Abstract:Yersinia enterocolitica is an important psychrophilic pathogenic bacterium in the intestines. There are more than 60 serotypes in the world. The serotypes of the pathogenic strains are the bioserovars 3/O:3 and 2/O:9 type in China. Y. enterocolitica has six biotypes including 1A, 1B, 2,3, 4, and 5. Five biotypes among them have been identified being pathogenic and type 1B is high pathogenic. Meanwhile, type 1A has potential pathogenicity. The virulence factors are mainly ail, ystA, ystB, yadA, and virF, which are usually used to determine Y.enterocolitica pathogenicity. Y enterocolitica is resistant to penicillins and first generation cephalosporins naturally, and has different resistant rates to other antimicrobial agents and many strains with multiple drug resistance. Pulsed-field gel electrophoresis (PFGE), repetitive elements sequence (REP/ERIC)-PCR, multi locus sequence typing (MLST) and so on are the most frequently used methods for Y. enterocolitica molecular typing nowadays. ERIC-PCR typing has easy operation and high polymorphism, which will also play a good role in the molecular typing of Y. enterocolitica.

Abstract:The quality and safety in all aspects of the production of food crops involve planting, harvesting, purchasing, transportation, and processing, while the planting process safety is the most important aspects for the production of pollution-free, green, and organic agricultural products. The safety problems during the planting processes, such as variety selection, production safety technical regulations, safety standards, and control of environmental factors, are outlined. Measures include the selection of anti-pest species, strict enforcement of technical standards and technical regulations for pollution-free production, reinforcement of strengthen temperature, humidity, soil, and other environmental factors control, comprehensive application of biological and physical control measures, and strict production and sales channels, which can ensure the production of pollution-free, green or organic agricultural products.

Abstract:This paper outlines some of the factors affecting grain quality and safety during the acquisition and storage & transport processes and explored some of the control measures. The factors include the drying conditions about harvested grain, the detection capabilities at the acquisitions site, the improper application to grain storage technology, the illegal use of pesticides, the cross-contamination in the leasing warehouse, and no ventilation measures in the transport. Control measures are as follows:promotion of agricultural standardization in the grain production process, the development of green grain storage technology, the establishment of an integrated transport to bulk grain intermodal integration model, constructing the grain quality, and safety of the traceability system.

Abstract:In vitro protein digestion was used to analysis the digestibility of millet milk, foxtail millet prolamine and millet protein isolate. Compared with soybean milk, the foxtail millet had a low protein digestibility (only 35.2%), which was mainly caused by foxtail millet prolamine. Disulphide crosslinking and its strong hydrophobicity were the key factors.

Abstract:In order to reduced the number of experiments of the multi-factor complexity system, the corn meal treated by the extrusion technology was used to produce starch syrup using the “π” experimental design method based on the improved dimensional analysis. The moisture of extrusion material, heating temperature of extruder barrel, diameter of extruder screw, rotation speed and length of die nozzle, and distance from screw end to die nozzle were considered as experiment parameters. The results showed that the relative error between numerical value of forecasting and fact at experiment points was less than 0.44%, and the relative error at other points in the range of experiment parameters was less than 2.61%. Meanwhile, the relative error at most points out of the experiment parameters was less than 5%. The empirical formula has higher precision of prediction and will provide a reference for the production practice.

Abstract:The effects of individual treatments with hypobaric storage on fruit quality of blueberry were analyzed by the multivariate analysis. The results showed that fruit firmness, total acid, quality, color, aroma, and flavor decreased, and the solid acid ratio slightly increased during the hypobaric storage. The results of the principal component analysis (PCA) indicated that fruit flavor, solid acid ratio, firmness, and total acid were significantly affected during the 29 days storage at 0.050MPa. Whereas 0.050MPa and 0.075MPa treatments significantly affected fruit color, flavor, solid acid ratio, firmness, total acid, quality evaluation, sugar, and sweet and sour ratio after the 49 days storage. The results of partial least squares regression (PLSR) showed that flavor and quality were positively correlated with sweet and sour, acidity, and solid acid ratio, and flavor and quality were strongly correlated in a negative manner with aroma, firmness, sweetness, and color. The results of path coefficient analysis indicated that color, sweet and sour ratio, acidity, and solid acid ratio, total acid, and sweetness had the strongest effects on the quality and flavor.

Abstract:In this study, conjugated linoleic acid was embedded by sodium octenylsuccinate starch. Through the response surface methodology experiment, the optimum parameters of conjugated linoleic acid microcapsulation were as follows:core material/wall material 1∶2.87, embedding time 1.56h, and embedding temperature 42℃.Under this optimum condition, encapsulation percentage of conjugated linoleic acid microcapsulation was 93.22%. Microencapsulated powder particles after spray drying was plump, inseparable, orderliness, and smooth through the scanning electron microscopy.

Abstract:phenylethanol is an important flavour and fragrance compound, which has positive synergy effects for other aroma components in food, cosmetic, tobacco, and daily chemicals. The metabolism mechanism and latest research of 2-phenylethanol in microbes and plants were reviewed in this paper.

Abstract:Because of the wide use of the natural bioactive substance, a continuous and efficient countercurrent chromatography and the separation equipment based on it were presented. The dynamic balance was one of the important factors to evaluate the equipment. The dynamic balance testing system was designed using piezoelectricity type acceleration sensor, optical encoder, and the main controller K60. The result could be shown on the host computer in order to instruct eccentric mass adjustment. The testing system had high automation and accuracy and it was real-time monitoring. The testing system provided the foundation for the stable of the equipment and practical experience for other industrial equipments and eccentric mass adjustment.

Abstract:Lotus seed native starch was obtained by the wet milling method, and the ultrasonic pretreatment combining autoclaving method was applied to prepare resistant starch. The influence of starch concentration, ultrasonic power, ultrasonic time, autoclaving temperature, and autoclaving time on the yield of lotus seed resistant starch was explored. The technology parameters of preparing resistant starch were optimized by orthogonal optimization analysis. The results revealed that the best conditions for lotus seed resistant starch preparation by ultrasonic-autoclaving were starch concentration 45%, ultrasonic power 300W, ultrasonic treatment time 55min, autoclaving time 15min, and autoclaving temperature 115℃. Under the conditions, the yield of lotus seed resistant starch was approximated to 56.12%.

Abstract:Response surface methodology was applied to optimize the water extraction processing of total flavones from sea-buckthorn leaves. The optimal extraction conditions were pH 11.4, temperature 75.5℃, extraction time 2.0h, and the ratio of material to liquid 1∶35g/mL. Under the optimal conditions, the extraction yield was 1.23%. After being precipitated by phosphoric acid solution, the crude flavonoids were separated by macroporous resins AB-8, DM301, and HPD-100. Macroporous resin AB-8 had the highest adsorption rate under the conditions of sample concentration 1.0mg/mL, pH 6.0, and adsorption time 1.0h. About 3 times of column volumn distilled water were used to wash the unabsorbed samples and different concentrations ethanol solutions (30%, 50%, 70%, 80%, and 90%) were used for desorption. The purity of quercetin were detected by high performance liquid chromatography (HPLC) and the purity of quercetin of 80% and 90% fractions was above 97%.

Abstract:In this study, the volatile odors of grass carp stored at different temperatures (-4-15℃) and storage times (0-7d) were analyzed by the principal component analysis (PCA) and shelf life (SL) using electronic nose technology. Meanwhile, the total volatile base nitrogen (TVBN), aerobic plate count (APC), and other physical and chemical quality indexes were also analyzed. The results showed that both TVBN value and total number of bacterial colony of grass carp increased along with the storage time at different storage temperatures, and that the total number of bacterial colony was accord with pseudo-first-order chemical kinetics model (R²>0.9). Based on the analysis of the shelf life at -4-15℃ using electronic nose, the result of grass carp in odor changes had good corresponding correlations with the physical and chemical quality index.

Abstract:Damage identification of beer bottles could be realized by using the BP neural network. First, beer bottle mouth images were collected and processed. Four characteristic parameters including the perimeter, area, circularity, and the relative center distance were calculated and constituted a feature vector group. Then, the BP neural network model with the 4-7-1 model was established and the feature vectors group was inputted to the neural network. Finally,beer bottle damages would be trained. The weight and threshold matrix were acquired according to the training results. Beer bottle mouth damages would be easily obtained through logic relations. The experimental results verified that this method had good accuracy and inspection efficiency.

Abstract:A high performance liquid chromatography (HPLC) method for determination of citrinin in red sofu was developed. The effects of different factors including extracting solvent, material-liquid ratio, extraction temperature, ultrasonic extraction time, and extraction times on the extraction of citrinin were compared. The chromatographic separations was carried on a ODS WondaSil C₁₈ (150mm×4.6mm i.d., 5μm) column by using acetonitrile and 0.03% phosphoric acid(45∶55, v/v), and then was detected by a fluorescence detector at λ_ex=331nm, λ_em=500nm. The results showed that citrinin was completely extracted by toluene-ethyl acetate- formic acid(1∶9∶1,v/v/v) at material-liquid ratio of 1∶15(v/v), ultrasonic extraction 10min at 60℃ for 3 repeated extractions. There was a good linear relationship between the fluorescence detection values and citrinin contents in the range of 0.5-1000μg/L (R²=0.9999). The minimum detectable content of citrinin was 0.5μg/L. The RSD of repeated test was 1.58%. The average recovery with standard was 94%. This method could be used for determining the citrinin content in red sofu products.