Abstract:In this review,the detection targets such as bacteria colonies,bacteria cell i,DNA and bacteria metabolic products are firstly introduced.Then thedetection methods which can synchronously indentify Multiplex Food-borne Pathogens electrochemical DNA biosensor,Aptamer biosensor,Electrochemical immunosensor,Surface plasmon resonance biosensor and Multiplex PCR were summarized.Based on the above progress,the the challenge and perspective of detection method were put forward.

Abstract:Antifreeze proteins(AFPs) is the general name of proteins which have the ability to enhance antifreeze capacity of organisms.They can lower the freezing point,modify morphology and inhibited the recrystallization of the ice,etal.In this article,applications of AFPs in food material production,processing and storage were outlined and its safty were analysised briefly in order to provide reference to future application of AFPs in food industry.

Abstract:In order to elucidate the regulation mechanism of 1-MCP on the physiological quality of Mopan persimmon with different de-astringency degree,the effects of 1-MCP on quality,physiological,metabolic and softening related indexes of astringent and incomplete de-astringent fruit during ice temperature storage was studied.Results showed that 1-MCP efficient inhibited the decline of fruit firmness,the accumulation of alcohol,the increase of respiration intensity and cell membrane permeability,furthermore,it was found that 1-MCP can reduced the wastage of titratable acidity,total sugar and Vc content.the change of the soluble tannin to unsolvable tannin,delayed the appearance of PE activity peaks and lowered the PG activity peaks were also detected.

Abstract:Aflatoxins are a group of mycotoxins with strong mutagenic and carcinogenic properties.Various commodities including crop and feed materials are easy to be contaminated with aflatoxin.Saccharomyces cerevisiae have been reported to bind or degrade aflatoxin.Here,detoxification of aflatoxin B1(AFB1) by wild-type strain of S.cerevisiae(BY4742) and three mutants of anti-oxidative relating genes(zwf1Δ,sod2Δ and glr1Δ) were determined by HPLC.In PBS buffer,AFB1 binding abilities of viable and dead cells were 74%-76% and 71%-73%,respectively,indicating AFB1 was removed by yeast cells mainly through cell adsorption.In YPD medium,clearance of AFB1 by three mutant viable cells reduced,while that by wild-type BY4742 remaining high.AFB1 binding ability of glr1Δ decreased most seriously,then was that of sod2Δ and zwf1Δ.Thus,the deletion of critical anti-oxidative relating genes would decrease the AFB1 binding ability of S.cerevisiae growing cells.

Abstract:To purify and identify stem bromelain for further study on its activity and mechanism after treated with ultrasound.Stem bromelain was purified and identified with carboxymethyl cellulose chromatography and polyacrylamide gel electrophoresis(PAGE) respectively.Enzyme activity,kinetic parameter,ultraviolet spectrum and fluorescence spectrum were studied on purified enzyme treated with ultrasound.Three single protein apex regions were separated with gradient elution.The ingredient with the highest activity in the second protein apex region was identified with PAGE,showing considerably high purity.After treatment with ultrasound,both Km and Vm decreased.No clear changes were observed in the ultraviolet absorption spectrum and the fluorescence emission spectrum while positive and negative peaks occurred in the differential ultraviolet spectrum.Conclusion: Considerably pure component of stem bromelain can be obtained after purified with carboxymethyl cellulose chromatography.It’s probably conformation change that results activity change after treatment of the ultrasound on stem bromelain.

Abstract:The characterization of protease from Aspergillus oryzae has a significant impact on soy sauce quality.In this study,an Aspergillus oryzae CICIM F0899 capable of producing neutral protease was investigated.Morphology of Aspergillus oryzae F0899 and Aspergillus oryzae 3.042 were imaged by SEM.The conidial head of Aspergillus oryzae F0899 was relatively smaller than that of the strain 3.042.Its conidia were larger than that of the 3.042 strain.In addition,properties of the protease secreted by this strain were tested and compared with profiles of an industrially strain Aspergillus oryzae 3.042.The results showed that the optimum temperature for the extracellular protease from F0899 was 60℃,with the stable temperature range between 20~40℃.The optimal pH was 8.0,with the stable pH range between 6.0~8.0.It could tolerate 18% sodium chloride and still retains 20% activity,which is as high as 2.2 times than that from 3.042 under the same condition.The activity of the enzyme was severely inhibited by Ag+,but affected by Fe3+ only slightly.Therefore,protease from Aspergillus oryzae F0899 can bear higher temperature,lower pH and higher NaCl concentration than that from 3.042.

Abstract:Fermented amaranth stem is a special traditional characteristics pickled food in east Zhejiang provice,and it is necessary to understand the microbial community structure and influence on physical and chemical properties such as nitrite concentration of fermented amaranth stem to ensure food safety.The bacterial community diversity of fermented amaranth stem was investigated based on the method of 16S rDNA clone library.The results indicated that 6 bacterial communities in sample were detected including Myroides,Arcobacter and Lactobacillus,etc.The predominant community was identified as Lactobacillus,which account for 83.9% in total 16S rDNA sequences.In the mean time,the pH value,salinity and nitrite concentration of pickled product of amaranth stem were also detected,they are 4.35,5.5% and 3.99 mg/kg,respectively.The population of bacteria and lactic acid bacteria were 8.8×106 CFU/mL and 1.6×106 CFU/mL,respectively.These data are within national standard.The research results can provide microbial and theory identification for process parameters of fermented amaranth stem.

Abstract:In this manuscript,an RP-HPLC method was developed to determine simultaneously adenosine phosphate and coenzyme I in Saccharomyces cerevisiae,in order to monitor metabolic state.The intracellular metabolites extracted by the method of rubbing with liquid nitrogen were separated on an Agilent Zorbax SB-Aq column(5 μm,4.6 mm×150 mm).A 0.025 mmol/L triethylamine-phosphoric acid buffer solution(pH 6.0) and acetonitrile mixture was used as mobile phase,with a flow rate of 1 mL/min.Detection wavelength was set at 254 nm.Under these conditions,three kinds of adenosine phosphate and two kinds of coenzyme I could be well separated.The recoveries were between 98.30% and 103.42%,and the RSD of the method was less than 3%.The results showed that this method is sensitive,accurate,reproducible and can be applied to determinate the content of intracellular adenosine phosphate and coenzyme I of S.cerevisiae.

Abstract:Objectives To establish allergic model with ICR mice for milk and shrimp protein,develop a novel technique based on determining histamine release from mouse sensitized cells stimulated in vitro for assessing and identifying food allergens.Methods The ICR mice were immunized by injection of river shrimp proteins or milk proteins with aluminum hydroxide as adjuvant.The sensitized mouse were challenged for one time at 7th day after sensitization.The sIgE of food allergens was measured by indirect ELISA at 7/14and 21days after challenge;and the peritoneal Mast cells were collected at 14th day and were stimulated by allergen in vitro.The liberation of tryptase was measured by ultraviolet spectrophotometry assay and was converted to releasing rate for statistical analysis with Student’s system.Results ①The levels of sIgE in the experimental groups were higher than on control at three different points.They reached the peak at14day after challenge,with a value of 1/25600 in river shrimp and 1/12800 in milk group.②The tryptase liberation ratio group was 38.5% in milk group and 36.14% in control group;The liberation ratio was 74.5% in river shrimp group and 47.1% in the control.All the model groups revealed significant difference compared with the control(P< 0.05).Conclusion The present data indicated that tryptase release test with sensitized cells from mouse model challenged by food allergen in vitro maybe a prospective technique for assessing and identifying food allergens.

Abstract:Chitosan was covalently coupled to protease(Savinase 16L) with water-soluble carbodiimide to enlarge its molecular weight,with the purpose of reducing enzymatic damage to wool fibres in anti-felting finishing.It was found that the secondary and the whole structures of the modified protease were much more regular and compact than the native one.The conjugated protease presented a lower affinity towards casein with an increase in Km from 20.62 g/L to 35.21 g/L.There was no change in optimum temperature(55 ℃)for the modified protease while its thermal stability at 55 ℃ was improved.Compared to the native enzyme,the modified protease displayed higher stability above 70℃.

Abstract:This manuscript studied the antibacterial action of Nisin and potassium sorbate compound in the cooked duck meat products.It resists bacterial spores in meat products by adding Nisin,thereby reducing the sterilization intensity.The results showed that: When the concentration of nisin and potassium sorbate in the cooked duck meat were achieved at 0.5 g/kg and 0.05 g/kg,respectively,the sterilization conditions reduced to 110 ℃ for 25 mins,under the optimum conditions,the cooked duck meat′s shelf-life is 6 months.

Abstract:The aim of the present study was to evaluate the technological properties of a probiotic strain Lactobacillus plantarum K25,isolated from Tibetan kefir.The results showed that the strain displayed weak milk-coagulating activity,some proteolytic activity and strong autolytic activity.The strain also showed a strong antimicrobial activity against Shigella,while no inhibition was observed towards the commercial yogurt starters.Antibiotic susceptibility test found that the strain was sensitive to erythrocin.Among all the microbe inhibitory agents in the test,only calcium propionate did not significantly affect the growth of the strain.Furthermore,the strain maintained high viability in fermented milk during storage,and it did not cause post-acidifying profile to fermented milk.

Abstract:The desalting process and process technology of dried Grass Carp were studied in this manuscript.The optimum desalting parameters were determined by comparing the change of conductivity and soluble proteins in clear water desalination and vacuum osmosis desalination,and listed as follows: the ratio of water and material 10∶1,water temperature 30 ℃ and desalting time 180 min.Then the process parameters was determined by orthogonal experiments:first step drying time 1.5 h,marinating time 2.5 h,drying time1.5 h,saucing time 1 h.Volatile flavor compounds of Marinated Fish were analyzed by headspace solid phase microextraction(HS-SPME)combined with GC-MS.Results indicated that total 48 volitile flavor compounds were identified.

Abstract:In this study,six kinds of the chitosan oligosaccharide derivatives,named CA-8,CA-16,CA-24,CN-8,CN-16 and CN-24were prepared though Maillard reaction by heating chitosan oligosaccharide and α-alanine/ asparagine(the ratio of carbonyl group and amino group was 4:1) at different time.Then,the antioxidant activity of those derivatives was investigated with superoxide anion radical/1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging and reducing power and index.The results indicated that the chitosan oligosaccharide derivatives exhibited more strong antioxidant activity than that of chitosan oligosaccharide.Furthermore,the derivatives from chitosan oligosaccharide with α-alanine had the better antioxidant activity than that of the derivatives prepared by chitosan oligosaccharide and asparagine.The reason is that the derivatives prepared by chitosan oligosaccharide and amino acid with the smaller molecule had the better antioxidant activity.

Abstract:The aim of this study was to investigate the effect of chinese medicinal herb extract on the spinach fresh-keeping For this,the material liquid ratio of 1:10 extracting solutions were prepared and its effect on the spinach quality was investigated.The formulations were based on licorice,hance ginger and its complex extract.Spinach were subjected to a treatment by dipping in these extracts for 5 min,and with the distilled water as a control.All products were stored at(3±1)℃ and the quality parameters such as sensory evaluation,decay rate,weight lose,respiration rate,total acid content,Vc content and chlorophyll content were evaluated.The effects of different treatments on the keeping fresh quality of spinach were investigated.The results showed that all chinese medicinal herb extracts could improve the sensory quality,decrease the decay rate,inhibit the respiratory intensity and weight loss,delaying of the decline of titratable acidity,vitamin C and chlorophyll contents.It has been proven that the material liquid ratio of 1:10 complex extract significantly(P<0.05) improve the fresh-keeping effects of spinach compared with that of the control.

Abstract:The cryoprotective effects of distilled water,4 g/dL trehalose,4 g/dL trehalose+0.4 g/dL sodium polyphosphate,and 4 g/dL trehalose+0.4 g/dL sodium polyphosphate+0.05 g/dL ε-polylysine in puffer fish(Takifugu obscures) were studied during storage at-18 ℃and-25 ℃ for up to 180 d using pH value,total volatile basic nitrogen(TVB-N),salt-extractable protein content and sulfhydryl(SH) content as indicators.The results showed the addition of trehalose and sodium polyphosphate could retard the protein denaturation of frozen puffer fish.This effect was better than that of cryoprotectant only included of trehalose,and the effect of distilled water was the worst.The antifreeze effect of ε-polylysine,trehalose and sodium polyphosphate compound produces at-25 ℃ was better than that at-18 ℃,which could restrain the protein denaturation and decomposition,and then improve the quality of frozen puffer fish.

Abstract:In this manuscript,endophytic actinomycetes were isolated from the root,stem and leaf of Taxus chinensis by the method of tissue homogenate.Antimicrobial activities of endophytic actinomycetes fermentation broth were determined with filter paper and molecular identification of some potential strains were also carried out.The result indicated that 55 strains of endophytic actinomycetes were isolated,21 of them have varied antimicrobial activity,accounting for 38.2% of all strains and 4 strains have higher antimicrobial activity.Results of 16S rDNA gene sequences analysis of the 4 strains showed that 3 of them belong to Streptomyces sp.,1 belongs to Mciromonospora sp..

Abstract:In order to take full advantage of pseudosciaena polyactis and increase their added value,the hydrolyzing of small yellow croaker fish protein were studied in this manuscript.The enzymatic hydrolysis of protein in small yellow croaker fish by alcalase,flavourzyme,papain and protemex were firstly studied and papain was selected for further study with the degree of hydrolysis(DH) as index.Then the effect of papain on the the degree of hydrolysis(DH) was investigated by single factor test and orthogonal experiment.The results of the single factor test showed that DH increases with the amount of enzyme,hydrolysis time,the ratio of small yellow croaker fish to water and the temperature and the optimum conditions listed as follows: 0.2 mg/dL enzyme,reaction time 4 h,the ratio of small yellow croaker fish to water 1∶3.Furthermore,the optimum conditions was determined by the orthogonal experiment,and listed as follows: the amount 0.4 mg/dL,hydrolyzed for 4h at 60 ℃ and the ratio of mall yellow croaker fish to water at the ratio of 1∶5.The effect those factors on DH was the ratio of small yellow croaker fish to water>temperature> amount of enzyme>time.