To optimize the process for the synthesis of starch acetate from corn starch, the effects of catalyst amount, the volume mixing ratio of acetic acid to acetic anhydride, and reaction time and temperature on the degree of substitution (DS) of starch were evaluation by single factor experiments, and a mathematical model describing the functional relationship between starch DS and the above four variables was set up based on a 29-run, 4-factor, 3-level response surface design coupled with multiple regression fitting. The model was subjected to analysis of variance and response surface analysis, and the results showed that the optimum conditions for the synthesis of starch acetate were as follows: catalyst amount of 0.11 mL and the mixing ratio of acetic acid to acetic anhydride of 1:1.39 by volume for a reaction period of 1.59 h at 87.61 ℃. Validation experiments indicated that the maximum substitution degree of starch acetate was 2.95 under these conditions. FTIR results indicated that the hydroxyl groups in each glucose unit of starch acetate were gradually esterified, and meanwhile the content of acetyl group became higher with the increase of substitution degree. Scanning electron microscopic (SEM) observations revealed that the surface of starch acetate was much rougher, had increased porosity and displayed cellular structure, indicating that the esterification occurred not only on the surface but also inside of starch granule.

Soy protein isolate (SPI) was modified by transgultaminase (TG) to improve its emulsifying properties so as to obtain modified SPI suitable for cold drinks and foods. Response surface design was used to explore the effects of enzyme addition amount and hydrolysis time and temperature on emulsifying activity index (EAI) and establish a mathematic model of optimal enzymatic hydrolysis conditions. Results showed that the optimal modification conditions were TG dosage of 0.93×10-4 g, hydrolysis temperature of 46 ℃and hydrolysis time of 1.2 h. Under the optimal conditions, the experimental EAI was 1.9658 m2/g, which was close to the predicted EAI of 1.9623 m2/g. Moreover, modified SPI revealed higher emulsion capacity than that of native SPI.

The microwave-assisted alkali extraction of polysaccharides from Mesona Blumes was optimized in this paper. To do this, the effects of four factors including water-bath boiling time, alkaline concentration, material/liquid ratio and microwave treatment time on the extraction rate of polysaccharides were explored by single-factor and orthogonal design methods. Results indicated that alkaline concentration was the most critical factor affecting the extraction rate of polysaccharides, followed by material/liquid ratio. Microwave treatment time and water-bath boiling time exhibited less effect on the extraction rate of polysaccharides. The optimal extraction conditions were microwave treatment time of 90 s, extraction power of 400 W, water-bath boiling time of 1 h, alkaline concentration of 0.125 mol/L, and material/liquid ratio of 1:35. Under these optimal conditions, the extraction rate of polysaccharides from Mesona Blumes was up to 43.84%.

The experimental material used to prepare Chinese-style bacons by dry salting and following air-dried ripening was pork belly pieces in this study. A 9-run, 4-factror, 3-level orthogonal array design was employed to investigate the effects of four process parameters, namely salting time, air-dried ripening temperature, relative humidity, repeated time of chitosan coating on physico-chemical and quality indices and proteolysis in bacon. Results indicated that proteolysis index (PI) and total free amino acids (TFAA) significantly increased (p＜0.05) with the increase of temperature during processing. The PI and TFAA in the treatment group of 17－32 ℃ increased 20% and 28%, compared with those in the treatment group of 13－28 ℃, respectively. TBARS was significantly correlated with temperature during preparation processing (r = 0.93, p＜0.01), and the maximal value of TBARS was (0.65 ± 0.26) mg/kg. The products with water content of (59.75 ± 1.89)% and salt content of (3.49± 0.49)% exhibited a better sensory quality. The TFAA and total scores of sensory evaluation as target functions revealed that the optimal processing conditions were air-dried ripening time of 5 days, drying temperature of 17 ℃, repeated coating number of 2 and salt addition amount of 1.5%.

The adsorption and desorption effects of 6 kinds of macroporous resins on anthocyanins from red-core radish were compared. The adsorption and desorption properties of resin AB-8 on anthocyanins from red-core radish were further investigated. Results indicated that the adsorption equilibrium time of anthocyanins on resin AB-8 was 4 h. The highest adsorption capacity of resin AB-8 towards anthocyanins from red-core radish was achieved under the conditions of pH 3 and 20 ℃. In addition, 75% ethanol could provide the best desorption effect on anthocyanins from resin AB-8. The purified anthocyanins obtained under the optimal conditions were purple dark powder with color value of 47.8, which exhibited 12-fold enhancement compared with the color value of anthocyanins before purification.

In order to optimize the ultrasound-assisted extraction of pectin from potato pulp left after starch extraction, five key factors affecting pectin yield including ultrasound power, extraction temperature and pH, the length of extraction time and solid-to-liquid ratio were investigated by one-factor-at-a-time experimental design, and a mathematical model representing the relationship between the function and the five variables was constructed using quadratic regression orthogonal rotation combination design, and the effects of pairwise cross-interactions among the above factors on pectin yield were evaluated by response surface analysis (RSM). The optimal process for the extraction of pectin from potato pulp was determined to be the extraction of the raw material at 80 ℃ for 47.6 min with a 21-fold volume of water under the assistance of ultrasound treatment at 300 W.  Under these optimal conditions, the yield of potato pectin reached up to 15.76%. Furthermore, the obtained product was analyzed for its physico-chemical parameters, and all the analytical results met the requirements of the national and industrial standards.

In this study, papain tenderization was applied for the air-drying processing of spent laying hen breast meat. In order to evaluate the influence of air-drying ripening on the tenderization of chicken breast meat, predictive modeling for proteolysis index (PI) and Warner-Bratzler shear force (WBS) as separate responses to enzyme dose and air-drying temperature and time were conducted using central composite design (CCD). Based on the models established, the optimum levels of the three factors were determined to be: enzyme dosage, 3.5 U/g; air-drying temperature,14 ℃ and air-drying time, 99.33 h, their sequential decrease order was enzyme dosage, air-drying temperature and air-drying time for influencing PI and air-drying time, enzyme dosage and air-drying temperature for influencing WBS, and a PI of 10.408% and a WBS force of 3.48 kg/cm2 were obtained under these conditions.

The central composite design (CCD) method was employed to study the cellulase-assisted extraction process of total flavonoids from onion peel, and their antioxidant activities were also evaluated. The results showed that the optimum extraction conditions were obtained as follows: cellulose added at a ratio of 0.52% to hydrolyze onion peel suspended in a 40-fold volume of water adjusted to pH 5.0 for 105 min. The extraction rate of flavonoids under these extraction conditions was 2.32%. Moreover, antioxidation experiments showed that flavoniods from onion peel had very strong scavenging effects on DPPH free and hydroxyl radicasl, and the corresponding IC50 values were 3.751μg/mL and 4.267μg/mL. Meanwhile, onion peel flavonoid showed stronger reducing power when compared to tea polyphenols. These findings suggest that onion peel flavonoids are a group of strong antioxidants and have promising application prospects in healthcare foods and drugs.

Acid modified attapulgite was used to clarify red wine. The clarification efficiency of red wine was evaluated through examining the effects of attapulgite addition amount, clarification time and clarification temperature. The optimal clarification  conditions of red wine were explored through combinatorial method of single-factor test and response surface methodology (RSM). Results indicated that attapulgite modified by 3 mol/L sulphuric acid could provide a better clarification effect and the optimal clarification conditions were attapulgite addition amount of 0.56 g/L, clarification temperature of 19 ℃ and clarification time of 11.2 h. The clarity of red wine was achieved up to 90.6% under the optimal conditions and the clarified red wine exhibited an excellent stability.

The preparation of dialdehyde starch (DAS) from mung bean starch was achieved by homogeneous sodium periodate oxidation. The effects of pre-treatment temperature, enzymatic treatment, ultrasonic activation in the pre-treatment stage and reaction temperature, reaction time, pH, sodium periodate/starch ratio and phase transfer catalysts in the oxidation stage on the preparation of dialdehyde were investigated. Ultrasonic activation and phase transfer catalysis were first studied in this study. Orthogonal test was applied to explore the optimal preparation conditions of DAS. Results indicated that ultrasonic activation of starch at 30 ℃ for 30 min was beneficial to improve reaction activation and the application of enzyme was not suitable in the pre-treatment stage. The optimal pre-treatment temperature was 50－60 ℃. In addition, phase transfer catalysis was also beneficial to improve the content of aldehyde group in final products. The optimal experiment conditions were cetyltrimethyl ammonium chloride (CETAC) as the phase transfer catalyst, reaction temperature of 40 ℃, reaction time of 2 h, pH 2, NaIO4/starch ratio of 1.0:1.0, NaIO4 concentration of 0.5 mol/L, and starch concentration of 10%. The obtained final products were white and the content of aldehyde group in final products was up to 96.81%. The spectral and physicochemical properties of DAS were consistent with previous reports.

Rinsing with sodium hypochlorite and hydrolysis with hydrochloric acid are two key procedures for the preparation of microcrystalline cellulose from apple pomace. In the present study, based on single factor experiments, by which hydrolysis time of 50 min and temperature of 100 ℃ were determined, the pairwise interactive effects of material/liquid ratio, hydrochloric acid concentration and the amount of sodium hypochlorite addition on microcrystalline cellulose yield were discussed by central composite design (CCD) in combination with response surface analysis. The significance of the above three factors affecting microcrystalline cellulose yield decreased in the following order: hydrochloric acid concentration ＞ material/liquid ratio ＞ the amount of added sodium hypochlorite. Analysis based on response surface and contour plots showed that all the pairwise interactions significantly affected microcrystalline cellulose yield. The regression equation based on the results from CCD design was resolved, and the results indicated that the optimal amount of added sodium hypochlorite for rinsing apple cellulose was 2.5 mL/100 mL, and that the optimal hydrolysis effect was achieved by the use of 6% hydrochloric acid to hydrolyze the substrate diluted 25-fold by volume. Under these conditions, a microcrystalline cellulose yield of 69.5% was obtained. 

Transesterification was conducted in soybean oil with phytosterol under the catalysis of Novozym 435 lipase. The optimum reaction conditions were obtained by single factor experiments and response surface analysis to be reaction between soybean oil and added phytosterol at a concentration of 5.2% for 3 h at 101 ℃ in the presence of 1% lipase. The rate of transesterification was 85.67% under these conditions.

A process for extracting procyanidins from lotus seed pods consisting of simultaneous double-enzymatic hydrolysis with pectinase and cellulose and subsequent extraction with 65% aqueous ethanol solution was proposed in this study. Central composite design (CCD) coupled with response surface methodology (RSM) was used to investigate the optimization of the double-enzymatic hydrolysis of lotus seed pods for improved procyanidin extraction. A mathematical predictive model for the extraction yield of procyanidins was established based on the experimental data from CCD design, and analyzed using SAS software. The results showed that the optimal technological conditions for the hydrolysis of lotus seed pods were as follows: hydrolysis temperature, 53 ℃; hydrolysis time, 1.6 h; initial hydrolysis pH, 4.8; and the ratio of pectinase to cellulose, 1: 1.1, and the yield of procyanidins was 5.20% after hydrolysis under these conditions followed by 120 min extraction at 55 ℃with 65% aqueous ethanol solution, 35.7% higher than that of single ethanol extraction. In addition, procyanidins extracted by the method had stronger ability to scavenge DPPH radicals than those derived from single ethanol extraction.

The process for extracting gingerol with ethanol aqueous solution under microwave assistance was optimized by evaluating the effects of extraction solvent type, ethanol concentration in water, microwave power, microwave treatment time and material-to-liquid ratio on gingerol extraction using single factor and orthogonal array design methods. The optimum conditions for gingerol extraction were found to be: ethanol concentration, 66%; material-to-liquid ratio, 1:16; microwave treatment time, 70 s; and microwave output power, 300 W. The extraction yield of gingerol was 1.76% under such conditions. Meanwhile, the anti-lipid peroxidation activity of gingerol was assessed and compared with those of two natural antioxidants, and the results revealed that the extract from ginger was able to protect vegetable oils and lard against lipid peroxidation, and that its anti-lipid peroxidation activity was superior to citric acid but inferior to tannic acid.

Response surface methodology (RSM) was applied to optimize the enrichment of α-linolenic acid in silkworm pupal oil by the method of urea adduction fractionation. This optimization was carried out based on our previous investigations on the effects of four process parameters, namely reaction temperature and time, the ratio of urea to fatty acids, and the ratio of 95% ethanol to fatty acids on α-linolenic acid content in urea inclusion compounds by single factor method, and the results showed that the optimum levels of the four parameters were determined to be －8.27 ℃, 8.91 h, 3.39:1 and 10.47:1, respectively. Under the optimum conditions, the content of α-linolenic acid in urea inclusion compounds was up to 70.28%. Urea adduction fractionation is an effective method for the enrichment of α-linolenic acid.

Previous studies have showed that Allium macrostemon Bunge is a broad-spectrum antimicrobial plant. In the present study, crude aqueous extracts isolated from Allium macrostemon Bunge under different levels of water amount as well as extraction time, temperature and number were tested comparatively for their anti-Escherichia coli and anti-Staphyloccocus aureus activities, and the plant showed better inhibitory effect against Staphyloccocus aureus than against anti-Escherichia coli. To obtain highly active anti-Staphyloccocus aureus substances from Allium macrostemon Bunge, the above four extraction conditions were optimized by response surface methodology based on inhibition circle diameter against Staphyloccocus aureus. The optimum levels of water amount as well as extraction time, temperature and number were determined to be 2-fold volume, 3 h (each time), 32 ℃ and 4, respectively, and under these conditions an extract with an inhibition circle diameter of 13.98 mm was obtained. Therefore, Allium macrostemon Bunge has the potential to be developed into a natural food preservative.

The purpose of the current study was the optimization of the process for the solvent extraction of proanthocyanidins from Areca catechu L. fruit with ultrasonic assistance. First of all, the selection of extraction solvent was investigated. Secondly, one-factor-at-a-time (OFAT) experiments were done to figure out the effects of five process parameters for the extraction of proanthocyanidins with acetone aqueous solution, including acetone concentration in aqueous solution, extraction temperature, material-to-liquid ratio, ultrasonic power and ultrasonic treatment time on the extraction rate of proanthocyanidins. Thirdly, the relationship of the extraction rate of proanthocyanidins with the other four extraction conditions except extraction temperature was mathematically modeled on the basis of a four-variable, three-level central composite design (CCD) with 26 runs. Finally, the model established was subjected to analysis of variance to test the significance of various variables and response surface analysis to understand their pairwise interactive effects on the function. From the above investigations and analysis, we determined the optimum conditions for the extraction of proanthocyanidins from Areca catechu L. fruit to be: ultrasonic power of 600 W, ultrasonic treatment time of 16 min, the ratio of material to solvent of 1:40 (g/mL) and acetone concentration of 81%. Under these conditions, the maximum extraction rate of proanthocyanidins was up to 3.41%.

Red skin seeds of lotus usually produce about 15% of red skin powder in the resurfacing process. It was determined that protein content in red skin of lotus seed is 17.65%. In the present study, the conditions for the salt-extraction of proteins from red skin of lotus seed assisted by microwave, such as the ratio of solid to liquid (m/V), the concentration of NaCl solution, extraction temperature, extraction time and the repeat times of extraction, were investigated using the extraction rate of protein as an evaluation index. On the basis of single factor and orthogonal array design investigations, the optimal extraction conditions were obtained as follows: under the assistance of 600 W microwave irradiation twice-repeated extraction at 35 ℃ for 20 min each time at a ratio of solid to liquid 1:12 (g/mL). Under the above conditions, the extraction rate of protein was 85.52%. When HCl was used to precipitate protein, the precipitation rate of protein was 35.96% at an isoelectric point of pH 4.9. The yield and purity of lotus proteins extracted by this method were 30.75% and 83.67%, respectively. As a conclusion, lotus seed red skin has good development prospects.

With the aim of optimizing the process conditions for the microwave-assisted solvent extraction of raspberry seed oil, this study was designed as follows: 1. For solvent selection, a comparison of raspberry seed oils extracted was carried out with different solvents such as ethanol, petroleun ether, n-hexane and ethyl acetate. 2. A series of one-factor-at-a-time experiments were conducted to investigate the effects of four operating parameters including solid/solvent ratio, temperature, extraction time and microwave output power on extraction efficiency of raspberry seed oil. 3. A mathematical predictive model for extraction efficiency of raspberry seed oil as a response to the four parameters was established by multiple polynomial regression with SAS software based on central composite design, and response surface analysis of the model was performed to probe into the pairwise interactive effects of various variables on their function. The above investigations showed that n-hexane was the best solvent for the extraction of raspberry seed oil, and that solid/solvent ratio of 1:10 (g/mL), temperature of 64 ℃, extraction time of 9 min and microwave output power of 657 W provided optimum extraction of raspberry seed oil, with an extraction efficiency of 17.73%.

Objective: The conditions for the extraction of trypsin inhibitor from low-temperature defatted soybean meal were optimized. Methods: pH, thermal denaturation temperature and ammonium sulfate saturation were identified to be main variables that influence extraction efficiency by the one-factor-at-a-time method. Based on the principles of Box-Behnken central composite design, response surface analysis was employed to explore the effects of pairwise interactions among the three variables at three levels on extraction efficiency. The optimum conditions for extracting soybean trypsin inhibitor from low-temperature defatted soybean meal were found as follows: extraction solvent pH of 5.1, thermal denaturation at 72.8 ℃ and ammonium sulfate saturation of 54.5% for the precipitation of trypsin inhibitor. Under these conditions, the extraction efficiency of trypsin inhibitor was up to 86%. Consequently, response surface methodology is feasible for the optimization of the extraction process for trypsin inhibitor from defatted soybean meal, and the optimized process is reliable.

Objective: To obtain the optimum process conditions for the synthesis of lactosucrose under the catalysis of β-fructofuranoside. Methods: Lactosucrose was prepared from lactose as an acceptor and sucrose as a fructosyl donor by a fructose-transferring enzyme, β-fructofuranoside derived from Arthrobacter sp.10138. The process was optimized by Box-Behnken experimental design followed by response surface analysis. Results: Adding the same volume of β-fructofuranoside solution to a mixture of lactose and sucrose in equal proportion by weight in aqueous solution to catalyze the reaction between the two sugars for 22.77 h at 35.0 ℃ provided optimum synthesis of lactosucrose, and the content of lactosucrose in reaction product was 22.70%. Conclusion: Combined use of Box-Behnken experimental design and response surface methodology has the feasibility to be used as a mathematical approach to optimize the synthesis process for lactosucrose, and the established model is reliable in predicting the content of lactosucrose in reaction product.

To optimize the conditions for chilli sauce sterilization by means of microwave treatment, Box-Benhnken experimental design was utilized to develop a quadratic polynomial model describing order-of-magnitude reduction in total viable count as a function of three key sterilization conditions, namely microwave power, temperature and treatment time, with verified validity, and response surfaces and contours were plotted to analyze the effects of pairwise interactions among the three conditions on their function. The order of importance of the three factors affecting the sterilization of chilli sauce from high to low was microwave power, temperature and treatment time. Microwave treatment with a 960 W power for 8.9 min was the optimized sterilization condition. Under this condition, the developed regression predicted a 3.75-order-of-magnitude reduction in total viable count, in good agreement with the observed value. Thus, the model is reliable. 

Purpose: To optimize the ultrasonic-assisted extraction process for water-soluble polysaccharides from Sophora japonica flower for improved extraction efficiency. Methods: The optimization strategy used was a series of one-factor-at-a-time investigations and subsequent response surface analysis based on a quadratic regression rotary combination design. Results: Within tested level ranges, the importance of four process parameters affecting extraction yield of polysaccharides from big to small was ultrasonic treatment time, liquid-to-solid ratio and ultrasonic power in turn. Ultrasonic treatment time of 58 min, ultrasonic power of 217 W and extraction temperature of 30 ℃ were found optimum for polysaccharide extraction. Conclusion: ultrasonic assistance is beneficial to shorten extraction time and improve extraction efficiency and consequently, suitable for the extraction of water-soluble polysaccharides from Sophora japonica flower.

In combination of hot-air drying, vacuum frying was utilized to process peach chips. Vacuum-frying temperature, moisture content after vacuum drying and hot-air drying temperature were recognized as main factors that affect oil content of peach chips. From the results of response surface analysis, it was found that the optimum conditions for the combined vacuum and hot-air drying of peach chips based on oil content of peach chips were sequential operations of 3 min blanching followed by vacuum drying at 87.1 ℃ until a moisture content of 15.9% and hot-air drying at 65.5 ℃ for processing 2 mm thick peach slices. Considering actual operating situations, vacuum-frying temperature, moisture content after vacuum drying and hot-air drying temperature were modified to be 87 ℃, 16% and 66 ℃, respectively, and the other conditions were kept unchanged. Under the modified processing conditions, the actual value of oil content in peach chips after hot-air drying was 12.5%, exhibiting 5.9% relative error when compared to the theoretically predicted value.

The optimization of the extraction of volatile oil from Asarum forbesii Maxim with microwave assistance was studied through one-factor-at-a-time instigations followed by mathematical modeling for extraction efficiency as a response to liquid-to-solid ratio, microwave power and treatment time based on the principle of Box-Behnken experimental design and response surface analysis of model. Liquid-to-solid ratio of 8.3:1, microwave power of 309 W and treatment time of 154 s were found optimum for the extraction of volatile oil with ethyl acetate, which was selected out of four common organic solvents based on oil yield. Under these conditions, the experimental value of oil yield was 7.96%, substantially complying with the theoretical value. This indicates good reliability of the developed regression model in predicting oil yield. The volatile oil extracted by the optimized method was subjected to separation and identification on a gas chromatography-mass spectrometry (GC-MS) system. A total of 25 constituents were separated and 19 of them were identified and quantified by area normalization method. This study can provide useful references for the development and exploitation of Asarum forbesii Maxim.

Objective: Ultrasonic treatment was introduced to the ethanolic extraction of antioxidants from the fruiting body of Flammulina velutipes with the aim of enhancing cell disruption, and the extraction process was optimized by response surface methodology. Methods: For the evaluation of the ability of extract to scavenge free radicals, a DPPH free radical system was constructed. Ethanol concentration, ultrasonic power and extraction time were selected as major factors that influence DPPH radical scavenging ratio, and the pairwise interactive influences of the three factors at three levels on DPPH radical scavenging ratio were probed by response surface analysis. According to the results of canonical analysis, the optimum conditions for the extraction of antioxidants with high DPPH radical scavenging activity were using 95% ethanol for 20.24 min extraction under the assistance of ultrasonic treatment at 40 kHz and 400 W. The extract under these conditions presented a DPPH radical scavenging ratio of 85.32%. Conclusion: Ultrasonic treatment is helpful to extract highly DPPH radical scavenging antioxidants. Response surface methodology has good feasibility to be used as a mathematical approach to optimize process parameters for the extraction of antioxidants from the fruiting body of Flammulina velutipes.

In the present study, process optimization for the extraction of polyphenols from pineapple peel residue with ethanol aqueous solution was carried out by Hartley’s experimental design method combined with response surface analysis based on a series of one-factor-at-a-time experiments. A regression model for total polypenhols yield as a function of four factors, namely temperature, extraction time, ethanol concentration and liquid-to-material ratio was built. The importance of the four factors affecting total polypenhols yield declined in the following sequence: temperature, extraction time, liquid-to-material ratio and ethanol concentration. Extraction at 48.4 ℃for 73.6 min with a 46.8-fold volume of 41.6% ethanol aqueous solution yielded the most total polyphenols, reaching 7.77 mg/g, which was basically in accordance with the model-predicted value. In conclusion, the optimized extraction process is reliable and can be used for the development of products based on pineapple peel polyphenols.

The effects of three freeze-drying parameters, including winter jujube slice thickness, sublimation drying temperature and desorption drying temperature on vitamin C content in winter jujube after freeze-drying were studied under 200 Pa vacuum condition by conducting 20 experimental runs generated by quadratic generalized rotary regression design to build a regression model between vitamin C content in winter jujube after freeze-drying and the three parameters. The model was subjected to response surface analysis with SAS 9.2 software. The analytical results showed that the optimum freeze-drying conditions for winter jujube were slicing winter jujube to a thickness of 5.5 mm for sublimation drying at －22.1 ℃ and desorption drying at 20.6 ℃. The built model was found to have excellent goodness of fit. Hence, it can provide a reference for practical production.

We report the cloning of two flanking sequence of the integrated gene construct of genetically modified maize 59122 by inverse PCR method and the design of even-specific primers based on the left flanking sequence with the aim of developing of a duplex PCR assay for the event-specific transgenic detection of genetically modified maize 59122 using semi-nested PCR, result ing in an amplification fragment of 100 bp in length stretching from the terminator of the pat gene to the 59122 flanking genes. This assay has been successfully applied to detect genetically modified maizes 59122, MON863, MON810, GA21, NK603, genetically modified Roundup Ready soybeans and genetically modified oilseed rape GT73, with high specificity. The optimum concentration of linear DNA in a connection system for detecting genetically modified maize 59122 by this assay was around 1 ng/μL, which exhibited a limit of detection of 0.1% and a sensitivity of 38 copies of haploid genome. Therefore, the developed PCR assay is applicable to detect genetically modified maize and its derivates accurately, fast and efficiently, and can serve to verify routine PCR qualitative detection.

A sensitive HPLC-MS/MS method with high selectivity was developed for the determination of cyanuric acid residues in dairy products. Cyanuric acid in samples was extracted into acetonitrile/water system. The extract was deproteinized by adding additional acetonitrile, followed by high-speed centrifugation, before HPLC-MS/MS analysis in the internal standard mode. Electrospray ionization was applied and operated in the negative ion mode. An excellent linear range of this method for the determination of cyanuric acid was 0.005－0.2μg/mL with a correlation coefficient of more than 0.999. The average recovery rates in dairy products spiked with standard material at concentration levels of 0.2, 0.5, 1.0 mg/kg and 2.0 mg/kg were in the range of 91.7% to 99.6% with relative standard deviations less than 10%. The limit of detection of this method was 0.2 mg/kg.

In order to determine the types and relative contents of fatty acids in 4 kinds of silkworm pupal oil, oil transesterification was carried out with KOH/CH3OH, followed by gas chromatography-mass spectrometric analysis. Results indicated that acid values, saponification values and peroxidation values differed significantly among the 4 kinds of pupal oil. All the four tested materials contained the following major components: linolenic acid (LNA), palmitic acid, stearic acid, oleic acid andα-linolenic acid, which exhibited different relative contents. Among them, the relative content of unsaturated fatty acids in oak silkworm pupal oil was the highest, which was up to 77.29% and castor silkworm pupal oil contained the mostα-linolenic acid, with a relative content of 50.52%. Desilked pupal oil contained more unsaturated fatty acids than silkworm pupal oil.

A GPC-HPLC-DAD method was established for the simultaneous determination of 14 kinds of phthalate esters (PAEs) in chili sauce. Samples were extracted with petroleum ether in an ultrasonic field, followed by clean-up by gel permeation chromatography and concentration by nitrogen gas blowing. The chromatographic separation was achieved on  Waters-C18 column (250 mm × 4.6 mm, 5μm) using an acetonitrile-water mobile phase. A HPLC system coupled with a diode array detector (DAD) was used to analyze the analytes. The developed analytical method exhibited a linear correlation coefficient of more than 0.998 and detection limits ranging from 0.25 to 2.0 mg/kg. Spike recovery rates between 85.7% and 100.8% were obtained, with relative standard deviations (RSD) of 0.37%－4.57%. Therefore, this method is a sensitive, rapid high throughout method and has good suitability to be used to analysis 14 kinds of PAEs in chili sauce.

Total flavonoids in Actinidia arguta were determined separately by ZrOCl2 colorimetry, NaNO2-Al(NO3)3 colorimetry, AlCl3 colorimetry and HPLC. Wavelength scanning of flavonoid extracts and rutin after reaction with different chromogenic reagents was performed in a range of 200－600 nm. Results showed that NaNO2-Al(NO3)3 colorimetry and AlCl3 colorimetry were fount not suitable for the determination of total flavonoids in Actinidia arguta. An excellent linear equation for ZrOCl2 colorimetric determination at 284 nm wavelength was obtained as follows: Y284 = 0.0114X－0.0001, R2 = 0.9991. The average recovery rate was 99.4% with a RSD of 1.61% (n = 5). ZrOCl2 colorimetry is a quick accurate method for the determination of total flavonoids in Actinidia arguta.

A HPLC coupled with immunoaffinity column cleanup method for the determination of citrinin in agricultural products such as rice, corn and pepper was established. Samples were extracted with methanol aqueous solution and cleaned up on a column containing anti-citrinin specific antibody. The chromatographic separation was performed on a C18 column (150 mm × 4.6 mm, 5μm) eluted by a mobile phase composed of acetonitrile and TFA solution at a ratio of 60:40 (V/V). A fluorescence detector with 331 nm excitation wavelength and 500 nm emission wavelength was used for the quantification of citrinin in an external standard mode. Peak area and citrinin concentration displayed an excellent linear relationship. The limit of detection of this method was 10μg/kg and limit of quantitation was 30μg/kg. The spike recovery rates for citrinin were between 61% and 96.6%, with relative standard deviations ranging from 3.72% to 6.40%. This method has the characteristics of ease of operation, accuracy, high recovery, excellent precision and good reproducibility and is suitable for the determination of citrinin in rice, corn and pepper.

To investigate the distribution of omethoate residues in fruits and vegetables, different parts of Chinese cabbage and apple were analyzed by gas chromatography (GC). The results indicated that the contents of omethoate residues in Chinese cabbage leaves was higher than that in the stems and declined gradually from outside to inside in the whole cabbage; the highest, middle lowest contents of omethoate residues was found in the peel of apple, followed by in the pulp and in the core of apple successively; and the maximal natural degradation rates of omethoate in Chinese cabbage and apples appeared around 10－15 days after spraying on their surface.

Recent years, nitrate content in vegetables has gained extensive attention. The contents of nitrate, nitrite and vitamin C in 52 kinds of vegetables from Beijing suburb were determined. Results indicated that a difference in nitrate accumulation was observed among different species, cultivars and parts of some vegetables. The contents of nitrate in different vegetable species calculated on the basis of fresh weight declined in the following order: root vegetables (420.66 mg/kg), leafy vegetables (281.24 mg/kg), stem vegetables (279.54 mg/kg), fruit vegetables (176.54 mg/kg) and flower vegetables (157.93 mg/kg). The contents of nitrate in different cultivars from one species exhibited 1.13－5.48 fold difference. Meanwhile, the content of nitrate in different leaf parts of Chinese cabbage and cabbage revealed a gradual decrease trend in following sequence: rossette leaf, middle head leaf and inner head leaf. The content of nitrate in cucumber also exhibited a gradual decrease trend in top part, basal part and middle part. Moreover, a decrease trend for the content of nitrate in cucumber was also observed in fruit mesocarp, exocarp fruit endocarp, placenta and seeds. The content of nitrate exhibited a declined trend in root periderm, secondary phloem in radish, secondary and primary xylem of the root. The contents of nitrite in the majority of vegetables were under 1 mg/kg although some vegetable species such as garland chrysanthemum could reach up to 6.74 mg/kg. Nitrite accumulations less significantly differed among different cultivars, species or parts as compared to nitrate accumulation. The content of vitamin C in fruit, leafy and flower vegetables was generally higher than that in other species although pepper could reach up to 146.56 mg/100 g. However, no significant difference in vitamin C content among different cultivars was observed. It is suggested that consumers scientifically and reasonably vegetables for health, although the majority of vegetables from Beijing suburb have the contents of nitrite and nitrate within their safety ranges.

A high performance liquid chromatography (HPLC) method was used to determine the contents three soluble sugars (fructose, sucrose and glucose) in fresh corn. The chromatographic column used was an Agilent Zorbax carbohydrate (4.6 mm × 250 mm, 5 μm) column held at 25 ℃, and the mobile phase was a mixture of acetonitrile and water (V/V, 75:25) at a flow rate of 1 mL/min. The established cabliration curves of fructose, sucrose and glucose displayed correlation coefficients ranging from 0.99839 to 0.99995 (n = 5). In precision experiments, relative standard deviations (RSDs) between 0.90% and 3.8% were obtained (n = 5). The average spike recoveries of the method ranged from 95.28% to 101.02%. This method can be used for accurate, reasonable and rapid analysis of soluble sugar in fresh corn.

Objective: To develop an ultra performance liquid chromatography (UPLC) method for the determination of five synthetic pigments such as tatrazine, amaranth, carmine, sunset yellow and brilliant blue in beverage. Methods: Synthetic pigments in beverage were extracted by polyamide adsorption method, separated on a Waters ACQUITY UPLCTM BEH C18 column by gradient elution using a mobile phase made up of methanol and 0.02 mol/L ammonium acetate, and detected at 254 nm and 629 nm. Results: The five synthetic pigments were separated in 5.5 min. The UPLC method exhibited excellent linearity over a range of 3－80 mg/L (r ＞ 0.9995). The detection limit, recovery rate and relative standard deviation (RSD) of this method were 0.03－0.10 mg/L, 97.4%－107.3%, and 0.22%－3.20%, respectively. Conclusion: The analytical method is simple, accurate, sensitive and suitable for the determination of pigments in beverage.

This study was aimed at establishing a laboratory method for the quantitative detection of tetrodotoxin (TTX). A bioassay was developed by injecting intraperitoneally TTX at various dosages to Kunming strain male mice with body weights of 19－21 g. Results indicated that the 50% lethal dose (LD50) of TTX for Kunming strain mice was 0.18μg. The relationship between TTX dosage and the mean death time of Kunming mice could be expressed as Y = e(0.357/ X +1.005). In addition, a high recovery rate of TTX was achieved by using 0.5% (V/V) acetic acid to extract TTX from globefish, which reached up to 90%. However, the detection limit of the assay for samples was 0.56μg/g. Therefore, Kunming strain mice can be used to quantitatively determine TTX in an accurate, stable and convenient manner, which is promising in the safety control of fishery products.

Objective: To establish a method for the simultaneous determination of avermectin and ivermectin residues in pork liver using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Methods: Avermectin and ivermectin residues were extracted with acetonitrile, cleaned up on a solid phase extraction (SPE) column containing alkaline aluminum oxide, separated on a C8 column, detected by tandem mass spectrometry with electrospray ionization and multiple reaction monitoring interface and quantitatively determined by high performance liquid chromatography in an external standard manner. Results: The limits of detection (LOD) for avermectin and ivermectin were 2μg/kg and limits of quantitation were 5μg/L. Both the linear ranges of avermectin and ivermectin were 5－100μg/L with correlation coefficients of both 0.9999. The recovery rate range of this method was 77.0%－83.3% for avermectin and 76.9%－79.8% for ivermectin with relative standard deviations (RSD) of 8.6%－12.1% and 9.9%－13.0% at spike levels of 2, 10μg/kg and 20μg/kg, respectively. Conclusion: This method is simple, sensitive and accurate, which can meet the domestic and international requirements for the detection of both veterinary drugs.

A quantitative determination method for Brilliant Black PN, Fluorescein Sodium, Red 2G, Phloxine B and Rose Bengal in drink and candy was established using high performance liquid chromatography (HPLC). For sample preparation, extraction by polyamide adsorption and desorption with ethanol-ammonia solution-water (7:2:1, V/V) were carried out.  An ODS C18 column (250 mm × 4.6 mm, 5μm) was used for chromatographic separation, which was eluted with methanol-0.02 mol/L ammonium acetate aqueous solution as mobile phase at 35 ℃. The linear range of the developed method was 1.0－10.0 mg/L with relative standard deviation of 1.99%－5.95% and the detection limit was 1.0 mg/kg. The average recovery rates were 82.95%－95.43%. This method is simple, accurate, and suitable for the determination of these illegally-added colorants in drink and candy.

A gas chromatography-mass spectrometry method was established to determine 2,4-D butyl ester in meat and meat products. Samples were extracted using acetonitrile and purified on florisil solid-phase extraction cartridge, quantified by external standard method. This reliable and stable method exhibited recovery rates of more than 70% at spike levels ranging from 5 to 100μg/kg, relative standard deviations of 1.0%－3.6%, a linear regression coefficient of 0.99996 and a detection limit of 5μg/kg.

In order to obtain a convenient method for the determination of volatile phenols in freshwater fish, the optimal extraction and determination conditions were explored in this paper. Water without phenols was replaced by distilled water. For the elimination of foam, stearic acid was used. The fixation of phenols in fish was achieved by adding NaOH at a concentration of 100 g/L. Acidification with sulfuric acid followed by direct distillation was used for sample extraction of volatile phenols from fish. The measurement of volatile phenols was performed based on 4-anminoantipyrine (4-AAP) staining method. Results indicated that the linear range, detection limit, recovery rate of this method were 0.002－6 mg/L, 0.05 mg/kg, and 98.4%－107.0%, respectively. Compared with traditional methods, direct distillation is a convenient, time-saving and energy-saving method, which is suitable for extensive applications.

A wide variety of analytical instruments have been recently developed for the rapid determination of pesticides using the principle of enzymatic inhibition. In this study, a GDYN-1096SC type rapid pesticide residue analyzer was selected to determine 8 kinds of pesticides such as methamidophos, prarathion, dichlorvos, omethoate, chlorpyrifos, carbaryl, methomyl and carbofuran with acetylcholinesteras or wheat esterase, two enzymes from different sources based on measurements of repeatability, stability, absorbance linearity and channel consistency of the instrument. When various technical parameters met the requirements for testing, the analyzer could accurately determine pesticides. Enzymes from different sources, however, were the main factors that influence the determination of enzymatic inhibition rate of pesticide.

Objective: To develop a rapid and simple method for qualifying Listeria monocytogenes in foods using 1oop-mediated isothermal amplification (LAMP), and to preliminarily develop a fluorescent quantitative method for the determination of this bacteria spices based on LAMP. Methods: According to the principle of LAMP, primers were designed for the development of measurement methods for Listeria monocytogenes. Meanwhile, the specificity, sensitivity and repeatability of the developed method were assessed, and the linear relationship between the logarithmized number of initial copies and reaction time was examined. Results: The detection of Listeria monocytogenes with designed LAMP primers could be finished in 0.5 h. The developed detection technique showed a sensitivity over 100-fold higher than PCR, and the limit of detection was 1.72 × 101 copies per reaction. No cross-reactivity with other foodborne pathogens was observed. Avery intra-test coefficients of variation at five gradient levels of concentration were all smaller than 5%. There was an excellent linear relationship between reaction time and initial template concentration found, with a determination coefficient R2 equaling 0.9994. Conclusion: This method is characterized by rapidity, high sensitivity and specificity, ease of operation, and low equipment requirements, with extensive application prospects.

Objective: To establish a method for detecting pathogenic bacteria quickly and accurately combinedly using DNA chip and tyramide signal amplification method. Methods: According to the sequences of 16S and 23S rDNA gene, common primer pairs and specific probes were designed. The primer pairs labeled with biotin group were used for PCR amplification, and then PCR products were hybridized with probes on the DNA chip. After the above process, the coloration was done using tyramide-Cy3. Finally, hybridization images were scanned by a fluorescence scanner. Results: Eight pathogenic bacteria were detected using this assay described here. The targets were Salmonella spp, Shigella spp, Vibrio parahaemolyticus, Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes, Vibrio cholera, Bacillus cereus. The sensitivity of this assay was approximately 5 ×102 CFU/mL for Vibrio parahaemolyticus. When 20 double-blind samples were detected, the results were in accordance with those of conventional methods. Conclusion: The specific and sensitive assay reported in the article can be applied for disease controlling and clinical diagnosis.   

The development of an indirect fluorimetric method for the determination of folic acid using Fenton reagent as oxidant is presented in this paper on the basis of the fact that after heating in a water bath at 80 ℃ for 8 min, hydroxyl radicals generated from Fenton reagent oxidize folic acid into pterin-6-carboxylic acid, whose fluorescence intensity is much higher than that of folic acid. The method displayed a linear relationship between fluorescence intensity and folic acid concentration over a range from 0.02 to 1.0 mg/L. The limit of detection was 2.69μg/L. The average recoveries for folic acid in pear, apple and cabbage separately spiked at three levels were between 91.0% and 96.1%. This method has been applied to determine the three fruits or vegetables, with satisfactory results. 

Here, we adopted microbiological cylinder plate method to detectβ-lactamase in milk. Since penicillin inhibits the growth of Micrococcus luteus, producing a zone of inhibition, the difference between the diameters of inhibition zone produced by penicillin alone and together with sulbactam, which specifically inhibits the activity ofβ-lactamase, will indirectly suggest whether or not a sample contains the enzyme. The optimum working concentration of penicillin G determined in this study was 0.5μg/mL. The influence ofβ-lactamase products from different manufacturers with different given units on the antimicrobial activity of penicillin G in liquid skim milk was evaluated, and the results showed that the limits of detection of the developed method for them were different. Addition of sulbactam at 50μg/mL provided optimum detection ofβ-lactamase. Based on the above investigations, the optimum protocol for detectingβ-lactamase by cylinder plate method in milk was that the presence or not ofβ-lactamase was identified based on differences in the diameter of inhibition zone among additions of penicillin G alone or in combination with sulbactam or/andβ-lactamase to one sample together with the results from constructed positive and negative controls.

Objective: To develop a method for the rapid qualitification of glutin-adulterated milk. Methods: For the precipitation of milk proteins, Hg(NO3)2 solution was used, and the supernatant resulting from centrifugation was then added with saturated picric acid solution. After thorough mixing, whether or not the reaction system becomes turbid was identified by comparison with a negative control. The sensitivity of the established method was evaluated by using simulated adulterated milk samples with varying amounts of glutin. Meanwhile, Hg(NO3)2 solution amount and centrifugation conditions were optimized. Results: Addition of a half volume of 1.4 g/100 mL Hg(NO3)2 solution to milk samples provided optimum precipitation of milk proteins. The detection sensitivity of the method for glutin was 300 mg/100 mL. Conclusion: This method is rapid, convenient and highly sensitive, and has the potential to be developed into reagent kit products, which can meet the requirements for detection of real samples.

In this study, factors affecting the determination of KMnO4 consumption of food contact plastics by the method of the Chinese National Standard GB/T 5009-2003 were analyzed, the main sources of measurement certainty were summarized, a procedure for certainty evaluation was established, and a relative standard uncertainty was obtained after calculating and synthesizing various uncertainty components and expanded. Potassium permanganate consumption was determined to be 2.26 mg/L for a polyethylene food box from a certain manufacturer, and the relative standard uncertainty for the determination was 0.039, and the expanded uncertainty was 0.176 mg/L (k = 2).

The effect of nitric oxide fumigation on storage characteristics of harvested  Sui You No.2   papaya in relation to fruit quality was investigated. Papayas were fumigated with NO at varying concentrations (0, 10, 40, 60μL/L and 100 μL/L) for 3 h, before storage at 20 ℃. Two key physiological parameters associated with senescence, namely ethylene production and respiratory rate and various quality parameters (degrees of ripeness, rotting rate, weight loss rate, firmness, total soluble solids and vitamin C) were evaluated. The results showed that 60 μL/L NO treatment significantly inhibited respiration rate and ethylene production, delayed skin change, the decreases in firmness and the contents water and vitamin C and the increase in soluble solids. In addition, it also maintained a high level of total nutrition without decay over the entire storage period.

Changes in physical and chemical properties such as sensory quality, water-loss rate, stiffness period, hardness degree, total volatitle base-nitrogen (TVB-N) value and water activity during the storage of tilapia fillets subjected to both partial freezing and vacuum packaging at －4 ℃ or －7 ℃ were analyzed to evaluate the fresh-keeping effect of vacuum package and partial freezing storage. Results indicated that tilapia lived in 3 ℃ water for 30 min would die. Its stiffness period was extended to 100 min compared with that of the normally dead tilapia. Initial vacuuming treatment followed by partial freezing treatment could reduce water loss rate by 2.6%, when compared with partial freezing first and then vacuum packaging. After 15 days of storage at －4 ℃ or －7 ℃, (TVB-N) values of tilapia fillets were less than 15 mg/100 g, and the values after the storage period at －7 ℃ were approximately 25% lower than those at －4 ℃.

Nano-ZnO/high density polyethylene (HDPE) composite film was prepared by the melt blending method. The properties of nanocomposite film were characterized to explore its preservative effect on cheese. Results indicated ZnO nanoparticles had a good dispersion in HDPE matrix. An improvement of mechanical and barrier properties of the composite film was achieved after adding nano-ZnO to HDPE resin. In addition, sensory quality, pH and bacterial growth of the cheese packaged by HDPE film and nano-ZnO/HDPE composite film were evaluated. The nano-composite film revealed good antibacterial preservative effect on cheese.

The microfloral change in vacuum-packaged pork during 4 ℃ storage was explored by traditional bacterial cultivation and PCR-denaturing gradient gel eletrophoresis (PCR-DGGE). Results indicated that lactic acid bacteria (LAB) exhibited a rapid increase and excessive total bacterial counts in the late stage during chilled storage. DGGE combined with the analysis of 16S rRNA gene sequence revealed a complex microflora in chilled pork at the early stage during chilled storage; in contrast, Vagococcus, Carnobacterium, Lactobacillus and Lactococcus, and Brochothrix thermosphacta were the predominant spoilage bacteria at the end of storage period.

In the present study, litchi and litchi wine were used as the materials to study the properties of polyphenol oxidase (PPO) in litchi, and explore browning mechanisms and controlling strategies of litchi wine during fermentation process. The isoenzymes of PPO were observed in litchi and the optimal substrate of PPO in litchi was gallic acid. The optimal pH and temperature for PPO from litchi were 8.0 and 50 ℃ using gallic acid as the substrate. Kinetic parameters such as Km and Vmax of PPO from litchi were 26.033 mmol/L and 34.816 g/(L·min), respectively. The PPO from litchi was not stable at the conditions of 50－80 ℃, strong acid and strong alkali. Higher PPO activity in litchi was the major browning cause of litchi wine during fermentation process. Therefore, low-temperature storage and heating treatment can effectively inhibit the browning of litchi and litchi wine.

Pork that had been stored for 15 days at －18 ℃ was thawed to count harmful bacteria using different selective culture media, typical colonies growing on culture medium plates were separated and preliminarily identified, and an investigation into the regrowth of various harmful bacteria was carried out at 4, 0 or －5 ℃. It was found that the dominant harmful bacteria in thawed pork were Pseudomonas spp., Brochothrix thermosphacta, Enterbacteriaceae. Each harmful bacterium could grow at 4 or 0 ℃ of storage temperature. Further studies showed that Pseudomonas spp. and Brochothrix thermosphacta grew faster than others, with more colony forming units (CFU) observed. While most of the harmful bacteria grew slower at －5 ℃, and even decreased to some extent.

A quick and accurate method for the determination of histamine content in tuna was proposed using high performance liquid chromatography with C18 column and UV detector. Besides, fish meat from different parts of tuna was soaked in aqueous solutions containing sodium D-isoascorbate alone, sodium citrate alone, or both of them for 2－3 h before －20 ℃ storage, and the production of histamine was measured during the storage. The linear regression equation of the proposed method was obtained as follows: Y = 5.3748X＋11.42, of which the linear range was between 10μg/mL and 1000μg/mL. The detection limit of the method was 3.684 μg/mL. This method is a simple, accurate and widely applicable method, and has been used to determine real samples with satisfying results. Antioxidant-treated tuna meat revealed a much lower level of histamine than its untreated counterpart. Among three treatment ways, combination of the two antioxidants best inhibited the production of histamine, followed by sodium D-isoascorbate alone, and the inhibition effect of sodium citrate alone was the worst. Our results demonstrated that antioxidant treatment not only prevented tuna meat from becoming dark due to oxidation, but effectively inhibited the production of histamine as well.

In this paper, the fresh-keeping effect of equilibrium modified atmosphere packaging (EMAP) conditions on quality parameters of Laiyang pears was explored. Results indicated that EMAP storage maintained a good level of fruit firmness, and inhibited the activity of polyphenol oxidase (PPO). After 120 days of the storage, the control group (without any packaging treatment) showed a PPO activity of 40.9 U/g, even higher than 28.4 U/g of the EMAP group, with a significant difference (P ＜ 0.05). EMAP treatment delayed the reduction in peroxidase (POD) activity and the increase in membrane permeability; the activity of POD in the EMAP group was 0.25 U/g, significantly higher than 0.04 U/g of the control group; and relative membrane permeability of EMAP-packaged pears was increased to a lower level after 120 days of the storage, with a smaller amplitude fluctuation over the entire storage period, and there was a extremely significant difference between the two groups (P ＜ 0.01). A reduction in vitamin C loss was observed for the EMAP group as compared to the control. After 30 days of the storage, the content of vitamin C in the EMAP group was higher than that in the control and the difference between them was exceedingly significant (P ＜ 0.01). The optimum gas composition for EMAP storage of Laiyang pears was found to be made up of 2.2% CO2 and 14.0% O2 or of 2.6% CO2 and 12.9% O2. The shelf life of Laiyang pears stored in two such atmospheric environments could reach up to more than 200 days.

Freshly harvested Yizhou papaya fruits with 80% maturity degree were subjected to coating with chitosan solutions at different concentrations or plain water and subsequent storage at 23－25 ℃ in order to examine the fresh-keeping effect of chitosan coating on papaya. During the storage, changes in total sugar and vitamin C contents, sensory quality, weight loss rate, firmness and decay rate of papaya were measured. Results showed that chitosan coating could delay the reductions in firmness, total sugar and VC contents, weight loss rate and sensory quality, decrease the percentage of rotten fruits, and substantially extend the shelf life of Yizhou papaya fruits, especially at a concentration of 1.5%.

As a representative of non-melting-flesh peach, Wanhujing peach cultivar was used to investigate the degradation of cell wall polysaccharides in non-melting-flesh peach during its softening and the activities of related enzymes. During peach fruit ripening, CDTA-1 pectin content increased, and the contents of two kinds of Na2CO3 soluble pectin were decreased by 22.5% and 27.4% until the late stage. KOH soluble pectin content did not change significantly throughout the ripening process. The degradation of pectin main chains in CDTA and Na2CO3 and the loss of arabinosyl and galactosyl from pectin side chains in cellulosic polysaccharides mainly happened at the end of the ripening process. β-galactosidase was associated with the start-up of peach fruit softening. Polygalacturonase and Cx-Cellulase were important enzymes that contributed to the end of peach fruit softening. Na2CO3-1 pectin was an important factor affecting non-melting-flesh peach fruits softening. The degradation of KOH-1 and KOH-2 fractions may promote peach fruit softening. The fracture of pectin chain rich in galacturonic, as well as the degradation of neutral sugars such as arabinose and galactose in pectin, hemicellulos and cellulose, and a variety of polysaccharides degrading enzyme were likely to be important factors affecting non-melting-flesh peach fruit softening.

Trichiutus haumela samples packaged in controlled atmosphere with 40% CO2＋10% O2＋50% N2, 60% CO2＋10% O2＋30% N2, or 80% CO2＋10% O2＋10% N2 were stored at (4 ± 1) ℃ for 14 days. Changes in sensory evaluation values, total bacteria count, total volatile base nitrogen (TVB-N), pH value, the 2-thiobarbituric acid (TBA) and drip loss were determined during the storage period to evaluate the effect of CO2 concentration in MAP environment on cold storage characteristics of Trichiutus haumela. It was showed that Trichiutus haumela had lower total bacteria count and total volatile base nitrogen in MAP environment than in normal atmospheric environment. High CO2 MAP had better antimicrobial effect, but drip loss became more serious with increasing CO2 concentration. MAP, however, did not obviously inhibit lipid peroxidation in Trichiutus haumela. MAP with a gas composition of 80% CO2＋10% O2＋10% N2 could extent the shelf-life of Trichiutus haumela to more than 14 days.

A novel casein immunosensor for detectingαs-casein was developed through the modification of chitosan and nano-gold on the glassy carbon electrode. The modification procedure was electrochemically monitored by cyclic voltammetry to explore the characteristics of the electrode surface and the performance of the immunosensor. The developed immunosensor was used to detectαs-casein in phosphate buffer. An excellent linear range between response current andαs-casein concentration was observed in the concentration range of 1－10000 ng/mL. Therefore, this developed immunosensor is characteristics of simple preparation, low cost, convenient operation, and can be applied to the safety detection of milk.

An indirect enzyme-linked immunosorbent assay(ELISA)kit was developed to monitor phorate residue. The optimal concentration of coating antigen was 4 mg/L and the optimal dilution ratio of antibody was 8000. The cross-reaction ratio was less than 20%. The regression equation of inhibition rate for phorate was y = 18.846x＋6.9949 with a linear detection range of 1－5000μg/L. Results indicated that the detection limit was 4.90μg/L and IC50 was 191.37μg/L. The recovery rates were higher than 75%. The intra-assay and inter-assay coefficients were less than 10%. The developed kit can be stored at 4℃ or－20 ℃ for 270 days.

Compound venison sausages with balanced nutrition and unique flavor were processed using venison meat and pork meat differing in price, nutrients, flavor and processing characteristics as the main materials with the additions of nutritional supplements such as fruits and vegetables, dietary fiber and isomaltooligosaccharide. An investigation to probe the effects of soybean protein, potato starch, isomaltooligosaccharide, dietary fiber and fruits and vegetables, the mixing ratio of venison meat and pork meat on texture properties of compound venison sausages was carried out by single factor experiments. The formulation of some of the above ingredients was optimized by orthogonal array design based on texture properties and sensory evaluation. Soybean protein and potato starch had large effect on texture properties of compound venison sausages, which was little affected by isomaltooligosaccharide. The optimum amounts of added soybean protein and potato starch were 6% and 5%, respectively. Apple peel was the best dietary fiber for compound venison sausages, and shiitake mushroom was the best vegetable. Based on the results from orthogonal array design, factor analysis and range analysis were conducted to determine the following formula for compound venison sausages (calculated on the basis of weight): the mixing ratio of venison meat and pork meat 4:6, shiitake mushroom 15%, apple peel 5%, and isomaltooligosaccharide 4%. Compound venison sausages processed following the optimized formula met the national standards for similar products in terms of both physicochemical and microbiological indicators.

In this study, optimization of three process conditions (temperature, sucrose amount and inoculum size) for wine fermentation from Radix Astragali was done using response surface methodology. It was found that the optimum fermentation conditions for Radix Astragali wine were mixing dried and pulverized Radix Astragali with a particle size of 40 mesh with a 60-fold volume of water, inoculation with active dry wine yeast at 0.71%, adding sucrose at 19%, and fermentation at 22 ℃. Under these conditions, alcohol concentration in obtained Radix Astragali wine was 12.3%, which contained 29.05 mg of total flavonoids, and 123 mg of total saponins per liter, displayed golden yellow color, had a strong, sweet and mellow taste and an aromatic smell and harmonious body without soybean odor. This product is a low-alcohol nutritional wine that is in accordance with modern people  s health concept.