Abstract:Cutinase is a kind of multifunctional hydrolase, which has important application value in the food processing and textile refining industry. The recombinant expression system of Escherichia coli (E.coli) BL21 (DE3) was used to achieve the recombinant expression of Humicola insolens cutinase in E.coli, and the activity of extracellular supernatant in shaking flask level reached 170 U/mL. The recombinant cutinase was characterized. The optimum pH was 8.5, the optimum temperature was 80 ℃, with good pH stability and temperature stability. In order to further improve the possibility of the industrial application of H.insolens cutinase, the recombinant E.coli was cultured in 3 L fermentor and the cultivation condition is optimized. The optimum fermentation conditions: maintain pH 7.0 and 37 ℃ in early culture phases about 12～14 h; when the cell concentration OD₆₀₀ up to 50, fermentation entered induced phases，adjust the temperature to 30 ℃, 0.2 g/(L·h) lactose solution were added with constant flow rate. The total fermentation period was about 36 h. The highest activity of enzyme reached to 2 233 U/mL, which is 13 times about the enzyme activity in shake flask level.

Abstract:Freeze-tolerance is a necessary characteristic of yeast used in frozen dough. Target freeze-tolerant strain was screened using liquid fermentation (LF) medium method, applied for frozen dough production, and the relationship between the content of intracellular compounds and cell survival and relative fermentation ability in different yeasts was analyzed. The isolated strain was identified mainly by morphologic observation and 26S rDNA gene sequence analysis. The results showed that seven strains were selected from four various sourdoughs, their freeze-tolerance rate ranged from 9%～86%, and relative fermentation ability ranged from 9%～67%. Two strains, Y-3 and H-1, had highest survival ratio of 86% and highest relative fermentation ability of 67%, respectively. The result of correlation analysis showed that survival ratio was significantly positively correlated with trehalose, glycerol , proline level, but negatively correlated with arginine, aspartic acid，glutamate and relative fermentation ability; relative fermentation ability was significantly positively correlated with aspartic acid and glutamate, and negatively correlated with trehalose, glycerol, proline and arginine level. Strain Y-3 was identified as Debaryomyces hansenii, and strain H-1 was identified as Saccharomyces cerevisiae. Comprehensive consideration of freeze-tolerance, fermentative ability and safety, mixed fermentation of Y-3 and H-1 will be used to produce of frozen dough.

Abstract:On the purpose of explore the yeast resources in traditional fermented milk in XinJiang, taking the traditional fermented milk produce in the small family workshop on south region of Xinjiang as raw materials, there were 78 strains which were isolated for molecular identification and antioxidant ability. The results showed that 42 of the 78 yeast strains had total antioxidant activity, and the antioxidant ability of NG-40 was prominent, with the total antioxidant activity of （106.41±3.92) U/mL, the ability of inhibiting hydroxyl radicals of （651.24±3.75) U/L, the ability of resisting superoxide anion of （104.11±3.25) U/mL, and the content of lipid peroxide of （1.99±0.65） μmol/L. Molecular identification results showed 38 of the strains belonging to Saccharomyces cerevisiae, 36 of them belonging to Kluyveromyces marxianus, 4 strains belonging to Pichia kudriavzevii. Among them, strain NG-40 was identified as Kluyveromyces marxianus. This experiment identified the yeast species of dairy products in Xinjiang area, and its antioxidant ability was preliminarily tested. Provides a theoretical basis and research basis for the development and utilization of yeast resources in southern Xinjiang.

Abstract:In order to understand the differences of volatile aroma components between distilled liquor obtained from different varieties of wine grapes in Xinjiang, the methods of headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectro-metry (GC-MS) were used to investigate the aroma component in different kinds of distilled liquor. Distilled liquor was obtained from Cabernet Sauvignon, Chardonnay, Italian Riesling, Cabernet Sauvignon with Chardonnay blend and Chardonnay with Italian Riesling Blend. The differences were analyzed and compared, and the results showed as follows. The types and contents of volatile aroma components of distilled liquor obtained from different grape varieties, and a total of 78 volatile aroma components were detected in 5 wine samples. The portion of the ester, alcohol, acid, aldehyde, ketone and others were 44, 10, 4, 3, 2, and 15 respectively. In the blending samples of distilled liquor, some new aroma components were found produced with the retaining of their original aroma components. The results in this study laid basis for the future research and development of distilled liquor in Xinjiang.

Abstract:To investigate the bacterial diversity of Zhaguangjiao in Dangyang area, and evaluated their functions on flavor quality of samples. The bacterial microbiota of Zhaguangjiao were revealed by Miseq technology, and flavor quality were evaluated by electronic nose. Firmicutes, Proteobacteria, and Bacteroidetes were the most dominant bacterial phyla with the relative abundance of 62.36%, 25.97%, and 4.13%, respectively. At the genus level, Lactobacil-lus, Weissella, Pediococcus, Staphylococcus, Carnimonas, Enterobacter, and Prevotella were constituting more than 1.0% of total sequences, with the relative abundance of 77.33%, 2.24%, 2.18%, 1.27%, 5.66%, 2.47%, and 1.05%, respectively. There were positive relations among the relative abundance of Prevotella and contents of aromatic compound, but Lactobacillus and organic sulfide showed an opposite trend. The results indicated that the bacterial microbiota of Zhaguangjiao main consisted by several genera belong to Firmicutes and Proteobacteria, meanwhile Lactobacillus and Prevotella played active roles in the flavor formation of samples.

Abstract:In order to explore the influence of high hydrostatic pressure on the physicochemical properties of lotus root starch, effects were studied, including pressures, holding time and starch concentration on the changes of gelatinization, rheological and texture properties of lotus root starch. The results showed that the peak viscosity, valley viscosity, final viscosity and paste temperature of lotus root starch increased with the increase of pressure in the range of 200～500 MPa, while the breakdown viscosity and setback viscosity did not change significantly. However, when the pressure reached 600 MPa, The peak viscosity and breakdown viscosity of lotus root starch showed the opposite trend, decreasing by 37.65% and 96.49% respectively, and the average setback viscosity decreased by 43.34% within the concentration range of 10%～20%, which effectively delayed the starch retrogradation; With the prolonging of pressure holding time, the decrease of peak viscosity and breakdown viscosity was more obvious, indicating the shear resistance and heat resistance of starch were improved. After 30 min of treatment, except for the final viscosity, other parameters cannot be obtained. In addition, the fluid index n of lotus root starch after high hydrostatic pressure treatment was less than 1, which was still pseudoplastic fluid. After 200～500 MPa treatment, the consistency coefficient K, G′ and G″ increased more significantly and the thickening effect increased. When the pressure was 600 MPa, both of them began to descend and enhanced with decreased starch concentration and increased holding time. At the same time, the texture of lotus root starch changed with certain high hydrostatic pressure, notably when increasing starch concentration and reducing holding time, the elasticity and chewiness of lotus root starch increased significantly, while the hardness decreased, but had no effect on cohesiveness.

Abstract:In order to improve the quality of sliver carp surimi, the effects of curdlan with different concentrations (0～10 g/kg) on the gel properties of surimi after sterilization at 120 ℃ for 10 min were investigated. Rheological measurement, breaking force, deforma-tion, gel strength, cohesiveness, chewiness, color, water-holding capacity (WHC), TCA-soluble peptide content and SDS-PAGE electrophoresis of obtained curdlan-surimi gel were determined as the quality indexes for evaluating the rheological properties, textural properties, color, WHC and protein composition of surimi. The results showed that addition of curdlan could increase rheological properties and significantly reduced the content of TCA-soluble peptide (P＜0.05), thereby improving thermal stability and water-holding capacity of surimi. Curdlan had no effect on surimi protein composition and could decrease the whiteness. The optimized content of curdlan was 6 g/kg, which had positive effect of the gel quality and could significantly improve gel strength and rheological properties (P＜0.05).

Abstract:Brabender viscometer and differential scanning calorimetry were used to study the effects of mango peel powder (MPP) on the pasting and thermal properties of corn and rice starch. Moreover, the changes in the transmittance, sedimentation rate, gel hardness and color of the two kinds of starch were also analyzed, and thus impacts on starch gelatinization and retrogradation were evaluated. The results showed that with the increase in the amount of added mango peel powder (0%～15%), the pasting temperature of corn and rice starches were decreased, while breakdown values were increased. Corn starch showed the highest peak viscosity with the addition of 15% mango peel powder. The peak viscosity of rice starch showed a reducing trend when more mango peel powder was added, and the breakdown value reduced and then increased. In addition, the setback value of the two starches were both reduced significantly. Enthalpy values of gelatinization and retrogradation were reduced for both starches, and the downward extents of transmittance and sedimentation rate during storage were also reduced. The color change of both starches during storage was also reduced, and gel hardness of corn starch was decreased with the addition of mango peel powder. These results suggest that adding mango peel powder could impact the gelatinization property of starch, although the influencing trend vary with starch species. It could however effectively inhibit starch retrogradation for both corn and rice starches.

Abstract:Oil heat-transfer cooking is a typical cooking way of Chinese cuisine, so an oil bath was chose to simulate the oil frying and combined with the kinetics means to determine and analyze the maturity quality changes including color and shear force and the overheated quality changes including cooking loss of pork loin. The results showed that the changes of color and shear force followed first-order kinetics model and cooking loss followed zero-order model during oil fried treatment. Meanwhile, the z-value of brightness, redness ,whiteness and shear force were 33.1,26.1, 41.0 and 17.9 ℃, whose corresponding Ea-value were 68.6, 86.8, 55.4 and 127.1 kJ/mol. Moreover, the Ea-value of cooking loss was 28.9 kJ/mol and the z-value of cooking loss was 32 ℃ under first-order kinetics reaction which was greater than the redness and shear force. The conclusion was consistent with the culinary optimization preconditions proposed by the mature maturity value theory, which proved the existence of optimal space during oil heat transfer process. Further, kinetic parameters were obtained for the quality optimiza-tion of Chinese cuisine and the further study on oil frying of pork.

Abstract:The differences of the main nutrient quality of bramley apples under different pollination conditions respectively with the pollen of First red, Dahongrong, MOLEX, Red Fuji, Gala and Grieve were analyzed in this experiment, and the natural pollination was used as control. The results showed that the contents of total sugar, VC, flavonoids, protein, ash and polyphenols among bramley apples with different pollination varieties reached significant or extremely significant levels; three principal components be selected in this experiments, and the cumulative percent of that three principal components reached 85.072% respectively. It was considered that pollination varieties could affect the nutritional quality of bramley apple based on the results of each index, combined with membership function and principal component analysis; the nutritional quality of tested‘Bramley’apples be ranked from high to low were Red Fuji, Dahongrong, MOLEX, First red, Gala, natural and Grieve.

Abstract:The differences of volatile flavor components and fatty acid composition between salted goose at 75, 150 and 300 days old were compared and analyzed to provide theoretical basis for selecting the best slaughtering period in the production of Yangzhou salted goose. The volatile flavor and fatty acid of the leg samples were determined by gas chromatography-mass spectrometer (GC-MS) using saltwater goose leg meat as raw material at different days old. The relative contents of aldehydes, esters, acids, ketones, benzene and ethers in volatile flavor substances of salted goose increased, while the relative contents of terpene hydrocarbons and furans decreased with the increasing of age. The relative contents of unsaturated fatty acids, polyunsaturated fatty acids, essential fatty acids and polyunsaturated fatty acids/saturated fatty acids (P/S) were decreased with the increasing of age, and the volatile flavor substances and fatty acids were the highest in 150 day salted goose. Yangzhou White Goose at 150 days old can guarantee the flavor and nutrition of the salted goose simultaneously.

Abstract:2-L-Alanine-2-deoxy-D-Glucose(Ala-Glu) was synthesized from L-Alanine(Ala) and D-fructose(Fru) through condensation dehydration and rearrangement reaction. The thermal weight loss and pyrolysis properties of Ala-Glu were investigated by thermogravimetry-derivative thermogravimetry(TG-DTG) and pyrolysis gas chromatography-mass spectroscopy(Py-GC/MS). Using the moisture content (d.b.) of tobacco shred as an indicator, the physical moisture retention properties of Ala-Glu were measured. The effect of these compounds on sensory comfort of cigarette was investigated. The results show that: ① The synthetic product was the target compound; ② The primary pyrolysis temperature of Ala-Glu was 178.9 ℃, and the thermal mass loss reached about 90% at 800 ℃. The number of pyrolytic products of the target compound increased with the rise of temperature, and the major pyrolytic products of Ala-Glu were including pyrazine, pyridine, pyrrole, furan, pyrone; ③ Moisture retention of Ala-Glu was better than that of propylene glycol and glycerin; ④ Ala-Glu can make mainstream cigarette smoke mellow and full, reduce irritation and miscellaneous odor, and have a role to enhance on cigarette sensory comfort.

Abstract:In order to study the pyrolysis characteristic of the heat-not-burn reconstituted tobacco, eight kinds of reconstituted tobacco, three kinds of non-tobacco fiber and tobacco own fiber were tested by TGA (Thermogravimetric Analyzer) technology, and the resulting DTG（Derivative Thermogravimetry）data were analyzed by NRMSE (normalized root mean squared error) to calculate the pyrolysis difference degree. The results showed that the pyrolysis behavior of the reconstituted tobacco used in heat-not-burn cigarettes was much different from that in traditional cigarettes and the pyrolysis difference degree was 37.97%. There was an additional peak in DTG curve of the reconstituted tobacco used in heat-not-burn cigarettes, which can be attribute to the humectants. Compared with the reconstituted tobacco used in traditional cigarettes, the contents of water, extracting solution and lignin were relatively higher, and the contents of hemicellulose and cellulose were obviously lower in the reconstituted tobacco used in heat-not-burn cigarettes.

Abstract:Rice was inoculated with spore suspension of Aspergillus flavus, and far-infrared radiation (FIR) was used to study the disinfection on curve and toxin production ability of A. flavus in rice with different water contents. Moreover, the effect on the quality of rice color, free amino acids, and soluble protein was considered. The results showed that the decontamination of FIR radiation on A. flavus was significantly enhanced with the increase of temperature and time. When the rice moisture content was 30%, FIR heating at 115 ℃ for 5 minutes resulted in 2.96±0.28-log reductions of A. flavus spores in rice. The total amount of aflatoxin B₁ (AFB₁) and the amount of AFB₁ produced by unit cell decreased by 63.09% and 38.44%, respectively. When the moisture content of rice was 20%, FIR heating resulted in 2.04 ± 0.17-log reductions. The total amount of AFB₁ was decreased by 55.04% and the detoxification by unit cell was 22.54%. After FIR heating at 115 ℃ followed tempering at 70 ℃, the logarithmic amount of residual spores was more than 3.87. L value, b value, △E and free amino acid content had no significant difference. The content of soluble protein of rice decreased with the increasing of treatment time.

Abstract:Aiming at the problem that the solid-state fermentation of liquor depended on the artificial experience to judge the quality of Daqu without quantitative judgment standard, a set of Daqu quality detection system based on machine vision was studied. The dynamic threshold segmentation method was used in this system, RGB transform Lab color space, CNN convolutional neural network and other methods were used to extract three kinds of visual information characteristics of Daqu, the geometric parameters, color and crack. Therefore, the corresponding relationship between the visual information characteristics and the quality of Daqu was established, and the quality of Daqu was judged according to the established relationship. The experimental results showed that the measuring accuracy of the system was 1mm. At the same time, the system could accurately identify and extract the visual characteristics of milky white hyphae, Monascus and Daqu surface fractures of relative sections. Through 1 000 experiments, the accuracy of the identification of Daqu visual information could reach 99.0%, which couldmeet the requirements of the related wine production.

Abstract:Food crime has various kinds, multitudinousness, wider range and faster spread rate, which brought a certain degree of difficulty to criminal punishment. Chinas criminal legislation on food safety has gone through periods of non-criminalization, criminalization, and expansion period. Although the legislation has gradually enriched the content of the criminal law of food crimes, it still has many problems at the same time. In terms of incriminating, all aspects of food activities have not been fully protected, and the scope of food protection is too narrow, and the subjective aspects of food safety crimes are not perfect. In terms of penalties, the penalties for food crimes are incomplete and unbalanced. Future legislative amendments should improve the criminal protection mechanism for food safety from three aspects, such as criminal policy, constituent elements, and types of penalty. So it can strengthen food safety management, and maintain social order stability.

Abstract:The structure of rectangular microwave spouted bed was optimized based on the good electric field intensity and distribution. The evaluation index was the coefficient of variation COV which reflected the uniformity of the electric field distribution, and the average electric field intensity E_mean and the local gathering parameter E_max/E_mean. The numerical simulation of the electric field intensity in the spouted bed was carried out by using the COMSOL Multiphysics to analyze the effects of the parameters a (spouted bed width), H (waveguide position) and L (spouted bed height). The results showed that the effect of a value on COV and E_max/E_mean was the most significant, but H value on E_mean was the most significant. The interaction between a and L was significant for COV, E_mean and E_max/E_mean. The optimized structure of rectangular microwave spouted bed with single waveguide was: a=427 mm, H=200 mm, and L=1 000 mm.

Abstract:V type slot nozzle in an impact type quick freezer was selected as the research object, and the surface heat transfer characteristics of the freezing area of the freezer were studied, based on different cutting ratio, the ration of distance between the belt and nozzle inlet H to slit width S, Hs. The results showed that the steel surface heat transfer intensity was obvious different along with width of freezer when the Hs<10 and Ψ=0. The steel surface Nu number in X/S=0 was significantly higher than that of X/S=150(The ratio between width direction of quick freezer coordinates and nozzle width S ). With the cutting ratio increasing along the X direction of the strip surface, heat transfer intensity difference gradually decreased, after the cutting critical ratio Ψ₀, the metal surface heat transfer intensity reversed growth, which indicated that the Nu number at X/S=0 was less than that at X/S=150. The cutting critical ratio with the increasing of Hs increased first and then decreased. When Hs>10, the heat transfer coefficient was even in the direction of X, however, the adjusting of the cutting ratio would adversely affect the freezing heat transfer surface area.

Abstract:In order to reduce the effect of electric defrosting heat on the cold storage temperature change during defrosting process, a heat insulation defrosting device with a return air cover and outlet baffle was designed, through the different condition of experiments, then the questions that how the return air cover and partition device to influence the temperature field around the air-cooler, the cold storage temperature and the consumption of electric heating defrosting were studied through comparing the experimental data whether the return air cover and partition device was used or not. The results indicate that after using the return air cover and partition device, the temperature distribution inside the cooling fan coil is more uniform, the fluctuating temperature field outside the fan is decreased 3.2 ℃. meanwhile, the defrosting time with the device is shortened by nearly 360 s and reduce energy consumption around 9.54%, which proves that the return air cover and partition device can stabilize the storage temperature and shorten the defrosting time and energy consumption saving in the defrosting process.

Abstract:According to the characteristics of the roller during dry granulation process, the dry granulation roller mechanics model was established by Von Mises criterion. The model was solved and simplified to calculate its equivalent stress. The mechanical properties of the dry granulation roller were qualitatively analyzed theoretically. The 3D solid model of the squeeze roll was established by using SolidWorks software. The mechanical properties of the dry granulation roller were quantitatively analyzed by finite element software ANSYS Workbench. The theoretical analysis and simulation results showed that the deformation of the dry granulation roller was mainly concentrated along the width of the dry granulation roller in the range of 30～150 mm, and the maximum deformation occurred in the center of the dry granulation roller surface (z/a=0) with a deformation of 0.026 4 mm. The maximum stress of the dry granulation roller occurred at the depth of z/a=0.5 with the cylindrical layer at 43.2 MPa.

Abstract:In order to realize the efficient processing function of removing head and tail of freshwater fish, a continuous device for cutting head and tail of freshwater fish was designed. The device consisted of intermittent feeding system, tool and fixture driving system, control system and so on. The rated power of the device was 2.3 kW, including a 1.5 kW system for the intermittent feeding, a 0.75 kW for the drive system of cutter fixture and a 0.05 kW control system. The test of processing effect of the device were conducted using （0.400±0.100） kg Parabramis pekinensis and （1.200±0.300） kg Ctenopharyngodon idellus. The research showed that using the device to process P. pekinensis and C. idellus, the rate of meat-getting is 82.1% and 76.3%, sensory score was 0.81 and 0.79, the success rate was 90.00% and 80.00%, respectively, with the processing efficiency of up to 1 350 h^-1.

Abstract:According to the problems that drying quality was affected by the automatic grading and uneven distribution of grain in the inlet of material during drying process, the rotary shower distributing was researched to increase section area by 20～50 time, and the disturbance distributing was applied to maintain the cone-top angle of grain between 110°～170°. The distributing device combined rotary shower and disturbance was designed in order to increase transverse movement of grain on the top of dryer and to stabilize volume density of grain of cross section in dryer. The test of grain drying has showed that the distributing combined rotary shower and disturbance can control impurity content unevenness of cross section in dry storehouse less than 2% when grain moisture is less than 1%, which is a stable and reliable distributing device and better than that of throw tray or turntable widely used at present.

Abstract:As the temperature control system of beer fermentation has the characteristics of time-varying, nonlinear and lagging, the traditional control method can not be used to control the beer fermentation temperature accurately. In this paper, the variable universe fuzzy PID controller was designed by introducing the extension and reduction factors of the universe, and the PID parameters were on-line fine tuning. Based on S7-1200 controller and KTP1000 touch screen, the automatic control system of beer fermentation was developed to achieve human-machine interaction. The results of beer fermentation test showed that: the control error of beer fermentation temperature ±0.09 ℃, the control accuracy 0.75%. The tempera-ture control system designed has good stability and high accuracy, which can increase the quality of beer.

Abstract:Because the jujube quality of deep processing could not guarantee and pitting by hand could not hygienically, a type of household and automatic pitting machine for jujube was designed. The research status of the jujube to remove kernel was analyzed, and the design requirements were made. Based on the analysis of processes, the system of basic machine was designed. The critical component of positioning device and removing kernel device were analyzed, and the crank movement guide mechanism was adopted in the pitting mechanism and pushing Jujube meat mechanism. The results indicated that the automatic charging and positioning rate was 93%, the pit removal rate was 95%; the average rate of production yield was 90% and the machine operated steadily.

Abstract:Portable NIR spectrometers was used for the identification of six kinds of food-contacted plastic material including polyethylene terephthalate (PET), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyvinyl chloride (PVC), polystyrene (PS) and polycarbonate (PC). Four kinds of spectral preprocessing methods including 5-point smoothing, multivariate scattering correction (MSC), first-order derivative and standard normal variable transformation (SNV) were used to preprocess the spectra of plastic samples. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were used to analyze the spectral space distribution of plastic samples and establish qualitative discriminant models. The results showed that six kinds of food-contacted plastic material could be clearly separated in the first three principal component spaces after the pretreatment of SNV and MSC methods. The PLS-DA combined with SNV could be used to get a concise plastic material qualitative discriminant model, and the correct recognition rates (CRR) were 100% both for calibration and prediction datasets. The method was expected to be a reference method for rapid identification of food-contacted plastic materials.

Abstract:Under the trend of low-carbon vision in the food package industry, an analyzed and completed method of low-carbon package based on life circle of product was introduced into food packages. During the study, a low-carbon concept was raised first, coupled with the life cycle vision, and a systematic low-carbon model was also put forward at the point of product, which is helpful in the later process of how to devise a total low-carbon procedure for food package. Finally, a environmental-friendly dishware package was adopted as a example to demonstrate the practicability and efficacy of both the specific concept and model in the practice of package design.

Abstract:Objective To explore the application methods and influence of flat visual elements in packaging design and enriche the creative concept and style of packaging application design. Method Pentaw-ards award-winning works was investigated, and the flattening features and principles of core visual elements including graphics, text, color, and layout, were comprehensively analyzes. Conclusion Flat visual elements in the packaging design were simple vector graphics, color lumpy block, flat text modular, simple layout of the page and other methods of use, resulting in a personalized brand image, information transmission efficiency, multimedia applicability. The feasibility and effectiveness of the flat design concept in packaging design was verified.

Abstract:In this research, high quality mints were used in the orthogonal test of different packaging materials, modified atmosphere and volume ratio. The mints of these groups were stored at low temperature (4 ℃) for 12 h. The variation of the sensory quality and the physical and chemical indexes of mints were studied during the storage period. The results showed that the loss rate and VC content of mints were inhibited significantly in group of packing with HDPE, MAP of 6% O₂9% CO₂85% N₂ and having the volume ratio of 15 g. Mints in this group also maintained the higher sensory quality, chlorophyll content and POD enzyme activity. The shelf life was prolonged to 14 days.

Abstract:In order to solve the problem of consumers misjudgment by hitting watermelon because of different watermelon varieties, a vibration detection system was built to get the frequency response functions of “Huang guan”, “Zaojia8424”, “Jng xin” and “Xisha” watermelon. Using the PNN neural network model achieved the identification of watermelon varieties, and the accuracy was more than 92%.At the same time,according to the relationship between the sugar content and the main resonant peak frequency, the prediction model of the sugar content of each variety of watermelon was established by stepwise multivariate linear regression analysis, and the coefficient were all above 0.86.The prediction set samples were identified and then predicted the sugar content. The measurement error of the sugar content of the watermelons which were identified accurately was less than 6.2%. The measurement error of the sugar content was larger for the watermelon which was identified mistakenly because of error prediction model. On the above basis, the unknown watermelons in the market could be identified, and then the appropriate corresponding model was selected automatically to measure the sugar content.

Abstract:The preservation of lemon juice and the positive control of 1-MCP were used for Wulongzhuyao jujube fruits were stored at 4 ℃ for 40 d. Over the storage period, decay index, mass loss rate, ascorbic acid (V_C), total soluble solids (TSS), malondialdehyde (MDA), superoxide dismutase (SOD), peroxidase (POD) were measured at 5 day intervals, and then the comprehensive evaluation on fresh-keeping effect was carried out by using principal component analysis. Results showed that both 1-MCP and lemon juice can prolong the shelf life of jujube, and can reduce decay rate, mass loss and the degree of cell membrane lipid peroxidation, delay the decrease of fruit firmness, V_C content, organic acid and TSS, increase the activity of antioxidant enzymes in fruit. Consistent with the results of the comprehensive evaluation, lemon juice treatment is more conducive to maintaining the quality of jujube,keeping higher nutritional value, and can significantly prolong the storage period of jujube fruit.

Abstract:The dried day lily had ugly appearance about color because that the green of day lily had not been faded completely. In order to fade the green and improve the color quality of dried day lily, the lily was soaked with complex ripening agent for some time, then sealed with PVC plastic bags and stored at certain temperature for a period of time before the lily was dried, subsequently, the change of color and nutrient content of day lily were determined and analyzed. The results showed that fading green completely and better nutritional quality was obtained if day lily was treated by complex ripening agent with ampelopsis grossedentata and sealed with PVC plastic bags storing at 50 ℃ for 5 h, at the same time, Ampelopsis grossedentata was such plant with health functions that is safer than sodium metabisulfite and ethephon, which has greater practical value for large scale processing of dried day lily.

Abstract:The antibacterial effects of complex preservative of sorbate, sodium diacetate and sodium erythorbate on Staphylococcus saprophyticus in shrimps were investigated in this study. To determine the minimum inhibitory concentration of compound preservative on tested strain by ELISA method (MIC), and determination of antimicrobial activity, bacterial growth curve, cell membrane integrity, alkaline phosphatase (AKP) levels and other indicators, combined with the observation of ultrastructure of bacteria, were used to evaluate the antibacterial influence of composite preservative on the S. saprophyticus. The results showed that the complex preservative can significantly reduce the growth rate of S. saprophyticus, its MIC is 109 μg/mL, the minimum bactericidal concentration (MBC) of 219 μg/mL, antimicrobial activity at the initial stage of use (around 3 h) was the strongest. The amount of alkaline phosphatase in bacterial solution significantly increased with the prolongation of time, and the absorbance at 260 nm was significantly increased. It indicated that the bacterial DNA and protein leakage, cell wall and cell membrane was destroyed. Scanning electron microscopy showed that the dry rupture occurred for the experimental group, as well as rupture of cell wall and cytoplasm from the cell exudation. The compound preservative agent of certain concentration had inhibitory (killing) effect on S. saprophyticus in shrimps and showed certain destructive effect to the cell.

Abstract:The enzymolysis technology for soybean protein isolate peptides (SPIP) and preparation technology of soybean protein isolate peptide-Se complex (SPIP-Se) were optimized. The structure properties of SPIP-Se were characterized by absorption spectrum and fluorescence spectrum, and its antioxidation was studied. Results showed that SPIP after enzymatic hydrolysis in temperature 50 ℃, with substrate concentration of 3%, and enzyme-substrate ratio of 5 g/100 g, and chelation at pH 10 in 2 h, for 78 ℃, the selenium binding capacity of SPIP reached 38.143 mg/g. The structural characterization demonstrated that SPIP-Se could cause fluorescence quenching showed higher antioxidant activity than SPIP.

Abstract:The extraction process of total steroidal saponins was optimized by the response surface method and its in vitro radical scavenging activity was also evaluated by the methods of α-deoxyribose, pyrogallol autoxidation, DPPH and ABTS. The results showed that the content of total steroidal saponins would be the highest if the time, liquid-solid ratio and temperature of ultrasonic treatment was 0.5 h, 19.51.0 (mL/g) and 39.7 ℃, and the soxhlet extraction time was 3 h. At this point, the Liriopesides B could reach 0.073 8 mg/mL. In addition, the antioxidant activity test showed that steroidal saponins had some antioxidant activities, and positive correlations were found between its antioxidant activities and its concentration. In particular, it had the obvious scavenging activity to OH free radicals and superoxide anions, which reached 59.66% and 52.3% respectively at the highest concentration of 1.28 mg/mL.

Abstract:The effects of methionine (Met) in dietary on hair growth and organs indexes were investigated. A total of 80 Kunming mice with a similar genetic background and weight were randomly divided into 0.12% (the control), 0.80%, 1.60%, and 2.40% Met treatments with five replicates per treatment, including two female and two male mice per treatment. The hair fibers, heart, liver, spleen, lungs, kidneys and thymus were collected in catagen and telogen, respectively. The results showed that hair diameters of mice were significantly decreased by adding 0.80%, 1.60% and 2.40% Met to diet (P＜0.05) in catagen and telogen. The length of hair in catagen and telogen were significantly reduced by 0.80% and 1.60% Met supplement (P＜0.05), but no changes were observed in hair diameters of the mice among four groups (P＞0.05). Compared with 0.12% Met group, spleen, lung, and renal indexes of mice from 0.80% and 1.60% Met groups were significantly improved (P＜0.05), but no significant effects of methionine were found on heart and thymus indexes (P＞0.05). Mice liver and renal indexes were significantly increased by 1.60% Met (P＜0.05), but no changes were observed in cardiac and spleen indexes (P＜0.05). In conclusion, the length and diameter of hair was significantly reduced, and spleen, lung and renal indexes were improved the by 0.80% and 1.60% Met in dietary.

Abstract:Peony seed oil was obtained by ethanol-assisted aqueous enzymatic extraction after the acid-heat pretreatment on peony seeds. The microstructure of pretreated peony seeds was analyzed by confocal laser scanning microscope. The optimal conditions of this aqueous enzymatic extraction of peony seed oil through the optimization were: finely grounding 8 times (the particle size was 33.62 μm), solid-liquid ratio of 17 (g/mL), the α-amylase enzymolysis at 70 ℃ for 1 h, pH 5.5,dosage 2 mL/100 g·material), and the glucoamylase enzymolysis at 60 ℃ for 1 h, pH 4.5, dosage 3 mL/100 g·material), the ethanol solution extraction at 60 ℃ for 1 h, pH 9.0, the volume fraction of 35%. Under the optimal conditions, the free oil yield reached 90.08%, and the residual oil content in water and sediment phase was 6.60% and 2.78% respectively. The quality indexes of the peony seed oil obtained by the aqueous enzymatic extraction were determined to show that the quality of the crude oil was excellent so that all the indexes reached the standard of the first-grade peony seed oil after simple refining.

Abstract:In this paper, the latest advances in immune-informatics methods for predicting the binding ability of active peptides to MHC are reviewed. The related tools and methods for predicting the binding of commonly used peptides to MHC molecules are introduced. The characteristics, research focuses, and difficulties of various methods are analyzed. Finding immune-active peptides provides a faster method.

Abstract:The research status of graphene modified electrode in heavy metal detection was intensively reviewed in this paper and would provide a couple of references and directions for the future researches.

Abstract:This paper introduces the types of glycosyltransferases in fruit and their roles in the formation of color，flavor and texture, which will provide a reference for the application and further research of glycosyltransferase.

Abstract:The survival of Lactobacillus casei was investigated through four kinds of composite wall materials by internal emulsification method followed in simulated gastric and intestinal juice. The results suggested that the microencapsulated L. casei was prepared by using 2% of alginate, with the ratio of alginate to whey protein content 11, the quality of oil to water volume 31, alginate to calcium carbonate content 31, and the maximum embedding rate of microcapsules was 87.50% with the global microcapsules. Taking gelatin and alginate as composite wall material, the minimum particle size of microcapsule was 89.88 μm. When soy protein isolates and alginate were used as composite wall material, the survival rate of microencapsulated L. casei in simulated gastric juice was around 90.39% after 2 h. When using casein and alginate as composite wall material, the microcapsule had good intestinal soluble, and microencapsulated L. casei was basically released after 30 min. Because the microcapsule used protein as composite wall material was safe to eat and has good embedding effect, it could be widely used in food processing.

Abstract:With the purpose of providing theoretical basis for further processing and utilization of Chinese chestnut, the microwave-vacuum drying characteristics and the optimum process parameters of chestnut were investigated. The effects of microwave intensity and chamber pressure on the mass and heat transfer in the drying process of chestnut were studied. The microwave power, pressure and drying time were optimized using Box-Behnken design and response surface methodology for achieving minimum moisture content and maximum whiteness value. The results showed that the microwave-vacuum drying process of chestnut slices was mainly divided into acceleration and deceleration stages, and the constant velocity phase was shorter. Both microwave power and vacuum degree had a significant influence on the drying time, the higher the power, the higher vacuum, the faster the drying rate was. The dry moisture content and moisture ratio decreased gradually with the extension of drying time of Chinese chestnut. The optimum process parameters of microwave-vacuum drying of chestnut were obtained by regression model, with the time of 12 min, the pressure of -56 kPa and the power of 3 kW. The microwave power, chamber pressure and drying time had a significant influence on the quality of drying Chinese chestnut by Microwave-vacuum. The drying parameters obtained from drying-mode ensure the edible value of Chinese chestnut with high efficiency and low energy consumption.

Abstract:The water chestnut starch were tested through intermittent microwave drying, and the effects of comprehensive quality were researched including water content, whiteness, acidity and iodine blue value of chestnut starch, optimized by orthogonal tests. The results showed that the optimum drying conditions for water chestnut starch intermittent microwave were microwave power 210 W, loading 1.47 kg/m², heating for 14 min and intermittent time 0.75 min. Under the optimum conditions, after intermittent microwave drying, water content of water chestnut starch was 10.12%, the whiteness was 97.5%, and the acidity was 0.21 mL, iodine blue value was 17.90. At present, water content reached the safety standard, and whiteness increased slightly, with the acidity decreasing and iodine blue value increasing. Therefore the quality was improved. The results could provide a reference for the actual production of water chestnut starch microwave drying technology.

Abstract:To enrich the form of tofu deep-processing products, jade-like dumpling, a special traditional tofu dish, was prepared using tofu and minced pork as dumpling paper and stuffing respectively. The effects of different coagulants on quality parameters, including the texture, color, sensory characteristic, water holding capacity and nutritive compositions, of jade-like dumpling were compared. The results indicated that the optimal concentration of MgCl₂, CaSO₄ and GDL for jade-like dumpling was 2.5 g, 2.5 g and 2.0 g per 100 g dried soybeans, respectively. The water holding capacity of CaSO₄-dumpling and GDL-dumpling had no significant difference (P＞0.05), which were significantly higher than that of MgCl₂-dumpling (62.89%) (P＜0.05). The hardness of CaSO₄-dumpling and GDL-dumpling which was 760.88 g and 745.08 g, respectively, and were obviously lower than 861.86 g of MgCl₂-dumpling (P＜0.05). However, the dumpling made from different coagulants showed no significant difference with respect to chewiness, resilience, cohesiveness and adhesiveness. The a^* values for the CaSO₄-dumpling was significantly less than MgCl₂-dumpling and GDL-dumpling, while there was no significant difference in L* values. The CaSO₄-dumpling was superior to others with regard to sensory characteristic such as damage during wrapping, taste and appearance. Therefore, 2.5 g CaSO₄ per 100 g dried soybeans could be chosen to prepare jade-like dumpling.