Abstract:Bacterial endotoxin,also known as lipopolysaccharide,forms the outer monolayer of the outer membrane in most Gram-negative bacteria. The biosynthesis pathway of endotoxin is complicated and evolves dozens of enzymes. The biosynthesis of endotoxin starts form the cytoplasmic surface of the inner membrane. During the process,the size of endotoxin molecule becomes bigger. Endotoxin is flipped to the outer surface of the inner membrane,crossed the periplasmic space and the outer membrane. Endotoxin could activate the innate immune system through TLR4/MD2,therefore,it could be used for developing new vaccines and adjuvants.

Abstract:Composition changed in the germination of grains and legumes;many new compositions were produced and have more significant biological activity than seeds. Hence sprouts are widely used not only in the food industry,but also in pharmaceuticals,health care products and cosmetics.In this review,after presenting general aspects about composition change in germination,is to focus on the biological activity of sprouts,as well as to summarize the application of sprouts.

Abstract:4α glucanotransferase(4αGtase) has the ability of catalyzing starch to form large ring cyclodextrin(LR-CD). In this study,in order to analyze the structure characteristics and key amino acid in the catalytic region,series of amino acids modifiers,such as arginine modifier DIC,methionine modifier Ch-T,tryptophan modifier NBS,histidine modifier DEPC,carboxyl modifier EDC,disulfide bond modifier DTT and protein denaturant mercaptoethanol,were applied to modify the 4αGtase,respectively. Results showed that the key amino acids existed in active center of4αGtase are histidine,glutamic acid/aspartic acid. The disulfide bond is very important to stabilize the activity of 4αGtase. From these results we deduced that 4αGtase contained two domains inactivity center,methionine and tryptophan are in different region of these two domain. A proper change of spatial structure will promote the combination of enzyme with starch to increase the total activity of 4αGtase.

Abstract:In this paper,guaiacol and catechol oxidation method were used to study the effect of different blanching on the peroxidase and polyphenol oxidase activity of Brassicachinensis L. The results show that the peroxidase activity of Brassicachinensis L. respectively were37.30,39.28,34.34,24.95 after blanching for 4 min at 90 ℃,2 min at 95 ℃,3 min at 95 ℃,4 min at 95 ℃,the relative residual dynamic activity decreased to 8.11%,8.53%,7.46%,5.42%. The polyphenol oxidase relative residual activity of Brassicachinensis L. were 16.49% after blanching for2min at 95 ℃ without rapidly transferring to ice bath to cool. If we transferred to ice bath to cool,the polyphenol oxidase relative residual activity of Brassicachinensis L. were 1.24%. Therefore,when the Brassicachinensis L. was blanched for 2min at 95 ℃ and then quickly transferred to ice bath to cool,the activity of peroxidase(the relative residual activity was 8.53%) and polyphenol oxidase(rhe relative residual activity was 1.24%) had been well suppressed and the relative residual activity was less than 10%,what’s more,in this blanching conditions,the content of chlorophyll was higher(2.31 mg/g),the color(the value of-a was 22.84,the value of saturation Cwas 35.56) was better.

Abstract:Traditional preference test is a forced-choice test which requires consumers to make a preference choice between two products and it has been extensively applied in consumer tests.However,due to consumers’ psychological hint in the test situation causing preference bias,the results are not consumers’ real preference for the tested stimuli and thus it is questionable to predict the tendency of the market with the method. In order to solve the problem,some researchers proposed ’operational preference’. This review mainly summarized how to get the consumers’ "operational preference",including improving preference test with "no preference",repeating preference test,preference test after screening consumers with placebo test,monitoring consumers’ behavior,auction and exchanges,’take away’ preference test. Furthermore,the future applications of these methods were discussed.

Abstract:In order to purify α-ketoglutarate acid from fermentation broth,the purification technology of α-ketoglutarate acid by ion-exchange method was studied after decolored by activated carbon.The results showed as follows. Firstly,the decolorization ratio reached 89.2% under the following optimal conditions:carbon dosage 1.5 g/L,pH 3,bleaching time 1 h,bleaching temperature50 ℃. Subsequently,the process of ion-exchange was studied and among 6 different resins D301weakly-based anion resin was the optimal one for α-ketoglutaric acid abstraction by comparison of the adsorption capacity. And the optimal absorption efficiency was achieved when the α-ketoglutarate acid concentration in the fermentation broth was 20 g/L,the sample flow rate was 2.67BV/h and the diameter to height ratio was 1 ∶12. Finally,a process of stepwise elution wasinvestigated. In the first step,0.01 mol/L NaCl and 0.01 mol/L HCl mixed solution was used as eluent and in the second step,0.3 mol/L HCl was used as eluent and the flow rate was 6 BV/h.With the elution strategy above,the final yield of α-ketoglutaric acid reached 93.2% and an excellent purification result was achieved with the increased mass ratio of α-ketoglutaric acid to pyruvic acid from 1.5∶1 to 10∶1. Therefore,ion-exchange method was valid to purify α-ketoglutaric acid from fermatation borth.

Abstract:Two sudanI hapten derivatives were synthesized by diazotization and the resulting products were characterized by liquid chromatography-mass spectrum. The haptens were conjugated with bovine serum albumin(BSA)and ovalbumin(OVA) respectively. UV spectrum and electrophoresis confirmed the successful conjugation. The BSA conjugates were used to immunize New Zealand rabbits for preparation of antibody while OVA conjugates were used as coating antigen. Indirect competitive ELISA methods were developed. Various factors including coating buffer,blocking solution,sample solution,antibody solution,reaction time and so on were optimized.Under the optimum conditions,an inhibition curve was established with IC50value of 3.0 ng/mL and linear range 0.3~23.4 ng/mL. The limit of detection(LOD) was calculated as 0.1 ng/mL. Crossreaction tests showed that the antibody recognized para red well with cross-reactivity of 140% while little recognition to sudan Ⅱ(1.1%),sudan Ⅲ(6.85%),sudan G(6.5%) and sudan Ⅳ(less than0.1%). Fortified chili powder of two levels(5 ng/g and 10 ng/g) were tested using the developed immunoassay. The recoveries were 90.4% and 96.0% with coefficients of variation 1.8% and 4.9%.

Abstract:In order to evaluate the quality and safety of farm produce cold chain,this paper combines the characteristics of farm produce with its special conditions and equipment and puts forward the comprehensive index system from the perspective of logistics environment,facility and equipment,process and personnel quality. FHAP(Fuzzy Hierarchical Analytical Process) is utilized to calculate the weight of each index. Together with the Fuzzy Comprehensive Evaluation,the evaluation model is designed. A Farm Produce Cold Chain serves as an example to demonstrate the effectiveness of the proposed model.

Abstract:The first order reaction kinetics and Arrhenius equation was employed to analyze the effects of storage temperature on total bacterial count,total anthocyanin content and color of blueberry juice,and establish relative kinetics models. The blueberry juice was treated with thermal treatment and microwave treatment,and then stored at different temperatures. The results showed all the changes of total bacterial count,total anthocyanin content and color of blueberry juice accorded with the first order reaction kinetics(R2>0.9),and could be fitted by Arrhenius equation(R2>0.98).At a low storage temperature,total bacterial count increased slowly and little loss was found in total anthocyanins and color,so the blueberry juice could remain good quality for a long time. Compared with thermal sterilization juice,anthocyanins,color and antioxidant activity could remain better inmicrowave sterilization juice grew up a litter faster,but its quality guarantee period was shorter. All the relative errors of the model predicted value and actual value were less than 2%. That indicated all the models were credible.

Abstract:The relationship among sensory quality,components and pericarp thickness of 11varieties of waxy corn were investigated in order to study the main effectors on sensory quality of the waxy corn. Sensory evaluation results showed that the differences in taste and chewing quality among 11 waxy corns after cooking were almost unobvious,while the flavor and color are significantly different. The results of colorimeter and sensory evaluation suggested that except colored waxy corn,corn varieties with high value of L and b would be more accepted. The content of reduced sugar and surface color of corn showed a very significant positive(p<0.01). The difference among the components content like water,amylose,amylopectin,reduced sugar and total sugar and pericarp thickness of the 11 waxy corn are obvious,while others like free amino acid,lipid,ash are unobvious. However,there are no obvious correlation between the sensory evaluation results and components and pericarp thickness.

Abstract:Using the right storage methods of postharvest raw material can reduce the browning degree of Frozen Komatsuna. In this work,effects of different temperature(nomal temperature,nomal temperature after cold storage and cold storage in 5~10 ℃ temperature) storage of the postharvest raw material on the temperature of raw materia、brix degree、PH and browning of Fast-frozen Komatsuma were investigated. The result indicated that if the postharvest raw material is processed in 4 h,nomal temperature is the best,and if the postharvest raw material is processed over 4h,cold storage in 5~10 ℃ temperature is the best.

Abstract:Rice soaking is an important step of the Chinese rice wine production. 160 strains of lactic acid bacteria were separated from the samples of rice wine brewing process and quickly screened according to the transparent circle on the potassium permanganate-potassium bromide agar plate. According to the results of physiological characteristics,acid yield of seriflux,antibacterial activity and produce of biogenic amine,one lactic acid bacteria suitable for biological acidification of rice soaking process was obtained. Strain B101 was identified to be Lactobacillus plantarum by16S rRNA sequencing. After inoculating L. plantarum B101,it can quickly improve the acidity of seriflux,shorten the time of soaking,and inhibit bacterial growth,improve the stability of the process of soaking,and effectively reduce the biogenic amine content of seriflux.

Abstract:36 yeast strains were subjected to analysis of Selenium-resistance,and a Selenium-resistant and Selenium-enriched Candida tropicalis strain named 1254,was obtained,whose Se content and biomass were 5.48 mg/l and 4.1 g/l,respectively. The strain 1254 was subjected to genetic breeding via N-methy-N-nitro-N- Nitrosoguanidine(NTG) and UV irradiation mutagenesis successively,to screen high Selenium-resistant and ethionie-resistant mutants. As a result,A mutant 1254-6-1 was obtained,and the biomass,total selenium content,organic selenium content and conversion rate of organic selenium increased to 7.60 g/l,5 626.00 μg/g,4 879.99 μg/g,86.74%,much higher than that of the parent strain. Especially,the content of methionine and cystine were increased by 135% and 194.10%.

Abstract:The polysaccharide from Chinese Venus was firstly separated through acolumn of DEAE-cellulose(Whatman DE 52). As a result,three independent elution peaks(F1,F2and F3)were obtained. The three fractions were loaded onto a column of Sephadex G-100,affording f1,f2and f3,respectively. Purity of f1,f2and f3was further confirmed by using HPLC,and results showed that f1,f2and f3were homogeneous polysaccharides respectively. The chemical characterizations of polysaccharides were investigated by various methods. As to CP,f1,f2and f3,polysaccharides content,measured by employing the method of sulfuric acid-phenol coloration,was 83.81%,98.75%,95.58% and 84.71%,respectively. Uronic acid content,determined by using the method of sulfate-3-phenylphenylol assay,was 1.58%,0.16%,0.96% and 2.13%,respectively. Sulfuric radical content,determined by employing the method of gelatin-barium chloride assay,was 0.92%,1.22%,2.08% and 3.58%,respectively. Protein content,measured by applying the method of coomassie brilliant blue coloration,was 3.08%,not detected,not detected and 6.34% respectively. The relative molecular weight of f1,f2and f3,determined by HPLC,was 68 600,80 600 and 100 600,respectively. The CP,f1,f2and f3had different reducing power,lipid peroxidation inhibition effect and ferrous ion chelating activity.

Abstract:To explore the effect of Cynanchum auriculatum on melanin synthesis. The polysaccharides,C21steroidal glycosides,and phosphatide were extracted and separated from Cynanchum auriculatum. The effects of polysaccharides,C21steroidal glycosides,and phosphatide extracted from Cynanchum auriculatum on mushroom tyrosinase activity were detected respectively by measuring the oxidation rate of l-dopa. The results indicated that the soluble polysaccharides of Cynanchum auriculatum could inhibit the activity of mushroom tyrosinase obviously and concentration that resulted in 50% activity lost for diphenol oxidase activity was 31.8 μg/mL. The polysaccharides from Cynanchum auriculatum was a reversible competitive inhibitor for the oxidation of l-dopa. The phosphatide extracted from Cynanchum auriculatum had weak inhibitory effect on activity of mushroom tyrosinase while the C21steroidal glycosides had activation effect on the tyrosinase. The results suggest that polysaccharides of Cynanchum auriculatum might be used as a skin whitening agent or as a hyperpigmentation inhibitor. It also have the potential to be further developed into a safe and effective food browning inhibition agent.

Abstract:Formation of mannose during high fructose syrup production was studied. The results showed that glucose isomerase and alkali pH conditions could make fructose transfer to mannose.Long reaction time of glucose syrup with isomerase and impurities in it both could induce enzyme catalyze mannose synthesis. And mannose also could be transferred from fructose when pH was higher than 10. Some formic acid,acetic acid,5- hydroxymethylfurfural and colored substance also could be detected under alkali pH conditions.

Abstract:In order to develop a kind of non-dairy creamer with high stability and turbidity,and used in fish head Soup,the non-dairy creamer was mainly made with refined vegetable oil in the study,stability and turbidity was analysed by particle size and turbidity determination. The result indicated:particle size and turbidity of this non-dairy creamer were respectively 0.670 μm and 2939 NTU. The Orthogonal Design analysis method was used in optimizing processing conditions of fish head soup. Optimized results were as follows:The weight ratio of fish head and water was 1∶6,the additive amount of non-dairy creamer was 2.5%(based on fish head quality),the non-dairy creamer stewing time was 10min.In this condition,the sensory grade was 7.1(full mark was 10),the turbidity was 36 NTU,fat content was 2.85%,protein content was 1.34%.Compared with traditional method of fish head soup making,the protein content increased 4.69%,the turbidity increased140%,the fat content reduced 34.18%.

Abstract:The method for determination of shikimic acid in the production of microbial fermentation was established. Using ultraviolet-visible spectrophotometry for determination of shikimic acid in the fermented liquid of shikimic acid producing bacteria. The detection wavelength was 245 nm,Linear equation of shikimic acid standard solution was A=3.084 4C-0.004 8(R2=0.9999). The recovery was 96.7% ~103.7% with average recovery of 100.04%,RSD was 0.32%. The method is simple,fast,stable and accurate,and suitable to determine the shikimic acid in the production of microbial fermentation.

Abstract:To develop a sensitive and specific high performance liquid chromatography(HPLC)method to determine four flavonoids in Apocynum venetum gathered in different seasons,so as to determine the optimal gathering season. The sample was extracted with ultrasonic method and then separated on Zorbax Eclipse C18(150 mm ×4.6 mm,5 μm) with a mixture of methanol-0.4%H3PO4(volume ratio 50∶50) as mobile phase at flow rate of 1 mL/min. The UV detective wavelength was 360 nm,and the column temperature was set at 50 ℃. With this method,four flavonoids were separated efficiently. The liner relation,stability and the recovery rate were all good. The four flavonoids were determined with this method. The flavonoids content of Apocynum venetum leaves gathered in August was the highest. The optimal gathering season of Apocynum venetum was August. The result indicated that the proposed method was simple,rapid,accurate,sensitive,and low cost,thus it provides an effective scientific means for assaying flavonoids in Apocynum venetum.