Abstract:Dendrobium nobile Lindl.(Orchidaceae), a rare Chinese herbal medicine, contains rich functional ingredients, such as alkaloids, polyphenols, polysaccharides. It has become a hot spot of research in the field of modern medical treatment, health care food, etc. This review summarizes the research progresses on the extraction, detection, structural identification and functional ingredients.The development status on health care food of D. nobile, which shows that Dendrobium nobile Lindl. has depth development prospects.

Abstract:Ethyl carbamate(EC, or urethane), a by-product of fermented food, has been shown to be possible carcinogenic and genotoxic to human. Enzymatic removal of EC from fermented foods and beverages is an efficient and safe method. Lysinibacillus fusiformis, a strain isolated from the gastrointestinal tracts of mice, showed the activity of hydrolyzing urethane. The protein with urethanase activity was purified to electrophoretic homogeneity by ammonium sulfate precipitation, ion exchange chromatography, hydrophobic interaction chromatography and gelfiltration chromatography. The monomeric molecular weight of this urethanase was detected to be approximate 50 kDa by SDS-PAGE. Enzymatic properties analysis demonstrated that the purified enzyme was stable at temperature range 10~45 ℃, the optimal reaction conditions of it was determined to be at 35 ℃ and at pH 7.0. Using urethane as the substrate, the kinetic constants of Km and Kcat were detected to be 37.2 mmol/L and 1 176.4 s-1, respectively. The activity was inhibited by metal ions while EDTA had no effect on enzyme activity. The results showed that the urethanase was not an ion-associated enzyme. In addition, the enzyme showed tolerance to low concentration of ethanol and NaCl, indicating its potential applications in removing urethane from fermented products(rice wine and soy sauce).

Abstract:To explore the expression level of co-expression of folding factors Ero1, PDI and BiP on production of IFNβ-HSA by Pichia pastoris GS115. The pGAP-Ero1, pGAP-PDI, pGAP-BiP expression plasmids and the empty plasmid pGAPZ B(control) were linearized and integrated into the genome of P.pastoris GS115-IFNβ-HSA by electroporation. The recombinant yeasts were screened with 400 μg/mL zeocin. Positive recombinants were identified by genomic PCR and Western blot. The transformants were fermented in flask and the expression products were confirmed by SDS-PAGE and Western blot. The expression levels of IFNβ-HSA co-expressed with Ero1, PDI and BiP were analysed. The results indicated that Ero1, PDI and BiP were successfully expressed in recombinants with no effect on growth. Compared with Bip, co-expressed with Ero1 and PDI significantly improved the expression level of IFNβ-HSA, the expression level was 80%(Ero1) and 90%(PDI) higher than control.

Abstract:This manuscript introduced the treatment project for anaerobic effluent of landfill leachate from a waste incineration plant. A vertical anaerobic/aerobic reactor was used in the project, which could reduce the floor space. Contaminant removals during the reactor's startup and commissioning were investigated. The results showed that the effluent COD and NH3-N concentrations were respectively below 1 900 mg/L and 180 mg/L when the processing loads were around 1.8 kg COD/(m3·d) and 0.36 kg NH3-N/(m3·d). And the removal efficiencies of COD and NH3-N were respectively reached at 80% and 90%. The reactor exhibited a good resistance to impact load, and the effluent complied with design requirements after 120 d full-load operation. Moreover, the third grade criteria specified in the Discharge Standard of Integrated Wastewater could be reached via subsequent treatment using membrane bioreactor.

Abstract:Postnatal 6 week ICR mice were exposed to 0.3 g/L caffeine solution for 21 days. After exposure, the influence of caffeine on intestinal villi morphology, expression of sweet receptors and taste signal transduction protein, release of insulin and GLP-1, glucose tolerance of mice were detected respectively by using the methods of stereomicroscope observation, western-blotting, ELIASA and blood glucose measurement technology. Compared with the control, the height of intestinal villi increased, the depth of crypt of intestinal villi decreased, thereby the ratio of villi and crypt of mice after long-term chronic caffeine exposure. Besides, long-term bitter taste exposure of mice increased the expression of TIR2 and TIR3, but decreased the expression of taste signal transduction molecule α-gustducin, however had no remarkable effect on the expression of SNAP 25. In addition, long-term caffeine exposure significantly increased the release sensitivity of insulin and GLP-1 of mice intestine, so notably increased the blood glucose tolerance of mice. The results indicated that caffeine exposure could alter the sweet perception pathway in intestine, and affect the blood glucose homeostasis of mice.

Abstract:A comprehensive analytical method based on high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) was developed in this manuscript, for measuring 9 exogenous endocrine disruptors-bisphenol diglycidyl ethers, including BADGE, BADGE·H2O, BADGE·HCl, BADGE·2H2O, BADGE·2HCl, BADGE·H2O·HCl, BFDGE, BFDGE·2H2O and BFDGE·2HCl. The samples were extracted with methyl tertiary butyl ether by ultrasonic wave assistant extraction(UAE). The extracts were cleaned up and concentrated on graphene SPE column. The targeted compounds were analyzed by HPLC-MS/MS under positive ion mode using COSMOSIL C18 column as analytical column. Under the optimal conditions, 2 analytes had a good linearity in the concentration range of 0.5~10.0 ng/mL. 2 analytes had a good linearity in the concentration range of 5.0~100.0 ng/mL; and the other 5 analytes had a good linearity in the concentration range of 2.0~20.0 ng/mL. The correlation coefficients(r2) were higher than 0.992 2. Recoveries of 9 analytes in canned meat at three spiked level ranged from 60.0%~97.6%, the recoveries of 9 analytes in canned oranges at three spiked level ranged from 65.7%~111.3%, with RSDs less than 20％. The detection limits of the method ranged from 0.1 to 1.0 μg/kg. The method was sensitive, simple, and suitable for the rapid determination of exogenous endocrine disruptors-bisphenol diglycidyl ethers in food contact materials.

Abstract:Three succinyl xanthan oligosaccharides(XGOSSA-1, XGOSSA-2, and XGOSSA-3) were prepared. The products were characterized by FT-IR, and the molecular weights of the products determined by GPC method were 7 560, 6 400 and 7 430, respectively. The pyruvic contents of the three derivatives were 4.6%, 4.9% and 4.9% respectively. The reducing sugar contents were 20.5%, 19.4% and 19.0%. The substituting degrees were 0.18, 0.32 and 0.43. Antioxidant activity of the derivatives was evaluated by the scavenging of superoxide anion radical(O2-), hydroxyl radical(·OH), 2, 2-diphenyl-1-picryhydrazyl(DPPH) radical, hydrogen peroxide(H2O2) and determination of reducing power. The order of antioxidant activity was：XGOSMA-1>XGOSMA-2>XGOSMA-3. It indicated that the antioxidant activity of succinyl xanthan oligosaccharides derivatives decreased with the increasing of substituting degrees when they have the similar molecular weight and contents of pyruvic acid and reducing sugar. The results may be related to the fact that the active hydroxyl group decreased with the increasing of the substituting degrees.

Abstract:The effects of pH-value, metal ions and organic acids on the color characteristics and stability of anthocyanins off-flavor from purple sweet potato were studied in this manuscript. The results showed that the anthocyanins was most stable when pH lower 3.0; Fe3+ in lower concentration could increase the color intense most largely. But it could accelerate anthocyanins to degrade and brown in high concentration over extended time.Fe2+ led to degradation.Ca2+, Mn2+ and Cu2+ in low concentration had good copigmentation effects. Oxalic acid, malonic acid, and L-malic acid could enhanced the absorbance values and improved the thermal stability, which showed an increased tendency with organic acids concentration. Among the three organic acids, oxalic acid showed the best copigmentation effects, followed by L-malic acid and malonic acid.However, ferulic acid and citric acid had no significant copigmentation effect. Ascorbic acid was subtractive.

Abstract:Gene expression profiles of Torulopsis glabrata at different osmolarity(860, 1 765, 2 603 mOs mol/kg and 3 324 mOs mol/kg) were investigated by microarray. Significantly upregulated genes were mainly involved in regulation of cell wall, cell membrane and pheromone-regulated membrane proteins. The genes in central metabolic pathway, such as glycolysis, Krebs cycle and oxidative phosphorylation pathway, were mainly upregulated, especially the genes associated with ATP or NADH formation. Futhermore, the genes associated with potential key compatible solutes, such as proline, arginine and glutamate synthesis pathway were upregulated, and urea carboxylase which involved in arginine catabolism was drasticly downregulated to only about 1/100.

Abstract:An amphiphilic material(HA-F127) was prepared by conjugating hyaluronic acid(HA) and pluronic(F127) via "Click" chemistry. The chemical structure of HA-F127 was identified through 1H NMR spectrum, and the degree of substitution was 13%. HA-F127 could self-assemble into nanoparticles in aqueous solution and load model anticancer drug doxorubicin. In vitro drug release assay showed the nanoparticle behaved temperature sensitive drug release profile. Since hyaluronic acid could recognize CD44 receptor, which over-expressed on cancer cell surface, the nanoparticles could targetedly deliver drug into cancer cells and obtain promoted therapeutic effect.

Abstract:Aflatoxin B1 (AFB1)and Sterigmatocystin(ST) are two fungal toxins that are commonly coexisted in many crops, and their joint cytotoxicity to human hepatoma cell line HepG2 was investigated. HepG2 was treated with different concentration of AFB1(0.1, 1, 5, 10 μmol/L), ST(0.5, 2.5, 5, 7 μmol/L) and their mixture for 24 h or 48 h to analyze their combinative toxic effect through measuring the toxicity end points including change of cell proliferation, ATP content, degree of DNA damage, change of mitochondrial membrane potential and active oxygen content. The IC50 of AFB1 and ST was found to be 16.989 μmol/L and 7.258 μmol/L, respectively. There was no significant difference(P>0.05)between the theoretical value compared with the actual value of all the end points.In the mean time, the end points of cytotoxicity can be divided into three categories by principle component analysis(PCA)：the first category is the cell proliferation, the second class includes ATP content, DNA content; the third class is the active oxygen content and the mitochondrial permeability transition. The results indicate that interaction type between AFB1 and ST is additive joint effect.

Abstract:To develop a sensitive high performance liquid chromatography(HPLC)method to determine Limonin in Citrus Changshan peel. Different extraction technologies were compared in this study. There are three methods which were selected：organic solvent extraction, water extraction and ultrasonic extraction. The optimum conditions of ethanol extraction were achieved as follows：soaking temperature as 50 ℃, the ratio of materials to solution as 1∶20(g/mL), extraction time as 60 min. The Limonin content of Citrus Changshan peel was 2.97 mg/g. The optimum conditions for water extraction were achieved and listed as follows：soaking temperature as 80 ℃, the ratio of materials to solution as 1∶25(g/mL), extraction time as 90 min. The Limonin content of Citrus Changshan peel was 2.42 mg/g. The Limonin content of Citrus Changshan peel with ultrasonic extraction was 3.32 mg/g by ethanol and 2.87 mg/g by water.

Abstract:The phylogenetic diversity of culturable pullulanase producing strains from hotsprings of guanzhong region, including Xi'an, Lintong District, Chang'an District and Yangling. A total of 105 pullulanase producing strains were isolated and 21 strains were analyzed. Analysis of 16S rDNA gene sequences revealed that Klebsiella and Bacillus is in the advantage position in the hot springs ecosystem. According to statistics, the isolated strains between species and within species showed a significant difference in enzyme activity. The optimal pH and temperature of GP-1 were 6.0 and 50 ℃ respectively. The enzyme showed stability at 65 ℃ after incubating for 30 min.

Abstract:In this study, the changes of microorganisms amount and chemical compositions of tobacco leaves during high moisture solid-state fermentation. The experimental results showed that：In high moisture normal temperature aerobic solid-state fermentation, the tobacoo leaves became moldy after 2~3 days, aerobic bacteria gradually reduced, yeasts and moulds grew rapidly. In high moisture normal temperature anaerobic solid-state fermentation, the amount of anaerobic bacteria had a slight reduction, but the amount of yeasts increased substantially at the early days and stabilized after 4 days. In high moisture high temperature aerobic and anaerobic solid-state fermentations, yeast and mould did not grow, both of aerobic and anaerobic bacteria reduced significantly. In all four fermentations, the content of starch and protein in tobacoo decreased with time.

Abstract:The extraction of da-hong star anise oleoresin by supercritical fluid CO2 was studied. The results showed The optimum process parameters were as follows：mesh size was 1.50 mm, the pressure was 25 MPa and 55 ℃ for 2.5 h(extraction kettle of 5 L, the flow rate of CO2 was 55 L/h). In this condition, the yield was 12.83%, the extraction rate was 92.31%. In addition, the volatile components of star anise oleoresin were analyzed by GC-MS. The main components were trans-anethole(83.74%), D- Limonene, estragole, etc.

Abstract:The aim of this study is to develop MAE-GC/MS method to determine the Benzo(α) pyrene (B(α)P) content. For this, the sample was pre-treatment by MAE(microwave-assisted extraction technology)and then separate by, DB-5MS fused silica capillary column(30 m×0.25 mm×0.25 μm) with B(α)P m/z=252 asthe selected ion, the detection is the series four quadrupole selected ion monitoring(SIM) mode with 9-phenyl anthracene as internal standard. A series of results were achieved： B(α)P detection limit was 0.01 μg/kg and the standard curve was linear at the range of 0~10 μg/mL. The correlation coefficient was 1.000, with the recoveries of 97%~103% and good precision: Days RSD/%<0.5%, day RSD/%<1%. The good accuracy, the negative sample as the base material, containing 0.1 mL methanol and benzo (α) pyrene national standard component analysis (GBW08702) spiked levels, the measured values within the standard value range. Based on the above results, conclusion could be arrived: the method is simple, high recovery, detection limit, linear range, accuracy, precision results meet the requirements for the determination of food in B(α)P content.