Abstract:As one of the important nanotechnology,nanoemulsion system exhibits a big potential benefit for the delivery of food active ingredients,such as nutraceutical,flavorant,colorant,and antimicrobial.In this review,the mechanism and influence parameters for the biological fate and potential toxicity were analyzed by focusing on the systems utilizing within the food and beverage industry.Based on the above progress,the perspective of nanoemulsion delivery system was put forward.

Abstract:This research aimed to investigate the effects of 3-Monochloropropane-1,2-diol(3 MCPD) on the cell growth in Rat Leydig tumor cells R2C.R2C cells were exposed to 0.5,1,2,4,6 mmol/L 3-Monochloropropane-1,2-diol for 48 h,different concentrations(IC25,IC50,IC75) of 3 MCPD were elected by MTT assay.Three specific concentrations of 3-MCPD were cultured with R2C cells for 4 h and 24 h,respectively.The damage of DNAs in R2C cells was investigated by single cell gel electrophoresis(SCGE).Progesterone level in the supernatant of cell culture medium was measured by radio immunoassay(RIA).Results indicated that 3-MCPD could inhibit cells growth,the IC25,IC50 and IC75 value were 1.027 mmol/L,1.802 mmol/L and 3.160 mmol/L,respectively.Compared with the control group,IC75 concentration of 3-MCPD incubated R2C cells for 4h,the damage of DNAs were obviously higher and the progesterone level were decreased 16.0%.In addition,three concentrations of 3-MCPD incubated R2C cells for 24 h,the progesterone level were obviously decreased from 9.5% to 61.2%.The study suggested that 3-MCPD could directly affect cell growth and the progesterone synthesis of R2C cells.

Abstract:Four brewer’s yeasts with different autolysis performance were used to study their microscopic morphology by scanning electron microscopy(SEM) and changes in solution during autolysis in order to find out the optimal evaluating indicator of yeast autolysis.Results showed that α-amino nitrogen,formaldehyde nitrogen,each molecule of protein content,and free long-chain fatty acid content had certain variations during autolysis,but there was no obvious regularity.Meantime,single factor was not suitable for the evaluation of autolysis as a direct indicator.Nevertheless,(A260 /A280)/yeast mortality showed an obvious and consistent trend during autolysis.When the yeast autolysis degree increased,the value of(A260 /A280)/yeast mortality gradually decreased.This indicator had the advantages of comprehensive,high sensitive,and less time consuming,also the method was easy to operate.It could reflect different autolysis performance of different strains,as well as differences of the same strain at different stages of autolysis.So(A260 / A280)/yeast mortality was a good indicator to evaluate yeast autolysis.

Abstract:In order to establish the two-dimensional electrophoresis(2-DE) conditions of Zizania latifolia,the effects of different protein extraction methods,loading amount,pH ranges of IPG strip and gel concentration,etc.on 2-DE maps were investigated.The results showed that the modified phenol extraction protocol is more suitable for total protein extraction of Z.latifolia compared with TCA/acetone protocol.And a high quality 2-DE map with more protein spots,clear background and high protein point resolution was obtained using the following optimized procedure:loading 1.0mg protein sample on 17 cm IPG strip with pH 4-7,SDS-PAGE with 12 g/dL gel concentration,and finally detecting proteins with coomassie brilliant blue G250 staining.The research provides a basis for further study of the Z.latifolia proteomics.

Abstract:In order to study the changes of the acidity in apple produced in different habitat during the storage time and predict the acidity,Computed tomography(CT) was used in the apple nondestructive testing,and a prediction model was also established by the quadratic fitting.The changes of apple during the storage time were proven by the results,what’s more a response surface model combining the acidity and the CT number and an acidity prediction model were established.The confirmation experiment indicates that the average error rate was12.14%,which shows a good adaptability and predicting effect.

Abstract:The effect of rare earth element Ce3 +on hydrogen production was investigated in this study.The data indicated that the hormesis effect of Ce3+was performance on hydrogen generation,the maximum hydrogen yield reached 123.2 mL/g by adding Ce3+concentration of 0.1 mg/L,which was 120.3% of control.The concentration of VFA by adding 0.1 and 0.05 mg/L Ce3+was 4 511.8 and 4 420.3 mg/L after reaction,which was 1.49 and 1.46 times of control,respectively.The utilization of glucose in each group was between 76.2% and 92.1%.The dehydrogenase activity represented initially increased then decreased trend,the maximum dehydrogenase activity was 5 042.3 μg/(g·h) by adding 0.1 mg/L Ce3+,which was 110.0% of control.

Abstract:The effect of NaCl on the fermentation process of kitchen wastes was indicated by adding different concentration of NaCl,gas production yield,intermediate metabolite,enzyme activity were analyzed during the biogas process.The results show that adding low concentration of NaCl had little influence on gas production,but adding high concentration of NaCl had obviously inhibition on the anaerobic fermentation.Biogas production of kitchen waste by anaerobic fermentation remained unchanged in adding concentration of 2 g/L NaCl,while it promoted 7.5% gas production by adding 5 g/L NaCl.Gas production was reduced by 17%,24%,51% by the adding NaCl concentration was 10,20,30 g/L,which compared to the control.The data of fitting parameters by adding NaCl concentration 5 g/L indicated that the correlation coefficient R2of the methanogenic process with Cheynoweth equation was 0.991,the methane production B0 was 399 mL/g VS and the reaction rate of constant k was 0.114 d-1.High NaCl concentration lead to the accumulation of total acid and propionic acid concentration.The experiment found that adding concentration of 20、30 g/L NaCl was severely restrained dehydrogenase enzyme activity.When adding NaCl concentration was 10、 20、30 g/L,dehydrogenase activity lose 15%,55%,60%,respectivly.

Abstract:The fermentation process for P.variabile JN-A525 was optimized by single factor experiment and orthogonal tests.The results showed that the medium was composed of glucose 20 g/L,beef extract 10 g/L,KH2 PO4 5 g/L,NaCl 1 g/L and KCl 5 g/L.The optimum fermentation conditions was 32 ℃,inoculum volume 3%,the optimum amount in flask 70/250 mL and the rotation speed of 100 r/min.Under these optimal conditions,the highest urethanase activity is 3.47 fold more than that of previous cinditions.After sonication methods,sodium-sulfate salting-out and superdex G-75 gel filtration chromatography,the urethanase from Penicillium variabile JN-A525 is further determined substrate specificity.Under simulated conditions,the urethanase has a relatively strong catalytic activity to urea and EC.Meanwhile,urethanase cannot catalyze the decomposition of amino acids and esters.

Abstract:To explore the effects of lipoic acid(LA) on oxidative stress,the lipid metabolism,and the expression of related gene.C57BL / 6 were randomly divided into four groups,control group,high fat group(HF) and LA group(high fat plus 0.05%LA and 0.1%LA respectively).After 6 weeks,the lipid level,the activity of lipoproteinlipase(LPL) and hepaticlipase(HL) in plasma were determined.Reactive oxygen species(ROS) and the oxidative stress indices of whole blood,gastrointestinal system and liver were also examined.The expressions of ApoE and Cpt1a were analyzed by RT-PCR.Plasma lipid level significantly increased while the activity of LPL and HL significantly declined as induced by high fat diet,and all of them recovered when LA was added.In comparison to control,the ROS and MDA markedly increased while the antioxidant enzymes decreased in HF group,LA group showed the similar trend like control.The expression of Cpt1a decreased and ApoE increased in HF group,while LA group reserved all the changes above.Oxidative stress and lipid metabolism disorder were observed in mice feed high fat diet.LA can improve liver function by altering lipid metabolism through scavenging reactive oxygen species

Abstract:The aim of this study was to improve the production capacity of glucose oxidase.A gene of glucose oxidase(GOD) from Aspergillus niger TCPC was cloned and sequenced.The whole open reading frame(ORF) consisted of 1 772 bp bases and encoded a putative protein of 589 amino acids.The gene was fused to the pPIC9k plasmid and expressed in Pichia pastoris GS115.The recombinant GOD(rGOD) was secreted into the culture under the control of methanol and α factor signal peptide.After screening by G418 gradient resistance plate,color plate and shaker culture,one strain named GOD2-14 was obtained,which gave the higest enzyme activity(0.342 U/mL) after 4day induction by methanol.Shake flask experiments were conducted to optimize the culture conditions for the enhanced production of GOD.Highest enzyme activity of 25 U/mL was achieved in the shake flask by induction for 7 days under the optimal conditions(200 r/min,pH 5,22 ℃,inoculation amount of 50% and 1.5% methanol).The result showed that GOD gene has been successfully transferred and expressed in the Pichia pastoris GS115。

Abstract:Aminopeptidase which was isolated from Bacillus subtilis was purified by ammonium sulfate precipitation and ultrafiltration using of a 30 kDa MWCO polyether sulfone(PES) membrane.Succinic anhydride(SA) was used as a modifier for the chemical modification of the purified Aminopeptidase.The effects of modification were characterized using the 6-trinitrobenzene sulfonic acid method,ultraviolet spectroscopy,and CD spectroscopy.The results showed the structure of native and modified Aminopeptidase is different.The average amino modification yield of the modified Aminopeptidase was 55.86% and the enzymatic acticity increased to 105.81%.Compared with the native Aminopeptidase,the modified Aminopeptidase exhibited apparently higher thermal stability.The Km of the modified Aminopeptidase(Km =0.75 mmol/L) was lower than native Aminopeptidase(Km =1.0 mmol/L).The result indicated that the chemical modification of Aminopeptidase increased the affinity.In addition,enzyme properties have been changed after modification.

Abstract:Diabetes mellitus(DM) are induced in ICR mice with the dose of 180 mg/kg of streptozotocin(STZ) and then the morphological changes and the expression related with taste signal transduction of taste buds in vallate papillae are evaluated by hematoxylin-eosin staining and immune-histochemical methods.The results show that the number and the size of taste buds have no significant difference between control and DM mice.Whereas,compared with control mice,the DM mice have more number of α-gustducin and phospholipase Cβ2 positive cells per taste bud(P< 0.05/P<0.01).By contrast,the DM mouse have less number of SNAP-25 cells per taste bud than that of control mice(P <0.01).In a word,taste changes caused by DM maybe result from the expressed change of the taste signal transduction proteins,which block the peripheral taste signal to transmit to to the gustatory afferent nerve.

Abstract:The objective of the study was to investigate the intervention effect of soyasaponins on the oxidative stress of liver in mice with an acute liver injury induced by carbon tetrachloride(CCl4).The mice were randomly assigned to 4 groups:normal control,model control,silymarin(positive control),as well as high and low dose groups of soyasaponins.Animals were treated once daily for 7 days.At the end of the experiment,CCl4 was given intraperitoneally to the mice of groups,then the albumin(Alb),alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GPx),Na+-K+-ATPase,Ca2 +-Mg2 +-ATPase,as well as the contents of reduced glutathione(GSH) and malondialdehyde(MDA) were detected by the colorimetric method.The results showed that the administration with soyasaponins increased the serum Alb level and reduced the ALT,AST and ALP activities of serum,increased the total SOD,CAT,GPx and GSH level and decreased the MDA content of liver,increased the Na+-K+-ATPase,Ca2 +-Mg2 +-ATPase and Mn-SOD activities and decreased the MDA content of liver mitochondria in mice with acute liver injury.It is suggested that the soyasaponins reduces the oxidative stress of liver tissue in mice with acute liver injury induced by CCl4 and has a protective effect on liver injury.

Abstract:Plasmids of Lactobacillus are precious genetic resources,which carried with some characteristics of Lactobacillus and used in construction of Lactobacillus cloning expression vectors.To investigate resources of Lactobacillus plasmids from Chinese pickle,we collected 52 samples of Chinese pickle,and isolated Lactobacillus strains from these samples using rapid-detection PCR technology which was designed by us.Isolated Lactobacillus strains were further confirmed by 16s rDNA sequencing.Finally,plasmids of isolated Lactobacillus strains were extracted.One Lactobacillus sakei strain and 18 Lactobacillus plantarum strains were detected,and the detection rate of Lactobacillus strain was 36.5%.Eleven Lactobacillus strains contained plasmids,and the detection rate was 21.2%.The results of agarose gel electrophoresis showed 9 band profiles which detection rate was 17.3%.The results of our investigation indicated Chinese pickle are rich in Lactobacillus plasmids,which need to be further study.

Abstract:Bacillus tequilensis CGX5-1 is a newly screened strain which can effectively secrete β1,3-1,4-glucanase.Fractional factorial design was used to clarify the medium components and the concentration of barley flour and soy bean flour were found to be the key factors.The steepest ascent experiments was applied to determine the optimal domain and the central composite design was used to estimate the quadratic response surface,thus we acquire the factor values for maximum production of β-1,3-1,4-glucanase.The final composition of fermentation medium was determined via response surface methodology,which was(g/L):barley flour 68.4,corn flour 40,soybean flour 61.1,KH2 PO4 1,MgSO4 ·7H2 O 0.1,CaCl2 0.1.The highest activity of β-1,3-1,4-glucanase was 191.96 U/mL at 52 h culture using optimized medium,which was 1.91 times higher than that from original medium.

Abstract:In order to determine the adsorption characteristics of congo red by biosorbent chitosan,we studied the effects of pH,initial concentration,contact time and temperature.The result showed that the biosorption of congo red was significantly affected by initial solution pH,and the optimal pH of biosorption was 4 ~7.The kinetics of the interactions showed better agreement with the Lagergren second order kinetics,and indicated that capacity decreased with increasing temperature.The activation energy of biosorption(Ea) was determined to be 2.90 kJ/mol using Arrhenius equation.The adsorption data showed a good fit with Freundlich isotherm equation.Thermodynamic parameters,such as △Goand △Howere found as-10.10 kJ/mol(303 K) and-87.36 kJ/mol,respectively.The results indicated that the adsorption of congo red by chitosan was spontaneous and exothermic.The FTIR data showed that some functional groups mainly including-OH and-NH2 in chitosan were responsible for the adsorption of congo red.

Abstract:Conjugating enzyme with nanoparticles is an effective approach to enhance the characteristics of enzyme molecule in biosensor.A highly active enzyme-nanoparticle complex,HRP-IgG GNP,was prepared by immobilizing horseradish peroxidase labeled antibody(HRP-IgG) onto the surface of gold nanoparticle(GNP).The HRP-IgG GNP complex was applied to the enzyme-linked absorbent immunoassay(ELISA) and a highly sensitive nanopaticle-enhanced ELISA method was developed against nortestosterone(NT).The sensitivity of the novel method reached 0.01 ng/mL and the linear range was 0.03 ~10 ng/mL.the nanopaticle-enhanced ELISA method was 10 times more sensitive than the traditional ELISA method.The above method has promising applications for developing highly sensitive immunoassay methods.

Abstract:An effective method to keep the stability of cholesterol oxidase(COD) was provided by studying on stability mechanism of COD.Deactivation mechanism of COD was analyzed by fluorescence spectra,circular dichroism spectra and SDS-PAGE.We added two additives into the preparation of COD and stabilization mechanism was studied.The results indicated that 15% glycerin was selected as the best protector at 37 ℃ and the remained enzyme activity was increased by 58% after 45 hours.Riboflavin had no significant effect on enzyme stability.A mechanism for the glycerin effect on inhibiting protein aggregation,protecting protein secondary structure and maintaining high activity was proposed.It also showed that riboflavin had no protective effects against protein aggregation.

Abstract:The remnant proteinase A in draft beer seriously affects its foam stability,which restricts the improving of draft beer quality.In order to explore the effect factors of proteinase A secretion in beer fermentation process,this paper examined the impact of the strain,physiological state of yeast,yeast generation,wort concentration and fermentation stage on the secretion of proteinase A.It was found that strain with high proteinase A secretion,yeast after stable phase,high yeast generation,high original wort concentration,late fermentation stage would result in high proteinase A activity in fermentation broth.Therefore,in the actual production,the introduction of few proteinase A secretion strains,adjusting the physiological state of yeast,using yeast less than 3 generations,fermenting with less than 18° P wort,ending the fermentation as soon as possible would play an active role in reducing the secretion of proteinase A.