Abstract:The new biological preservation technology has the incomparable advantages, such as less pollution and low cost, compared with the conventional fresh-keeping technology. This paper mainly reviews several techniques frequently used in fruits and vegetables preservation. Firstly, the principle of antagonistic bacteria preservation technology and its application are discussed. Secondly, gene engineering preservation technology is mainly discussed from aspects of reducing the generation of ethylene and regulating the activity of cell wall-degrading enzymes. Thirdly, enzyme engineering preservation technology is also reviewed from the view of enzyme preparation.

Abstract:Interleukin-2（IL-2） plays an important role in immune response and is wildly used as therapeutic protein to treat diseases，such as cancer，hepatitis and immunodeficiency. In this study，the pMH3 plasmid containing fusion protein of human serum albumin and IL-2 was constructed and then transfected to Chinese hamster ovary（CHO） cells by electroporation. CHO cells stably expressing the target protein were selected by neo gene in pMH3 plasmid and determined by Dot-blot during 96-plate culture. The titer of HSA-IL-2 was 2.26 mg/L in the 24-plate culture. Reverse transcription PCR and western blot showed that the gene encoding HSA-IL-2 was integrated to genome of recombinant CHO cells and the secreted fusion protein was detected by antibody to be HSA and IL-2. The biological activity of fusion protein was analyzed by IL-2 dependent CTLL-2 cells，and the result showed that the recombinant protein possessed a high activity. In conclusion，the recombinant CHO cells producing biological fusion protein of HSA-IL-2 were successful established.

Abstract:To study the pharmacokinetic and bioequivalence of Arparaginase Hyaluronic acid-graft-poly(ethylene glycol) / γ-cyclodextrin nanocapsules (AHRPs) in SD rats. We observed the image of AHRPs under the transmission electron microscopy. The size, zeta potential, entrapment efficiency were detected. The activity of AN was assayed after respectively intravenous injecting AHRPs and free AN in rats. The pharmacokinetic parameters were calculated by software DAS 2.1.1, then the bioequivalence was judged. After calculating, the average particle size was (410.30±3.20) nm, zeta potential was (-31.40±1.65) mV, average entrapment efficiency was (42.80±4.37)%. AUC(0-48h) of AHRPs and free AN was (104.01 ±1.68) U/mL*h and (46.38 ±1.98) U/mL*h, AUC(0-∞) was (131.03 ±19.67) U/mL*h and (51.44 ±3.01) U/mL*h, t1/2 was (4.31±1.53) h and (1.86±0.38Z) h, respectively. Compared with free AN, the AUC(0-48h), AUC(0-∞) and t1/2 of AHRPs increased 2.24, 2.55 and 2.32 times, respectively. The 90% confidential intervals of AUC(0-48h), AUC(0-∞) and Cmax of tested formulation were 77.1%~78.7%，76.7%~78.3%，98.9%~100.5%, respectively. AHRPs can improve the bioavailability and extend the biological half-life of AN in rats. AHRPs and free AN are not bioequivalent.

Abstract:A method based on network analyzer with an open-ended coaxial cable and mixture equations was used to analyze dielectric properties of Chinese steamed bread by microwave heating. Dielectric properties of Chinese steamed bread were measured under the different densities. Regression analysis method was used to get the relationship between dielectric properties and frequency. By comparing the measured values of dielectric properties with the calculated ones，the Bottcher equation was obtained for the calculation of dielectric constants and the Landau and Lifshitz，Looyenga equation for loss factors. The effects of frequency（915~2 450 MHz），moisture content（40.12%~48.50%（w.b.） ） and temperature（25~100 ℃） on dielectric properties were studied. Results showed that dielectric constants decreased with the increased frequency，loss factors first decreased then slowly increased with the increased frequency. Both dielectric constants and loss factors increased with increased temperature and moisture content. The penetration depth of Chinese steamed bread in microwave heating decreased with the increased factors. Within the temperature range of 25~100 ℃，the optimal thickness of steamed buns at 915 MHz and 2 450 MHz in microwave heating was 12.82 cm and 10.62 cm，respectively.

Abstract:In an aqueous/organic two-phase，cascade catalysis was carried out for the efficient preparation of（S）-styrene oxide（SO） by a combination of carbonyl reductase（SyS1），glucose 1-dehydrogenase（SyGDH） and halohydrin dehalogenase C（SyHheC）. The firststep was to asymmetrically reduceα-bromoacetophenone into（S）-2-bromo-1-phenylethanol（（S）-BPE） and to regenerate NADPH in situ. The optimized conditions were 100 mmol/L potassium phosphate buffer（pH 8.0）/n-hexane（v∶v=4∶6），40 mmol/L α-bromoacetophenone，80 mmol/L D-glucose，0.2 mmol/L NADP+ and 70 mg/mL wet E. coli/Sygdh-Sys1 cells（co-expressing both SyGDH and SyS1） in a volume of 1.0 mL at 35 ℃ for 8 h. The second step was dehalogenation ring-closure of（S）-BPE into（S）-SO by adding potassium phosphate buffer（pH 8.0） and 0.3 U SyHheC into the above reaction system， in a volume of 2.0 mL，at 35 ℃ for 30 min. Through two steps of enzyme catalysis，the final product（S）-SO was obtained with a molar yield of 99% and an enantiomeric excess value more than 99%.

Abstract:Yunnanopilia longistaminata is a wild woody vegetable in China，and its tender stems and leaves are edible. So far，studies of Y. longistaminata have mostly been focused on tissue culture，physiology and biochemistry，while less concentrated on the gene level. Gibberellin（GA） can enhance vegetative growth，such as the bolting，and the growth of stems and leaves. Using molecular biology methods，we studied the ent-kaurene synthase，a key enzyme in the synthesis pathway of gibberellins. Ent-kaurene synthase gene（YlKS） was cloned from the leaf of Y. longistaminata through RACE-PCR. The full gene length was 2 512 bp（GenBank accession number KP872698）. Results showed that the ORF length of YlKS was 2 232 bp and the molecular weight of its encoded protein（YlKS） was 84 987. The theoretical isoelectric point of YlKS was 5.264，which suggested that YlKS protein was acidic. The gene was cloned into the vector pET32a to get the plasmid pET-32a-YlKS. Plasmids pIRS，pGG/An2 and pET-32a-YlKS were co-transformed into BL21（DE3） strain to obtain a new recombinant strain，and then the recombinant strain was used for fermentation. The SDS-PAGE analysis showed that the recombinant protein was expressed successfully. Finally，we used n-hexane to extract the fermentation products and the GC-MS analysis confirmed that the gene in this study was Ent-kaurene synthase encoding gene.

Abstract:The study compared the performance and kinetics for the generation of methane by different ratios of food waste to excess sludge at 1∶0，0∶1，1∶1. Results showed that the co-digestion not only shortened the time of methane generation when compared to food waste alone treatment，but also improved the production efficiency with a yield of 233.394 mL/gVS，which was 17.4% higher than the calculated value of 198.939 mL/gVS according to food waste and excess sludge alone groups. The correlation coefficient R2 was greater than 0.989 by the first order kinetics fitting. The G∞ of food waste，excess sludge and co-digestion groups was 276.5，113.955 mL/gVS and 248.81 mL/gVS，respectively. They were similar to the actual measured values of 285.24，112.238 mL/gVS and 233.94 mL/gVS，respectively. Also，the comparative study of pH，VFAs，ammonia-nitrogen，SCOD and dehydrogenase enzyme was carried out and showed that the co-digestion balanced nutrients and decreased the system acidification，which resulted in a better buffer capacity and the system stability for the mixed substrates. It increased the amount of easily degradable organic matters and improved the methane producing efficiency as compared to the excess sludge only group. The dehydrogenase activity of co-digestion group was higher than that of kitchen waste only digestion group during the whole digestion process，with a maximal value of 657.2 TFμg/（mL·h）.

Abstract:Peanut protein, as a high quality vegetable protein, rich in resources and high nutritional value, and it has good development potential.Nanoparticles were synthesized from peanut protein isolate, and optimized their preparation process. The size and spherical shape of nanoparticles were characterized bynanolasergranulometer and transmission electron microscopy (TEM). The results show that the nanoparticles were achieved with good dispersibility, round shape and narrow particle size distribution. The average particle size was （94.66±0.53） nm. The preparation of nanoparticles from peanut protein not only can broaden the field of peanut protein application, but also provide a basis for the development of new formulations of protein nanoparticles.

Abstract:Using the content of protein and polysaccharide and the content of nucleic acid separately as indicators of total extracellular polymeric substances（EPS） and cell autolysis，five different extraction methods，including thermal，EDTA，NaOH+NaCl，ultrasonic+CER and high speed centrifugation（control） treatments，for EPS from natural biofilms were studied. Results showed that NaOH+NaCl treatment was the most effective for EPS extraction with less nucleic acid contamination. The optimal extraction conditions were 2 mol/L NaOH，0.85% NaCl，extraction time 2.5 h and centrifugal force 7 000 g. With these parameters，the extraction content of EPS was 157.57 mg/L.

Abstract:Insulating package can effectively protect fresh food from the impact of extra temperature during transport. A mathematical model for the design of insulating package was proposed based on the prediction model from the previous study，and a solution boundary of insulating package was also presented according to the design model. Furthermore，a design process was established through the model and solution boundary and its validity was confirmed by storage experiment. Results showed that insulating package can be effectively designed using the design model and process，and the model value had a good great agreement with test data.

Abstract:This study investigated kinetics and thermodynamics for the ultrasonic-circulating extraction of Lepidium meyenii Walp.（maca） alkaloids. The extraction was carried out with different temperatures or acoustic energy densities. Two site model was applied to simulate the extraction kinetics and Van't Hoff equation was used to calculate thermodynamic parameters. Results showed that two site model gave satisfactory data fit. Alkaloid yield and rate constants were enhanced with increased temperature or acoustic energy density. The activation energy values were 16.41 kJ/mol and 17.52 kJ/mol for washing and diffusion stages，respectively. The alkaloid extraction was endothermic，irreversible and spontaneous. In addition，compared with maceration，ultrasonic- circulating extraction resulted in significantly higher yields of alkaloids at 20 ℃ and 50 ℃（p<0.01）. Therefore，ultrasonic-circulating extraction is an effective technology to extract maca alkaloids.

Abstract:The study investigated the effects of pressure，temperature，dwell time and pH on the enzyme activity of lipase Lip2 from Yarrowia lipolytica（YLLIP2） in high hydrostatic pressure（HHP） treatment. Results showed that HHP improved the activity of YLLIP2 and pressure，temperature，dwell time and pH had significant effects on the enzyme activity. Optimal parameters were found by orthogonal test to be pressure 450 MPa，temperature 45 ℃，dwell time 10 min and pH 7.5. The optimal pH was increased 0.5 in HHP.

Abstract:To determine the optimal extraction of total flavonoids from Zingiber mioga by the response surface methodology and then to study the in vitro antibacterial activities. On the basis of single factor experiments，a 4-factor，3-level Box-Behnken center-united experiment was conducted. The Box-Behnken experiment optimized the processing conditions by response surface methodology. Then the extract from the optimal conditions was concentrated. Finally，the in vitro antibacterial activitie were determined by oxford plate tests and doubling dilution method. The optimal conditions were as follows：ethanol concentration 94.75%，treatment temperature 100 ℃，liquid-to-solid ratio 85∶1（mL∶g），treatment time 70 min. Under the optimal conditions，the extraction rate of total flavonoids was 39.87%，of which the relative error was only 2.26% compared with the predicted value of 40.79%；total flavonoids from Zingiber mioga had no inhibitory effects on Escherichia coli，Saccharomyces cerevisiae and Aspergillus niger，but did inhibit the growth of Bacillus subtilis and Staphyloccocus aureus with the minimal inhibitory concentration（MIC） 3.245 9 mg/mL and 1.622 9 mg/mL and the minimal bactericidal concentration（MBC） 12.983 5 mg/mL and 6.491 8 mg/mL，respectively. CONCLUSION Total flavonoids from Zingiber mioga could be a new type of antibacterial agents and the extraction was suitable for the regression analysis and parameter optimization by response surface methodology.

Abstract:The research studied the chemical composition of tomato extract prepared by complex enzyme hydrolysis coupled with Maillard procession and its application in cigarette. Results showed that：with the hydrolysis of pectinase - glucoamylase - cellulase complex enzymes and then the Maillard reaction，the tomato extract contained 13 kinds of volatile components by GC-MS analysis；the tomato extract was rich in low molecular weight compounds such as aldehydes，ketones，esters and alcohols，which were relatively simple with good solubility and better cigarette absorption when used in cigarette flavoring；the mixtures of volatile fragrant components obtained by distillation and latent fragrant components obtained by sediment extraction with different proportions，possessed different sensory effects；the sensory evaluation indicated that the mixtures improved smoothness，enriched incense smoke，increased a sense of sweet rhyme and reduced irritation，and thus improved the quality of cigarettes.

Abstract:Paeonia ositii，known as Tong Lin peony，belongs to the Jiang Nan group. In this experiment，amino acids of the Paeonia ositii seed protein were analyzed using an automatic amino acid analyzer（L-8900） and the nutrition of the amino acid composition was evaluated compared with the whole egg protein，isolated soy protein and the FAO/WHO recommended model. Sixteen amino acids were detected（except tryptophan） and the content of essential amino acids was 38.9%. Nutritional values including essential amino acid index（EAAI，72.3），Biological Value（BV，67.1），Amino Acid Ratio Coefficient（SRC，81.6） and the close degree to whole egg protein（0.90） by the fuzzy recognition method were all higher than those for isolated soy protein. Most of the chemical scores（CS） of Paeonia ostii seed protein were superior or close to those for isolated soy protein. These indicated that Paeonia ositii seed had a good balance index of amino acid composition and could become a new source of high quality amino acids in the near future.

Abstract:This article constructed the algorithm of mutation degree by comparing the difference of two consecutive year's reports on HA protein sequences of pandemic influenza virus. Based on 1916～2014 HA protein sequences，the mutations of every year were calculated by the algorithm，and thus it was observed that the mutation values of four major flu outbreak years were higher than those of the adjacent years，and the higher of the mutation value，the greater the scope and impact of pandemic influenza. This approach was rational and would benefit the study of influenza outbreak as well as the early warning and defense.

Abstract:L-2-methyltryptophan plays an important role in many physiological processes. This paper investigated the synthesis of L-2-methyltryptophan in an aqueous/organic biphasic system，and optimized the synthetic method. The optimal transformation conditions were 150 mmol/L L-serine，2% toluene，0.1 mmol/L Ca2+，2% Trion X-100，40 ℃ and pH 8，which resulted in a content of over 21.17 g/L for L-2-methyltryptophan. Thus，the strain can be used to produce L-2-methyltryptophan and has an excellent converting capability of L-2-methyltryptophan.

Abstract:In order to analyze the antineoplastic activity of human interleukin-29（hIL-29） variant，a mutant gene of hIL-29 was amplified by megaprimer PCR，and the Arg35 of hIL-29 peptide chain was mutated to Lys35. A recombinant plasmid was constructed and transformed into Pichia pastoris GS115，the recombinant protein rhIL-29mut35 was induced and purified. The purified rhIL-29mut35 had a relative molecular mass of about 23×103 on SDS-PAGE profile and showed specific reaction with goat anti-human IL-29 polyclonal antibody in Western blotting. With the Cell Counting Kit-8 reagent，the rhIL-29mut35 was found to has anti-proliferation effect on tumor cells SGC7901，BEL7402，A549 and HCT8 separately with inhibition ratios of （34.20±1.50）%，（27.30±0.31）%，（30.20±0.68）% and（29.13±1.40）% in the high dose group. The anti-proliferation effect of rhIL-29mut35 was stronger than that of wild type rhIL-29（P<0.01），which supported the development of antineoplastic drugs of IL-29.