for the development of probiotic products for the prevention and treatment of hyperuricemia.

To explore the effects of CaCl₂ concentration on the gel properties and sensory quality of kelp alginate edible granules, the effects of CaCl₂concentration on the product of gel system of calcium alginate was characterized by texture properties, sensory scores, water holding capacity, cooking loss, freeze-thaw stability, and microstructure of the product, and the optimum CaCl₂ concentration of the product was determined.Results showed that with the increase of Ca²⁺ concentration (10-50 g/L), the values of water holding capacity and freeze-thaw stability of the product were significantly decreased, and the cooking loss was significantly increased.At a high level of Ca²⁺, a dense gel layer was formed on the surface of the product, which could prevent the construction of a uniform gel system and decrease the water stability of the gel system.As the concentration of Ca²⁺ was 20 g/L, the texture properties and sensory quality of the product were optimized.Meanwhile, the dense and uniform gel network structure was established, and the gel system was stable.The above results indicated that kelp alginate edible granules prepared by 20 g/L CaCl₂ had good overall properties, and the texture properties and sensory quality were optimal.The research results could provide a reference for the development of calcium alginate gel products of kelp.

This study focused on the effects of dry curing, wet curing, and ultrasonic curing on the structure and properties of mutton myofibrillar protein.The total sulfhydryl group, surface hydrophobicity, carbonyl group, Zeta potential, particle size, Fourier transform infrared spectroscopy, muscle fiber fragmentation index (MFI), and gel electrophoresis were used to analyze the structure and properties of mutton myofibrillar protein.Results showed that with the prolongation of curing time, the total sulfhydryl group of dry-cured mutton myofibrillar protein increased and the surface hydrophobicity decreased.The surface hydrophobicity of wet-cured mutton myofibrillar protein decreased with the total sulfhydryl group increased and the carbonyl content increased.The ultrasonic-cured mutton myofibrillar protein was found with the increased surface hydrophobicity and carbonyl group, while its total sulfhydryl group decreased, and the protein oxidation degree was the highest among the 3 methods.The absolute value of the Zeta potential of ultrasonic curing and wet curing increased, and the absolute value of the Zeta potential of dry curing decreased.The particle size of the three curing methods decreased compared with the control group, and the content of β-sheet structure in mutton myofibrillar protein in the three curing methods was found to have a significant reduction, and the content of β-turn was increased.The MFI of ultrasonic curing decreased while the MFI of dry curing and wet curing increased.Gel electrophoresis showed that the dry-cured protein bands tended to be shallower with time, and the wet-cured and ultrasonic-cured mutton myofibrillar protein myosin heavy chain and actin bands deepened.The above indicators showed that ultrasonic curing would accelerate the oxidation and degradation of myofibrillar protein structure, improve the tenderness of mutton, and play an important role in improving the deep processing products of mutton.

To study the changes in quality and volatile components of low-temperature prepared cooked Xiang pork during different sterilization processes, gas chromatograph-ion mobility spectrometer (GC-IMS) technology was used to qualitatively analyze the volatile components of non-sterilized, water bath sterilized, ultra-high pressure sterilized, irradiated sterilized, and high-temperature and high-pressure treated Xiang pork.A total of 63 volatile flavor compounds were identified, including 5 aldehydes, 10 ketones, 11 alcohols, 13 esters, 6 ethers, 4 furans,4 pyrazines,2 thiazoles, and 8 other types.According to the relative content of volatile compounds in each group, the Xiang pork in the ultra-high-pressure group was closer to the control group than in the water bath sterilization group.The microstructure of low-temperature conditioned Congjiang Xiang pork under four sterilization methods was compared using scanning electron microscopy.Radiation sterilization and ultra-high-pressure sterilization could better preserve the muscle fiber structure of the original sample.According to comprehensive analysis, ultra-high-pressure sterilization had better maintain the original quality and flavor of the product and had a good application prospect in the field of sterilization of low-temperature conditioning meat products and prefabricated dishes.

Low-temperature storage is currently the most widely employed preservation method, however, loquat is susceptible to chilling injury in low-temperature environment.Therefore, this study aimed to investigate the effect of different gradient precooling combined with low-temperature storage (11→8 ℃, 11→8→5 ℃, 11→8→5→2 ℃) on the storage quality of Dawuxing loquat compared to a control group at normal temperature (20 ℃).Results showed that the 11→8→5 ℃ treatment significantly maintained the desirable appearance of loquat fruits, effectively inhibited the increase of browning degree, hardness, and lignin and malondialdehyde contents.Moreover, it prevented a decrease in soluble solid, titritable acidity, ascorbic acid, and juice percentage in fruits.Additionally, this treatment kept the ·O^-₂ production rate and the content of H₂O₂ at a low level, inhibited the increase of the activities of phenylalamine ammonia lyase and polyphenol oxidase, but maintained the high activities of superoxide dismutase and ascorbate peroxidase.Consequently, the 11→8→5 ℃ treatment can effectively prolong the storage life of loquat, avoid chilling injury, and maintain good postharvest quality.This study aims to explore the feasibility of combining gradient precooling with low-temperature storage for loquat preservation while providing theoretical basis and technical support for postharvest storage practices.

Processed Mozzarella, a type of cheese with certain stretchability, is made mainly from the natural cheese, casein and emulsified salt.In recent years, sales of processed Mozzarella have increased with the rise of western-style food products such as pizzas and cheesy hot dog sticks. To understand the rule of quality change of the processed Mozzarella cheese during the storage period, this study was carried out to analyze seven kinds of domestically produced processed Mozzarella cheese and two kinds of natural Mozzarella cheese for the change of stretchability, oiling-off level, protease activity, intact casein content, microstructure, and organoleptic property during the period of storage at 4 ℃ and -18 ℃ for 180 days.Results showed that the processed Mozzarella cheese had a tendency to decrease in stretchability, increase in oiling-off level, and decrease in intact casein content and organoleptic quality, accompanied by microstructural changes with deformation of fat globules and swelling of proteins.These quality changes were more obvious in the processed cheese than the natural cheese.The quality deterioration was also faster under refrigerated storage at 4 ℃, the lower the intact casein content was, the lower the stretchability of the processed cheese, and the more pronounced the deformation of the fat globules was, the greater the deterioration of the oleaginous properties.The results of this study provide important technical advice for the improvement of production technology and product quality of processed Mozzarella cheese.

Flaxseed oil and flaxseed meal were obtained by different oil extraction methods including screw pressing, hydraulic pressing, and solvent extraction, and then the effects of different methods on the quality of flaxseed oil and protein were investigated.Results showed that different oil production processes had a significant impact on the physicochemical indicators of flaxseed oil (P<0.05), of which the highest acid value of screw pressing oil, 0.37 mg/g, while the hydraulic pressing group had the highest saponification value of 189.57 mg/g.The fatty acid composition and content were not significantly affected by the oil production process (P<0.05).A total of five fatty acids were detected, the content size in the order of linolenic acid, oleic acid, linoleic acid, palmitic acid, and stearic acid.The screw-pressing group had the smallest change in peroxide value in the oven experiment, and its oxidative stability was the best among the three groups of oil samples, whereas the hydraulic press group was the worst.The quality of the meal protein of the three groups was analyzed, and the results showed that different oil production processes affected the infrared spectral peak intensity of flaxseed meal protein and its ratio of β-sheet and β-turn to different degrees.The results found that the hydraulic press meal protein had the highest fluorescence intensity and the lowest solubility, foaming ability, and emulsification ability.Solvent extraction meal protein had the highest solubility, foaming ability, and emulsification ability.In summary, a suitable oil production process can be selected according to the actual needs.

In this study, the mycelia of Ganoderma sessile were used to prepare mycelium base composites (MBCs), C-MBCs (corn stalks), and H-MBCs (hemp stalks), respectively.To obtain more active mycelium seeds, the liquid cultivation conditions were optimized.The study included the effects of carbon sources, nitrogen sources, initial pH, temperature, G.sessile content, liquid volume, and rotating speed on the mycelial biomass of fermented products.Both C-MBCs and H-MBCs were measured for scanning electron microscope, compressive strength, and thermogravimetric characteristics.Results showed that the best mycelium cultivation medium was 25 g/L corn flour, 14 g/L soybean powder, 3 g/L KH₂PO₄, and 3 g/L 7H₂O·MgSO₄.The optimized fermentation conditions were fermentation temperature at 28 ℃, initial pH 5.5, G.sessile content with 5%, liquid volume 150 mL/500 mL flask, and rotating speed 180 r/min.Under the optimized conditions, the mycelial biomass in the cultural broth was 18.73 g/L, which increased by 34%, compared with those before optimization.The compressive strength and thermogravimetric characteristics of C-MBCs and H-MBCs were both better than expanded polystyrene.It’s concluded that this result will provide a reference for the application of MBCs instead of foam plastics in cushioning packaging.

The addition of adjunct culture has a significant impact on the quality of cheese.To screen adjunct culture with high protein hydrolysis and antioxidant capacity, this study evaluated 12 strains of lactic acid bacteria based on the acid production, protease activity, proteolysis, and antioxidant capacity.The potentially beneficial strain was used as adjunct culture to make quark cheese.The effect of adjunct culture on cheese quality was assessed by examining physicochemical indices, titration acidity changes, lactic acid bacteria count, texture alterations, and antioxidant activity during storage.Results showed that Lactobacillus kefiranofaciens XZ-54, which had a weak acid-producing capacity, high protease activity, protein hydrolysis, and antioxidant capacity, had the potential to be used as an adjunct fermenter for quark cheese.The addition of XZ-54 had no significant effect on the physicochemical parameters, hardness, and spread ability of quark cheese (P>0.05), and the viable counts of XZ-54 in the cheese were maintained above 10⁷ CFU/g during the 21-day storage period.Additionally, it significantly enhanced the DPPH free radical, ABTS cationic radical, and hydroxyl radical scavenging activities of the cheese.Therefore, Lactobacillus kefiranofaciens XZ-54 could be effectively employed as an adjunct culture in quark cheese, improving its antioxidant qualities and demonstrating significant potential for development and application.

Frozen storage is one of the important ways to maintain fish quality.The methods of conventional chemistry and lipidomics were applied to investigate the effects of varying temperatures on lipid alterations in whitespotted conger (Conger myriaster) during frozen storage.Chemical results showed that the lipid hydroperoxide (LPO) contents and thiobarbituric acid reactive substances (TBARS) levels had an increasing tendency in the period of 120-day frozen storage, and the increase was more remarkable in the -18 ℃ group than that in the -60 ℃ group.Lipidomics results indicated 353 lipids were detected in whitespotted conger, which could be divided into seven major categories and corresponding 22 lipid subclasses.Among them, the subclasses with the largest number of lipid molecules were phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), diacylglycerol (DG), and sphingomyelin (SM).In addition, compared with the fresh samples (0 day), 38/22, 52/19 up-regulated differential lipids and 6/3, 5/2 down-regulated differential lipids were detected in the -18 ℃ group and -60 ℃ group under the positive/negative ion mode, respectively.Compared with the -18 ℃ group, 15/14 up-regulated differential lipids and 9/15 down-regulated differential lipids were identified in the -60 ℃ group.The amounts of PC, PE, and lyso-phosphatidyl choline (LPC) related to freshness in the differential lipids of the -60 ℃ group were lower than those in the -18 ℃ group.Therefore, PC, PE, and LPC could be used as the biomarkers of whitespotted conger to distinguish fresh from frozen.In conclusion, -60 ℃ can inhibit lipid oxidation and decline the extent of quality deterioration of whitespotted conger better than -18 ℃.This study offers a reference for the quality control of whitespotted conger during frozen storage.

The objective of this study was to improve the stability of catechins and expand their applications in food processing.To achieve this, catechins were encapsulated at different mass fractions (0%, 0.4%, 0.8%) in co-crystallized sucrose.Meanwhile, catechin co-crystallized microcapsules were mixed with chicken batter to prepare gels and investigate their effects on heat-induced gelling properties.The study found that the co-crystallization treatment significantly improved the water solubility and digestive stability of catechin.Scanning electron microscope (SEM) and differential scanning calorimeter (DSC) analyses confirmed that catechin clusters adhered to the porous space of recrystallized sucrose and modified the melting properties of sucrose.Compared to the blank control and free catechin-added groups, the chicken batters added with encapsulated catechin significantly reduced cooking loss and increased gel hardness, chewiness, water-holding capacity, and whiteness values.The addition of encapsulated catechin reduced the drip channels and aggregated voids in the chicken batter compared to the control group.Furthermore, the incorporation of co-crystallized microcapsules containing 0.8% of catechin minimized the carbonyl content and maximized the free and total sulfhydryl content of chicken mince gels.In conclusion, the sucrose co-crystallization method can significantly enhance the environmental stability of catechins, and the co-crystallized catechins can effectively improve the texture and water retention of heat-induced chicken batters by improving the gel organization and reducing the degree of protein oxidation.

By simulating the solid-state fermentation process of sesame-flavored Baijiu, this study investigated the interaction of main microorganisms in grains, changes in physical and chemical indexes of grains, and alterations in flavor substances.Further explored were the acid reduction in grains and the varying ratios of grains and sorghum.Sequencing revealed that Saccharomyces and Pichia were the predominant fungal genera during the build-up fermentation stage of sesame-flavored Baijiu grains, with Bacillus and Lactobacillus being the primary bacterial genera.Experiments on single and mixed bacteria accumulation fermentation demonstrated that distiller′s grains notably inhibited S.cerevisiae and Bacillus subtilis, reducing the count of P.kudriavzevii and Lacticaseibacillus paracasei in the early stages of accumulation.However, P.kudriavzevii and Lacticaseibacillus paracasei post-accumulation attained a bacterial mass comparable to that of pure sorghum fermentation samples.Post addition of distiller′s grains, the acidity of P.kudriavzevii significantly decreased during the accumulation, dropping from (2.10±0.25) mmol NaOH/10 g fermented grain to (0.95±0.43) mmol NaOH/10 g fermented paste.Orthogonal partial least-squares discrimination analysis identified ethyl acetate, n-butanol, n-propanol, isobutanol, and isoamyl alcohol as critical volatile flavor components in different groups (variable importance in projection value>1).Compared with the sc+pi group, the ethyl acetate content in the sc+pi group increased by (113.43±0.86) mg/L (P<0.05), whereas the contents of isoamyl alcohol and isobutanol decreased (16.63±0.82) mg/L (P<0.05) on the 25th of fermentation.Moreover, solid-state fermentation experiments of P.kudriavzevii in sorghum grains with varied levels of lactic and acetic acid indicated that the yeast could reduce lactic acid in the system.Furthermore, at a 1∶1 ratio of distiller′s grains to sorghum, the starch utilization rate peaked at 71.32%, and the flavor substance was most abundant, enhancing resource utilization and improving the flavor profile of fermented grains.This study offers a theoretical foundation for controlling the acidity of stacked grains in sesame-flavored Baijiu distiller′s grains addition.

Acetaldehyde is a toxic compound to the human body.Acetaldehyde dehydrogenase (ALDH) can oxidize acetaldehyde to non-toxic acetic acid and convert NAD(P)⁺ to NAD(P)H.At present, the methods for acetaldehyde detection are complicated and time-consuming.In this study, acetaldehyde dehydrogenase derived from Candida tropicalis LBBE-W1 was displayed on the surface of “microcapsules” of Saccharomyces cerevisiae spores to establish a novel and rapid detection method for acetaldehyde.Firstly, it was confirmed that ALDH could be expressed and localized on the spore wall based on western blotting and fluorescence results.Then, the enzymatic properties of ALDH on the spore surface and free ALDH were determined.Results showed that the optimum temperature and pH for ALDH displayed on spore surface and free enzyme were 40 ℃ and 9.0, respectively.Compared with free enzyme, ALDH displayed on spore surface showed higher activity and better temperature and pH stability.In addition, ALDH on the surface of spores had stronger tolerance to SDS and protease K.The most suitable substrate for both ALDH on spore surface and free enzyme was acetaldehyde, and ALDH on spore surface showed good reuse performance.Finally, ALDH displayed on the spore surface was used as a biosensor to detect acetaldehyde.The results showed a good linear relationship in the concentration range of 0-500 μmol/L with R² value of 0.999 2.In this study, a novel biosensor was successfully constructed to provide a new method for acetaldehyde detection.

Camellia oil is often adulterated with other cheap cooking oils in the market.Raman spectroscopy was employed to quantitatively detect adulteration in the ternary system of camellia oil.The optimal multivariate adulteration detection model for soybean oil, corn oil, and camellia oil was determined by comparing the advantages and disadvantages of different preprocessing methods, modelling methods, and optimization algorithms.To eliminate the effect of external factors on the spectrum, four preprocessing methods were employed, including first-order differentiation, second-order differentiation, multiple scattering correction, and standard normal variation.The competitive adaptive reweighted sampling algorithm was employed to extract the characteristic spectral bands.The adulteration detection model for camellia oil was developed using partial least squares regression and support vector machine regression.The support vector machine was optimized using both grid search and particle swarm optimization algorithms.Among the preprocessing methods, the models based on standard normal variation yielded the most favorable outcomes.The particle swarm optimization-support vector machine (PSO-SVM) model proved to be highly effective in predicting soybean oil and camellia oil, while the grid search-support vector machine (GS-SVM) model demonstrated superior performance in predicting corn oil.The predicted coefficient of determination (R²) and the predicted root mean square error (RMSEP) for soybean oil, corn oil, and camellia oil were 0.998 6, 0.999 4, and 0.999 9, and 2.73%, 1.62%, and 0.40%, respectively.The study presented an optimal multivariate model for detecting adulteration in soybean oil, corn oil, and camellia oil.The support vector machine model, based on Raman spectral analysis and optimization algorithms, provides a valuable reference for non-destructive and rapid quantitative detection of camellia oil adulteration in the market.

This study aimed to investigate the feasibility of the application of stable hydrogen isotopes in the field of lycopene adulteration detection.The method using the technique of temperature conversion/elementary analyzer-stable isotope ratio mass spectrometers (TC/EA-IRMS) was developed for the determination of stable hydrogen isotopes of lycopene from different sources.It was verified that the purity of lycopene samples was ≥94.14% after pretreatment, and the pretreatment process would not change the determination of lycopene hydrogen stable isotope ratio.The standard deviation of the δ²H value of the method was 1.99‰ for repeatability and the standard deviation of the reproducibility was less than 3‰.The stable hydrogen isotope ratios of 13 lycopene raw materials and lycopene standards were determined, the δ²H values of the synthetic lycopene ranged from -29.21‰--56.22‰, the δ²H values of the lycopene from natural sources ranged from -225.76 ‰--256.98 ‰, and the δ²H values of the lycopene from fermentation sources ranged from -81.35 ‰--141.24 ‰.The stabilized hydrogen isotope ratios of the three are significantly different, and the method can be used for the identification of lycopene from different sources.

To ensure liquor quality and improve the brewing process, this study employed headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (HS-SPME-GC×GC-TOF-MS) to analyze Maotai-flavor Baijiu of various qualities.It was determined that Maotai-flavor Baijiu contains 1 063-1 347 components, including esters, acids, alcohols, aldehydes, ketones, and sulfur-containing substances.The percentages of esters in high-quality Baijiu A1 and A2, as well as mixed-flavor Baijiu B1 and B2, were 58.75%, 55.47%, 42.05%, and 41.55%, relative contents of alcohols were 17.14%, 16.15%, 26.77%, and 26.92%, respectively.The percentages of acids present were 1.47%, 2.05%, 6.71%, and 7%.69%.High-quality Baijiu exhibited high levels of ester, low alcohol, and moderate acid, while mixed-flavor Baijiu had low ester, high alcohol, and high acid.Sulfur-containing components such as sulfur ethers, sulfones, thioesters, and thiophenes were more prevalent in mixed-flavor Baijiu, whereas they were either negligible or undetectable in high-quality Baijiu.The use of principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) revealed significant variations in flavor between high-quality Baijiu and mixed-flavor Baijiu.A total of 85 potential flavor components were identified, each with a variable importance in the projection (VIP) value ＞1.Notably, components with VIP>1 and P<0.05 were mapped using a heatmap.The study identified that high-quality Baijiu was characterized by high levels of ethyl butyrate, ethyl caproate, nonanal, and octanal, while mixed-flavor Baijiu had high levels of caproic acid, acetic acid, isobutanol, isoamyl alcohol, etc.The sensory evaluation revealed that the mixed-flavor Baijiu had a lower intensity of ester aroma, a stronger advanced alcohol flavor, a slightly acidic flavor, a slightly unusual aroma, and a lack of crispness, which was consistent with the result of low ester, high alcohol, high acid, and the presence of more sulfur-containing substances.The results of this study indicate that HS-SPME-GC×GC-TOF-MS technology can be used to investigate the Maotai-flavor high-quality Baijiu at the molecular level.This provides effective technical support for the subsequent quality improvement and process control of Maotai mixed-flavor Baijiu.

Physical aging as a novel maturation method for fruit wine is gradually gaining attention and utilization from various research institutions and enterprises.This paper aims to grasp the current research progress and future development trends of physical aging in fruit wine.Using bibliometrics, this study conducted statistical analysis on relevant studies from the China National Knowledge Infrastructure (CNKI) and Web of Science (WOS) core collections.This study also utilized the SooPAT patent search engine and the commercial query platform Tianyancha to summarize the industry’s current development status.Results indicate that the total publication volume on the physical aging of fruit wine is on the rise, with Spain actively engaging in international cooperation and producing the most outcomes.Literature related to this topic in China is primarily funded by national funds and is mostly published in China Brewing journals.Through keyword analysis, current research focuses on exploring the application of physical aging technology in grape wine, examining the impact of physical aging on phenolic substances in fruit wine and investigating the influence of physical aging technology on sensory quality.In terms of industry development, relevant enterprises in China are densely distributed in coastal areas, accumulating a total of 93 patents in this field.The physical aging technology for fruit wine offers advantages such as low cost and quick effectiveness, indicating significant development potential and prospects.

As an important type of Gram-positive bacteria, lactic acid bacteria (LAB) play a crucial role in food fermentation and human health maintenance.sRNA is a post-transcriptional regulatory factor existing in prokaryotes and eukaryotes.It regulates gene expression in cells by combining with target mRNA or protein, and its length is about 40-500 nucleotides.In recent years, with the continuous deepening of research on bacterial sRNA, the function and regulatory mechanism of LAB sRNAs have gradually attracted attention.This article reviews the mechanism and biological functions of bacterial sRNAs, with a focus on the latest progress of sRNAs in LAB such as Lactococcus lactis, Lactobacillus, Lacticaseibacillus casei, and Streptococcus thermophilus.It also looks forward to the development direction and challenges of sRNA research in LAB.In-depth research on sRNA facilitates a comprehensive understanding of the physiological characteristics and environmental adaptability, which paves the foundation for the development of LAB and their application fields.

Astaxanthin is widely used in industries such as cosmetics, feed additives, and healthcare due to its antioxidant, coloring, and health-promoting properties.The traditional production process of astaxanthin mainly includes natural extraction and chemical synthesis.However, they cannot meet the growing market demand and consumer demand for natural products.With the rapid development of synthetic biology, the synthesis of astaxanthin by microbial fermentation is a more efficient way.Many naturally occurring sources of astaxanthin, such as Xanthophyllomyces dendrorhous and genetically engineered yeasts such as Saccharomyces cerevisiae, Yarrowia lipolyticus, and Kluyveromyces marxianus, have been isolated and constructed.To improve the efficiency of astaxanthin production through industrial yeast fermentation, researchers used a variety of strategies such as mutagenesis, genetic modification, and fermentation regulation, and explored ways to synthesize astaxanthin using different cheap substrates.Therefore, this study systematically reviews the research progress of yeast astaxanthin synthesis, analyzes the main factors affecting astaxanthin synthesis from the metabolic pathway of yeast and the current status of astaxanthin synthesis using different raw materials, and proposes methods and strategies for yeast to produce astaxanthin.

The formation and growth of ice crystals during the freezing process can greatly impact the quality of food products.Therefore, rapid and accurate detection of ice crystals in frozen foods, to effectively control and regulate their nucleation and growth, holds significant scientific value.This paper, building upon a summary of the ice crystallization process and its impact on the quality of frozen foods, outlines recent advancements in the detection technologies for ice crystals in frozen foods.Additionally, it analyzes and forecasts future development trends and challenges faced in this area.Among these, novel ice crystal detection technologies based on physical methods, such as optics, electrics, magnetics, and acoustics are crucial.These methods hold the potential for non-destructive online detection and can be significantly enhanced in accuracy and efficiency through the integration with artificial intelligence technologies, representing an important future trend in this field.

As global fishery outputs grow and demands for fish quality assurance rise, traditional fish processing and quality monitoring methods are increasingly unable to meet modern requirements.The integration of machine vision and deep learning technologies presents an efficient and automated solution to enhance the accuracy and efficiency of fish processing and quality monitoring.This review outlines the applications of machine vision systems and deep learning in fish processing, including tasks such as sorting, cutting, and mass estimation.It delves into the latest research on quality monitoring using hyperspectral imaging, near-infrared imaging, colorimetric sensors, and traditional imaging, emphasizing the potential of deep learning to improve recognition, classification accuracy, and the processing of complex image data.Despite the success of machine learning in addressing specific processing issues, its adaptability to complex data and changing environmental conditions remains limited, underscoring the increasing importance of deep learning research.However, research in the fish processing domain that utilizes deep learning is still relatively sparse, with a notable absence of comprehensive systems capable of addressing multiple processing and monitoring challenges.This study found an urgent need for future research focused on developing integrated systems that could tackle a variety of tasks in fish processing and quality monitoring.Such systems promise not only to improve efficiency and reduce costs but also to ensure product quality through real-time surveillance.

Employing bibliometric methods, this study conducted a visual analysis of the fermented milk flavor research literature published between 2003 and 2023 in the Web of Science Core Collection and the China National Knowledge Infrastructure (CNKI) database.The analysis indicates that China (247 publications), Brazil (131 publications), Turkey, and the United States (each with 120 publications) are leading countries in this field.Internationally, the Egyptian Knowledge Bank (EKB) and the Inner Mongolia Agricultural University are pivotal and critical institutions, with close collaborative ties between them.Domestically, the Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, the School of Food Science and Technology at Jiangnan University, the Junlebao Dairy Co., Ltd.in Shijiazhuang, and the College of Food Science and Technology at Yunnan Agricultural University form the core strength in the fermented milk flavor research field, yet collaboration among them is relatively sparse.Research hotspots primarily focus on lactic acid bacteria, flavor compounds, fermented milk processing technology, flavor evaluation, and quality and application.Future efforts should enhance inter-institutional and interdisciplinary collaboration, employing innovative technologies to develop fermented milk products of superior flavor and safety.

Squid belongs to the cephalopod class of mollusks, with short survival time, fast reproduction speed, comprehensive nutrition, high protein content, low-fat content, and low-calorie content.Squid skin accounts for 8%-13% of squid processing waste, and full utilization of squid skin can prevent resource waste.This article reviewed the nutritional components, peeling methods, extraction methods of collagen and gelatin from squid skin, as well as the preparation methods of squid skin collagen peptides with antioxidant activity, anti-hypertension, anti-skin aging, anti-tumor activity, and anti-freezing activity.The application of squid skin collagen products in industries such as food, medicine, cosmetics, and cosmeceuticals was also introduced.This article provided a systematic introduction to the research progress in the processing and utilization of squid skin, aiming to provide a theoretical basis for the deep processing of squid skin and promote the sustainable and healthy development of China’s aquatic product processing industry.In the future, the research should focus on optimizing the extraction process of squid skin collagen, improving the targeting of its target peptide screening, and conducting active clinical validation studies, to provide reference for the development and high-value utilization of squid skin.