Abstract:Flavonoids are abundant in citrus and widely used in food， medicine， cosmetics， and other industries due to its various physiological activities. Flavonoids are mostly extracted from citrus and other plants， and a small amount is synthesized chemically or modified structurally. In recent years， the microbial method of constructing metabolism pathways in a host， such as Escherichia coli and Saccharomyces cerevisiae， has entered the research stage， which has sustainable application prospects due to its high safety， environmental protection. Collectively， this study briefly describes the synthesis of flavonoids in citrus and focuses on the research progress on the microbial synthesis of naringin， hesperidin， eriocitrin， etc. We also propose several problems with the heavy metabolic burden of the host， the low efficiency of gene expression， unreasonable distribution of carbon flux， and put forward solving methods including optimization of the host selection， microbial coculture， the expression system， and carbon flux. We hope to provide references for the current research on the microbial synthesis of flavonoids in citrus.

Abstract:In this study， we investigated the abundance and diversity of lactic acid bacteria（LAB） and Bifidobacterium in 27 healthy young people from Hainan province using laboratory-designed LAB primers and Bifidobacterium-specific primers； this work also aimed to discuss the influence of sex， age， and body mass index （BMI） on the quantities of these two bacterial groups. The fecal LAB in the volunteers were mainly composed of Streptococcus， Lactobacillus， Weissella and Ruminococcus. According to the composition of LAB at species level， all volunteers could be divided into two enterotyping. The proportion of Streptococcus salivarius in the two enterotyping had significant difference（P<0.05）. The abundance and diversity of LAB in the gut of male volunteers were significantly higher than that in women. In addition， volunteers’ could be divided into three different groups according to the diversity characteristics of bifidobacteria. The representative bifidobacterial strains are B. catenulatum， B. longum and B. stercoris， respectively. Both gender and BMI are factors influencing the composition of bifidobacterial. This study has established accurate methods in determining LAB and bifidobacteria in human intestinal samples， as well as preliminary described the LAB and bifidobacteria subpopulations in subjects of Hainan province. Results obtained in this paper serve as good reference for other studies.

Abstract:Objective： To explore the anti-obesity effect of Monascus-fermented Radix Puerariae extracts（MRPE） on high-fat induced obese C57BL/6J mice. Method. Thirty-two C57BL/6J mice were fed with high-fat diet to induce obesity. Then， the 32 obese mice were irrigated with distilled water （HF group， n = 8）， Monacolin K （MK group， n = 8）， normal dose of MRPE （MRPE-C group， n = 8）， and high dose of MRPE（MRPE-H group， n = 8）， respectively. After 4 weeks， the body weights， body lengths， abdominal fat， body-fat ratio and Lee’s index were recorded. Moreover， serum total cholesterol， triglyceride， HDL， LDL and serum lipopolysaccharide （LBP） were also measured. Results Compared with HF group， the body weight， body-fat ratio， Lee’s index， the serum contents of TC， TG and LBP of the mice from both MRPE-C group and MRPE-H group were reduced （P<0.05）. The serum HDL-C levels were also increased by MRPE treatment （P<0.05）. Moreover， high dose of MRPE treatment could significantly reduce the serum LDL-C level of mice （P<0.05）. In general， a dose-dependent anti-obesity effect of MRPE was observed. Compared with MRPE-C group， body-fat ratio and serum LDL-C level of the mice treated with high dose of MRPE were reduced by 20.43% and 8.22%， respectively. In addition， the anti-obesity and lipid profile modification effect of high dose of MRPE was similar to Monacolin K. Conclusion MRPE can alleviate fat accumulation and reduce body weights of high-fat induced obese mice effectively， which indicated the anti-obesity effect of MRPE.

Abstract:Influence of different amylose/amylopectin ratio of starch on the gel property of high methoxyl pectin were studied by using an oscillatory rheometer and Texture Profile Analysis. Dynamic rheological studies suggested that as the proportion of amylose increased， the G′ and G″ values of the mixed gel increased， the tan δ decreased， and gave rise to better viscoelasticity. In static rheological studies， pectin gel remained pseudo-plastic fluids despite the presence of starch， and in the presence of higher proportion of amylose， the mixed gel showed higher consistency coefficient K and lag ring area， and lower fluid index n. The textural properties of the mixed gel were influenced by the proportion of amylose. Hardness， adhesiveness and cohesiveness of the gel significantly increased with the increase of the proportion of amylose. It is concluded that the amylose proportion of the starch in the pectin gel was a great determinant of gel property. Hydrogen bonding between pectin and starch might was a major physical force affecting gel texture as testified by adding urea.

Abstract:Objective： The alginate lyase gene from Pseudomonas syringae was cloned and expressed in Escherichia coli BL21（DE3）. After the recombinant alginate lyase was purified， the enzyme and the antioxidant activity of the enzymatic hydrolysates were characterized. These will set up a good foundation for further researches of structure and function of this enzyme. Methods： The alginate lyase gene was amplified by PCR and cloned into pET-28a expression vector. After the recombinant enzyme was purified using affinity chromatography， it was characterized. The antioxidant activities of the enzymatic hydrolysates were analysed by detecting the reducing ability and scavenging power on ABTS+ and hydroxyl radicals. Results： The molecular weight of the recombinant alginate lyase from P. syringae was 40.8 kDa. The recombinant enzyme showed activity towards polymannuronate. The optimal temperature and pH of the enzyme were 30 ℃ and 7.5， respectively， and it was stable at temperature below 50 ℃. In addition to SDS and DTT， the recombinant alginate lyase had good resistance to other detected inhibitors and detergents. The enzymatic hydrolysates had the reducing power. The half inhibitory concentration（IC50） values of scavenging ABTS+ and hydroxyl radicals were 1.56 mg/mL and 0.56 mg/mL， respectively. Conclusion： The enzymatic hydrolysates exhibited the antioxidant activity and had potential as antioxidant products.

Abstract:Objective： The effects of different culture conditions on expression of key extracellular gene PrtB of the protein hydrolysis system of Lactobacillus bulgarian was evaluated in the present experiment. Methods： Real-time PCR technology was used to determine target gene expression among different strains under different growth periods and different nitrogen sources， initial pH（5.6，5.9，6.2，6.5） and temperature（30，37，42，45 ℃）. The experimental results showed that the expression levels of PrtB were significantly reduced in three strains of Lactobacillus bulgaricus LB08012, LB08014 and LB08016 from the early logarithm phase to the stable phase（P<0.05）. Under the condition of N lack of culture， the expression of PrtB was significantly higher（P<0.05） than that of normal state culture. In addition， the expression of PrtB was significantly decreased （P<0.05） under the cultivation condition of adding the casein. The expression quantities of PrtB in the medium of pH5.9, 6.2 and 6.5 were significantly increased （P<0.05） in strains LB08006, LB08007, LB08012 and strain LB08016， however， the expression quantities of PrtB in strain LB08014， LB08015 and strain LB08017 was significantly decreased（P<0.05） compared to the control group （pH 5.6）. In liquid MRS medium at different temperatures， the expression of prtb of strains LB 08007, LB 08012, LB 08014 and LB 08015 increased first and then decreased at 37 ℃, 42 ℃ and 45 ℃， while the prtb expression of strains LB 08006， LB 08016 and LB 08017 increased first. After the reduction. At a temperature of 45 ℃, the expression level of PrtB tended to be 0， which was 10.7 times lower than that of the control group （30 ℃）.

Abstract:3-Aminopropanamide is one of the intermediate products during the Maillard reaction between asparagine and reducing sugars， as well as the direct precusor of acrylamide. In this research， we identified the adduct formed between the reactions of 3-aminopropanamide and acrylamide and investigate the effect of different parameters on the adduct formation. When the concentration ratio of acrylamide to 3-aminopropanamide was kept at 3 ∶ 5 and reacted at 160 ℃ for 20 min， 47.29% of acrylamide was eliminated through Michael addition reaction.

Abstract:Botrytis cinereais the main pathogenic fungi of post-harvested blueberry. The enzyme production condition of Botrytis cinerea was optimized by signal factor analysis and its enzymatic properties were studied. Results showed that the maximum lipase production was obtained after 96 h fermentation of medium contained 1%（m/m） of olive oil and 1% of peptone. Results of enzymaticproperties showed that this lipase had a wide adaptation to pH and temperature. The hydrolytic activity of crude lipase was highest when reaction temperature was 40 ℃ and pH = 9.0. The activity of crude lipase was activated by Na+ and Fe3+， but was inhibited by K+，Ca2+，Mg2+ and Cu2+. The crude lipase had good tolerance to isopropyl alcohol， methanol and acetone， and ethyl acetate and benzeneenhanced its activity. Optimizing the fermentationconditions of Botrytis cinerea could increase the production of lipase and lay the foundation for the furtherisolation and purification of lipases. Results of this study will provide a guidance on pre-harvest disease control and post-harvest quality protection of blueberries.

Abstract:The effect of culture conditions （initial pH， temperature and inoculum size） on the survival of Lactobacillus plantarum LIP-1 during freeze drying was investigated using single factor method. Based on these datas， the optimum culture conditions were obtained by response surface methodology. The results showed that the optimal culture conditions of Lactobacillus plantarum LIP-1 were pH 6.7， temperature 36 ℃， inoculum size 8.8%. Under this culture conditions， the number of viable cells of LIP-1 by high-density fermentation was 10.1855 lg（CFU/mL） and the survival rate of freeze-dried was 83.40%. Compared with the basic culture conditions increased by 0.2935 lg（CFU/mL） and 8.46% respectively， and showing a significant increase （P<0.05）. The results indicated that the optimum culture conditions is benefit to increase the number of viable cells through high-density fermentationthe and improve the survival rate of freeze-dried of lactic acid bacteria.

Abstract:L-valine， as one of the essential amino acids， has important applications in many fermented food ingredients. Timely understanding and monitoring its fermentation process is beneficial to improve the quality of L-valine products. In this paper， a new method for monitoring the production process of fermented food ingredients was developed. And the near infrared model of the main raw materials and products was established by analyzing the raw materials and products of fermentation. On this basis， combined with the metabolic flux model， the distribution and variation of metabolic flux in cells under different fermentation conditions can be rapidly analyzed monitor the parameters of the fermentation process in real time. The method can simultaneously detect the components quickly and accurately， thus making up for the shortcomings and shortcomings of the traditional detection methods； Meanwhile the method can quickly and accurately obtain the metabolic flow distribution in the cell during fermentation， so as to help control the fermentation process， monitoring the fermentation process parameters for real-time. It provides a theoretical basis for the automatic control of fermentation process， and provides a method for monitoring the production process of fermented food ingredients.

Abstract:The sunflower meal was used as experimental object in this experiment， getting water-soluble dietary fiber and insoluble dietary fiber by the method of water extract-alcohol precipitation， and using the ultrasonic modification treatment to compare the physical and chemical properties of SDF and IDF before and after modification， thermal stability and change of the internal microstructure. Results showed that ultrasound modification caused 3.09% and 8.96% increase of the holding water capacity for USDF and UIDF， respectively， whereas led to 23.73% and 17.45% increase of the oil force for USDF and UIDF， respectively. UIDF was superior to IDF on the scavenging effect of DPPH and ABTS+. Thermogravimetric analysis showed that dietary fiber showed three stages of weightlessness before and after modification. The analysis of laser particle analyzer shows that the particle size of UIDF particles decreased and the distribution was more concentrated. SEM analysis showed that the surface of USDF becomes smooth， while the number of UIDF pits and wrinkled skirts increased. FTIR showed that the peak shape and fundamental position of characteristic absorption peaks of USDF and UIDF are not changed， but the intensity of some peaks was weakened. XRD analysis showed that ultrasonic diffraction diffraction did not caused a change in the crystal structure of SDF and IDF； GC-MS results showed that the dietary fiber of the sunflower meal were mainly composed of arabinose， rhamnose， xylose， mannose， galactose， and glucose.

Abstract:Red raspberry seed was taken as main material in this study. The ultrasonic-cellulase assisted extraction on red raspberry seed flavonoids was optimized by response surface methodology. And changes of flavonoid content were investigated by establishing gastrointestinal model in vitro. Based on Box-Benhnken central combination design， extraction rate of flavonoids were taken as index， effects of three crucial factors were investigated by response surface experiment. The results showed that： optimum extraction conditions provided the maximum extraction rate（34.33 mg/g） of flavonoids were determined as follows： cellulase concentration was 0.009 mg/mL， ultrasonic extract power was 70 W， temperature was 55 ℃， pH was 5.5， volume fraction of ethanol was 60%， when the condition of solid-liquid ratio was 1 ∶ 40 g/mL. After the gastric digestion 2.5 h， quantity of flavonoids were 1.28 times higher than blank group. And after the digestion intestinal 2.5 h， quantity of flavonoids were 1.59 times higher than blank group. It indicates that both pepsin and trypsin could promote the release of red raspberry seed flavonoids.

Abstract:Chitosan oligosaccharides COS-N conjugate were prepared by Maillard reaction in solution condition. Infrared spectroscopic analysis and scanning electron microscope showed that COS and NISIN are cross-linked by covalent bonds， and the structure were also changed. The median lethal dose（LD50） of COS-N Mixture and conjugate on Escherichia coli and Staphylococcus aureus were measured. The results showed thatunder the same testing conditions， the LD50 of COS-N Conjugate to Escherichia coli and Staphylococcus aureus was reduced by 22% and 55% respectively. when compared with that of COS-NMixture. The study on the antimicrobial mechanism showed that COS-N conjugate could destroyed the integrity of cell membrane， released the intracellular substances and increased the permeability of bacterial cell membrane to a greater extent， when compared with that of COS-N Mixture. In summary， Maillard reaction can effectively improve the antibacterial activity of COS-N Conjugate， which can a novel way to synthesis natural preservatives.

Abstract:This work studied the inulin which is a kind of inulin-type fructans with high degree of polymerization and the oligofructose which is a kind of inulin-type fructans with low degree of polymerization at different concentrations on the quality of fermented milk containing Bifidobacterium BB-12. Based on the theory of Diffusing Wave Spectroscopy （DWS）， the changes in macroscopic viscosity index of fermented milk with the two kinds of inulin-type fructans was analysis， and the quality of inulin and oligofructose fermented milk was evaluated on the fermented time， the viable count of Bifidobacterium BB-12 and all Lactobacillus， titratable acidity， precipitate amount of whey and viscosity of fermented milk during storage. The result showed that inulin and oligofructose affected the progress of milk turning into a gel and they extent the fermented time. Additionally， during the storage time， inulin and oligofructose had an ability to decrease the decline of viable count of Lactobacillus， increase the viscosity， reduce the precipitate amount of whey and titratable acidity. Thus， they had improved the quality of fermented milk， and inulin had a better effect on it compared with oligofructose， but they may have different mechanisms on it， which reminds further study in microbial metabolism and interactions with protein.

Abstract:In this study， water-insoluble dietary fiber （IDF） was extracted from kelp and wheat bran by enzyme-assisted chemical methods， and the in vitro functional properties of the IDF samples were evaluated. The results showed that the extraction yields for kelp and wheat bran IDF were 8.52% and 77.93%， respectively. The swelling capacity of kelp IDF was 5.99 mL/g， the water holding capacity was 11.82 g/g， and the oil holding capacity was 10.05 g/g. The swelling capacity of wheat bran IDF was 3.10 mL/g， the water holding capacity was 5.97 g/g， the oil holding capacity was 5.95 g/g. In terms of the binding capacity for lead and cadmium ions， the kelp IDF reached 683.61 μg/g and 528.97 μg/g， respectively； the bran IDF was 583.23 μg/g and 548.09 μg/g， respectively. Kelp derived IDF had excellent functional characteristics， showing great application potential for the development of marine functional food.

Abstract:In order to effectively remove the tannin and pigment present in Rosa roxburghii Tratt juice and improve its quality， three kinds of adsorbent including β-CS-CD， β-CD and CS were studied. Results showed that β-CS-CD exhibited the best absorption performance and the removal rate of pigment and tannin. Moreover， the absorption isotherm of β-CS-CD， β-CD and CS were fitted to the Langmuir and Freundlich equations. The linear correlation coefficients R2 were greater than 0.98. The pigment and tannin fitting parameter of Langmuir of β-CS-CD were qm＝32.61 mg/g， 103×KL＝52.85 L/mg， qm＝22.37 mg/g， 103×KL＝29.90 L/mg， respectively. The pigment and tannin fitting parameter of Freundlich of β-CS-CD were n＝2.00， KF＝3.611， n＝1.18， KF＝1.53， respectively. The results indicated that the introduction of β-CD functional group could greatly increase the adsorption efficiency. Kinetic studies showed that the adsorption was fast and the adsorption process followed a pseudo-first-order kinetic model. We also find that for β-CS-CD the adsorption kinetic rate constant （k2） value was much larger on β-CD and CS. These results clearly indicate that the introduction of CD increases not only the adsorption capacity and intensity but also the adsorption rate of chlorophenol. Therefore， β-CS-CD was effective to remove tannin and pigment from Rosa roxburghii Tratt juice and therefore could improve its quality.

Abstract:The effects of high pressure homogenization （HPH） combined VC on the natural microorganisms， pH value， soluble solids content， color， total phenol and flavonoids in cloudy peach juice were studied. The aim of this study was to provide a theoretical basis for commercial application of HPH. The changes of the microorganisms and quality in cloudy peach juice with/without 0.15% Vc were evaluated after HPH at a pressure range of 0-190 MPa， a temperature range of 30 ℃， 45 ℃ and 60 ℃. The results showed that the total plate count， molds and yeasts reduced with the increment of the pressure of HPH in the peach juice. The increment of inlet temperature could significantly reduce microorganisms. No molds and yeasts were detected in the treated cloudy peach juice when the pressure of HPH was above 110 MPa with inlet temperature of 60 ℃. After addition of 0.15% VC to the cloudy peach juice， the pH value and soluble solid content were also not significantly changed by HPH. The color of cloudy peach juice was significantly improved by HPH with VC. HPH increased the L* and b* value of cloudy peach juice and decreased a* value. As compared with the sample without VC， the value of ΔE was significantly decreased after HPH， indicating HPH could better preserved the color of cloudy peach juice with VC. The total phenol and flavonoids were significantly increased in cloudy peach juice with addition of VC， which was 2-3 times than control sample. According to the study， it could be concluded that the treatment of HPH combined with VC could significantly reduce the microorganisms in peach juice， inhibit the browning and improve total phenol and flavonoids in cloudy peach juice.

Abstract:Objective： this study based on the chemical modification to prepare alcohol-soluble gardenia red pigment derivative， and evaluate its stability. Methods： the alcohol-soluble gardenia red pigment derivative was prepared by acetic anhydride esterification， and the optimum process conditions were determined. Then， alcohol-soluble stability of gardenia red pigment derivative was studied under different conditions. Results： UV-Vis spectra showed that maximum absorption wavelength of alcohol-soluble gardenia red pigment derivative was 531 nm； Determined the optimum technological conditions were： the ratio for material and liquid of water-soluble gardenia red pigment and acetic anhydride was 1 ∶ 20； incubated at room temperature for 4 h； Alcohol-soluble gardenia red pigment derivative can dissolve in anhydrous ethanol and water， expand the scope of dissolution； Alcohol-soluble gardenia red pigment derivative was stabilizable in indoor scattering light， high temperature， acid， oxidant and no Sn2+ and Fe2+ exists. Conclusion： the gardenia red pigment derivative was prepared by chemical modification method， as well as expanded the scope of the dissolution.

Abstract:The mixture of brown rice flour and extruded brown rice flour was prepared at ratio of 0 ∶ 10， 1 ∶ 9， 2 ∶ 8， 3 ∶ 7 and 4 ∶ 6， respectively. Each kind of mixture was mixed with gluten at ration of 8 ∶ 2 to make dough and bread， and the effect of addition amount of extruded brown rice flour on the quality of dough and bread was studied. The results showed that the network of brown rice dough became more loosened， the hole of the network became larger， and the viscoelasticity of dough became lower with the addition of extruded brown rice flour. The specific volume of the bread became smaller and then larger. The hardness of bread decreased and sensory value increased with the addition of extruded brown rice flour. In the shelf test， the increase amplitude of hardness decreased with the increase of extruded brown rice flour， the elasticity of bread was higher than that of bread without extruded brown rice flour. The utilization of extruded brown rice flour was beneficial for inhibiting retrogradation and improving quality of bread， and the quality of bread was the best when the ratio of brown rice flour and extruded brown rice flour was 6 ∶ 4.

Abstract:This is the first reported protein recovered from surimi rinse by high viscosity chitosan （viscosity>400 mPa·s）. In order to obtain the optimal process conditions of the protein recovery， the factors influencing the protein recovery of high viscosity chitosan were studied. The factors such as temperature， pH， time， concentration of chitosan were researched by single factor experiment and the optimum conditions were obtained by the orthogonal experiments. The concentration of protein and COD were determined by using biuret method and potassium dichromate method， respectively. The optimal conditions for protein recovery were as following： pH 6.5， 20 ℃， 90 min， concentration of chitosan 1.67 mg/mL. Under the optimum conditions， the recovery rate of protein was up to 43.68% and the removal rate of COD was 22.73%.

Abstract:To study the effect of ZnO films on the formation of Shewanella putrefaciens biofilm， the ZnO films were prepared by sol-gel method and hydrothermal synthesis method on the surface of stainless steel， and the films were treated by hydrophobic modified method. The antibiofilm properties and mechanism of stainless steel and ZnO films were studied against Shewanella putrefaciens biofilm. The results show that the ZnO is hexagonal wurtzite structure， and the hydrophobic of ZnO films is stronger than that of stainless steel. The ZnO films prepared by sol-gel method are accumulated by irregularly shaped nanoparticles， the ZnO films prepared by hydrothermal synthesis method are accumulated by uniform longitudinal nanorods， and the latter is more hydrophobic. There is no difference in the stability produced by biofilm of different material surface at the same period， the major factor affecting the adhesive of biofilm is the hydrophobicity of the material surface. In the process of biofilm growth， its synthetic EPS capacity， protein content and metabolic activity are gradually enhanced， the antibacterial effect of the ZnO films prepared by hydrothermal synthesis method is significantly inhibited the metabolism and growth of the membrane bacteria， which property of inhibited biofilm is optimum.

Abstract:Effects of complex plant-source extracts with ice on the quality and antioxidant activity changes of large yellow croaker（Pseudosciaena crocea） during logistics process was studied. Logistics process， such as sample handling， transportation， distribution and sales， were simulated. Sensory evaluation， microbiological（Total viable count， psychrotrophic bacteria count）， TVB-N value and antioxidant activity （Total antioxidant capacity， Superoxide Dismutase and Malondialdehyde） were measured respectively so as to research on the effects of complex plant-source extracts with ice on the quality and antioxidant activity changes of large yellow croaker （Pseudosciaena crocea） during circulation. The results show that sensory score of CK group was increased with the prolongation of the circulation time. The TVC， PBC and TVB-N value were increased significantly， and the growth rate of CK group was higher than that of treatment （T） group. The sensory scores and TVC of CK group reached （2.34 ± 0.09）lg（CFU/g） and （6.24 ± 0.13）lg（CFU/g） respectively， TVB-N value was （30.87 ± 1.56）mgN/100 g， which was beyond the acceptability limits， and that of T group could not reach the limits of shelf life at 395 h. The shelf life of CK group was 275-347h， while T group could extend the shelf life of more than 48h. The changes of T-AOC， SOD and MDA in CK group were higher than those in T group. The increase rate of MDA in CK group was also higher than that of T group. It was proved that ice with complex plant-source extracts treatment could exert its antibacterial and antioxidant activity， inhibit the growth of microorganisms， improve the antioxidant capacity of fish and prolong its shelf life.

Abstract:The inhibitory activity of silver nanoparticles and three commercial preservatives was studied against four bacteria isolated from the naturally spoiled fishes. Antimicrobial assay in vitro and the cell membrane assay were used to evaluate the inhibitory capacity and the possible mechanism of silver nanoparticles. The results indicated that silver nanoparticles showed great and broad antimicrobial activity. Silver nanoparticles had great inhibitory activities against all the tested Gram-negative bacteria with the minimum inhibitory concentration of 0.3125-1.250 mg/mL， while three commercial preservatives had no inhibitory activity. Silver nanoparticles could break the cell membrane and cause the release of UV-absorbing substances， such as proteins， and potassium ion in the tested bacteria, with good slow-release property. Silver nanoparticles has a good potential for the application of food preservative.

Abstract:Changes on the content of abscisic acid （ABA）， gibberellins（GA）， indole-3-acetic acid（IAA） and zeatin nucleoside （ZR） in different tissues of Agaricus bisporus （Lange Sing） mushroom during 20 ℃ storage were investigated in this study. Results showed that the change pattern of GA and IAA content is similar during postharvest A. bisporus mushroom storage. GA and IAA may synergistically control the processes of cap expansion， protecting veil break and the spore production. Both of ABA and GA play prominent roles in the postharvest senescence process of stipe tissue. ABA may promote and participate in the whole senescence process of harvested A. bisporus fruit bodies. Compared with ABA， GA and IAA， ZR is distributed obviously in different tissues and may closely relate to the gill thickening and spore production. The above mentioned results indicated that the production of the four hormones were difference in different tissues of the A. bisporus mushroom during postharvest storage， which is probably associated with the postharvest continued development and senescence processes. The discovery in this study will provide a theory base for seeking new methods to effectively maintain postharvest quality of A. bisporus mushroom.

Abstract:In order to extend the shelf life of chilled meat， biological preservatives such as antibacterial peptides from milk， chitosan， natamycin and， apple polyphenols were used to study the inhibitory effect on the main spoilage bacteria of chilled meat， then applied to the preservation of chilled pork and mutton. The results showed that the antibacterial peptides from goat milk had high antibacterial activity. On the main spoilage bacteria of chilled meat， the inhibitory effect of chitosan and antibacterial peptides from milk were stronger than others， apple polyphenols， e-polylysine， tea polyphenols， and Nisin had their advantages and disadvantages. Pullulan has no antibacterial effect. The good combinations of preservatives were determined through the single factor and uniform test， and the concentration of antibacterial peptide， natamycin and， apple polyphenol and chitosan were 14.25， 2.50， 4.00 g/L and 2.28 g/L， which could significantly slow down the spoilage process of chilled meat. Compared with the control group， the compound preservative can prolong the shelf life of chilled meat by 4~6 days.

Abstract:Effect of rosemary extracts on antioxidant capability of soybean oil during accelerated storage was researched by fatty acid composition， DPPH and ABTS free radical scavenging ability and oxidation induction period of soybean oil during accelerated storage. The saturated fatty acids were increased， the polyunsaturated fatty acids were decreased， as well as DPPH and ABTS free radical scavenging ability were both reduced during accelerated storage， which indicated that the antioxidant capacity of soybean oil was weakened. Adding rosemary extracts could reduce the loss of polyunsaturated fatty acids in soybean oil， enhance DPPH and ABTS free radical scavenging ability， extend the oxidation induction period of soybean oil， increases protection factor and antioxidant capacity ratio during accelerated storage. The effect of rosemary extracts was better than that of artificial antioxidants. It showed that rosemary extracts had better inhibiting the oxidation of soybean oil than artificial antioxidants， and effectively improved the antioxidant capability of soybean oil in the process of storage.

Abstract:In order to investigate the effects of damping material packaging on strawberry fruit loss and damage prevention under vibration stress， the effects of three vibration-damping materials： commercial polystyrene， self-developed polyvinyl formal （PVFM） and bacteriostatic PVFM， on the storage quality of transporting vibration strawberry were studied. The results showed that the bacteriostatic PVFM group had low weight loss rate， maintained the firmness， delayed the decline of VC and soluble protein content， promoted the synthesis of carbohydrates， inhibited relative conductivity and malondialdehyde content， protected the integrity of cell membrane structure and delayed the deterioration of quality of strawberry fruit. Addition of allyl isothiocyanate also maintained the phenol and total flavonoid content of strawberry. These results indicated that the use of appropriate damping material packaging had a good preservation effects on the transportation of strawberry. The antibacterial PVFM material was more useful for maintaining storage quality of strawberry， which provided references for strawberry logistics transportation packaging.

Abstract:The aim of this work was to study the effect of different packaging films on the storage quality of Okra in the low-temperature environment. Polymeric films namely PE， LDPE， PMP， PVDC of different thickness were used for packaging study then storage at 3 ℃ and respiration intensity， weight loss rate， brittleness， pectin， malondialdehyde and color were evaluated. The results indicated that packaging film was more effective in inhibiting respiration and the peak of respiratory peak， delaying the peak time of peak respiration compared with the control group， and especially PE， LLDPE and PMP treatment group effect were more obvious. Weight loss rate of packaging film group were 12% or less at the 24th day after storage， which were significantly lower than that of the control group（62.13%）（P<0.05）. The brittleness of the control group disappeared at 14 days， and film-treated group was delayed until 21-24 d. The results indicated that LLDPE and PVDC packaging film were more effective slowing the decrease of protopectin， increase of soluble pectin， and inhibiting the accumulation of malondialdehyde， maintaining color of okra better. Relatively， these results indicated LLDPE film treatment was better for the cold storage effect of okra， and PVDC was second.

Abstract:Apple fruits of 18 cultivars from 7 different main growing areas in China were collected for cloudy juice processing and the amino acid components and contents of fresh cloudy apple juices were measured. By descriptive and stepwise linear discriminant analysis （SLDA）， the results showed that the amino acid contents of cloudy apple juices differed from varieties and origins. In general， the variation coefficients of alanine， leucine， serine， valine and isoleucine were relatively high， which were 191.38%， 96.91%， 67.82%， 53.60% and 57.97% respectively. The variation coefficient of aspartic acid， threonine， glutamic acid， glycine， lysine， and total amino acid were relatively low， which were 43.92%， 45.70%， 28.37%， 35.16%， 47.47% and 39.40% respectively. Moreover， cloudy apple juice form Huajin contained the highest amount of aspartic acid， serine， alanine and total amino acids， which were 235.6 mg/100 g， 12.6 mg/100 g， 10.5 mg/100 g and 289.4 mg/100 g， respectively. Thus， with its highest contents in the above four amino acids， cloudy apple juice of Huajin located at the edge of the figure， showing the great difference with other varieties. Besides， the amino acid components and contents of apple juices were greatly affected by origins， and the samples from different areas were dispersed in the figure. Compared to other origins， cloudy apple juices from Xinjiang showed significant lower contents in threonine， serine， glutamic acid and valine， which were 1 mg/100 g， 2.4 mg/100 g， 7.1 mg/100 g， 1 mg/100 g respectively. Cloudy apple juices with different varieties from Shandong Province and cloudy apple juice of Fuji from different origins showed significantly different in amino acid constitution， which obtained 77.8% and 81.8% discriminant accuracy respectively based on SLDA. The above results show that cloudy apple juices could be differentiated for varieties and origins based on amino acid contents by SLDA.

Abstract:In order to separate and breed the main lactic acid bacteria from Yunnan Jianshui fermented soybean whey tofu， and pure breed ferment soybean whey， the isolation and identification of lactic acid bacteria in the coagulant of fermented soybean whey which was used in the production of Yunnan Jianshui fermented soybean whey tofu were carried out. Five strains of lactic acid bacteria were isolated and purified by plate streak. The strains were identified by morphological observation， physiological and biochemical characteristics and 16S rDNA sequences. The results showed that SYG01-SYG05 respectively was Lactobacillus brevis， Lactobacillus coryniformis， Lactobacillus curvatus， Weissella confusa and Lactobacillus concavus. The study not only provided a new source of resources for developing new probiotics fermented soybean products， but also provided theoretical basis for the preparation of standardized fermented soybean whey and scientific technical specifications for making fermented soybean whey tofu， and had great significance to the large-scale production and promotion of fermented soybean whey tofu.

Abstract:This study aimed to understand the bacterial diversity of wild carp in the Eerqisi River， Xinjiang， China. The V4 region of the 16S rRNA gene were analyzed by high-throughput sequencing to compare the bacterial community composition and diversity in the intestine of carp. Results showed that a total of 35289 effective sequences and 158 OTUs were obtained. Diversity analysis indicated that the Shannon index in hindgut of carp was lowest and bacterial community structure was the most complex； the Shannon and Simpson index of foregut was more close to that of midgut. At the phylum level， Firmicutes， Proteobacteria， Bacteroidetes and Actinobacteria dominated the microbiota of carp intestine， Proteobacteria was the most dominant in foregut and midgut. However， Proteobacteria was decreased significantly with increasing in hindgut， Firmicutes was increased sharply. On the genus level， Carnobacterium is the most abundant one in hingut， the proportion of its own sequences reached 30.52%. Acidithiobacillus was the main bacterial populations in foregut and midgut. Difference were observed the bacterial community composition and diversity in different sections of the carp intestine， and the bacterial community composition in foregut and midgut were relatively similar， there was no significant difference.

Abstract:An improved QuEChERs pretreatment method of 13 pesticide residues in aquatic products by liquid chromatography/tandem mass spectrometry （LC-MS/MS） was developed. The sample was extracted by 1%acidic acetonitrile and purified by polystyrene-divinylbenzene（PS-DVB） and primary secondary amine（PSA）. The analyte was ionized in the positive-ion electrospray ionization （ESI+） under multiple reaction monitoring （MRM） mode. Under optimized conditions， good linear relationship （R>0.99） was obtained in a concentration ranged from 1 to 100 μg/L by external standard method， and the limits of detection were range from 0.15 to 0.75 μg/kg. The recoveries of spiked aquatic product samples were found to be 75%-120% with RSDs under 15%（n=5）. The method was successfully applied in 12 fish and 18 shrimp， and the azoxystrobin was found in shrimps， the contents were 58.4 μg/kg and 38.6 μg/kg. The results indicated that the rapid cost-effective accurate method was proved successful in the determination of pesticide residues in aquatic samples. Furthermore， the method is more commercial than other QuEChERS methods with advantage of low cost of PS-DVB.

Abstract:Cancer is a important question of human health because of its disease rate and fatality rate. Bioactive peptides with the advantages of biological compatibility， targeting property， no immunogenicity， and low toxicity has become the latest must-haves in the prevention and treatment of cancer drugs， and has become the focus of researcher. In this paper， the antitumor activity of bioactive peptides， mechanism were analysed and reviewed， so as to help the researcher to provide ideas and guidance of the development of anticancer bioactive peptide.

Abstract:Aspergillus fungi often invade peanuts， soybeans， corn and other fat-rich crop seeds to produce a variety of mycotoxins， which causing nephrotoxic， hepatotoxic， genotoxic， immunotoxic， teratogenic， and carcinogenic to human and animal. This threaten to human’s food safety and health. Quorum sensing is a mechanism of signal exchange between microbes that depends on population density. Microbes monitor population density and regulate certain physiological activities by sensing changes in the concentration of specific small molecule chemicals（known as signal molecules）. It also found in Aspergillus fungi that quorum sensing can regulate mycelial growth， spore production and toxin biosynthesis and other physiological behavior. This paper reviews the factors involving in the mechanism of quorum sensing in Aspergillus fungi， including signaling molecules （mainly oxylipins）， G protein coupled signaling pathways， and oxidative stress， aiming at providing a reference for the study of the biosynthesis mechanism of the secondary metabolites of Aspergillus fungi and the genetic improvement of host resistance.

Abstract:This paper reviews the classification of gluten protein， the process of gluten formation and the factors affecting gluten formation and physicochemical properties. The molecular structure of wheat gliadin and glutenin， and the three levels of glutenin aggregates are summarized. The effects of internal and external factors such as glutenin aggregates， water， temperature， shear rate and pressure on the physical and chemical properties of gluten are analyzed. It is believed that the material basis of dough viscoelasticity is mainly glutenin and gliadin， and largely depends on the size and aggregation of aggregates formed by glutenin. The physicochemical properties of glutenin aggregates are influenced by internal and external factors such as glutenin protein type， water content， temperature and pressure. These factors not only determine the physicochemical properties of aggregates formed by glutenin， but also affect the rate of aggregate formation. Glutenin agglomeration kinetics is an important reference for selecting gluten protein or gluten formation techniques.

Abstract:In this paper， the progress of the mechanism of milk fat crystallization is reviewed， and the effects of milk fat chemical composition， kinetic properties， fractal properties of polymorphic crystallization， and fat crystal networks are described in detail. In milk fat， the chemical composition of triglycerides plays a decisive role in fat crystallization. The melting point increased with the increase of carbon chain length when carbon chain is the same， the melting point order is： saturated fatty acid> conjugated trienoic acid> monoacrylic acid> diacrylic acid> nonconjugated trienoic acid. The melting point of α crystals is low， poor stability and hard to form. The melting point of β crystals is high， more stable and easy to form. The β′ crystals are optimum， which have good plasticity and taste. It is known from the fractal theory that the partial and whole structure of the system is similar in terms of morphology， function， and information. Through the microscopic analysis of crystal network， the overall structural performance can be deduced. In summary， fat crystallization plays an important role in dairy science. How to control fat crystallization to improve the quality of dairy products is of great significance.