Heat treatment of postharvest Elizabeth muskmelons was performed respectively using hot water and hot air methods. The effects of operating parameters such as packaging methods, fruit size, cycling medium velocity, temperature and relative humidity on half heating time, three-fourth heating time, seven-eighth heating time and tissue weight loss rate were investigated. The results showed that the length of hot water treatment was only 50%－60% of that of hot air treatment for the same treatment effectiveness (the temperature at the center of a melon sphere reached between 38 ℃ and 53 ℃). The optimum medium velocities in hot water and hot air methods were 0.5－1 m/s and 1.5－2 m/s, respectively. Hot water treatment and high humidity hot air treatment could effectively reduce the tissue weight loss of muskmelon in hot air treatment. Muskmelon grading according to fruit size in advance promoted the uniformity of heat treatment. The optimum operating time was seven-eighth heating time (the dimensionless temperature θ = 0.125).

Box-Behnken experimental design and response surface methodology (RSM) were combinedly employed to evaluate the effects of the amounts of formic acid and oleoyl chloride as well as reaction temperature and time on the synthesis of oleoyl-alginate ester (OAE). The optimum synthesis conditions of OAE were found to be alginate amount of 0.5 g, formic acid amount of 4.95 mL, oleoyl chloride amount of 11.27 mL, reaction temperature of 50 ℃ and reaction time of 20 min. Under these conditions, the maximum degree of substitution (DS) and yield of OAE were observed to be respectively 4.93% and 92.27%, which were in accordance with the corresponding predicted values.

The fatty acid composition of gardenia fruit oils extracted with supercritical CO2 under varying conditions of pressure, temperature and CO2 flow rate was determined by gas chromatography. The results showed that there were mainly 5 fatty acids in gardenia fruit oil, namely linoleic acid, oleic acid, palmitic acid, stearic acid and linolenic acid, of which the contents were respectively 44.38%, 24.96%, 24.83%, 2.55% and 1.31% in the oil extracted under 30 MPa, 55 ℃ and CO2 flow rate of 15 kg/h. Each of the three extraction conditions had some effect on the composition of fatty acids in gardenia fruit oil, which showed no statistical significance. It was found that gardenia fruit oil had the ability to scavenge DPPH and ABTS+ free radicals, indicating its antioxidant activity. Moreover, extraction pressure, temperature and CO2 flow rate could affect the DPPH and ABTS+ free radical scavenging activities of gardenia fruit oil to different extents.

In order to maximize protein extraction from Ginkgo biloba L. seeds with NaOH solution, a mixed-level uniform design was employed to investigate the effects of time, solid-to-liquid ratio and NaOH concentration on the yield of protein extract. Through quadratic polynomial stepwise regression analysis, the optimum extraction conditions were determined as follows: extraction time 12 h, solid-to-liquid ratio 1:26, NaOH concentration 0.2%. Under such conditions, the yield of protein extract obtained from Ginkgo biloba L. seeds was 99.99 mg/g, and the recovery of protein was 89.14%. The extract obtained showed a superoxide anion free radical scavenging rate of 38.83% and a reducing power A700 of 0.807, thereby having excellent antioxidant effect and being worth further processing and utilizing.

Objective: To investigate the effects of temperature, time and ethanol concentration and material/liquid ratio on proanthicyanidins extraction from Amur grape seeds through single-factor and orthogonal tests and to explore the optimal extraction process. Methods: Ethanol was used for the extraction of proanthicyanidins. The total content of flavan-3-ol monomers and proanthicyanidins (both of them can be simultaneously extracted by ethanol) was determined by vanillin method, and the method used to determine the content of flavan-3-ol monomers was HPLC. Thus, the content of proanthicyanidins could be calculated as the difference between the two determined values. Results: The optimal extraction process conditions were extraction temperature of 60 ℃, ethanol concentration of 70%, extraction time of 120 min and material/liquid ratio of 1:5 (g/mL). Conclusion: Under the optimal extraction conditions, the extraction rate of proanthicyanidins from Amur grape seeds was up to 3.12%.

Wheat bran was used as raw material to extract protein, water-insoluble fiber and water-soluble fiber, respectively. Wheat bran protein and water-soluble dietary fiber were extracted simultaneously by alkaline ethanol extraction-salting out. The removal of water-insoluble dietary fiber was conducted using α-amylase hydrolysis. Based on single factor tests, the optimal extraction process was determined by using central composite design combined with response surface methodology. The results indicated that the optimal extraction process was enzyme addition amount of 270 U/g, enzymatic reaction temperature of 56 ℃, material/liquid ratio of 1:12, ethanol/alkali ratio of 1:4, extraction temperature of 51 ℃, and ammonium sulfate saturation degree of 33%. Under the optimal conditions, the extraction rate of wheat bran protein, water-insoluble dietary fiber and water-soluble dietary fiber were 5.23%, 88.76% and 3.08%, respectively. The fitted mathematical models for the extraction rates of wheat bran protein and insoluble dietary fiber had a good feasibility.

Objective: To accelerate and enhance the extraction of polysaccharides from shiitake mushroom by inner ebullition. Methods: A small amount of ethanol was used to wet the raw material for the dissolution of polysaccharides, and a given volume of hot water was then added to boil ethanol entering the raw material, resulting in rapid extraction of polysaccharides. Results: The maximum extraction of polysaccharides was obtained by wetting with 20% ethanol followed by 5 min extraction with a 25-fold volume of 90 ℃ hot water. The extraction yield and purity of polysaccharides obtained after concentration and subsequent ethanol precipitation was 5.05% and 51.6%, respectively. Compared to the traditional decoction method, the optimized method displayed an increase in polysaccharide yield purity respectively by 0.18% and 10.2% and a reduction in extraction time by 85 min. Conclusions: Inner ebullition has distinctive advantages in extracting polysaccharides from shiitake mushroom.

Objective: To optimize conditions for the extraction of polysaccharides from longan seeds. Methods: Based on single factor experiments, the optimal conditions for polysaccharide extraction were explored by Box-Behnken design (BBD) in combination with response surface methodology (RSM). Results: The optimal extraction conditions of polysaccharides were ethanol concentration of 70% (V/V), extraction temperature of 77.4 ℃, extraction time of 4 h, solid-to-liquid ratio of 1:20 (g/mL) and extraction number of 2. Temperature was the most important affecting factor of polysaccharide extraction, followed by extraction time and ethanol concentration. Under such extraction conditions, the experimental yield of polysaccharides obtained after the first extraction was up to 21.7079 mg/g, which was close to the model-predicted value. Conclusion: The established regression equation for polysaccharide yield has an excellent goodness of fit. Therefore it is credible and can be used for practical prediction

In order to screen the appropriate method for the extraction of high-quality grape seed oil, Soxhlet extraction, reflux extraction, ultrasonic extraction and microwave extraction were compared for their effectiveness in extracting oil from grape seeds remaining after wine fermentation. Microwave extraction was found to provide the highest oil yield, and the optimization of conditions for the extraction of grape seed oil by the method was performed using orthogonal array design. The optimal microwave extraction conditions were found to be: material/liquid ratio, 1:15; extraction time, 10 min; temperature, 70 ℃; and microwave power, 700 W, and the optimal refining conditions for crude oil were NaOH concentration 4.13 mol/L, excess alkali quantity 0.5%, and initial temperature 50 ℃. The physicochemical properties of the resulting refined oil were in line with the requirements of the national standard GB/T 1684－2006.

A comparative investigation was carried out to evaluate and analyze the effects of four solvents and three extraction methods on the extraction of lycopene from autumn olive berry. The optimal process for lab-scale extraction of lycopene from autumn olive berry was as follows: Autumn olive berry was extracted repeatedly 4 times using methyl acetate as extraction solvent at a material/liquid ratio of 1:40 with grinding under light-free conditions, and then the extract was vacuum concentrated at 57.8 ℃. The resulting yield of lycopene was 34.81 mg/100 g of fruit. Meanwhile, the extraction solvent could be recycled. The content of lycopene in the concentrated extract ranged from 6.4 mg/100mL to 7.5 mg/100 mL. This study can offer an experimental reference for future industrial production.

The conventional method, enzymolysis, ultrasonic extraction and ultrasonic-assisted enzymolysis were compared for their effectiveness in extracting polysaccharides from Polygonatum cyrtonema Hua in Jiuhua Mountain. Ultrasonic-assisted enzymolysis was evaluated as the best method due to the highest polysaccharide yield. The polysaccharide extract obtained by the selected method was a single polysaccharide component according to DEAE-cellulose column chromatographic analysis. Infrared spectral analysis revealed that the polysaccharide fraction was a hetero polysaccharide. Its relative molecular weight was determined by dextran gel filtration method to be 8912. Based on gas chromatographic analysis, its monosaccharide composition was composed of fructose and glucose at a ratio of 8.7:1.

The peels of citrus Changshan-huyou were used as the raw material to extract flavonoids by flash-extraction technology. Based on single factor experiments, extraction conditions such as solvent concentration, liquid/material ratio, and extraction time were optimized by response surface methodology. The results showed that each of the three extraction conditions affected flavonoid extraction significantly. The optimized conditions were as follows: 78% ethanol concentration, 31:1 liquid/material ratio, and 95 s extraction time, resulting in an extraction efficiency of 4.37% for flavonoids. As a conclusion, flash-extraction is an effective and efficient method to extract flavonoids from peel of Citrus Changshan-huyou.

Ultrasonic followed by microwave treatment was used to establish a novel method to extract total flavonoids from Radix Pueraria. The effects of five extractions, namely temperature during ultrasonic treatment, ultrasonic treatment time, microwave power and treatment time and solid-to-liquid ratio on the extraction yield of total flavonoids from Radix Pueraria were explored. The quantification of total flavonoids was conducted using a UV spectrophotometer. The results showed that the maximum yield of total flavonoids could reach 14.685 mg/g was attained by using 80% ethanol as the extraction solvent at a solid-to-liquid ratio of 1:25 under the assistance of 30 min ultrasonic at 50 ℃ followed by 9 min microwave treatment at 300 W power.

A molecular imprinted polymer was prepared using bovine serum albumin as the template molecule, iron oxide magnetic nanoparticles as the carriers and dopamine as the functional monomer. The prepared magnetic molecularly imprinted polymer nanoparticles (MNP-MIPs) were applied to adsorb protein and the protein adsorption capacity was measured. The results indicated that the adsorption capacity towards protein exhibited an increase up to the saturation level with prolonged adsorption time. Similarly, the adsorption capacity also revealed an increase trend as the template concentration rose and other conditions were kept unchanged. Moreover, bovine serum albumin could be specifically adsorbed by MNP-MIPs.

The purpose of this study was to optimize the extraction of polysaccharides from the fruits of Sorbus tianschanica Rupr.. Polysaccharide contents of different parts of Sorbus tianschanica Rupr. including roots, stems, leaves and fruits were assayed spectrometrically, followed by optimizing conditions for the extraction of polysaccharides from the fruits of Sorbus tianschanica Rupr. by orthogonal array design method. The fruits of the plant showed the highest polysaccharide content (4.63%) among the four parts. The optimized extraction conditions were using distilled water as the extraction solvent at a material/liquid ratio of 1:45 for 45 min extraction with the assistance of 240 W ultrasonic treatment. Under these conditions, the highest extraction yield of polysaccharides from the fruits of Sorbus tianschanica Rupr. could reach 5.92%. Moreover, material/liquid ratio was found to be the most significant factor affecting polysaccharide extraction.

Objective: To explore the optimal extraction parameters for water-soluble polysaccharides from litchi flesh. Methods: A series of single-factor investigations followed by response surface analysis were carried out to optimize conditions for the extraction of water-soluble polysaccharides from litchi fresh. Sulfuric acid-phenol method was used to quantify polysaccharides. Results: The optimal extraction parameters were litchi flesh-to-water ratio of 1:17 (g/mL), extraction temperature of 90.5 ℃, and extraction time of 4.0 h. Under these conditions, the extraction rate was up to 10.06%, and the crude extract obtained showed an average polysaccharide content of 6.71%. Conclusion: It is feasible to optimize extraction parameters of water-soluble polysaccharides from litchi flesh using response surface methodology.

The aim of the current study was to identify optimum process parameters for the vacuum drying of honeysuckle. The effects of heating temperature, drying pressure and material loading on drying characteristics were explored through single factor experiments. Meanwhile, two mathematical regression models were fitted with required drying time or chlorogenic acid content as a function of temperature, pressure and material amount. Both models had excellent goodness of fit. Multi-target nonlinear optimization indicated that the optimum vacuum drying parameters were drying temperature of 63.6 ℃, drying pressure of 800 Pa and material loading (a single layer) of 40 g, resulting in the highest comprehensive evaluation of required drying time and chlorogenic acid content, which were 215 min and 3.34%, respectively. Vacuum drying can allow the production of high-quality dried honeysuckle in a short time.

The water extraction and ethanol precipitation of polysaccharides from the roots of Cynomorium songaricum Rupr.were optimized by orthogonal array design and the contents of polysaccharides in samples from different habitats in Hexi Corridor were determined by benzenol-H2SO4 method. Results indicated that the optimal extraction conditions were material/liquid ratio of 1:15 (g/mL), refluxing extraction duration of 90 min and repeated extraction number of 2. Root samples of Cynomorium songaricum Rupr. from different habitats in Hexi Corridor were significantly different from each other in their polysaccharide contents. Therefore, polysaccharide content can be used as a quality control indicator for Cynomorium songaricum Rupr..

A new food resource, chaya was qualitatively and quantitatively analyzed for its polyphenol components. The extraction of polyphenols from the food resource was optimized based on total polyphenol extraction rate. The results indicated that chaya contained tannins, polyphenols and flavonoids, which were 0.49, 2.57 g and 1.29 g in 100 g of fresh chaya leaves, respectively. The optimal extraction conditions for chaya polyphenols that were determined by single-factor and orthogonal array design were: material/liquid ratio of 1:15, extraction temperature of 60 ℃, extraction time of 3 h and ultrasonic treatment time 20 min. Under the condtions, 408 mg of polyphenols was extracted from 100 g of fresh chaya.

In the present study, ultrasonic radiation was found to largely enhance the extraction of pectin from Promma microphylla Turcz leaves with ammonium oxalate solution. In order to further intensify pectin extraction, the ultrasonic-aided ammonium oxalate extraction process was optimized by orthogonal array design on the basis of a series of single-factor experiments. Under the conditions studied, temperature, length of extraction time, ammonium oxalate concentration and material-to-liquid ratio could affect pectin extraction differently, and the effects of ammonium oxalate concentration and temperature were significant, and the optimal conditions of the four parameters were 70 ℃, 70 min, 8 g/L and 50:1, respectively. Under these conditions, the extraction rate of pectin reached up to 63.79%. Furthermore, the quality indicators of the extracted pectin could meet the requirements of the industrial standard (QB 2484－2000).

In order to improve recovery rate, texture, color and taste of freeze-dried yam slices, crucial steps in the preparation process of yam slices such as blanching, soaking treatment and freeze-drying were investigated. The results indicated that the optimal blanching of yam slices at 95 ℃ for 60 s could prevent browning and consequently was beneficial to soaking and freeze-drying. The optimal soaking process at 30 ℃ for 30 min using soaking solution composed of 5% NaCl, 10% glucose and 10% maltodextrin could improve recovery rate. The optimal freeze-dried process was quick-freezing at －30 ℃, and then sequential freeze-drying at 5 ℃ for 7 h and 35 ℃ for 2 h. Freeze-dried yam slices obtained using the optimized process displayed better recovery and sensory quality.

The volatile compounds in cherry wine were determined using headspace-solid-phase micro-extraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Extraction conditions such as fiber type, extraction temperature, time, ethanol concentration and sodium chloride added were optimized as follows: 65μm PDMS/DVB fiber, extraction temperature of 40 ℃, extraction time of 30 min and ethanol concentration of 120 mL/L. Totally 65 compounds were identified in Zhongyingdimoer cherry wine, a Chinese domestic brand, where esters were the most diverse and abundant volatiles.

A stripping voltammetry method to determine lead in kelp was developed on a nafion modified electrode after microwave digestion. The oxidation peak of lead was well defined at －0.62 V. The influence factors nafion concentration, buffer pH, deposition potential, accumulation time and potential interferences were investigated. The sensor used exhibited linear behavior in the range of 6.0 to 16.0μg/L (0.9984 correlation coefficient) with a detection limit of 0.04μg/L. In addition, this sensor was ultrasensitive and effective even in the presence of several excess potential interfering ions.

A time-resolved fluoroimmunoassay (TRFIA) was developed for the rapid and sensitive detection of enrofloxacin (ENR). In indirect TRFIA format, the envelope antigen composed of ENR and ovalbumin (OVA) was coated onto the microplate, and followed by the incubation with free ENR and anti-ENR polyclonal antibody. A goat anti-rabbit IgG conjugated with europium (Eu3+) was used for the detection. The intra-assay CV (coefficient of variation) of the developed method was less than 10% and the inter-assay CV less than 15%. The average recovery rate was 91.62% and the sensitivity was 5 ng/L. The antibody had a linear response over the range from 0.01μg/L to 100μg/L. The ED20, ED50 and ED80 (80%, 50% and 20% effective doses) were 0.088, 3.40μg/ L and 32.81μg/ L, respectively. The high stability and broad detection range allows the TRFIA method to have promising application prospects.

The genome DNAs of Penicillium expansum and 6 control fungi were extracted by glass bead method, benzyl chloride method and their combination, respectively. The concentration and purity of DNAs were analyzed by UV spectroscopy and gel electrophoresis. Meanwhile, a pair of primers with a size of 288 bp were designed and synthesized based on a conservative sequence of Penicillium expansum's polygalacturonase gene to conduct the PCR detection. The results showed that combined use of glass bead and benzyl chloride was more effective than either alone. Good specific amplification of DNA was obtained, and the optimal range of annealing temperature was between 53 ℃ and 59 ℃, and the optimal range of primer concentration between 0.04 μmol/L and 0.16μmol/L, and the optimal range of template concentration between 2.40μg/mL and 5.28μg/mL. Meanwhile, dNTPs concentration had little influence on PCR amplification. The method requiring only 3 to 4 hours could evidently enhance detection efficiency when compared to traditional methods. As a result, it has promising potential to be further applied in practice.

To extract the characteristic information of total acid and improve model accuracy, simulated annealing algorithm was used to optimize window width and wavenumber in a total acid model obtained by the partial least squares analysis. Ninety different brands of vinegar samples collected from the whole country were used to acquire near infrared spectral data, and total acid content was measure by the general analytical method. Pre-processing methods were used to smooth the vinegar NIR spectra. A total of 17 wavenumbers were selected and the predictive model for total acid model revealed a correlation coefficient of prediction set of 0.9210 and its prediction ability was superior to that of the whole spectral partial least square model and interval partial least square model. These results showed near infrared spectroscopy in combination with simulated annealing algorithm allows to quickly predict total acid content of vinegar.

A direct competitive chemiluminescence enzyme immunoassay (DC-CLEIA) was developed to determine sulfadiazine (SD) residues in pork. Assay parameters including coating antigen (OVA-SD) and enzyme labeled antibody concentrations concentrations and reaction time were optimized to be 0.8μg/mL, 2000-fold dilution and 25 min, respectively. The analytical sensitivity of the developed method was 2.96 ng/mL, and the intra-assay and inter-assay coefficients of variation were below 8.32% and 13.4%, respectively. The recoveries for SD in negative pork spiked at three levels ranged from 75.6% to 103.7%. The McAb had no noticeable cross-reactivity to SD analogues. The standard curve displayed good linearity over the range of 4.14 to 244 ng/mL with a correlation coefficient of 0.9922. This DC-CLEIA may be used for routine detection and monitoring of SD in pork.

The contents of 20 elements in 15 cultivars of naked barley, including calcium, potassium, magnesium, natrium, phosphorus, sulfur, barium, copper, ferrum, lithium, manganece, molybdenum, nickel, strontium, titanium, zinc, aluminum, arsenic, chromium and lead were determined by ICP-AES to conduct a cluster analysis. No significant mutual interference was found among the tested elements. The recovery of the method varied from 95.4% to 101.2%, with a RSD of 1.2% to 5.3% (n = 7) and meanwhile the method showed high accuracy and precision. The 15 naked barley cultivars were all rich in minerals but with a significant difference, and the major ones are K, P, Mg, Ca, Na, S, Fe, Zn, Mn, Al and Cu. In terms of the contents of the 20 elements, these naked barley cultivars were clustered into three groups: green, red and white. Green and red naked barleys resembled each other highly, and white naked barley presented differences in quality. Cluster analysis further showed that trace elements in naked barley were considerably related to cultivars rather than geographic origins.

An efficient detection method for thiophanate methyl residue in plant-derived foods was established by combing a high-throughput automated homogenizer, an automatic online purification and concentration system and a liquid chromatography-tandem mass spectrometry. Samples were homogenized with acetonitrile on a high-throughput automated homogenizer, purified using an automatic online purification (gel chromatographic and solid phase extraction column) system, online concentrated and detected using a liquid chromatography-tandem mass spectrometer. The quantification of thiophanate methyl was carried out using the external standard method. The detection conditions were: acetonitrile-water (gradient) as mobile phase, ESI as ionization method, qualitative ion pairs of m/z 343.0＞151.1 and 343.0＞192.1, quantitative ion pairs of m/z 343.0＞151.1. With the addition of 0.01 to 10.0 mg/kg of thiophanate standard to samples, the recovery rate was between 88.4% and 97.9% and the relative standard deviations (RSDs) varied from 1.3% to 2.9%. The detection limit of the established method was 0.01 mg/kg.

In order to analyze the composition of volatile compounds in the Luzhou Laojiao Daqu by headspace solid phase micro-extraction coupled with gas chromatography mass spectrometry detection (HS-SPME-GC-MS), the effects of SPME fiber type, adsorption time, and extraction temperature on volatile extraction were investigated. Using a 50/30μm DVB/CAR on PDMS fiber for 30 min headspace adsorption at 50 ℃ provided optimum extraction for the Daqu. Then the fiber was introduced into the injection port of the GC-MS system (at 250 ℃ for 5 min). Fifty-five compounds were isolated and identified, among which alcohols, esters, and ketones were the prominent ones. In addition, some pyrazines were also found. In conclusion, the method is simple, fast and accurate with high reproducibility and sensitivity.

Internal quality characteristics such as soluble solids content (SSC), pH value and firmness of bruised samples of Huayou kiwifruits stored at 2 ℃ for four weeks were quantitatively evaluated by near-infrared (NIR) diffuse reflectance spectroscopy over the range of 12000－4000 cm-1 in combination with each of the three calibration methods multiple linear regression (MLR), partial least squares (PLS) regression and principal component (PCR) regression, respectively. Meanwhile, the results of PLS models based on different pretreatment methods such as the logarithms of the reflectance reciprocal D1 lg(1/R) and its first derivative D1 lg(1/R) and second derivative D2 lg(1/R) were compared. The results indicated the PLS prediction models for SSC, pH and firmness based on D1 lg(1/R) were the most accurate, exhibiting a correlation coefficient between predicted and measured values of 0.812, 0.703 and 0.919 and a root mean square error of prediction of 0.749, 0.153 and 1.700, respectively. Thus, it is feasible to use near-infrared diffuse reflectance spectroscopy to detect internal qualities of bruised kiwifruits such as SSC, pH value and firmness nondestructively.

objectives: The mineral contents were determined in 6 species of hot pepper seeds grown in Xinjiang and a cluster analysis was conducted to evaluate their nutritional values. Methods: The contents of Zn, Cu, Fe, Mn, Ca, Mg, Na and K were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Results: These species of hot pepper seeds were all rich in several mineral elements with high ratios of K/Na and Mg/Na, and the most abundant element was Fe, while Zn and Cu demonstrated a relatively smaller content, with a Zn/Cu ratio of 2.01 to 1.36. The 6 species of hot pepper seed could be divided into two groups from the perspective of mineral elements. Conclusions: As an abundant source of mineral elements, the species of hot pepper seeds grown in Xinjiang deserve to be developed into foods.

A multiplex PCR method was presented to detect Salmonella, Listeria monocytogenes, Staphylococcus aureus and Vibrio parahaemolyticus from Penaeus vannamei, which are main food-borne pathogens. Specific primers were designed according to the invasion protein A gene (invA), invasion associated protein gene (iap), thermo-stable nuclease gene (nuc) and thermo-stable direct hemolysin gene (tdh) from Salmonella, L. monocytogenes, S. aureus and V. parahaemolyticus, respectively. A fragment of conserved sequence of 16S rRNA gene was used as the internal control of amplifiable bacterial DNA. The optimal PCR reaction system was identified as a 20-μL mixture composed of 10 × PCR buffer (+Mg2+) 2.0μL, dNTP 200μmol/L, DNA template 1μL and Taq DNA polymerase 2.5 U, with primer concentrations of 200 nmol/L for 16S rRNA, 250 nmol/L for tdh, 300 nmol/L for nuc, 350 nmol/L for iap and 250 nmol/L for invA, respectively. One reaction cycle consisted of denaturation at 94 ℃ for 30 s, annealing at 57 ℃for 40 s, and extension at 72 ℃ for 1 min followed by 10 min, and this cycle was repeated 30 times. The method was validated using Penaeus vannamei artificially inoculated with tested pathogens. The results showed that various target DNA fragments could be amplified by the multiplex PCR method in both non-enriched and pre-enriched samples. However, the detection sensitivity was significantly increased by enrichment at 37 ℃. Thus, the multiplex PCR method developed in this study offers an efficient and rapid way for highly sensitive detection of pathogens in aquatic food products.

An analytical method for the simultaneous determination of 14 heavy metal elements (Pb, Ni, Cu, Zn, Cd, As, Mo, Se, Ca, Mg, Al, Mn, Fe and K) in wild grapes was proposed using microwave digestion followed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurement. Sample preparation was achieved by digestion with HNO3-H2O2 in a microwave system. The recoveries of the 14 elements from a sample from Benxi region, Liaoning province were obtained between 95% and 102.8%, with a relative standard deviation (RSD) of less than 2% ranging from 0.28% to 1.88% as reliable results. The method proposed in this study has the benefits of rapidity, simplicity, safety, time saving, and high accuracy and precision and also is suitable for determining heavy metal elements in similar samples.

In order to develop a microwave digestion followed by graphite furnace atomic absorption spectrometry (GFAAS) method to determine aluminum in aquatic products, sample pretreatment and instrumental conditions were optimized. The detection limit of the method was 1.63μg/kg and the linear range was from 1.63 to 40.0μg/L (Y = 0.0204x + 0.1461, r = 0.998). Adding 5.00 mg/kg aluminum solution into perch, prawn and portunid samples, the recoveries were from 100.20% to 101.73%, and the RSDs from 3.98% to 5.85%. The contents in the scallop certified reference material determined by the method were in the allowable range. The method has high sensitivity and accuracy and, consequently is suitable for the determination of aluminum in aquatic products.

A multi-walled carbon nanotubes modified electrode was fabricated and its electro-catalytic activity for nicotinamide was investigated. The effects of electrolyte type and acidity, scanning rate on the voltammetric behavior of nicotinamide were studied to acquire optimal conditions for detecting nicotinamide. In 0.1 mol/L phosphate buffer (pH 6.8), the differential pulse voltammetric determination displayed excellent linearity between reduction current and nicotinamide concentration in the range of 5.0×10-5 to 1.1×10-3 mol/L with a detection limit of 2.49×10-5 mol/L. Several ions, sugar and ethanol did not interfere with the determination.

An internal standard method for the determination of S-metolachlor and terbutylazine residues in soil and corn by gas chromatography-quadrupole mass spectrometry was developed. S-metolachlor and terbutylazine were extracted with acetonitrile by vortex and cleaned-up with base sorbent (primary secondary amine exchange material- PSA). The recoveries of S-metolachlor and terbutylazine in soil and corn were between 90.4% and 108.5%, and the relative standard deviations (RSDs) were between 1.9% and 5.3%, respectively.

A rapid method to determine 5 pyrethroid pesticide residues in wheat was established through optimizing the absorbent, elute, and sample to absorbent ratio. Wheat sample was treated by the matrix solid-phase dispersion (MSPD) technique using Florisil as absorbent. 5 pyrethroid pesticides were analyzed by gas chromatography with electron capture detector. The mean recoveries of 5 pyrethroid pesticides were ranged from 85.5% to 97.6% and the maximum RSD was 8.4%. This method is cost-saving, rapid, accurate, sensitive and can therefore be applied for simultaneous determination of pesticide residues in wheat.

Simultaneous distillation-extraction followed by gas chromatography-mass spectroscopy (GC-MS) analysis was conducted to analyze volatiles in fresh and dried Astragali Radix. The yield of volatile compounds from fresh and dried Astragali Radix was 0.64% and 0.43%, respectively. Totally 76 chemical components were identified and 11 compounds including 1-hexanol, (E)- 2-hexen-1-ol, hexanal, 2-hexenal were presented in both fresh and dry samples. Forty three compounds were identified in fresh sample and the major ones were 1-hexanol, (E)-2-hexen-1-ol, hexanal, (E)-2-hexenal, o-xylene ; 44 compounds were identified in dry sample and the major ones were hexanal, 1-hexanol, 2-hexenal. Significant difference was found in volatile types and concentrations in fresh and dry samples.

Essential oil was extracted by steam distillation from Ligusticum chuanxiong Hort leaves and analyzed by gas chromatography-mass spectroscopy (GC-MS). Totally 84 and 51 compounds were identified in essential oils from Ligusticum chuanxiong Hort leaves harvested in spring and summer, with a relative content of respectively 97.8% and 98.2%. No significant difference in chemical composition was observed between essential oils from the leaves harvested at both seasons. The major components were 3,4-dimethylenecyclopent-anone, 5,7,8-trimethyl-2-chromanone, caryophyllene, trans-ocimene, cis-ocimene, (+)-sabinene and α-pinene.

A new spectrophotometric method for determining manganese in wine was established by calcein oxide. In sulfuric acid medium, calcein can be oxidized by manganese (VII) oxide to fade. A linear relationship between fading and the concentration of potassium permanganate was observed. The decreased absorbance proportional to the concentration of Mn (Ⅶ) oxidized by sodium bismuth could be determined by spectrophotometry. The maximum absorption was at 480 nm and the apparent molar absorption coefficient was 1.74×104 L/(mol ·cm). The absorbance obeyed the Beer,s law in Mn (Ⅶ) concentration range of 0 to 2.7 μg/mL and the detection limit was 0.014 μg/mL. This developed method can result in results consistent with those from atomic absorption spectrophotometry. The spike recovery rates in beer, liquor and wine were between 97.0% and 102.7%.

A simple method was developed for determining lupeol in fruits by reverse-phase high performance liquid chromatography (RP-HPLC). Separation was carried out on reversed-phase Nucleosil C18 column (5μm, 250 mm × 4.6 mm i.d.) by using a mixture of methanol and water (20:80, pH 3.2 ± 0.05 adjusted by 50% phosphoric acid) as mobile phase A, and methanol containing 0.01% phosphoric acid as mobile phase B (A:B = 4:96) at a flow rate of 1.2 mL/min. The column temperature was hold at 40 ℃, and the detection wavelength was set as 210 nm. The correlation coefficient of the linear calibration curve (y = 4.6068x + 11.2640) was 0.9992 at the concentration range of 5 to 250μg/mL. The relative standard deviations (RSDs) of retention time and peak area in precision experiments for 5 replicate analyses and 9 replicate analyses in 48 h were 0.2107% and 1.2843%, and 0.3383% and 1.9737%, respectively. The recovery rate range was between 94.971% and 101.964% with a RSD of 2.5825%. The detection limit of this method was 1.8886μg/mL. The content of lupeol in dried Chinese olive powder was 359 μg/g, which was higher than that in strawberry, banana, Jufeng grape, American red grape and papaya. Therefore, the developed method is practicable for qualitative and quantitative determination of lupeol in fruits.

The determination of pectin and total sugar in Fuling mustard tuber samples by Fourier transform near-infrared spectroscopy (FT-NIRS) was studied. The original spectra of 50 Fuling mustard tuber samples were obtained by using FT-NIRS machine. Through math analysis, spectrum noise was decreased. Finally, the regression method was used by partial least square. Regression models between product quality and pectin or total sugar were established. The determination coefficients (R2) of the established model were 98.31 and 98.35. Its root mean square errors of cross-validation (RMSECV) were 0.513 and 0.0531, respectively. While the R2 and root mean square errors of prediction set (RMSEP) were 96.69, 95.63, 0.572 and 0.0671 in test set validation, respectively. Internal and external cross-validation tests exhibited that near-infrared quantitative analysis had high accuracy and could meet the requirement for predicting pectin and total sugar contents in Fuling mustard tuber products.

In this paper, steam distillation (SD) and ultrasound-assisted extraction (UAE) methods were separately coupled to gas chromatography-mass spectrometry (GC-MS) to the chemical composition of volatile oil from Asarum sieboldii Miq. As a result, 24 compounds including methyleugenol, 3,5-dimethoxytoluene, safrole, pentadecane, kakuol, 3',4'-(methylenedioxy)propiophenone, eucarvone, borneol, 2',4'-dimethoxy-3'-methylpropiophenone, N-isobutyldodecatetraenamide and sesamin were identified. However, UAE revealed a 1.2－24-fold increase in partial components in comparison with SD. The contents of sesamin and 6-octadecenoic acid obtained by UAE were 24 and 21 times larger than that by steam distillation method, respectively. These studies suggested that UAE is superior to SD for both thermally unstable and non-volatile compounds in volatile oil from Asarum sieboldii Miq..

A determination method for δ9-tetrahydrocannabinol (THC) in edible vegetable oil was developed on the basis of ultra-high performance liquid chrmatography-electrospray tandem mass spectrometry (UPLC-MS/MS) under negative ion mode using electrospray ionization (ESI) source. THC was extracted with methanol and then purified by LC-alumina-N solid phase extraction column. Qualitative and quantitative analysis were carried out for the analyte under a MRM mode after THC was separated on Waters ACQUITY UPLCTM BEH C18 (1.7 μm, 2.1 mm×100 mm) column. The limit of detection (LOD) of the developed method was 0.15 μg/kg and the limit of quantification (LOQ) was 0.45 μg/kg for THC. Quantitative analysis was corrected by internal standard method using delta 9-THC-D3 as internal standard. Average recovery rate of THC varied from 68.0%－110.0% with relative standard deviation ranging from 8.8%－18.1% at three spiked levels. Therefore, the developed method meets the requirements for the determination of THC in edible vegetable oil.

In order to establish a new method to quickly determine melamine in milk powder, a chemiluminescence (FI-CL) system of luminol and potassium permanganate was coupled with flow injection technology. In the method, the chemiluminescence (CL) reaction between luminol and potassium permanganate was significantly reduced by melamine. Under the optimal experimental conditions, melamine concentration in the range of 1 × 10-11 to 1 × 10-6 mol/L was linearly proportional to the depression of CL signals. The detection limit was 4.0 × 10-8 mg/L, with a RSD of 1.1% for 11 replicate determinations. The recovery rates for melamine in a certain brand of milk powder were in the range of 96.1% to 102.2%. This method has been successfully applied to the determination of melamine in real milk powder samples.

A method for detecting residues of nalidixic acid, tiamulin, trimethoprim, difloxacin, florfenicol and praziquantel in aquatic products by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)after liquid-liquid extraction approach was established. The samples were extracted using acetonitrile as the solvent, purified by hexane and detected by UPLC-MS/MS within 6 minutes. The linear regression coefficients corresponding to 6 spiked levels in the range of 5 to 200μg/L were between 0.9977 and 0.9999. The detection limit for each of the six substances was 1.0μg/kg, and their recoveries were in the range of 61.2% to 90.5%. The developed method is simple and sensitive and can meet the requirements for qualitative and quantitative analysis of aquatic products.

A new spectrophotometric method for determining trace potassium bromate in wheat flour based on oxidation-decoloration of butyl rhodamine B (BRB) was established. The effects of some important factors such as acidity, concentration and volume of BRB, reaction time and reaction temperature were investigated to acquire the optimal conditions. The results indicated that the optimal conditions were maximum absorption peak at 558 nm, 0.3 mol/L hydrochloric acid and 1.0 mL 1.00 × 10-4 mol/L BRB solution, reaction temperature of 80 ℃ and reaction time of 5 min. Beer's law was obeyed in the range of 0 to 0.3μg/mL for potassium bromate. The regression equation was δA = 1.607C + 0.0057 (C: μg/mL) with a correlation coefficient of 0.9996. The detection limit was 0.08μg/g with a molar absorption coefficient of 1.6×106 L/(mol ·cm). The developed method was used for the determination of trace potassium bromate in wheat flour with satisfactory results. The recovery rate of samples was in the range of 92%－109% with relative standard deviation of less than 5%.

The neomycin (NEO) was coupled to Ovalbumin (OVA) to form coating antigen NEO-OVA by the EDC methods, determined by SDS-PAGE, and then indirect competitive ELISA (ic-ELISA) method was established; The NEO was coupled to horseradish peroxidase (HRP) by NaIO4 method，making enzyme tracer NEO-HRP and direct competitive ELISA . Then, the direct ELISA was developed and optimized in many parameters, such as coating liquids, pH value, incubation time , incubation temperature and so on. At last, the IC20 value (20% inhibitory concentration) was less than 1 ng/mL and IC50 value (50% inhibitory concentration) was 7.6 ng/mL . The formation is y = -0.2798x + 0.74 56, R2= 0.991. The direct ELISA could run in only about 1 h while the indirect assay duration was at least 1.75 h.

Objective: To establish a HPLC method for the determination of schisandrin, schisandrol B, deoxyschizandrin and schisandrin B in Schisandra sphenanthera Rehd.et Wils. and Schisandra chinensis (Turcz.) Baill. from 17 growth areas. Methods: The chromatographic separation was carried out on Diamonsil C18 (250 mm× 4.6 mm, 5 μm) column using methanol-water (73:27, V/V) as the mobile phase at a flow rate of 1 mL/min. The detection wavelength was 250 nm. Results: A good linear relationship was achieved with a correlation coefficient in the range of 0.01 to 0.08 mg/mL (R2 = 0.9990) and a RSD of 0.86%, 0.37%, 0.19% and 0.15%, respectively. Conclusion: The developed HPLC method reveals a good separation efficiency, reproducibility and accuracy. This method can be used for determining schisandrin, schisandrol B, deoxyschizandrin and schisandrin B in herbs. Higher amounts of schisandrin, schisandrol B and schisandrin B are present in Schisandra chinensis than in Schisandra sphenanthera.

The objective of this study is to establish a rapid detection method for milk with urea content exceeding physiological range. Based on the fact that pH increase could result from urea enzymolysis positively correlated with urea concentration. Bromothymol blue was chosen as the acid-base indicator to determine high-urea milk. The indicator can develop color from yellow-brown to green-blue when urea content was higher than 40 mg/100 mL. On the basis of our present study, the developed reagent kit for the determination of high-urea milk is useful for practical application.

The method for analyzing cyanuric acid in milk powder by gas chromatography tandem triple quadruple mass spectrometry (GC-MS/MS) with an isotopic internal standard and a multiple-reaction monitoring (MRM) system was established. The milk powder samples were extracted by methanol, and derivatized with BSTFA+TMCS (1%). The optimal parameters for instruments, matrix effects, fragment pathways of cyanuric acid derivatives and MRM scanning modes were explored. The ion peaks of cyanuric acid were m/z 345＞215 and m/z 345＞330 for qualitative and quantitative analysis, which was consistent with the ion peaks of isotopic internal standard with m/z 345＞215 and m/z 348＞217. The linear range of the developed method was between 0.010 mg/L and 0.50 mg/L and limit of detection was 0.014 mg/kg (RSN= 3). The relative standard deviations of the developed method varied between 3.4% and 4.8% and the average recovery rates of cyanuric acid from spiked samples between 90.0% and 102.5% in the range of 0.20 mg/kg to 2.0 mg/kg. The validation results and comparison with external standard method revealed that the developed method was accurate and reliable.

A method for simultaneous determination of 4 tetracyclines and 3 epimers in honey samples was developed by high performance liquid chromatography coupled with tandem mass spectrometry. The residues in honey samples were extracted by EDTA-Mcllvaine buffer, and cleaned up and condensed by OASIS hydrophilic-liphophilic balance (HLB) column and weak cation exchange (WCX and carboxylic acid) sequentially. Sample solution eluted from the WCX SPE column by mobile phase was filtered by micro-pours membrane, separated by LC-MS/MS with gradient elution using acetonitrile-formic acid solution as mobile phase and then qualitatively and quantitatively analyzed by ESI-MS/MS in a MRM mode. Baseline separation of 7 target drugs was achieved within 7 min, and qualitative and quantitative analysis was completed. The recovery rates of the spiked samples at trace levels were in the range of 64.9% to 91.0% with the relative standard deviation (RSD) less than 10.5% (n = 7). The detection limits were 1μg/kg for oxytetracycline, tetracyclines, 4-epitetracycline, 4-epioxytetracycline and 2μg/kg for chlortetracycline, doxycycline and epichlortetracycline. The developed method was sensitive and reliable, and can be successfully applied to the simultaneous detection of 7 target tetracyclines residues including toxic metabolites in honey.

Gas chromatography-mass spectrometry (GC-MS) was used to analyze the compositions of the essential oil from Jiangxi R. damascene. A total of 64 components accounting for 92.80% of total relative content were identified by similarity searching in NIST mass database. Chromatographic profiles and mass spectra for seven components were resolved from six peak clusters of 2-dimensional multi-component data by using heuristic evolving latent projection (HELP). These components accounting for 49.77% of the total relative content were identified by similarity searches using the NIST, and verified by comparing the retention time with that of pure samples. Relative contents of phenethyl alcohol, nerol, L-citronellol and geraniol were close to requirements of the standard of ISO 9842:2003.

Objective: To analyze the compositions of flavonoids from reed leaves. Methods: The crude extract was prepared during the condensation of reed leaf extract. The primarily purified flavonoids were prepared by macro-porous resin. The hydrolysis conditions of flavonoids were optimized. Two samples were hydrolyzed to obtain two hydrolysis products. The compositions of flavonoids were determined by HPLC. Results: The contents of total flavonoids in crude extract and primary purified flavonoids samples were 57.1% and 18.5%, respectively. The optimal hydrolysis conditions for reed leaf flavonoids were hydrolysis temperature of 80－90 ℃, HCl concentration of 1.4 mol/L and hydrolysis time of 4 h. Totally 33 components were separated by HPLC from the crude extract and 8 components were identified based on their retention time. A total of 22 components were separated by HPLC from the primarily purified sample and 5 components were identified. A total of 28 components were separated from the hydrolysates and 7 components were identified. Similarly, 25 components were separated from the hydrolyzed primarily purified samples and 7 components were identified. Conclusion: Reed leaves contained rutin, scutellarin, hesperidin, luteolin, quercetin, apigenin, kaempferol, isorhamnetin or hesperetin, isoliquiritigenin, baicalein, and other unknown flavonoids. The content of apigenin among these components was the highest.

In this study, the effects of hot air and ethanol fumigation treatment applied separately or in combination on quality changes of Zhonghuashoutao, peach during cold storage and shelf life were investigated. The results showed that 4 hours of hot air in 48 ℃ combined with 300μL/L ethanol fumigation treatment exhibited better effects than the hot air treatment or ethanol treatment. It inhibited the flesh woolliness, and also slow down the decreasing of titratable acid, juice extraction rate and vitamin C content. This treatment also alleviated the increasing of electrical conductivity during storage, the cell membrane integrity and the softening ability. The combination treatment exhibited positive effect on storage quality and shelf life of the peach during cold storage.

In this study, Xueqing pear was packed in film package with high carbon dioxide permeability and stored at (0 ± 0.5) ℃. The changes of respiration intensity, firmness, content of total soluble solid, titratable acid, vitamin C (VC), malondialdehyde (MDA) and polyphenol oxidase (PPO) activity during storage were investigated. Results indicated that Xueqing pear was climacteric fruit. Film package with high carbon dioxide permeability delayed the appearance of respiration peak, the increase of PPO activity and reduced MDA content, and thus alleviated the senescence of the fruits. Meanwhile, this package significantly alleviated the decrease of firmness, TA content and VC content, the increase of TSS. Film package with high carbon dioxide permeability could be a good candidate for keeping the post-harvest quality and flavour of Xueqing pear and provided longer storage life.

NaCl, MnSO4 and NaH2PO4 were respectively sprayed on the leaves of pineapple (Bali variety) 20 and 30 days after anthesis in order to investigate the effects of these chemicals on the quality and stress resistance of pineapple fruits. The results showed that spraying of NaCl, MnSO4 and NaH2PO4 increased the single-fruit weight by 15.37%, 18.83% and 10.01%, respectively. All these treatments could increase the content of total soluble solid (TSS) and vitamin C, and MnSO4 treatment was the best, which decreased titratable acid content and increased superoxide dismutase (SOD) and peroxidase (POD) activities, but had no effect on total surge content. In collusion, MnSO4 and NaH2PO4 treatments can increase the quality of pineapple, and MnSO4 is superior to NaH2PO4.

Changes of qualities related to non-enzymatic browning in hot break tomato paste (HBTP) at different storage temperatures (0, 25 ℃ and 37 ℃) for 5 months were evaluated in this study, in order to guide the storage of HBTP. Changes of free amino acids, total sugar, vitamin C, 5-hydroxymethylfurfural (HMF) and browning degree (BD) were fitted with zero-, first-order and combined models, respectively, and it was found that the combined model could better explain the kinetic changes of non-enzymatic browning in HBTP during storage. At 25 ℃ or 37 ℃, a good correlation between HMF formation and BD was observed, and color parameters (lightness L*, redness a* and yellowness b*) could be expressed by combined equations as functions of HMF. Higher storage temperatures (25 ℃ and 37 ℃) had significant effects (P＜0.05) on changes of total amino acids, total sugar, vitamin C, HMF, BD and color parameters in HBTP. When stored at 0 ℃, changes of HMF, BD and color parameters in HBTP were not significant (P ＞0.05). All the results indicated that the quality of HBTP was deteriorated significantly during higher temperature storage, but could be protected well during lower temperature storage.

This study focused on the effects of the different vibration time on the quality of Kumaiti apricot fruits, which simulated the process of trucking under normal temperature (25 ℃± 1 ℃). The results showed that during the vibration of apricot, the respiration rate significantly increased (P＜0.05), and ethylene production and soluble solids content changed slowly, and vitamin C decreased slowly. However the organic acid content and firmness decreased obviously (P＜0.05); During the following storage, the respiration rate, ethylene production and fruit decay rate significantly increased (P＜0.05) with the extension of vibration time, the organic acid content and firmness decreased obviously, but the changes of soluble solids content and VC were not significant (P＞0.05). The foam-net packages may delay or reduce the respiration and ethylene peak, and it also can effectively slow down the changes of the organic acids, hardness and decay rate. Therefore, it is beneficial to maintain the quality of apricots.

Membrane permeability, leakage of K+, Na+ and Ca2+ of Honey Dew, muskmelon stored at different temperatures were investigated. Results indicated that low temperature storage promoted membrane permeability. The leakage of K+ increased with the decrease of temperature, and the leakage of Na+ increased with the increase of storage time and the decrease of temperature after 21d. The leakage amount of Ca2+ was at a low level, and not affected by storage temperature or time.

In this study, xuanhua-milk,, grapes were soaked in chitosan coating solution before harvest, and stored at 0 ℃ for 100 d. The respiration intensity, ethylene production, total phenolics content, polyphenol oxidase activity, chlorophyll content, titratable acidity, soluble solids content, weight loss, decay rate and browning index of the grapes were investigated during storage. The results showed that the coating treatment had good effect on inhibiting the respiration intensity, ethylene production and polyphenol oxidase activity. Compared with untreated grape, respiration intensity of grape treated with preharvest-coating were reduced by 42.5% at 50 day and 53.8% at 75 day, respectively. After storage for 100 days, decay rate was 5.2% in coating-treated group, and 92% in the control group. Browning index was reduced by 81.6% at 75 day compared with untreated grape. Meanwhile, higher soluble solids, titratable acid, chlorophyll and total phenolics content remained in grapes of coating-treated group than in the control. Furthermore, preharvest coating increased the shelf life and maintained the sensory quality of grape fruits, resulting in a 2-fold prolongation of shelf-life compared with untreated grape.

Fresh broccoli were dipped in 10%, 15% and 20% clove extract respectively for 15 min, dried in air, cut and packaged with LDPE film. The broccoli was dipped in distilled water for 15 min as control. Then these samples were stored at (4±1) ℃. The effects of three treatments on the physiological and biochemical changes of fresh-cut broccoli were investigated. The results showed that clove extracts could improve the sensory quality, inhibit the respiratory intensity and weight loss and delay the decline of vitamin C, titratable acidity and chlorophyll contents. Further, 15% clove extract could significantly (P ＜0.05) improve the preservation effects of fresh-cut broccoli, but 20% clove extract exhibited no significant difference (P ＞ 0.05) compared with the control group.

Vitamin-fortified extruded rice grains were packed in different packages and stored in different storage conditions, and the changes of vitamins, moisture content and acid value during storage were determined. Results showed that packages and storage conditions had effects on the changes of above indices in the rice during storage. The optimal storage conditions are that the vitamin-fortified extruded rice grains are stored at 4 ℃ in tinplate can. More than 80% of VC and VD3, 95% of VB in the rice remained after stored under the optimal conditions for 180 d, with the acid value below 1.0 mg/g and the water contents below 8%.

Effects of temperature, pH, substrate, ascorbic acid, L-cysteine, sodium bisulfite, citric acid and sodium chloride on the activity of polyphenol oxidase (PPO) from Chaenomeles speciosa Nakai were studied. Results showed that PPO activity was obviously higher in core than in the peel and flesh. The browning of C. speciosa fruit was significantly correlated to PPO activity. The PPO from C. speciosa fruit had the optimum substrate of catechol, with the optimum temperature 20 ℃ and pH 5.5. The enzyme lost its activity substantially after exposure to 80 ℃ for 5 min. Its activity was suppressed effectively by ascorbic acid, L-cysteine, sodium bisulfite, citric acid and sodium chloride.

This study was carried out to investigate the effect of pre-harvest spraying with 1-MCP on the postharvest mealiness development and shelf life of Taishan Zaoxia,apple. Results showed that spraying with 1-MCP 8 days before harvest did not affect the coloring of the fruit, but significantly delayed the decrease of fruit firmness, the increase of titratable acid and soluble solid, and the release of ethylene during shelf life. This treatment effectively controlled the development of postharvest mealiness of Taishan Zaoxia, apple, and its shelf life was extended to 10 d.

The objective of this study was to evaluate the effect of harvest maturity on the quality and aroma components of cherry fruits. The fruits with different harvest maturities were subjected to solid-phase micro-extraction and evaluated by gas chromatography and mass spectrometry for aroma components as well as quality parameters. A total of 30 aroma components were detected, which were aldehydes, alcohols, esters, acids and ketones. The contents of acids and ketones were increased as ripening period. Aldehydes including caproic aldehyde and benzaldehyde exhibited a large variance during ripening process. Alcohol and (Z)-2-hexen-1-ol were dominant alcohols in cherry fruits. In addition, the relative content of alcohol was increased and (Z)-2-hexen-1-ol was decreased during ripening process. The solid-acid ratios of cherry fruits at over ripening, ripening and middle ripening stages were 13.2, 11.1 and 7.6, and hardness of fruits at three stages were 3.13, 4.61 N/cm2 and 4.68 N/cm2, respectively. These results suggested that harvest maturity had a large effect on the quality and aroma components of cherry fruits. Therefore, cherry fruits should be harvested for reasonable utilization in ripening stage.

The effect of vacuum freeze-drying on highland barley green powder was investigated using freeze-drying velocity and retention rate of flavonoids and SOD as the indicators. The optimal process conditions were explored to be pre-freezing temperature of －40 ℃, pre-freezing time of 4 h, loading materiel thickness of 5 mm, working pressure of 60 Pa, sublimation temperature of 40 ℃ and resolution temperature of 50 ℃. Under the optimal conditions, the retention rates of flavonoids and SOD were 69.3% and 20.1%, respectively. The sample revealed bright green color and fresh grass smell. These results indicated that vacuum freeze-drying was a useful method to prepare highland barley green powder.

The optimal preparation process for quick-frozen noodles was explored by one-factor-at-a-time method in combination with quadratic regression orthogonal rotation composite design. The results indicated that the optimal noodles formula was dough with a stabilization time of 5－7 min, 40% water, 1%－1.5% starch, 0.35% guar gum, 0.40% glycerin monostearate (GMS), 0.15% compound phosphate and 6% modified starch, and the optimal freezing air-flow speed was in the range of 3－4 m/s. Under the optimized process conditions, the processed quick-frozen noodles achieved an excellent comprehensive evaluation.

The liquid cultivation conditions of Ganoderma lucidum mycelium and alcoholic fermentation using soybean residue as the culture medium were studied in this paper and a kind of new functional and healthcare beverage was developed. The culture medium based on soybean residue was better than PDA liquid culture medium. The optimal culture medium formula was composed of 90 g/L soybean residue, 20 g/L glucose, 1.5 g/L MgSO4 and 1.0 g/L KH2PO4. The optimal conditions for alcoholic fermentation were explored by orthogonal array design to be yeast inoculum concentration of 0.2%, fermentation temperature of 30 ℃, and fermentation time of 5 d. During the preparation of Gamoderma lucidum fermented beverage, the optimal formula was explored by orthogonal array design for the best comprehensive evaluation of color, flavor and taste.

Chitosan film and sodium alginate composite film were prepared by using edible raw materials. Chitosan film was prepared by dissolving chitosan in 4% acetic acid solution (V/V), adding 1% glycerin (V/V) as plasticizer and 0.1% liquid paraffin as release agent, and then drying at 70 ℃ for 7 h. The prepared chitosan film was characteristics of 100 nm in thickness, 240.0 kg/cm2 in tensile strength and 89.2% light transmittance. The optimal formula for sodium alginate composite film determined by orthogonal array design was 8 mg/mL sodium carboxy methyl cellulose, 12 mg/mL sodium alginate, 8 mg/mL gelatin, 2 mg/mL AGAR and 8% (V/V) glycerin. The resulting sodium alginate composite film was characteristics of 0.070 mm in thickness, 116.7 kg/cm2 in tensile strength and 71.6% light transmittance. The results of performance tests showed that both kinds of film exhibited an excellent resistance to oil and oxidants as well as high flexibility and thermoplasticity.