Abstract:It is a question in the field of food-safety that whether foreign genetically modified genes would transfer from the genetically modified cottonseed hulls to edible fungi. In this study, 15 Tremella fuciformis samples and 10 Pleurotus ostreatus samples (the cultivation media contained 75% and 92% genetically modified cottonseed hulls, respectively) collected from cultivation meida were evaluated by PCR to confirm whether the foreign genetically modified genes, CaMV 35S, NOS, CpTⅠ, Cry IA(c), were present. In addition, 47 samples which were probably grown in the media containing cottonseed hulls, were collected from the large and medium-sized supermarkets and farm produce markets. All of the results of PCR showed that the foreign sequences were not amplified by PCR. In conclusion, No exogenous transgenic fragments in the genetically modified cottonseed hulls was found transferred to the edible fungi.

Abstract:Potato protein was hydrolyzed by trypsin to prepare for ACE inhibitory peptides in our previous researches (the ACE inhibition rates was 61.20%±0.15%), and we used plastein reaction to modify potato protein hydrolysates for enhancing the ACE inhibitory activity of peptides in this study. The influences of the kinds of added amino acids, the substrate/enzyme ratio, pH value, the temperature and hydrolysis time on ACE inhibitory activity of the plastein reaction modification of potato protein hydrolysates were investigated. To achieve the maximum ACE inhibitory activity in the plastein reaction modification of cottonseed protein hydrolysates, the response surface methodology was applied to find the optimum conditions based on the single factor tests. \[E\]/\[S\] ratio at 3 565.05 U/g, substrate concentration at 30.0%, and extrinsic dose of glycine at 0.5 mol/g reacted at 43.68 ℃ and pH 8.05 for 3.0 h, were found to be the optimal conditions, and the ACE inhibitory activity could reached (82.89±0.05)%. Compared with unmodified potato ACE inhibitory peptide, its ACE inhibitory activity increased by 1.35 times.

Abstract:To investigate the feasibility of testing pork quality by terahertz (THz) spectroscopy nondestructively, refractive indexes and extinction coefficients of fat, muscle and skin of porcine tissue were collected by attenuated total reflection (ATR) mode in the range of 0.2～2.0 THz. The results showed that THz spectra of these tissues were different obviously in 0.2～1.6 THz. Water content was found to be a main factor affecting THz absorption of fresh tissues. The optical characteristic difference in THz band of different tissues could be utilized to identify tissue types rapidly and nondestructively. Moreover, it could be predicted that the pork quality could be tested nondestructively by establishing relationship model of THz spectrum and porcine tissue quality.

Abstract:The antioxidant activity of polyphenol from Cortex Mori (CMP) was examined by 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assays. Fibroblasts HS68 cells were induced by ultraviolet (UV) irradiation to establish the photoaging model. Cell proliferation was investigated using a methyl thiazolyl tetrazolium (MTT) assay. The content of procollagen typeⅠprotein (PIP) in cells was measured by enzyme-linked immunosorbent assay (ELISA). The matrix metalloproteinase-1 (MMP-1) and PIP mRNA expressi-ons were detected by qRT-PCR. CMP exhibited significant antioxi-dant activity in ABTS, DPPH free radical scavenging assays, with IC₅₀ values of 1.49, 8.94 μg/mL, respectively. The IC₅₀ values of butyl hydroxy anisd (BHA) against ABTS, DPPH radicals were 11.25, 11.03 μg/mL, respectively. The results showed that CMP had stronger scavenging effect on free radicals, and its clearance rate was higher than that of BHA. Compared with the UV group, CMP not only significantly enhanced the fibroblasts proliferation (P<0.05), but also dose-dependently increased the content of PIP (P<0.05). At the same time, CMP down-regulated the MMP-1 mRNA level, and promoted the mRNA expression of PIP (P<0.05). To conclude, polyphenol from Cortex Mori could repair fibroblasts against UV-induced photoaging, and its mechanism may be related to its scavenging effect on free radicals, the inhibition of the expression of MMP-1, and the regulation of the synthesis of PIP.

Abstract:For establishing an efficient and stable mutagenesis method on breeding Schizochytrium DHA higher producers, the wild-type strain named Schizochytrium sp. 31 was mutated combining Ethylmethylsulfone (EMS) and Atmospheric and Room Temperature Plasma (ARTP) treatment. Mutagenic efficiency, fermentation indexes of the mutants were compared and analyzed. Under this compound mutagenesis method, the positive mutation rate reached 32.2%, which was much higher than that under other two single-factor mutagenesis methods. Besides, DHA production and DHA percentage in total fatty acids reached to 7.2 g/L and 43.2%, which were 35.6% and 19.2% higher than that of the wild-type strain, respectively. After five rounds of cell culture passages, mutants induced from compound mutagenesis method showed up with better genetic stability. This mutagenesis method was proved to be an efficient strategy of breeding Schizochytrium DHA higher producers. It also provideed references to the breeding practices on the algal higher producers for synthesizing other types of polyunsaturated fatty acids.

Abstract:In this study, the extraction technology and enzymatic property of xylanase produced from engineered Escherichia coli are fully examined. The extraction of production process of xylanase was determined and the forage enteric xylanase was successfully obtained after cell broken (high-speed ball grinding), solid-liquid separation, aseptic (filtering) hollow fiber membrane, ultrafiltration concentra-tion and drying packaging orderly. This production showed desirable thermal stability and its release rate was 5% and 98.5% in pH 2.5 and pH 5.5 phosphate buffer, respectively. The product appearance exhibited good gloss and it could meet the requirements of feed enzyme market well. The xylanase showed the maximal activity at pH 6.4 and 55 ℃, and xylanase with 17% water content just lost 13.6% activity at 90 ℃ after dealing with for 2.5 min. By measuring the oat spelt xylan degradation products, the enzyme was revealed to be a kind of Endo-xylanase.

Abstract:To enrich the variety of tallow products and reduce its melting point and hardness, the melting point and fatty acid composition properties of tallow, rapeseed oil, soybean oil, olive oil and cooking oil were analyzed. With the binary compatibilities of tallow and other four kinds of plant oil, their compatibility was studied through isothermal curve (SFC-T) and deviation curve (△SFC-T). The results suggested that four kinds of binary compatibilities mainly showed partial crystal phenomenon at different temperatures. The linear relationship of isothermal curve was good at 0～40 ℃ centigrade of each group(R²＞0.95). Among the four plant oils, rapeseed oil had the best compatibility with tallow. The mix proportion of tallow and cooking oil were better when any component was 10%, 20%, 30%; Olive oil was better when any component was 10%, 20%. Each group of tallow and soybean oil were the worst, and all the value of △SFC were in the range of ±2%. This study provides a theoretical basis and practical experience for the development of butter products.

Abstract:The main taste components of eight typical natural mature cheeses were analyzed by gas chromatography-mass spectrometry and amino acid analyzer. The taste activity values and sensory evaluation were used to clarify the differences among the eight kinds of cheeses, so as to provide a theoretical basis for precise control of cheese flavor and market positioning. The results showed that in addition to Goat Cheese and Brie Cheese, free amino acids contributed to the taste of the other six type of cheeses. The common taste amino acids were valine and lysine. Cheeses were bitter and sweet. And blue Cheese had the strongest taste because of the most of free amino acids. In addition, eight kinds of cheese were detected 11 kinds of fatty acids. The common taste fatty acids were caproic acid, nonanoic acid, capric acid, lauric acid and tetradecanoic acid. The Edam Cheese had the strongest acidity, and Parmesan Cheese had the strongest mellow feeling. Meanwhile, the sodium chloride contents of eight kinds of cheeses were significantly higher than their threshold. The cheeses could be clearly felt the salty taste. The taste of cheeses was more salty and umami, and Blue Cheese was strongest taste by sensory evaluation.

Abstract:In order to improve oxygen delivery efficiency and dissolved oxygen levels for the production of avilamycin in the fermentation broth, the effects were studied, including the various oxygen carriers on the synthesis of avilamycin and the growth of Streptomyces viridochromogenes. The results showed that Tween-80 was the most effective vector to promote growth and the ability of Streptomyces viridochromogene to produce avilamycin.With the addition of 3 g/L tween at 8 h fermentation ,the biomass reached 11.82 g/L and the avilamycin titer increased to 340 mg/L, which was 20.63% and 21.42% higher than the control group. Result show that the oxygen carrier of Tween-80 can increase the production of avilamycin by increasing the biomass and yield coefficient.

Abstract:The effects of fermented and unfermented Ziziphus jujuba polysaccharide on the physical fatigue alleviation in mice was investigated in this study. 56 male SPF class Kunming mice were fed with different doses of polysaccharides, and their body weight, exhaustive swimming time and related anti-fatigue evaluating indexes were measured after treated for 4 weeks. Tests showed that, compared with the normal control group, the mice fed with the polysaccharides from fermented and unfermented Ziziphus jujuba had a prolonged exhaustive swimming time. The percentage elongation was 32.01% for the high-dose unfermented jujuba polysaccharide treated group, and the percentage elongation was 47.98% for the medium dose of the fermented one. The effect of the medium-dose fermented jujuba polysaccharide on alleviating physical fatigue was remarkable, and the content of hepatic glycogen and muscle glycogen, and the activities of glutathione peroxidase and superoxide dismutase increased. Moreover, the content of urea nitrogen, lactic acid and the activity of creatine kinase decreased. The polysaccharides from both fermented and unfermented Ziziphus jujuba had the effect of relieving the physical fatigue in mice, and the effect of medium-dose of the fermented group on alleviating physical fatigue was more remarkable.

Abstract:A large amount of reusable potato residues were obtained from starch production, and its compressibility had great effect on the production process selection and the design of equipment. The compressibility of potato residue was experimentally studied, and the stress-strain curve was measured and regressed. The results showed that the potato residue experienced three stages of being loose, transitional and tight during the compression, and the parameters, related to the compressibility, were obtained, such as bulk modulus and specific energy consumption. In the study, the compressibility and energy consumption under different compression rates and different feed quantities were also analyzed, and the results indicates that potato residue could have good compressibility until it was compressed to the transition stage (the density is 750～1 150 kg/m³). This was due to the low pressure and low specific energy consumption. When potato residue was compressed to the same strain, the compression rate was related to the pressure, specific energy consumption and the feed quanity. Therefore, compressing to the density of transitional stage and adjusting feed quantity could help to improve the compressibility of potato residue, both for increasing production efficiency and reducing energy consumption, and its pretreatment process would be optimized finally.

Abstract:In this study, we established multicomponent trans-fatty acids(TFAs) synchronous detection method, and on this basis the content of various components of TFAs from 38 batches of commercial infant formula farina was investigated. The results showed the average content of TFAs in infant formula farina was 0.749 3 mg/g, and the overall content was low. The TFAs total content was within a range of 0.04～1.0 mg/g in approximately 76.3% of samples. The main component was C_18:1-11T, C_19:1-7T, C_{18:3-9T/12T/15T}, C_18:1-9T and C_18:2-9,12TT. Moreover, we found that the ingredient formula and processing technology were two main factors that could fluctuate the TFAs content in infant formula farina.

Abstract:The ethanol content of beverages was measured by two methods, the static headspace gas chromatography and the traditional method of gas chromatography after distillation, using TG-WAXMS chromatographic column. The two methods had good linear relationship in the volume fraction of ethanol ranging from 0.01% to 5.00%. In traditional distillation method, the detection limit of volume fraction of ethanol was 0.003%, and the detection limit of static headspace was 0.001%. The results showed that due to the complicated pre-treatment processes, the recovery rate of the gas chromatography after traditional distillation was relatively low (83%~91%). While the method of direct determination of ethanol in the beverage by static headspace method was simple, and kept the ethanol stable during the detection. The recovery rate was between 97% and 100%.

Abstract:The inductively coupled plasma mass spectrometry (ICP-MS) combined with microwave digestion was employed in this study for the determination of forty five elements in Yingde black tea. The results showed that 45 elements had good linearity and correlation coefficients all greater than 0.999 5. The limits of detection (LODs) were ranged from 0.000 1 to 20.090 0 μg/L. The recovery rates were between 82.58% and 119.19% with the relative standard deviations (RSDs) of 0.20%～7.03%. The RSD of all the elements except Sb was 0.15%～9.14% in precision experiments. The method was validated by standard reference material (GBW10083), the determination values of elements other than Cd are all within the standard value range. It showed that the method had the advantages of rapidness, simplicity and accuracy, which met the requirements of sample determination in terms of linearity, detection limit, precision, accuracy and recovery rate.

Abstract:The purple bud tea zijuan,zixuan9803,Hongyafoshou an An73 shoots were used as research objects. Using three plant anthocyanins as external standards,a HPLC method for simultanteous detection of various anthocyanins in purple bud tea tree was established. That is: after been extracted with 80% ethanol and refluxed, the tea is degreased with a volume ratio of 112 mixture of n-hexane:ethyl acetate:water. A C₁₈ column was used with acetonitrile and 0.2% phosphoric acid ultra-pure water as the mobile phase. Gradient,the organic phase elution gradient: 0～55 min, 10%～40%, flow rate 0.8 mL/min, column temperature 30 ℃, detection wavelength 520 nm. Each anthocyanins can be effectively separated, and the correlation coefficient of the standard curve is ≥0.99, the linear range is 5.00～75.00 μg/L. The precision and repeatability of the method is good. The relative standard deviation of the stability≤10%, the recovery rate is 75%～88%.Seven major anthocyanin components in four kinds of purple bud tea samples are effectively separated. The method has the characteristics of rapidity, sensitivity, accuracy, and low cost. It is also an analysis method which can be used to simultaneously detect and analyze various anthocyanin components in the purple bud tea.

Abstract:A silane derivatization gas chromatography (GC-FPD) detection method was established to determine the residual amount of ethylene in vegetables and fruits. Samples from ultrasonic extraction by methanol, liquid-liquid extraction by ether, and concentrated blow drying，were compared the derivative effects of 2 kinds of silanylation reagents under different derivatization conditions.After that, they were determined by gas chromatograph with flame photometric detector (P filter), external scalar method. The optimum derivation was as follows.Adding 100 μL BSTFA and 50 μL acetonitrile to the dry extract , derivation 35 min in the oven at 65 ℃. The external has good linear relationship in the concentration ranged from 10 to 5 000 μg/L, and the correlation coefficient was above 0.999, with the detection limit of 1 μg/kg and the limits of quantification of 3 μg/kg. The recovery rate of ethephon in different substrates at 3 concentrations was 84.3%~95.1%, and the relative standard deviation was 1.31%～3.92%. The method was simple, strong anti-interference ability, sensitive and stable, and was suitable for the determination of ethephon residues in vegetables and fruits.

Abstract:Compared with developed countries in Europe and America, the construction of China's food safety law started relatively late, and there are still a series of imperfection at the legislative level. This paper uses literature analysis and comparative analysis to analyze the theoretical framework of the food safety risk exchange system, from the three aspects of the food safety risk exchange management department, the food safety risk exchange legislation system, and the food safety risk exchange mechanism. A comparative analysis of the food safety risk exchange system in Europe and the United States resulted in a useful inspiration for China's food safety risk exchange system. It pointed out that China should improve the Food Safety Law, enhance the operability of the food safety risk exchange system, and clarify the organizations in food safety for risk communication. Establish an information platform for food safety risk communication to achieve diversification of communication channels.

Abstract:Non-GM(O) label is widely used on food in our country. The existence of information asymmetry increase the risk of misuse of non-GM(O) label,while the market mechanism itself can not regulate the misuse. In China,the legislation regulating the non-GM(O) label is not specific, thus misuse of non-GM(O) label was generally not considered to be illegal in judicial decision. Existing research mainly focuses on non-GM(O ) advertising instead of non-GM(O) label. By contrast, there are specific legislation which restrict the scope of food on which the non-GM(O) label can be used in Germany, Japan and the United States. The use of Non-GM(O) label is comprehensively regulated through certain authentication management systems which guarantee the identification of food with non-GM(O) label, and the forms of Non-GM(O) label are unified to maintain a single market and avoid the misundestanding of comsumers. The competent authority in China should draw lessons from their common experiences. Special laws and regulations regarding use of non-GM(O) label are supposed to be enacted in China, and the requirements of the non-GM(O) label form should be detailed. Specialized non-GM(O) food certification system which will be managed by the State Food and Drug Administration, is needed to established.

Abstract:In order to study particle rotary motion behavior and its mixing effect, five kinds of different speeds and fitted the mathematical model of particle mixing data applying to EDEM and MATLAB were stimulatedwith the model of Rotary mixing equipment and based on the theory of DEM simulated the. The virtual experiments predicted the best speed. The results showed that the virtual experiments not only could research particle cyclotron motion characteristics of the curve distribution, but also the method of DEM was conducive to study the mixing mechanism. Compared with the five speeds, the degree of mixing was 62.27%, closed to its optimal mixing degree (56.426%). And the relative error was 5.846%. The research provided the ideas and methods for design of discrete material mixing equipment.

Abstract:A method of improving the flow distribution within the heating chamber to enhance the fumigating effect through changing the fumigation oven structure based on the CFD technology were investigated in this study.. We established a two-dimensional and three-dimensional simulation model for the heating chamber, and the distribution of the fumigation vapor oven was compared by simulation. The results which showed that the optimized structure of the heating chamber could improve the distribution of the vapor flow field.

Abstract:To solve the problems of daily barbecue furnaces in the barbecue process, such as severe environmental pollution, great heat loss and inconvenient cleaning and carrying, the author designs a kind of portable barbecue furnace taking outdoor flat gas tank as heat source and combining infrared flameless burner with rotary barbecue grill. This paper introduces the structure and operation principles of the barbecue furnace, and uses FLUENT software to conduct a simulated analysis of the temperature field in the barbecue furnace. The results showed that the barbecue furnace has the reasonable temperature distribution in the overall structure; uniform air flow; the good heat preservation effect, and the grill high-quality food to meets the users’ requirements.

Abstract:A high ground clearance hydraulic four-wheel drive universal operation chassis was designed. Through the preliminary survey data, the initial target value of the design was established, the structure of the chassis and hydraulic system were designed. Combined with the target value of performance parameter, the type of walking pump and walking motor was determined, and the finite element analysis of steering leg and frame structure design were completed. Based on that, the chassis was passed through the performance analysis to determine the relationship between the wheelbase, and the structural parameters. Finally, the prototype was tested and the pass test was carried out. The tests resulted show that the pressure and flow characteristics of the hydraulic system during the climbing of the operating chassis were within the theoretical design range. Under the condition of full load, the highest steep slope that the universal chassis can pass is 41 degrees, the maximum step height is 490 mm, which can realize the in-situ steering the cement surface speed range is 0～13 km/h, and the speed range in paddy soil is 0～11 km/h. The test results meet the requirements of the universal operation chassis through the design goals, have a good pass performance, suitable for paddy and orchards field.

Abstract:Based on the thermal physical parameters of shrimp, the equivalent heat capacity method was used to process latent heat in phase change, the finite difference method was proposed for modeling irregular shrimp, and the freezing times of symmetrical section in the shrimp freezing layer from the refrigerator bottom with 15 mm, 50 mm and 100 mm upwards were predicted, which were also validated by experiments. Compared numerical simulation results with experimental verification, it could be found that the correlation coefficient between simulated freezing time and test time curve was 0.996, the maximum error in the section center of shrimp was 1.85 K. It could be concluded that the numerical simulation could effectively predict the temperature distribution in the process of food freezing, which was of great significance for freezing processing, quality control and optimization of equipment of shrimp.

Abstract:In order to investigate the sensitivity of freezing time to air temperature and velocity, and analyze the variation of the freezing conditions and freezing time of mashed potatoes in different locations, a three-dimensional unsteady numerical model was established. According to the thermo-physical properties of mashed potatoes, the process of the temperature decreasing during freezing was simulated by Fluent. The unevenness of freezing conditions and time was obtained under different air velocity-inlet and temperature-inlet. The results showed that the change in the percentage of air temperature-inlet had a greater effect on freezing time than air velocity-inlet. With the increase of the air velocity-inlet, the unevenness of the air velocity around the mashed potatoes increased, and meanwhile the unevenness of the air temperature around the mashed potatoes decreased. The variation coefficient of temperature among mashed potatoes and the unevenness of freezing time firstly increased and then decreased with the increase of air velocity-inlet, and they were minimum when the air velocity-inlet was 6 m/s. Under the same air velocity-inlet, the in-homogeneity of the temperature around the mashed potatoes is inversely proportional to the air temperature-inlet. The experimental result showed that the simulation data was in good agreement with the experimental data. The relative error of freezing time was 3.27%, and the average absolute error of temperature was 0.79 K, with the root mean square error of 2.11 K. These results reviewed some characteristics of the freezing process of mashed potatoes without packages in an air blast freezer, which could provide a reference value for the optimization of the equipment and technologies for the freezing of foodstuffs.

Abstract:It is of great significance to improve the quality of frozen dough by selecting yeast antifreeze. The enzymatic hydrolysates from silver carp were prepared by enzymolysis with protamex, and their degree of hydrolysis (%), composition and electrophoresis profiles were analyzed. Moreover, the effects of enzymolysis time and concentration of enzymatic hydrolysates on the survival rate of yeast were also investigated. The results showed that yeast had poor frost resistance, with only 0.69% of survival rate after the first freeze-thaw cycle. Components of hydrolysates prepared by enzymolysis for 15, 30, 60, 120, 240 min were similar, but the products of 15 and 30 min had better cryoprotective effect on yeast. By adding enzymatic hydrolysates of 30 min at the concentration of 4%, the survival rate of yeast was increased to 90.73%, which was 42.88% higher than that of the positive control (glycerol). Tricine-SDS-PAGE analysis indicated protein bands distribution of these hydrolysates were similar, but the band signals were gradually decreases with the prolongation of enzymolysis time, and it was interesting to suggest that the new 13 kDa protein might have important relationship to the cryoprotective activity of enzymatic hydrolysates.

Abstract:Most of the existing predictive models are empirical models which contain too many parameters without biological explanations. In this study, a non-empirical growth prediction model based on neural network was proposed. A BP neural network secondary growth model was established by using Listeria monocytogenes as an example, using the temperature, pH value and Aw value of the experimental environment. The growth rate and double time of microbes were fitted in different environments. Subsequently, combining with the initial concentration of microorganisms, the primary model of microorganism growth with time was predicted. Finally, the growth data of Listeria monocytogenes were tested, and the experimental results showed that the model could predict the growth period of microbes. Compared with the empirical model, this non-empirical prediction one was more suitable for predicting the microbial growth dynamics, and also the parameters of the empirical model could be solved effectively.

Abstract:At present, the main algorithm used in feature extraction of apple is the traditional Hough algorithm. The algorithm has the disadvantages of complicated operation and poor real-time performance. In view of this situation, a new algorithm of apple fruit feature extraction is proposed in this paper. A sliding Gaussian template and apple image are convoluted to extract apple circles in this algorithm. Experiments and simulation results show that this method can achieve high accuracy of apple fruit detection under single, adjacent and overlapping conditions. In the case of a single apple, the detec-tion accuracy of apple fruit can reach 96.6%. Even in the case of contiguous and overlapping, its recognition accuracy can reach 94.1%. It fully meets the needs of apple's real-time, efficient grading.

Abstract:The application of the glycerol monolaurate (GML) and glycerol monlaurate microemulsion (ME) in squid processing was studied. Effects of amounts and methods of ME addition on the preservation of squid shreds were investigated with the total number of colonies and sensory evaluation as the main evaluation index. The results showed that the effective bacteriostatic amount of GML monomer and ME was 0.50% and 1.00% (equivalent to GML monomer 0.12%) , respectively, in the processing of shredded squid, and the addition of two times seasoning was better than one seasoning. However, when the addition amount of GML monomer was more than 0.50%, the squid ribbon would have different odor. The dried squid shreds were prepared by adding 1.00% ME to the shredded squid at two times. The preservation experiments were carried out at 25 ℃ . The results showed that the storage period of the colony count was 5 months and the peroxide value (POV) as the index, the storage period was 6 months.

Abstract:In order to investigate the fresh-keeping effect of PCL modified atmosphere packaging film on spinach. The effects of unpacked, LDPE film（control）and PCL film packaging treatments on postharvest quality of spinach during storage at 4 ℃ were studied. The results indicated that compared with the control group of unpacked both of the packaging films could improve the postharvest quality of the spinach, and PCL packaging treatment group could be better in the development of initial atmosphere suitable for the storage of spinach. Moreover, PCL film was better in delaying the increase of weight loss ratio and inhibiting the degradation of chlorophyll and reduce its yellowing. In addition, it was found to be effective to inhibit the accumulation of malondialdehyde content and retard the postharvest senescence. Furthermore, it also could help to maintain the better sensory quality of spinach.

Abstract:The preservation effects of different storage temperatures (0，5，10，15 ℃) on ipomoea aquatica was studied on sensory evaluation, vitamin C, water migration by low-field nuclear magnetic resonance (LF-NMR) technique, etc.. The results show that the chilling injury happened easily under 0 ℃ cold store and senescence accelerated under 15 ℃. Under 5 ℃ and 10 ℃, the sensory quality, the content of chlorophyll, vitamin Cand other quality indexes of ipomoea aquaticawere maintained relatively well, and the quality above all maintained well for 8 d storage. Under 5 ℃, chilling injury happened at later storage (the tenth days later) and the quality indexes were significantly reduced. During the storage of ipomoea aquatica at at 10 ℃, most of the indicators (except the total number of colonies) maintained better than storage under 5 ℃.

Abstract:The effects on the yield of total flavonoids were studied by reference enzyme dosage, pH value, ratio of material to liquid, ethanol concentration, enzymolysis temperature and time. A 4 factor with 3 horizontal response surface test optimization were conducted. The optimal extraction conditions of the total flavonoids of dandelion were as follows: 122 (g/mL), pH 4.5, 52% ethanol concentr-ation, the hydrolysis temperature was 51 ℃. Under these condi-tions, the yield of total flavonoids was 15.09 mg/g. The results of in vitro functional experiments showed that the total flavonoids extract of dandelion had strong antioxidant activity and scavenging ability against free radicals.

Abstract:The volatile oil of Gracilaria lemaneiformis was extracted by direct steam distillation and solvent extraction-steam distillation, meanwhile gas chromatography-mass spectrometry (GC-MS) and antibacterial & insecticidal activity were conducted. The GC-MS showed that compared with direct steam distillation extraction, in solvent extraction-steam distillation extraction the relative content of aldehyde compounds which has lower odor threshold is 0.20%, meanwhile the relative content of carboxylic acid and ester is 21.54% in solvent extraction-steam and distillation extraction. The antibacterial activity of volatile oil on 5 kinds of pathogens （Escherichia coli O157, Staphylococcus aureus, Salmonella enterica, Listeria monocytogenes, Vibrio parahemolyticus） is moderate, and the median lethal dose LD₅₀ of volatile oil compounds in G. Lemaneiformis with solvent extraction-steam distillation and direct steam distillation broth were 0.126 and 0.162 mg/mL respectively.

Abstract:Based on the results of single-factor experiments, orthogonal test of ursolic acid from Amygdalus communis L. peel were carried out to determine the optimum process parameters.The antioxidant activities were evaluated by the reducing power, DPPH free radical, hydroxyl free radical and hemolysis of mice red blood cells.The optimum extraction parameters were determined as follows: alcohol concentration 65%,extraction temperature 80 ℃; solid-to-solvent ratio 120 (g/mL); extraction time 1.5 h. Under these conditions, the experimental yield of ursolic acid was 2.89%. The concentration of ursolic acid was 0.1 mg/ml, ursolic acid of Amygdalus communis L. peel displayed a strong antioxidant activity, the percentage scavenging of DPPH free radical and ·OH were 87.87% and 62.11%, respectively.The concentration of ursolic acid was 0.6 mg/mL ,the oxidation of mice red blood cell hemolysis inhibition rate was 97.83%.

Abstract:The oxidation value, acid value, color, fatty acid composition, volatile substances were measured to choose the optimum process for the preparation of chilli seed oil. The effects of two kinds of methods, enzymatic hydrolysis-ethanol-assisted and normal-temperature extraction, on the quality and aroma components of chilli seed oil were compared. The results showed that the chilli seed oil obtained by two kinds of preparation methods was orange-yellow, the acid value was less than 4.0 mg/g, the peroxide value was less than 12 meq/kg. The capsaicin contents of chilli seed oil obtained by enzymatic hydrolysis-ethanol-assisted extraction and normal-temperature extraction were 1.46,and 0.54 mg/g,respectively. The effect of preparation process on fatty acid composition was not significant (P>0.05), but it was significant on fatty acid content (P<0.05). The contents of saturated fatty acids in the oil by enzymatic hydrolysis-ethanol-assisted and normal-temperature extraction were 14.89% and 16.3%, respectively, and that of the polyunsaturated fatty acids were 69.8% and 70.87%, respectively. It can be seen that the content of polyunsaturated fatty acids in chilli seed oil is rich, and the enzymatic hydrolysis-ethanol-assisted process can significantly reduce the content of saturated fatty acids. It was identified 56 kinds of volatile substances in oil by enzymatic hydrolysis-ethanol-assisted method, higher than the 52 kinds by normal-temperature extraction method, and 42 species in commercial chili oil. It can be seen that the enzymatic-ethanol-assisted method is helpful to the improvement of the quality of chili oil.

Abstract:In order to purify flavones from Vaccinium Bracteatum Thunb Leaves(VBTL) preliminarily, the static adsorption and desorption properties of four resins were compared. The purification technology of flavones from VBTL was investigated by dynamic adsorption and desorption experiments. The effect of sample concentration, loading sample volume, ethanol solution for desorption, flow rate of the eluent and volume of eluent on adsorption and desorption rate were studied. In addition, the purification effect was evaluated by removal rate of proteins and polysaccharides and HPLC. The results showed that NKA-II resin had a relatively high rate of adsorption and desorption as well as a shorter adsorption time. NKA-II resin was determined as chromatographic column filler. The optimal purification technology was determined as follows: 0.75 mg/mL for sample concentration, 2 bed volume (BV) for loading sample volume, 50% (vv) ethanol solution for desorption, 1 mL/min for the flow rate of the eluent and 3 BV for the volume of eluent. HPLC analysis of flavones from VBTL before and after purifying suggested the purity of purified flavones from VBTL improved significantly, and the removal rate of proteins and polysaccharides reached 76.32% and 65.45% respectively, with the purity of flavones reaching 48.92% .

Abstract:The polysaccharide obtained from the branches and leaves of Chrysanthemum indicum was extracted by microwave assisted extraction after its powders decolorized and degreased, and then the polysaccharide extraction content was determined by phenol-sulfuric acid method. The extraction process of the polysaccharide was studied by single factor experiment which controlled liquid-solid ratio, extraction temperature, extraction time, and microwave power, and the orthogonal experiment was tested and based on single factor experiment, then determined the best extraction process. Those free radical cleared effects of its polysaccharide were tested by Fenton reaction and DPPH reaction. The results showed that the polysaccharide extraction content from the branches and leaves of C. indicum could reach 6.32% when solid-liquid ratio was 140 (g/mL), extracted by using microwave power (450 W) at 80 ℃ for 10 min. The anti-oxidant activity tests of the polysaccharide from the branches and leaves of C. indicum showed a good scavenging activity on ·OH and DPPH·, and the relationship between the polysaccharide and hydroxyl free radical clearance was found to be an concentration reliable. Finally, the polysaccharide was verified to be an untapped antioxidant substance.

Abstract:An effective method to extract Cyanobacteria polysaccha-ride was established in this study and a high yield of polysaccharide (25.1%) was achieved by optimizing extraction condition (hot water with ultrasonic treatment). After purification, a main purified polysaccharide (CB-2-1) with molecular weight of 8.4 kDa was collected and the compositions included rhamnose, arabinose, xylose, mannose, glucose and galactose, with mole percentages of 0.51%, 13.35%, 18.21%, 51.38%, 4.87% and 11.67%, respectively. The results of NMR showed that the CB-2-1 component of cyanobacteria polysaccharide was mainly α-type glycosidic bond. Moreover, the purified CB-2-1 polysaccharide had great anti-oxidant activities. The highest scavenging activities of DPPH and hydroxyl radicals with 2 mg/mL CB-2-1 were 98.75% and 72.64%。

Abstract:The current commonly used drug sensitivity test method such as diffusion method, dilution method and Etest method, as well as new methods including molecular biology and electrochemical method were summarized in this article. We briefly analyzed the principles, characteristics and limitations of the above methods. Future development direction and research trend of food-borne bacterial susceptibility testing methods had also been presented, which provided a reference for the development of new antimicrobial susceptibility test method.

Abstract:High performance liquid chromatography (HPLC) is one of the most important factors in monosaccharide analysis due to its simple operation, and high efficiency and sensitivity. In this study, several commonly used methods were described, for the analysis of monosaccharides by high performance liquid chromatography, i.e., liquid chromatography differential refractive index detection, liquid chromatography evaporative light scattering detection, PMP pre-column derivatization detection, para-aminobenzoic acid pre-column derivatization, the o-aminobenzoic acid derivative method and post-column derivatization method. Moreover, the advantages and disadvantages of these methods were demonstrated, and the sensitivity, operation method, and accuracy were compared and analyzed among these methods.

Abstract:The application of microbial conversion in the use of distiller grain is the by-products of the production of solid white liquor, which has become increasingly prominent. Themicrobial in detoxifying distiller grains, production of high added value feed and feed additive in recently years, especially the effect of it application in animal feed were reviewed. Moreover, a prospect of application of microbial technology in the transformation of distiller grains.

Abstract:To determine the optimum conditions for the production of low lactose milk by enzyme method, the hydrolysis process of low lactose milk was optimized by the response surface method, with the hydrolysis rate of lactose as an index. The results were as follows: the ratio of enzyme to substrate (\[E\]/\[S\]) was 1.50‰, and the hydrolysis was undertaken at 38.15 ℃ for 3.0 h. Under these conditions, the lactose hydrolysis rate of low lactose milk was 92.67%. Moreover,14.02% of the oligosaccharides were detected by HPLC detection, which showed β-galactosidase could hydrolysis lactose and turn glycosidic.

Abstract:In order to utilize defective fresh Jujube fruits, Jujube vinegar was explored by crushing, pulping, alcohol fermentation, batch and semi-continuous acetic fermentation. The fresh Jujube fruits were cleaned, washed, and then crushed and pulped with addition of water to 1.5 times. The Jujube pulp was inoculated Angel fruit wine yeast with inoculation quantity 0.1%. After fermentation 72 h at the room temperature, the alcohol concentration of Jujube wine could reach 8.07%Vol. Then Jujube wine was inoculated with the inoculum size of acetic acid bacteria 10%, and the first batch of acetic fermentation finished in 60 h. In the next acetic fermentation, it took only 30 h to finish each batch. And ten batches of Jujube vinegar were produced from the defective Jujube fruits in this study with the average titratable acidity 4.81 g/100 mL. Ten organic acids were identified in the Jujube vinegar by reversed phase high-performance liquid chromatography（RP-HPLC）. However, no obvious differences were found in the composition and contents of organic acids between vinegar samples produced from defective Jujube and high quality Jujube fruit. Acetic acid, malic acid and lactic acid were the primary organic acids in both fermented vinegar samples. The results showed that Jujube vinegar could be produced efficiently from defective fresh Jujube fruits by batch and semi-continuous fermentation, and the processing technology could be applied in jujube production regions to utilize the damaged or inferior Jujube fruits.

Abstract:In order to improve the production technology system and the product quality. Using the Sansui duck as raw material, the effects of pre-cooking time, curing time, salt concentration and cooking wine concentration on the comprehensive quality of duck meat were studied, and the dry-cured process of Sansui plasma duck was optimize. The results showed that Sansui plasma duck optimum parameters of dry-cured process in were obtained: pre-cooking time 2.4 min, curing time 39.0 min, salt concentration 3.0% and cooking wine concentration of 2.9%. Under this condition, the duck meat has moisted surface, color goldenand uniform, special duck fragrance, and its meat is tender and tight.