Soluble solids content (SSC) is a key index to evaluate the quality of strawberries. In order to achieve the non-destructive evaluation of SSC, the near infrared spectroscopy was used to build the linear partial least squares (PLS) and nonlinear least squares support vector machine (LS-SVM) models. Twenty-seven effective variables were selected from the original 4 254 variables by combining both successive projections algorithm and Monte-Carlo uninformative variable elimination. The quantitative analysis models were then established by using the selected effective variables. At the same time, color feature parameters were obtained based on components of RGB images of samples considering the influence of surface color on strawberries, and the multi-parameter PLS and LS-SVM models were constructed by further integrating spectra and color features. Based on the same correction set and prediction set, the prediction performance of all models for SSC was compared. The results showed that MC-UVE-SPA was an effective spectral variable selection algorithm, and the multi-parameter fusion nonlinear LS-SVM model was the optimal model for the quantitative prediction of SSC in strawberries. For samples in the prediction set, the correlation coefficient (RP) and root mean square error of prediction (RMSEP) of the model were 0.9885 and 0.1532, respectively. This study lays a foundation for the development of portable instruments and online detection equipments for the detection of soluble solids content in strawberries based on near infrared spectroscopy.

The effects of pretreatment of samples with lactic acid, acetic acid, and citric acid respectively on the physical and chemical characteristics and the changes in volatile flavor components of air-dried yak beef were investigated in this paper. Fresh yak meat was cured with different organic acids. After the curing process, the shear force of the fresh yak meat was measured firstly. Then the marinated fresh yak meat was made into air-dried yak meat, and the pH value, color differential, water content, Aw, MFI, sensory quality and volatile flavor substances of samples were measured.The results showed that as the organic acid concentration increased, the shear force value of fresh yak meat decreased significantly（P＜0.05）, the pH value and a* value of air-dried yak meat also decreased significantly（P＜0.05）, and the water content、 Aw、 L* value、 MFI of air-dried yak meat increased significantly（P＜0.05）, but the b* value of air-dried yak meat showed no significant change（P＜0.05）. The air-dried yak meat had the best taste after 3% citric acid treatment. The content of volatile flavor substances in air-dried yak meat treated with lactic acid and citric acid increased, but that of air-dried yak meat treated with acetic acid decreased. In conclusion, the texture improvement of air-dried yak meat with 5% acetic acid pretreatment was the best, and the flavor quality of air-dried yak meat with 3-4% citric acid pretreatment was the best.

In order to explore the effects of different pulping processes on the quality of soybean milk, the organoleptic, nutritional，physicochemical indexes of soybean milk produced by the slurryprocess, the primary pulp residue co-cooking process, the secondary pulp residue co-cooking process and the hot water slurry process were evaluated..In addition,correlation analysis was carried out for each index.The highest sensory score of soybean milk was the secondary pulp and residue co-cooking process, with a score of 87.7.Hot water slurry process score of 87.3 points, ranked second. The soymilk from secondary pulp residue co-cooking process produces a soybean milk stability coefficient of 94.9%, a protein content of 3.890g/100g, a fat content of 1.814g/100g, and a total sugar content of 1.267g/100g, which has the best stability and highest content nutrients. The pariticle size of the soymilk obtained by the four pulping processes is mainly distributed between 0.1μm and 2μm. The maximum particle size of the soymilk is secondary pulping process which D50 and D[4,3] is 0.500μm and 0.547μm respectively, and the particle size of the raw slurry process soymilk is minimum, which is 0.423μm, 0.454μm respectively. Correlation analysis indicated that there is a significant positive correlation between protein content and viscosity, soybean milk stability, average particle size and sensory score (P<0.01), and the correlation coefficients were 0.968, 0.843, 0.979, 0.975,respectively.Protein content is negatively correlated to sedimentation velocity Significantly , the correlation is -0.974. Under the same conditions, the secondary pulping process is more suitable for soybean milk processing.

The present study was designed to explore the effects of Plasma treatment on properties of protein-based film-forming solutions. For this purpose, the WPI-NaCas-GLY composite film-forming solution was treated with atmospheric pressure cold Plasma of 30 W at different temperatures for 0, 5, 10, 15, 20, 30, 40 and 60 min，respectively. Changes in chromaticity, pH, particle size, surface tension, foaming properties and emulsifying capacity of the film forming solution during the treatment were observed. The results showed that the yellowness of the film forming solution rose, and the pH value waved to decline, protein polymerization increased the size of protein macromolecule particles in solution at a rate of doubling every 5 minutes with the extension of treatment time, due to the action of reactive oxygen species and nitrogen species induced by plasma. The protein carbonyl groups and free SH groups of the protein increased and decreased at the rate of doubling respectively, the surface tension of the matrix was reduced to about 35 mN/m, the foaming capacity was reduced by 10%, and the foam stability was significantly improved (P<0.05), increasing from 74.99 % to 94.60 %, and the emulsification capacity reached 0.12 m2/g. The tensile strength of the composite protein film was increased by 0.5 Mpa, light transmittance decreased, the oxygen transmission rate was reduced to 0.53 cc/(m2?day), and the water vapor transmission coefficient was reduced by about 40%. It was inferred that the timely Plasma treatment can effectively improve the hydrophobicity, foaming ability, and emulsification properties of protein-based film-forming solution, and got the ideal composite protein film.

Studying the adsorption properties of the porous magnesium oxide, which providing theoretical basis for its application in sugar industry. The porous magnesium oxide was synthesized by burnning the porous hydromagnesite which was synthesized by stir-the ageing method. By studying remel syrup of brown granulated sugar as the object, exploring the feasibility of the process of decolorization by the porous magnesium oxide. Through decolorization rate as the index, evaluation of variables effects such as the porous magnesium oxide dosage, preliming pH value, adsorption time, adsorption temperature for the decolorization for the remelt syrup of brown granulated sugar. the results showed that the optimal process conditions for the decolorization rate were:the porous magnesium oxide dosage:0.1 g, adsorption temperature60 ℃, adsorption time:60 min, preliming pH value:8.00, Under these optimal conditions, the decolorization rate:84.7% .The porous magnesium oxide was used to further investigations. The adsorption kinetics of the porous magnesium oxide was consistent with Lagergren equation Ⅱ. Moreover, the adsorption isotherm also complied with the Langmuir equation.

The apparent enzyme activity of immobilized papain was taken as the index,the effects of ultrasound frequency and power on the kinetics of immobilized papain chemical reaction were investigated. It was found that  the reaction of the immobilized papain decompose casein is consistent with the first-order reaction rate formula. Ultrasonic treatment can significantly reduce the apparent activation energy.The ultrasonic power was 0.05W/cm²,and the ultrasonic frequency was 28,40,50 and 135kHz,the apparent activation energy decreased gradually,and the apparent activation energy was the lowest at 135kHz 0.25W/cm²,it was38.23±0.53kJ/mol.When the ultrasonic frequency was 135kHz and the ultrasonic power is increased from 0.05W/cm² to 0.45W/cm²,the apparent activation energy was the lowest under the ultrasonic condition of 135kHz 0.25W/cm²,which was 32.81.When the ultrasonic power continues to increase,the apparent activation energy shows an upward trend.Under the ultrasound condition of 135kHz 0.25W/cm²,The apparent activation energy was the lowest, which was 32.81±0.09kJ/mol,the apparent activation energy decreased by 52.48% .

The atrazine-degrading strains were selectedusing high atrazine concentration solid culture and high performance liquid chromatography (HPLC), then the dynamics of growth and atrazine degradation rate were determined, and the effects of co-substrates and environmental condition ondegradation rate were also evaluated. The results showed that 10 strains had degradative capability for atrazinewith the degradation rate from 13.3% to 41.1%, and the maximum degradation rate was obtained with strain XQB-33. Among 10 strains, 4 strains (XQB-1, XQB-21, XQB-25, XQB-33) showed the higher atrazine degradation capacity (38.1%, 34.6%, 37.3% and 41.1%, respectively)．Furthermore, 4 strains with higher degradative capacity reached logarithmic phase, and showed the highest atrazine degradation rate after 72h liquid medium culture. After addition of glucose, sodium citrate, sucrose and succinic acid sodium acetate as co-substrates, the degradation rate of 4 strains increased significantly, especially for 0.5% glucose, the degradation rate of XQB-1 and XQB-1 increased by 15.2% and 14.3%, respectively.The environmental factors can affect the degradation efficiency. The optimum reaction conditions for 4 strains degradation were inoculation amount 2.0%，initial concentration of atrazine 100-200 mg.L-1, initial pH value 5-6, culture temperature at 30℃, and volume at 75-100100mL/150mL.

The drying technology of hot air drying, vacuum freeze drying and spray drying were used to prepare Rosa xanthina Lindl powder. The effects of different drying methods on the physicochemical properties and effective components of the powder were investigated. The results showed that the powder obtained from three kinds of drying methods were good in water solubility and low in moisture content. The flowability, moisture absorption and CRH of the powder prepared by hot air drying were better than others drying methods, but the color of this powder was brown and the active ingredient of anthocyanin was not detected. The powder prepared by spray drying had the lowest yield 77.51%, meanwhile, the powder had bright purple color, the best water solubility, the smallest particle size 7.71 μm, and the content of anthocyanins, polyphenols and flavonoids was the highest than others drying methods. Based on the results of comprehensive scoring, the quality of Rosa xanthina Lindl powder by spray drying was the best. Considering the quality of the powder and the efficiency and cost of drying methods, spray drying method was selected as the most suitable method, which showed potential application in Rosa xanthina Lindl powder processing industry.

Fermentation was optimized for succinic acid production of recombinant Yarrowia lipolytica PGC11505 using 2.5-L bench-top fermenter.. The results showed that, the output of succinic acid was enhanced substantially after the optimization of speed of revolution, aeration rates, initial concentrations of glycerol and peptone, pH value of the fermenter. For detail, production of succinic acid was doubled under the speed of 600 r/min versus 400 r/min. Aeration rate of 1.0 vvm was appropriate when compared with 0.5 vvm and 2.0 vvm. Oxygen was deficient if aeration rate was low and it would waste power and energy when aeration rate was high. PGC11505 grew well and fermentation was done totally when the initial glycerol concentration was 100 g/L, the output of succinic acid reached 21.0 g/L. It was optimal for succinic production with 10.0 g/L peptone. PGC11505 performed the best when the pH value was kept natural as compared with pH value of 4.0, 5.0 and 6.0, which achieved 26.3 g/L succinic acid and a yield of 0.27 g/g. Finally, fed-batch fermentation was taken under natural pH value for 138 hours. A total of 192.5 g/L glycerol was consumed and 46.9 g/L succinic acid was produced with a yield of 0.24 g/g and productivity of 0.34 g/g/h. After optimization, the output of succinic acid was improved by 4.7.

Lactobacillus plantarum was used as starter to ferment compound soybean milk. The changes of proteins, peptides, lipids, lactic acids, amino acids and 4 kinds of isoflavone were determined before and after fermentation. Three antioxidant models were used to analyze the changes of antioxidant activity of the compound soybean milk. The results showed that after fermentation the contents of peptides, lactic acids and amino acids in compound soymilk increased significantly; isoflavone glucoside declined while the content of isoflavone aglycone increased. The antioxidant activity of compound soymilk after fermentation was enhanced. The results of gas chromatography-mass spectrometry showed that alcohols, acids and esters aroma components increased significantly after fermentation, which improved the flavour of compound soymilk.

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.

Monensin is a kind of polyether antibiotic produced by Streptomyces cinnamonensis, which is widely used in fields including medicine and agriculture due to its environmentally friendly and efficient properties.However, the low oxygen condition commonly existing in the monensin production process strictly limited the monensin fermentation level.Based on the previous integrated expression of the monensin biosynthesis pathway specific regulatory genes monH and monRII, this study attempted to integrating Vitreoscilla hemoglobin gene vgb by heterologous expression to increase the monensin fermentation titer by improving the oxygen uptake capacity of strains.Results showed that the optimized conditions (40 mmol/L Ca²⁺, donor-recipient ratio 100∶1, antibiotics adding time 18 h) significantly improved the conjugation efficiency by 3 times.With successful integration of vgb with monH and monRII, two engineering strains, 2110-monH-vgb and 2110-monH-monRII-vgb were obtained.They produced 18.0% and 21.3% of the monensin higher than that without heterologous expression, respectively, under the extremly weak oxygen shake-flask condition.The biomass of 2110-monH-monRII-vgb in a 5 L bio-fermentor was slightly higher than that of the starting strain, but its monensin titer reached 13.4 kU/mL, which was 55.7% higher than that of the starting strain.In conclusion, by optimizing the conjugation efficiency of S.cinnamonensis and applying it to the genetic engineering of S.cinnamonensis in monensin fermentation, this study successfully obtained a vgb integrated strain by heterologous expression that effectively increased the monensin fermentation level, which would supply a substantial foundation for its subsequent industrial application.

Fermented corn sauce powder is a fermented product with freshening and flavoring effect made of corn and edible salt as the main raw materials, through special strain fermentation and other processes, which can be applied in food to provide umami and salty taste.A variety of volatile and non-volatile compounds work together to determine the flavor characteristics.Therefore, this article uses solid-phase microextraction (SPME) combined with GC-MS and HPLC to quantitatively analyze volatile and non volatile compounds (free amino acids and 5′-nucleotides) in a fermented corn sauce powder on the market, and studies the freshening application characteristics of fermented corn sauce powder in soy sauce.The results showed that fermented corn sauce powder had rich flavor characteristics.A total of 34 volatile compounds were detected.Among them, 12 volatile compounds were OAV≥1.In terms of non-volatile compounds, some amino acids and 5′-nucleotides contribute to the umami taste of sauce powder, amino acids such as Ala can provide sweetness to sauce powder, and amino acids such as Arg provide bitterness.Combined with the orthogonal experiment and sensory evaluation, it was found that the soy sauce prepared by adding white granulated sugar (12%), fermented corn sauce powder (5%) and yeast extract (1%) had the best sensory evaluation, which could increase the flavor and sweetness of soy sauce crude oil while inhibiting its bitter and astringent taste.This study can provide theoretical support for the flavor research of fermented corn sauce powder and its deep application in other seasonings.

The production of 1,6-hexanediamine as the synthetic monomer of nylon 66 is mainly monopolized by foreign countries, and the traditional chemical synthesis of hexanediamine contains highly toxic cyanide, high technical barriers, long production process, how to use the biological method to make innovative breakthroughs in the context of carbon neutrality has become a challenge.However, up to now, no natural hexanediamine synthesis pathway has been reported.In this study, 6-aminohexanoic acid, a widely available substrate, was used to construct a synthetic pathway for hexanediamine through component-adapted assembly, and fermentation enhancement was combined to increase the yield of hexanediamine in engineered strains.Finally, excellent carboxylic acid reductase MAB CAR L342E, single transaminase HATA, and double transaminase combination PatA/VFTA were obtained through screening, and the initial hexanediamine yields of the engineered strains after combination could reach 3.01 mg/L (DAH4) and 8.50 mg/L (DAH37), respectively.On this basis, the fermentation conditions were optimized, and the yields of 1,6-hexanediamine reached 64.33 mg/L and 153.93 mg/L, which were 20.37 times and 17.11 times higher than those before optimization, respectively.This study has successfully constructed a pathway for the synthesis of hexanediamine by biological method, which provides technical support for the breakthrough of domestic chemical products.

This study aimed to study the uric acid (UA) lowering activity of Sanghuangporus sanghuang ethanol extract in vitro, the inhibitory activity of free phenol extracts of four different sources of Sanghuangporus sanghuang (wild Phellinus vaninii, cultivated Inonotus hispidus, cultivated Phellinus vaninii, and wild Inonotus hispidus) on xanthine oxidase was determined.Furthermore, the inhibitory effect of free phenol extracts on uric acid production in high uric acid cell models.Additionally, the main compounds in strong active extract were analyzed by UPLC-MS/MS.Results suggested that cultivated Inonotus hispidus, cultivated Phellinus vaninii, and wild Inonotus hispidus showed strong inhibitory effects on xanthine oxidase (XOD), the IC₅₀ values were (94.63±2.73) μg/mL, (99.69±2.50) μg/mL, and (106.32±5.06) μg/mL, respectively.Cultivated Inonotus hispidus and wild Phellinus vaninii showed better UA lowering ability than those of wild Inonotus hispidus and cultivated Phellinus vaninii in the high UA cell model (P<0.05).Results obtained from UPLC-MS/MS showed that the strong active components of flavonoids including hyperoside, (-)-epicatechin, theaflavin, diosmin, and cynaroside, may be the active components for lowering uric acid.This study may provide some theoretical references for the application of uric acid-lowering products of Sanghuangporus sanghuang.

‘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.

Diacetyl is one of the most important substances in dairy products and contributes to buttery flavor in cheese.Based on the biosynthesis pathway of diacetyl, 23 strains of lactic acid bacteria were screened according to the ability to produce diacetyl, activities of acetoin reductase, α-acetolactate decarboxylase, and diacetyl reductase for adjunct culture, the growth ability in ripening environment of cheddar cheese, and autolysis degree.The impact of the selected adjunct culture on the properties of cheddar cheese was evaluated with a rapid ripening model.The ripening experimental results showed that the addition of adjunct cultures did not result in significant difference in the physical and chemical indicators, proteolysis, and texture of cheddar cheese except the flavor profile.Compared to the other groups, diacetyl content and buttery flavor was higher in the cheddar cheese prepared with CCFM 601, and the decline of diacetyl was slower during ripening.Therefore, the addition of adjunct cultures in cheddar cheese with high production ability of diacetyl could enhance the milky flavor of cheddar cheese during ripening.

Fresh meat, legumes, aquatic products, and vegetables transformed into fermented foods with significantly different flavor after a period of time of microbial fermentation naturally or artificially, which have been widely loved by people all around the world since ancient times.Organic acids, amino acids, peptides, and sugars formed in the fermentation process of food raw materials are important flavor substances, which determine the taste and flavor of fermented food.Based on extensive literature review, this paper reviewed the research progress of six main taste substances of fermented food, such as sourness, sweetness, bitterness, saltiness, umami, and kokumi, mainly focused on the formation mechanism of six taste substances, and the foreground of its application and development were pointed out, for the purpose of providing reference for the quality control of high-quality fermented foods.

To study the sensory characteristics and different aroma compounds of wines made from grapes with different maturities, grapes with four maturities of 20, 23, 25 and 27.5 °Brix were selected for small-scale fermentation, and the wines with different maturities were analyzed by GC-MS and flash profile (FP).Results showed that with increasing maturity, the alcohol content in the wine body increased, the total acid content decreased, and the alcohol content showed an overall increasing trend, while the acid content showed an initial increasing and then decreasing trend.The content of 2-methylbutanol and ethyl butyrate in T27.5 wine sample was highest (620.62 mg/L, 5.45 mg/L) and the wine body showed the strongest fruit and fat aroma.The content of ethyl isobutyrate in T25 was highest (2.77 mg/L) and the wine body showed the strongest floral and sweet aroma, while T23 and T20 had no prominent aroma characteristics.Sensory evaluation analysis showed that the grass aroma was prominent in T27.5 wine sample, the red berry aroma was prominent in T25, and T23 and T20 had obvious sensory characteristics in acidity and color.In summary, among the four maturity wines, the appearance and flavor of T20 and T23 wine samples were the best, and the active aroma compounds of T25 and T27.5 wine samples were the most.This study provides a theoretical basis for the scientific control of grape maturity and the production of diversified wines.

The effects of adding cellulose with different particle sizes and proportions on the gel properties of three common surimi products, namely fish balls, fish intestines, and fish cakes, were studied, and the best particle sizes and proportions were selected.This experiment determined the best particle size and proportion by studying the effects of adding different particle sizes and proportions of cellulose on the whiteness, water holding capacity, gel strength, total texture analysis, water distribution, and sensory aspects of fish balls, fish intestines, and fish cakes.The experiment found that the addition of cellulose could effectively improve the whiteness, water retention, gel strength, and texture characteristics of three common surimi products, and reduce the content of free water.The water holding capacity of fish balls, fish intestines, and fish cakes, gel strength, hardness, chewiness, and the proportion of water that was difficult to flow would increase with the increase of cellulose particle size, and first increase and then decrease with the increase of the addition proportion.It was found that the particle size of cellulose was 200 μm.When the addition ratio was 2%, the sensory evaluation would be more popular with consumers.After comprehensive consideration, the particle size of added cellulose was 200 μm.When the addition ratio was 2%, the quality of three common surimi products could be improved to the greatest extent, and the water holding capacity of fish balls, fish intestines and fish cakes can be increased by 14.5%, 22.1%, and 8.9% respectively.Gel strength increased by 121.9%, 108.7%, and 65.5%.Hardness increased by 97.5%, 107.0%, and 158.8%.The proportion of non-flowing water increased by 0.8%, 1.7%, and 1.7%.

Recombinant collagen is a biopolymer with broad potential applications in various fields, such as biomedicine and tissue engineering.The triple-helix structure of collagen imparts unique biological functions and biocompatibilit but also increases the complexity of its expression in microbial systems.In this study, bacterial collagen V-B was used as a model protein to promote the expression of recombinant collagen in Corynebacterium glutamicum through optimization of expression elements.Firstly, the most efficient promoter tac-R0 was obtained through promoter screening and fermentation duration optimization.Subsequently, the RBS calculator was used to design a mutation library for ribosome binding sites (RBS) and aligned spacing (AS).The RBS and AS with the highest strength were identified, which increased the yield of V-B to 514 mg/L.Furthermore, through the tandem combination of multi-gene expression cassettes, the final yield of V-B increased by 8.4-fold compared to the initial level, reaching 697 mg/L.This study lays a foundation for the industrial production of recombinant collagen.

To study the fresh-keeping effect of nutmeg essential oil/hydroxypropyl-β-cyclodextrin (NEO/HP-β-CD) inclusion complex on chilled pork, the chilled pork was treated with different concentrations of NEO/HP-β-CD inclusion compound in combination with the soaking method, smear method, and non-woven fabric method.The indexes including total bacterial count, pH, volatile basic nitrogen, thiobarbituric acid value, texture, juice loss rate, color, and sensory indicators were measured every two days.Results showed that the non-woven fabric method containing 1% NEO/HP-β-CD inclusion complex could effectively reduce the total bacterial count, pH value, and volatile basic nitrogen content of chilled pork during storage, delay the deterioration of texture and color of pork, and improve sensory quality.Compared with the control group (6 days), the storage period of this group could be extended by 6 days.Therefore, the non-woven method containing 1% NEO/HP-β-CD inclusion complex has a good preservation effect on chilled pork.

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.

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.

To explore the protective effect of component from Poria cocos polysaccharide (PCP) on freeze-drying of compound lactic acid bacteria, purified component from Poria cocos polysaccharide was prepared successfully and its structure was characterized, studying its protective effect and mechanism on freeze-drying of compound lactic acid bacteria.Results showed that PCP-1 with total sugar content of (96.21±0.39)% was obtained after isolation and purification, and the weight average molecular weight of PCP-1 was 11 732 Da.PCP-1 is mainly composed of glucose and glucuronic acid, with the molar ratio of 0.989∶0.011.Moreover, there are hydroxyl groups and both α and β glycosidic bonds in PCP-1.Adding PCP-1 into the basic protective agent increased the freeze-dried survival rate of compound lactic acid bacteria by 11.29% when compared with PCP.The surface of lactic acid bacteria powder with PCP-1 was denser by observed with scanning electron microscope.Furthermore, the activities of Na⁺-K⁺-ATPase and lactate dehydrogenase of compound lactic acid bacteria were significantly enhanced by adding PCP-1 to the basic protective agent, which increased by 0.66 U/mg prot and 1.46 U/mg prot, respectively.The cell membrane integrity of the compound lactic acid bacteria added with PCP-1 was better maintained after double staining with propidium iodide and fluorescein diacetate.In conclusion, PCP-1 may reduce the freeze-drying damage of compound lactic acid bacteria by forming hydrogen bonds through the existence of hydroxyl groups, and improve the freeze-drying survival rate of compound lactic acid bacteria.

Acidic stress has limited the development of industrial microorganisms during the fermentation process.Fine regulation of biofilm formation is an effective strategy to improve the acid tolerance of Escherichia coli.A dual-plasmid regulatory system based on the EL222 blue light-inducible protein was successfully constructed with an 8.6-fold increase in regulatory efficiency.This dual-plasmid expression system was further used to regulate the expressions of a biofilm formation key regulatory factor CsgD and diguanylate cyclase M (DgcM) proteins.The results indicated that the acid resistance of CsgD and DgcM overexpressed strains was improved by 22.3% and 16.4% under conditions of pH 5.0 and 15 mW/cm² blue light irradiation.Moreover, the biofilm content was increased by 2.7 and 3.4 times, respectively.The analysis of biofilm composition revealed that the level of polysaccharides and proteins increased, while the soluble microbial products decreased under acid stress.These changes promoted bacterial aggregation, contributing to the formation of a more stable biofilm structure.Quantitative reverse transcription PCR (RT-qPCR) results further showed a significant upregulation in the transcription levels of biofilm formation-related genes.This blue light-regulated system successfully improved the acid resistance of E.coli by controlling key genes for biofilm formation, which will offer potential references and guidance for microbial organic acid fermentation.

In order to investigate the inhibitory activity of oyster peptides against dipeptidyl peptidase Ⅳ (DPP-Ⅳ), as well as their synergistic effects with anthocyanins, oyster peptides were obtained using the enzymatic hydrolysis method, and their structures were characterized.Furthermore, an in vitro DPP-Ⅳ activity inhibition model and the Compusyn collaborative calculation model were used to analyze the synergistic effect of oyster DPP-Ⅳ inhibitory peptides and anthocyanins in inhibiting DPP-Ⅳ activity.The results indicated that the molecular weight of oyster peptides was primarily below 3 kDa (55.44%), with branched-chain amino acids (BCAAs) and proline (Pro) accounting for 60.84% of the total hydrophobic amino acids.Peptide profiling analysis revealed that the predominant 17 peptide segments in oyster peptides were significantly enriched in BCAAs and Pro at the N-terminus, displaying significant structural characteristics of DPP-Ⅳ inhibitory peptides.Among the five peptides synthesized through screening (FPVGR, APPNIT, IAPPERK, LDFYLDIP, LAIL), FPVGR exhibited the strongest DPP-Ⅳ inhibitory activity (P<0.05).Moreover, among the six common anthocyanins (peonidin/cyanidin/malvidin/delphinidin/pelargonidin/petunidin-3-O-glucoside:Pn3G, C3G, Mv3G, D3G, Pg3G, Pt3G), Pn3G, C3G, and Mv3G demonstrated the strongest DPP-Ⅳ inhibitory activity (P<0.05).Synergy studies revealed that FPVGR and Pn3G/C3G/Mv3G displayed synergistic inhibitory effects against DPP-Ⅳ (with CI values of 0.89, 0.93, and 0.89, respectively, at a 50% inhibition rate).This study provides a scientific foundation for further research on the synergistic activity of DPP-Ⅳ inhibitory peptides and anthocyanins.

Lactic acid bacteria (LAB) fermentation of oats is a new processing method for oat products.However,there is still lack of suitable strains for oak, and the quality traits were not well characterized.This study evaluated the fermentation performance of 20 different strains of LAB in MRS broth, and two optimal strains (Lactobacillus plantarum) were screened.These two strains were combined with common milk fermentation strains Streptococcus thermophilus and Lactobacillus bulgaricus to ferment oat.The fermentation performance of different stains combinations in oat and their effects on physicochemical parameters and flavor quality of oat were studied.Results showed that L.plantarum generally exhibited higher growth and acid production performance, and the amylase activity of L.plantarum was above 7.69 U/mL.The viable count of fermented oat increased to above 10⁹ CFU/mL.Fermentation significantly reduced the reducing sugar, accumulated organic acids, promoted the release of polyphenols and flavonoids, and improved the antioxidant activities of oat.Fermentation increased the water holding capacity of oat and produced more volatile substances.The fermentation with L.plantarum improved the phytochemistry content and antioxidant capacity of mixed stains fermentation group.Fermentation increased the water holding capacity of oat pulp and produced a large number of volatile substances.Compared to pure fermentation of L.plantarum, the mixed fermentation group contained a higher content of 3-hydroxy-2-butanone with a creamy aroma.Among them, L1-L4-F showed the best overall sensory quality, antioxidant activities, and flavor quality, making it a suitable fermenting combination for oat, with greater research and development value.

Oxidative stress is one of the important pathogenesis of Parkinson's disease (PD), and chitosan oligosaccharides have good antioxidant activity and protective effects in neuropathic diseases such as PD.The mice were divided into a control group, model group, low dose group (35 mg/kg), medium dose group (70 mg/kg), and high dose group (140 mg/kg).The mice were intraperitoneally injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce PD mice models.To explore the dose-effect relationship and protective mechanism of chitotriose in PD mice, the mice in each group were evaluated by behavioral and pathological indexes and the related indexes of oxidative stress.Results showed that low, middle, and high doses of chitotriose could alleviate the behavioral disorder and the decrease of tyrosine hydroxylase (TH) expression in the striatum of PD mice, and the middle dose group had the best effect.The chitotriose intervention significantly reduced the content of malondialdehyde (MDA) in the striatum of PD mice, significantly increased the levels of glutathione (GSH), total antioxidant capacity (T-AOC), catalase (CAT), and superoxide dismutase (SOD), and up-regulated the nuclear factor E2 related factor (Nrf2)/heme oxygenase (HO-1) signal pathway.Results indicated that the middle dose of chitotriose had a more obvious alleviating effect on MPTP-induced PD mice.The mechanism of its action may be to reduce oxidative stress and alleviate PD by increasing the expression of antioxidant enzymes and up-regulating the Nrf2/HO-1 signaling pathway.

Triacetic acid lactone (TAL) is a promising platform polyketide with broad applications, especially it can be used as a precursor for the synthesis of various organic compounds.This study characterized the repeating sequences on the yeast genome to integrate the TAL biosynthesis pathway into these sites for enhanced gene expression and TAL production by Saccharomyces cerevisiae.Firstly, this study used the green fluorescent protein as the reporter to characterize multi-copy integration by the Delta1 site.It showed that truncating the promoter of a selection marker gene (for geneticin or hygromycin B) or increasing the antibiotic concentration, were effective in improving the integration efficiency and copy numbers.The highest copy number of multi-copy integration was obtained when truncating the antibiotic gene promoter to 15 bp, and using an antibiotic at 160 μg/mL.The optimization system was subsequently used to characterize the second multi-copy integration site, Delta2, with similar results.Then, the optimized multi-copy integration system was applied to introduce the TAL biosynthesis pathway into S.cerevisiae.The highest pathway copies using Delta1 and Delta2 sequences were 10 and 7, respectively, with Delta1 slightly better than Delta2.After 48 h fermentation in YTD medium, TAL titers of the Delta1-integration strain and the Delta2-integration strain were 1.50 mmol/L and 1.17 mmol/L, respectively, 460% and 337% higher than the single-copy integration strain.This study demonstrates that the multi-copy integration system is an efficient approach to introducing heterologous pathways into S.cerevisiae to improve biocatalytic efficiency.

Strains producing β-glucosidase were isolated by solid medium containing esculin and ferric.Then six strains having high β-glucosidase activity were selected with p-nitropheny l-β-D-glucopyranoside as substrate.Strain having high ginsenoside bioconversion was finally chosen with Rbl as substrate and converted products were determined by TLC and HPLC.β-glucosidase activity of this strain was 0.803 U/mL and ginsenoside Rd conversation rate was 97.234 2％.The selected strain was identified as Saccharomycopsisfibuligera based on the morphology and nucleotide sequence analysis of the 18S rDNA.Fermentation medium was optimized to contain lactose as carbon source and corn flour as nitrogen source,and Ca2+ as metal ion.Finally inducer was optimized to promote the ginsenoside bioconversion.Results indicated that inducer had little impact on the bioconversion but rutin,a kind of inducer,could promote the bioconversion of Rd to CK.The selected strain with high ginsenoside bioconversion had good potential application.

Microbial food cultures are important germplasm resources of the traditional fermented food industry.Based on the research of the first edition of the inventory,this study reviewed,analyzed and updated the microbial food cultures isolated from Chinese traditional fermented foods such as baijiu,dairy,condiments and tea et al.It is proposed the second inventory of microbial food cultures used in Chinese traditional fermented foods,which contained 56 genera and 124 species,including 74 bacteria,22 yeasts,and 28 filamentous fungi.Compared with the first inventory,49 new species have been added,such as the genus of Acetobacter spp., Bacillus spp., Companilactobacillus spp., Lactococcus spp., Weissella spp., Clostridium spp., Candida spp., Debaryomyces spp., Pichia spp., Aspergillus spp.,Eurotium spp. and Rhizopus spp., et al.Furthermore,the taxonomy of 41 species have been updated.This research provides references and scientific basis for application and management of microbial food cultures used in traditional fermented foods and it also aims to promote the healthy development of Chinese fermented food industry.

Microbial food cultures are important resources of the traditional fermented food industry.In this review,the references related to functional strains from Chinese traditional fermented foods such as dairy,baijiu,tea,soy sauce,vinegar,sufu and pickle were gathered and analyzed.The scientific criteria for evaluation of microbial food cultures were summarized.The first inventory of microbial species used in Chinese traditional fermented foods was proposed,which contained 30 genera and 75 species,including 42 bacteria,12 yeasts,and 21 filamentous fungi.After analyzing the functions of microbial food cultures during the key fermentation processes,the main functions of microbial food cultures were producing flavor substances and functional enzymes,improving the nutritional value,inhibiting competitive microbes,and improving the food texture,which aimed to provide scientific basis for improving the management of microbial food cultures in China.

研究了分别用HCl和乳酸调节培养基初始pH以及在发酵过程中加入不同的酸中和剂对乳酸菌生长和乳酸产量的影响.结果表明,终产物乳酸的积累是抑制乳酸菌生长和导致乳酸产量下降的直接原因,该情况随发酵液中H+浓度的升高(即pH的降低)而增强,H+的积累对菌体生长和产酸的影响是间接的;用CaCO3调节发酵液pH优于用NaOH和NH4OH.

Single-factor experiment and response surface methodology were used to optimize the ultrasonic-assisted aqueous two-phase extraction of polysaccharides from Potentilla anserina L. Four key factors including ethanol concentration, ammonium sulfate concentration, solid-liquid ratio and ultrasonic power were selected by one-factor-at-a-time experiments. The optimum conditions of ultrasonic-assisted aqueous two-phase extraction of polysaccharides from Potentilla anserina L. were as follows: Ultrasonic power at 240 W with 31% ethanol volume and 19% ammonium sulfate, the extraction yield of polysaccharides from Potentilla anserina L. reached (9.035±0.119)%. Infrared spectrum analysis confirmed that the extracts were polysaccharides. Potentilla anserina polysaccharide was composed of rhamnose, mannose, glucose and galactose, with the molar ratio of 1.00∶1.69∶10.61∶2.66. The in vitro activity results showed that the antioxidant activity of polysaccharides extracted by ultrasonic-assisted two-phase extraction was better than that of traditional water extraction. Ultrasonic assisted aqueous two-phase technology was a reliable and efficient method for polysaccharide extraction.

研究了不同种类人参中皂苷含量,以及人参不同部位中的皂苷成分及比例.总皂苷含量测定结果为,三七参根中含14.2%,西洋参须中含10.1%,人参根中含4.4%,人参头中含8.6%,人参皮中含6.7%,人参叶中含7.7%,人参须中含9.9%.对西洋参须、三七参根及吉林产的人参头、人参皮、人参叶、人参根、人参须中的总皂苷作TLC检测及薄层扫描表明,三七参根中Rg1含量最高,西洋参须中Rb1含量最高,人参根中Rd的含量可以忽略,人参叶中含有特征皂苷F2;它们的Rb1/Rg1值分别为,西洋参须中22.2,三七参根中0.6,人参头中4.3,人参皮中6.7,人参叶中0.2,人参根中2.4,人参须中11.9.

花青素是一种存在于自然界的水溶性多酚类化合物,现巴发现其具有多种功能.有关花青素的提取、分离和纯化研究报道很多,文中就近年来国内外相关方面的研究进展进行了分析.

Purine, an important nitrogen-containing base in organisms, is metabolized into uric acid in the body. When ingestion too much purine or purine metabolism disorder, it will lead to hyperuricemia, increase the incidence of gout and harm to human health. Meat is an important source of purine intake, and high purine content in meat can significantly affect blood uric acid levels in the body. In this paper, the relationship between purine and gout, the methods of purine pretreatment, detection conditions, the content of purine and the methods of purine reduction were reviewed so as to provide reference for the further study of purine. It could also provide scientific guidance for consumers to choose meat products and how to reduce the content of purine.

植物油是食用油的主要来源,植物油氧化对食品安全和人体健康有重要影响.因受到环境及其组成因素的影响,植物油脂氧化过程有别于脂肪酸简单氧化过程,全面了解其氧化过程及机理对于开展抗氧化研究具有重要意义.该文归纳了植物油氧化过程以及宏观氧化机理,并对各阶段氧化产物检测技术的发展进行了总结,最后系统综述了植物油脂氧化的影响因素,以期为相关工作的深入研究提供借鉴.

Collagen peptides(CPs) emerging as a new functional protein ingredients,were developing rapidly at home and abroad in recent years.In order to scientifically guide the industry crowd engaged and concerned about the CPs and promote the healthy and sustainable development of the CPs industry,the CPs definition,properties,preparation technology as well as current situation of domestic and foreign CPs industry were reviewed in this paper.And the three questions which concerned about by the downstream production enterprises and consumers during the promotion process of CPs,including the relationship between raw material sources and CPs product quality,the relationship between CPs efficacy and molecular weight,and the applied laws and regulations of CPs,were clarified.Finally,the research and development trends of CPs were prospected.

介绍了固态发酵的技术、特点及其优越性,讨论如何对固态发酵的生物反应过程进行工艺条件控制.同时综述了国内外固态发酵设备的开发现状及最新研究动态,为开发研制新型固态发酵设备提供参考.

生物类黄酮具有多种生物活性,可用于延缓衰老,治疗和预防癌症、心血管病等退变性疾病,具有很大的开发应用价值.论文就生物类黄酮的生物活性、药理作用、提取分离方法及应用进行了详细阐述,旨在为生物类黄酮的研究、开发、应用提供参考.

木糖广泛存在于林业及农业废弃物中,木糖发酵生产乙醇是再生资源的有效利用.文中报道了近几年来在利用基因工程菌发酵木糖生产乙醇方面的研究进展.重点介绍了大肠杆菌、酿酒酵母、树干毕赤酵母及运动发酵单胞菌的基因改造情况.

综述了抗氧化剂抑制脂质氧化、清除自由基、抑制自由基对底物的氧化降解以及还原能力4类测定抗氧化活性的方法,并讨论了评价或表征测定结果的方法和参数以及对测定方法的要求.

简要介绍了我国果蔬贮藏保鲜的现状,指出了当前果蔬贮藏的主要问题.论述了国内外有关果蔬贮藏保鲜的新技术及研究进展情况,包括:天然果蔬保鲜剂的研究、利用调压技术贮藏、臭氧及负氧离子保鲜、利用生物技术保鲜、静电场处理贮藏、低剂量辐射处理和紫外线处理保鲜以及细胞水结构化气调保鲜等国内外近几年发展起来的现代果蔬贮藏保鲜技术.并阐述了科技对我国果蔬贮藏保鲜产业的支撑作用.

Flaxseed is a functional food with high nutritional value, which is rich in unsaturated fatty acids, flaxseed gum, lignans, cyclolinopeptides, and other bioactive compounds, showing various biological effects, such as antioxidation, anti-inflammation, anti-cancer, anti-hypertension, and preventing cardiovascular diseases. This paper reviewed the main functional components of flaxseed and its recent research in bioactivities, emphatically introducing the research progress of cyclolinopeptides in terms of structure, extraction and isolation methods, and functional activity, and further proposed the direction that needed to be explored based on current research. Therefore, this review is anticipated to provide a theoretical basis and reference for the in-depth research and development and utilization of flaxseed in the field of functional foods.

花色苷是高等植物中最重要的水溶性色素.因其种类繁多、来源广泛、安全无毒并有一定的营养和保健功效而引起国内外的广泛关注,具有十分重要的开发价值和广阔的应用前景.近年来,有关花色苷的研究一直是国内外研究的热点.文中系统地介绍了国内外花色苷提取、分离纯化及鉴定的研究方法,并对各种方法进行了分析评价.

The recent advances in the mechanism of L-arabinose to inhibit the intestinal absorption of sugar have been reviewed.The overview on the application of L-arabinose in the different field,including food industry,medicine,and flavor industry was summarized.The potential values,various challenges,the opportunities,as well as future research directions are also presented.

Microcrystalline cellulose(MCC) is produced by acid hydrolysis of natural cellulose to a level off degrees of polymerization(LODP).It had wide applications in food,pharmaceuticals,and other industries.This paper mainly reviews its physicochemical properties,its application in food industry,and the prospect of its future development.It also provides theoretical references for researchers for further in-depth study.

综述了美拉德反应产物性质的.包括美拉德反应产物在醇溶剂的变化、抗氧化性、以及对营养素生物效价的影响和对人体的安全性等方面研究进展.