Abstract:The mechanisms of the catalytic activity regulations and the conformation changes of enzyme under high hydrostatic pressure were summarized in this paper. Different characterization of the behaviour of enzyme under high pressure was also reviewed. In enzymology, high hydrostatic pressure could be used to modulate the enzymatic activities and explore the conformational changes, which has attracted more and more attention. This review also discussed the future developments of this technique.

Abstract:The algae protein has a variety of biological activities. This article reviewed its nutritional values and health effects including antioxidant, anticoagulant, antibacterial, antitumor and other functions. Its application in food, medicine and cosmetics was also concluded herein. This paper would arouse further research and development of algae protein.

Abstract:Optimization of Near infrared (NIR) spectroscopy for quantitative analysis of the anthocyanin content in scented tea was discussed by selecting the optimal spectra intervals from the whole NIR spectroscopy using two variable models: Ant colony optimization interval partial least squares (ACO-iPLS) and Genetic Algorithm interval partial least squares (GA-iPLS). The ACO-iPLS full-spectrum was split into 12 intervals. The optimal intervals selected were the 1st interval, 9th interval and 10th interval. The calibration and prediction correlation coefficient of ACO-iPLS model were 0.901 3 and 0.864 2, in which the root mean square error of cross validation (RMSECV) of 0.160 0 mg/g and the root mean square error of prediction (RMSEP) of 0.206 0 mg/g were achieved. As in the GA-iPLS model, the data set was split into 15 intervals for optimization where 1st and 5th intervals were selected. The calibration and prediction correlation coefficient of GA-iPLS model were 0.901 3 and 0.864 2, and the RMSECV and RMSEP of GA-iPLS models based on these intervals were 0.156 0 mg/g and 0.206 0 mg/g, respectively. The results showed that both ACO-iPLS and GA-iPLS models could efficiently select spectrum intervals for quantitative analysis of anthocyanin in scented tea. The optimal GA-iPLS model had better performance with higher accuracy.

Abstract:In order to tender the pork meat by the action of chemical agents and exogenous enzymes, sensory evaluation, cooking loss and chewiness force were evaluation to determine a group of agents which has the most significant tenderizing effect, and then determine the optimal experimental condition by the single factor experiment and the orthogonal experiment. Eventually, the best group was obtained. Then, on the basis of the single factor experiments, we designed the orthogonal experiment and obtained the optimal conditions. Finally, papain, sodium and compound phosphate were combined as the pork tenderness treatment. For papain, the optimum reaction temperature was 30 ℃, optimum reaction time was 1.5 hand the optimal concentration was 0.5 g/L For Na2CO3, the optimum added content(mNa2CO3∶vH2O)was 6%. The optimal content of phosphate compounds was 0.5%, and the ratio among these phosphate compounds was sodium polyphosphate : pyrophosphate : hexametaphosphate =2∶2∶1. Meanwhile according to the orthogonal experiment ,optimized conditions of papain was content of papain 0.7 g/L, temperature 30 ℃, 6% of sodium carbonate concentration, compound phosphate (sodium tripolyphosphate ,sodium pyrophosphate, sodium metaphosphate =2∶2∶1),0.5% addition level. Then the optimum time of pretreatment was 1.5h in this condition.

Abstract:This study aimed to investigate the effect of different positions on the hot-air and microwave coupled heating. Based on the mathematical model of hot-air and microwave coupled heating, distribution parameters of the end temperature field for seven spots were first obtained for whole potato heated in a particular cavity by numerical simulation techniques. The simulations were further by verified by the experimental results that different spots showed varied heat power values and density distribution after the conversion of microwave electromagnetic energy into heat power and uneven distribution of the temperature field. Therefore, great attention should be paid to the food spots in the hot-air and microwave coupled heating.

Abstract:Amino acid composition and molecular weight distribution of wheat oligopeptides (WOP) were analyzed, and the protective effect of WOP on hydrogen peroxide (H2O2)-induced HepG2 cell oxidative injury was investigated. After treated with different concentrations of WOP for 4 h, HepG2 cells were injured by 150 μmol/L of H2O2 for 4h, and then the cell viability and contents of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) were determined. Results showed that the percentage of WOP with molecular weight below 1,000 Da reached up to 93.44% and the contents of glutamic acid, glutamine and proline were relatively high. Furthermore, WOP increased the cell viability and inhibited the production of intracellular ROS and MDA, indicating beneficial effects of WOP on the reduction of oxidative stress and the improvement of cell antioxidant capacity. Thus, WOP could protect liver cells against the injury caused by peroxides.

Abstract:The research aimed to establish a Taqman real-time fluorescence quantitative assay for the rapid detection of milk allergen β-lactoglobulin in food. Specific primers and Taqman probe were first designed based on the gene sequence of β-lactoglobulin for real-time PCR. The purified DNA product was linked with the pMDl9-T vector to construct recombined plasmids as a standard PCR template. Plasmids were then identified with colony PCR and subjected to sequencing. Real-time fluorescence PCR assay was performed with plasmids and the standard curve was constructed with DNA copies and Ct. Sensitivity, specificity, reproducibility and application of the real-time method were also evaluated. Results showed that the β-lactoglobulin DNA fragment was successfully cloned and the standard curve had a good linear relationship ranging from 3.18×103 to 3.18×107 copies. The detection sensitivity reached up to 318 copies/μL. Furthermore, specificity and stability of the method were good. Ten foods were detected with the β-Lg DNA residue and the results were consistent well with their allergen labels. Therefore, the method may become a complementary tool for milk allergen detection and it is applicable for other food allergens.

Abstract:The effects of gamma-aminobutyric acid (γ-aminobutyric acid, GABA) on oxidative stress, liver function, hepatic steatosis and lipid metabolism-related gene expression were studied in the liver of high-fat diet fed mice. 50 C57BL / 6 male mice were randomly divided into five groups: normal group (normal diet), high fat diet group (high fat diet), and three GABA groups (0.2%, 0.12% and 0.06 % GABA in drinking water, respectively). After 18 weeks, reactive oxygen species (ROS) levels, antioxidant enzyme activities, contents of lipid and glycogen in liver and plasma activities of alanine aminotransferase and aspartate aminotransferase were measured. In addition, the morphological features of liver tissue were observed and the expressions of SREBP-1c, FAS, ACC1, PPARα, Cpt1a and the PGC-1α in liver were measured by using of RT-PCR. The results showed that in high-fat diet fed mice, liver weight, liver index, triglyceride and cholesterol contents in liver increased significantly with damaged liver function; 0.2%, 0.12% and 0.06% GABA treatments can significantly reduce liver weight and liver index; 0.2%, 0.12% GABA treatments significantly inhibited hepatic steatosis and improved liver function. Compared with that of in normal group, high fat diet treatment significantly reduced antioxidant enzyme activities and increased ROS and malondialdehyde (MDA) contents; 0.2% and 0.12% GABA treatments significantly alleviated oxidative stress. In liver of high-fat diet fed mice, expressions of PPARα, Cpt1a PGC-1α were significantly reduced, while, expressions of SREBP-1c, FAS and ACC1 were remarkably increased, but both 0.2% and 0.12% GABA supplements can significantly alleviate the gene expression changes that high fat caused. Thus, high-fat diet treatment led to oxidative stress in liver, steatosis and damaged liver function. Meanwhile, a certain dose of GABA can improve redox status and fat metabolisms, thereby preventing the occurrence of fatty liver.

Abstract:Abstract：The reconstructed fish tidbit from silver carp and salted egg white was obtained by microwave assisted infrared and negative pressure spouted drying. The optimal formula was 10% of tapioca starch, 3% of white sugar and 40% of salted egg white. The best processing parametes were: infrared drying to 25% of moisture content, spouting 6 times per minute, microwave power 33 w/g. With these conditions, the crispy and delicious fish tidbit was manufactured.

Abstract:A reasonable evaluation method for vinegar quality was established in this study. Eight samples of sonication aging vinegar, fresh fermented vinegar, and natural aging vinegar of 1 year, 2 year, 3 year, 4 year, 5 year, 6 year were used as the research objects. Seven measurements including the total esters, total acid, reducing sugars, alcohols, ketones, esters, total amino acids were used as variables. Principal Component Analysis was used to filter the main ingredients. Comprehensive evaluation model was established based on PCA, which was used to determine the index weights and sample distribution diagram. The conventional sensory evaluation method was used to assess and classify the quality of vinegar. The results showed that the frontal 2 principal factors contained 87.24% information about organic variable contents in the 8 kinds of vinegar samples, and the test result indicated that the model evaluation result was consistent with conventional sensory evaluation. The sample distribution diagram showed that sonication vinegar was located near the 4 year vinegar, which indicated that the comprehensive index of sonication vinegar was similar to natural aging 4 years vinegar.

Abstract:In this study, K5 polysaccharide (heparosan) was conjugated with anticancer drug DOX via hydrazone bond to obtain pH-sensitive K5-hydrazone-DOX (KHD) prodrug. The drug loaded capacity, morphology, and in vitro drug release were investigated. Its in vitro cytotoxicity and cellular uptake against HeLa cells were also evaluated. The results showed that the DOX content of KHD is 18.0%. The release rate of DOX at pH 5.0 was much faster than that at pH 7.4, revealing a pH-triggered release manner. The KHD prodrug could achieve intracellular delivery and showed effective cytotoxicity in vitro. This study indicates that the KHD prodrug may be a potential candidate for cancer therapy.

Abstract:A supramolecular hydrogel with dual function of anti-inflammation activities was prepared from chitosan-β-cyclodextrin and dextranmodified with a nonsteroidal anti-inflammatory drug (ibuprofen) self-assembled via a guest-host inclusion interaction. The hydrogel with uniform porous structure was observed under scanning electron microscope. Ibuprofen could be quickly released with esterase added and stays stable without esterase. In addition, the hydrogel has great potential of clinical application in wound healing since it possesses efficient anti-microbial and anti-inflammation activities.

Abstract:In order to make full use of resource of Toona sinensis and provide theoretical basis for the development and processing, the quality and vitro antioxidation activity of different parts (upper, middle, bottom) of Toona Sinensis immature leaves and stems were studied. The qualities include total polyphenol, Vc, soluble saccharide, chlorophyll, flavonoid, soluble protein and nitrite. Quality analysis showed that contents in leaves were significantly higher than that of in stems (p <0.01) except for soluble proteins and nitrites. Total polyphenols and Vc were mainly concentrated in the upper leaves, soluble saccharide content was the highest in the middle leaves, chlorophyll and flavonoids existed in the bottom leaves. Analysis of composition contents was no difference in stem. Antioxidant activity showed that scavenging hydroxyl free radical and total reduction power of leaves were far higher than that of in stems. Activities of scavenging hydroxyl free radical and total reduction power were strongest in upper leaves. There was little difference in scavenging DPPH·, ranging from 2.29 to 3.37.

Abstract:The sterilization effect of acidic electrolyzed water on fresh-cut apple against Staphylococcus aureus, Escherichia coli, salmonella and Listeria monocytogenes cells was studied by response surface methodology and a central composite design with one-factor-at-a-time. Studied variables of NaCl concentration, time, temperature and solid-liquid ratio were selected for the determination of optimal conditions with bactericidal ability evaluated. The optimal conditions were found to be as follows: 6 ：1 liquid-solid ratio (mL/g) and 4.5 g/L NaCl treated under 25 ℃ for 6.45 min. Under these conditions, the total bacteria count was reduced from 1.14×105 CFU/g to 9.3×103 CFU/g and the reduction rate of bacteria was up to 91.84%. Moreover, this treatment slightly affected the pH value and the soluble solid contents of fresh-cut apples, while effectively inhibited the degradation of vitamin c and provided surface browning control.

Abstract:Reclaimed water irrigation is a potential alternate source of water to help meet water shortages. There are few studies focus on the migration of heavy metals in soil and the topsoil contamination when reclaimed water is used for irrigation. The irrigation on vegetables using reclaimed water from different sources was studied. Reclaimed water irrigation didn't cause soil contamination and conserved fresh water resources comparing with sewage irrigation and tap water irrigation, at the meanwhile, it also could provide large amounts of nutrients for vegetables. The growth of vegetable irrigated by reclaimed water was better than those using tap water or sewage. The heavy metal accumulation in soil was observed after 60 days including Cr, Cd, As, Hg, Pb, Ni, Zn and Cu, which was low in concentration and stayed stable within irrigation duration. The vertical distribution of heavy metals in soil also changed little, with trends staying intact. The heavy metal content in soil was lower than the value in the soil environment quality standard (GB15618-1995), and better than the soil quality standard of vegetable planting. Risk assessment is within the generally acceptable risk range (a).

Abstract:The extracellular polysaccharides from submerged fermentation of Ganoderma lucidum exhibit low anticancer activity. Sulfation of polysaccharides is an important approach to improve anticancer activity of polysaccharides. In addition, the degree of sulfated substitution (DS) is closely related to its biological activities. In order to understand the relationship between DS and sulfated conditions and obtain the sulfated derivatives with different DS, the sulfuric acid esterification reagent and the relationship between the sulfated reaction conditions and DS were further investigated. The results showed that aminosulfonic acid offered milder reaction conditions than that of chlorosulfonic acid. On the other hand, the addition of urea also gave mild reaction conditions and improved DS.