Abstract:L-valine,one of the three branched-chain amino acids,is essential for human,and plays an important role in the metabolism of life,therefore,it is widely used in products of food,medicine and feed.L-valine is mainly produced by bacterial fermentation,and the most used bacterium is Corynebacterium glutamicum.In this article,the pathway and regulation of L-valine biosynthesis in C.glutamicum are analyzed and researches on metabolic engineering to increase L-valine production in C.glutamicum are reviewed.

Abstract:As a newly-developing heat technology,microwave has been used widely in food areas.For the protein as an important component of the food,the interaction between protein and microwave will affect the food quality significantly.However,the mechanisms of microwave interact on the protein are controversial.The recent advance in effect of microwave on the structure and functions of the protein and its derivatives has been summarized in this paper,hoping to provide reference for the researches of the mechanisms that microwave interact on the food macromolecules such as protein.

Abstract:In this review manuscript,the methods of immuno-assay detection for pyrethroid pesticides and their metabolites were mainly introduced including enzyme-linked immunosorbent assays(ELISAs) and fluorescence immunoassays(FIA).In addition,the application of novel nano-materials(such as magnetic nanoparticles,lanthanide light-emitting nano-materials),as well as phage-displayed technology were used to improve the sensitivity of immunoassay.Finally,the development trends of immuno-assay detection for pyrethroid pesticides and their metabolites were discussed.

Abstract:Due to high antioxidant activity,many foodstuffs and beverages such as fruits,vegetables,tea,and red wine were exhibited the excellent beneficial influence on human health.With increasing interest in the function and diversity of antioxidants in foods,several in vitro methods for measuring antioxidant activity of food,beverages and biological samples have been developed.The most commonly assay methods include oxygen radical absorbance capacity(ORAC),reducing power,determination of total phenols,2,2-azino-di-(3-ethylbenzothialozine-sulphonic acid)(ABTS),2,2-diphenyl-1-picrylhydrazyl(DPPH),hydroxyl radical-scavenger activity,superoxide radical-scavenger activity and lipid peroxidation inhibition.These methods differ in terms of their assay principles and experimental conditions.This review describes the methodology for assessing in vitro antioxidant capacity,including the principles,characteristics,merits and drawbacks of every method.In addition,their current status and problems in practical application are critically evaluated.

Abstract:In recent years,much attention has been paid to meat and its products with special functions to promote human-being health and prevent the risk of diseases.This manuscript reviewed the functional compounds such as n-3 polyunsaturated fatty acids,conjugated linoneleic acid,vitamin E and selenium in animal meats.The dietary manipulation strategies to improve the above functional compounds were also discussed.

Abstract:Welan gum,a kind of soluble extracellular heteropolysaccharide,is widely used in the oil exploration for enhancing oil recovery and construction due to its perfect stability and rheological properties.The precipitation characteristics of welan gum in the ethanol-water solution were investigated in this study.The influence of ethanol concentrations,pH,salt types and salt concentrations on welan precipitation and its rheological properties were investigated and the optimum parameters were listed as follows: 2.5 mol/L of CaCl2 was added until Ca2+ concentration reached at 0.1 mol/L,pH 2.0 and 37.6% of ethanol concentration in the bulk mixture.Welan gum was effectively precipitated and separated from the fermentation broth and the recovery yield achieved at 92.5%.Moreover,the rheological properties of the welan gum were kept robust,and 73.3% ethanol dosage was economized compared to the control experiments.

Abstract:The membrane-bound glycerol dehydrogenase(GDH) was the key enzyme of bioconversion of glycerol to 1,3-dihydroxyacetone by Gluconobacter oxydans.The membrane fraction of Gluconobacter oxydans was collected by ultra-centrifugation,and GDH was isolated from the membrane fraction and purified by CM-cellulose column and Sephacryl HR 400 column chromatography.The electrochemical regeneration of the membrane-bound glycerol dehydrogenase was studied by cyclic voltammetry.Using this system,the bio-electrochemical preparation of 1,3-dihydroxyacetone(DHA) from glycerol without coenzyme was investigated.When the temperature was 28±2℃,during 18 h,the DHA production reached at 27.21g/L and the conversion rate of glycerol was 52.93%.

Abstract:Using the sauce products of maanshan Huangchi food Co.LTD as research model,based on the production process of natural fermented yellow bean sauce and HACCP critical points,the moisture content,water activity,total acid content,amino acids nitrogen content,AFB1 content,bacteria count,mould count,pathogenic bacteria in production cycle of March-September,2010 were detected.A serial of result were acquired:(1) The time-course of AFB1 content was determined,furthermore,therelationship of AFB1 content and water activity,moisture content was established.Based on the relationship,the pollution source of natural fermented yellow bean sauce was identified.(2) the relationship of nitrogen amino acid content and acidity was established;(3) The relationship of the dynamics of microbes and pathogenic bacteria pollution condition was developed.

Abstract:The optimum extraction technology of polysaccharides from Pyrus betulaefolia was acquired by L9（33） orthogonal experiment design method.Physicochemical properties of Pyrus betulaefolia polysaccharide（PBP） were analyzed by ultraviolet spectra,infrared spectroscopy,and high performance liquid chromatography.The scavenging activities of hydroxyl free radicals,superoxide anion free radicals and DPPH free radicals were further evaluated.The results showed that the best condition was acquired when the ratio of solid to liquid was 1∶15 and extracting at 90 ℃ for 5 hours,and highest extraction yield of PBP was 18.65%.The molecular mass of PBP was 392.9 kD by multi-angle laser light scattering instrument.The monosaccharides of PBP were consisted of arabinose,galacturonic acid,rhamnose,galactose and glucose,with a molar ratio of 49.54∶28.68∶8.81∶8.45∶4.54,respectively.PBP not only showed obvious scavenging effect on hydroxyl and super oxygen-anion free radical,but also showed higher scavenging activity for DPPH free radical.

Abstract:An effective method to reduce organophosphorus pesticides in orange peel was established in this study.The changes of nutrient contents were also studied and the results indicated that the content of organophosphorus pesticides decreased more than 80% when orange peel was treated 20 min using ozone concentration of 50 mg/L and alkali of 10 g/L.The residue met GB/T 5009.199-2003 and the loss of nutrient contents were least.

Abstract:The purification of fusion protein of human interleukin-2 and human serum albumin(rhIL-2-HSA) that was expressed and secreted in fermentation broth with recombinent Pichia pastoris GS115/pPIH was reported in this paper.Highly purified rhIL-2-HSA was separated from fermentation supernatant by ultra filter,Blue Sepharose affinity chromatography,Octyl Sepharose hydrophobic chromatography,DEAE Sepharose ion exchange chromatography.The purified fusion protein showed one single band on SDS-PAGE.The purified fusion protein could react with antibodies to IL-2 and HSA in Western Blot analysis.CTLL-2/MTT cell proliferating assay showed that the special activity of rhIL-2-HSA was 1.147×107 IU/mg.

Abstract:Based on the results of the single factor(carbon and nitrogen sources),the effect of broth content,mycelial pellet amount,powder weight and fermentation time on alkaloids content and biomass growth were further discussed by using L16(45) orthogonal test.The optimized culture conditions were acquired and listed as follows: maltose is carbon source,soybean cake powder is nitrogen source and liquid volume of 100 mL(a 250 mL flask),by adding 0.25 g powder,inoculated three evenly sized mycelial pellet,cultured at 28 degrees celsius for 5 days.After optimization the total content of strychnine and brucine in the culture medium reduced 8.74% compared with the control.Biomass could reach 10.6 g/L.Its rising rate was 37.7%.Meanwhile strychnine N-oxide and brucine N-oxide increased.The results showed the drug could promote the fungal growth and it can decrease the content of toxic constituents by liquid fermentation.

Abstract:Glutamate decarboxylase(GAD) is the main enzyme for biotransformation glutamate to gamma-Aminobutyric acid(GABA),a functional factor.In order to obtain a genetically engineered bacteria with high activity of GAD,a gene encoding glutamate decarboxylase from Lactococcus lactis subsp.lactis IL1403 was cloned and over-expressed in Escherichia coli BL21(DE3).The bacterium was induced by IPTG and analyzed by SDS-PAGE.The recombinant glutamate decarboxylase was purified to electrophoretic homogeneity by affinity chromatography.Approximately 54 kDa exogenous proteins were observed on the SDS-PAGE.The activity of recombinant GAD was also studied,the bioconversion rate reached 98.2% after 30 minutes,which was a significant improvement when compared with that of the wild type strain.

Abstract:During the anaerobic digestion of biomass,large amounts of organic acids were produced.This results in an inhibitory effect on anaerobic microbiology,which in turn inhibits large-scale production of hydrogen.In this study,butyric acid was use as stress on the sludge,and it was found that the production rates of butyric acid,acetic acid and hydrogenwas reached at 400 mmol/mol,1100 mmol/mol,3690 mL/mol,respectively,which was higher 110%,54% and 65% than that of the corresponding values in the control group.Moreover,glutamate acid decarboxylase(GAD) activity,dehydrogenase activity and the content of DNA was increased to 11.6 μm/(g·TS·h),6982.12 μg TF/(g·TS·h) 14.72 ng/mL,with an increment of 48%,50%,10.7%,respectively.and the content of extracellular polymeric substances(EPS) have improved significantly,loose bound protein,loose bound polysaccharide,tight bound protein and tight bound polysaccharide content were 147%,34.8%,35%,21.6% higher than that of the control.The results demonstrate that the appropriate concentration of butyric acid stress on sludge can excite acid tolerance response(Acid tolerance response,ATR) and to improve acid tolerance of sludge,and improve the efficiency of anaerobic hydrogen production.

Abstract:In this manuscript,with a hydroxyl radical-generating system prepared by Fe2+/H2O2/Asc as model,the effect of H2O2 concentration on the total sulfhydryls and active sulfhydryls,surface hydrophobicity,carbonyl and secondary structure of bovine serum albumin（BSA） were investigated by spectrophotometric,fluorescence and FT-IR.The results showed that the contents of total sulfhydryls and active sulfhydryls decreased in various degrees,as the concentrations of oxidant increased and the time prolonged,both surface hydrophobicity and carbonyl increased,secondary structure of BSA also changed.

Abstract:Ultrasound-assisted extraction of protein from tea residue was investigated in this manuscript.Effect of ultrasonic power,ultrasonic frequency,ultrasonic temperature,ultrasonic time,alkali concentration and material-liquid ratio on extraction yield of protein was investigated by single-factor experiment.Based on the results,the response surface methodology was used to optimize the extraction parameters and the optimum conditions listed as follows: e ultrasonic power 300 W,frequency 26 kHz,temperature 54 ℃,time 61 min,alkali concentration 0.35 mol/L and material-liquid ratio 1g∶27mL.Under these conditions,the protein extraction rate achieved at 86.5 %,increased by 37.2 % when compared with that of hot water alkali extraction.

Abstract:Mushroom sauce was made from the dried Pleurotus eryngii and soy sauce.Rehydration conditions of dried pleurotus eryngii have been studied.Fuzzy sensory evaluation and the response surface method were used to optimize the formula of mushroom sauce with unique flavor.Finally,the odor components of mushroom sauce were analyzed by GC-MS.The results showed that the optimum conditions for mushroom sauce listed as follows: mushrooms∶sauce=2∶1,salt 7.50%,sugar 6.66%.Flavor of mushroom sauce is composed of ketones,aldehydes,alcohols,esters,acids,sulfur compounds.The main volatile component in mushroom is 1-octene-3-alcohol which account for 11.26%.