Objective: To optimize the extraction process for Pu-erh tea pigment and explore its antioxidant activity. Methods: Following single factor investigations, optimization of process conditions for the extraction of Pu-erh tea pigment based on the color difference value E between distilled water and Pu-erh tea pigment was carried out using central design composite design combined with response surface methodology (RSM). 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay was used to evaluate the antioxidant activity of the pigment. Results: The optimal extraction conditions for Pu-erh tea pigment were liquid-to-material ratio of 45:1 (mL/g), extraction temperature of 100 ℃ and extraction time of 150 min. Under the optimal extraction conditions, a color difference E value of 52.97 was obtained, which revealed 4.73% increase as compared to the highest color difference in single-factor investigations and Box-Behnken composite experiments. The IC50 value for the scavenging capability of Pu-erh tea pigment on DPPH free radicals was 30.83μg/mL. Conclusion: It is feasible to optimize the extraction of Pu-erh tea pigment by response surface methodology. The Pu-erh tea pigment with excellent antioxidant activity has the potential to be further developed and utilized as a natural antioxidant.

In order to prepare a heme-rich polypeptide product, mixed papain and neutral protease were used for the hydrolysis of porcine hemoglobin. The effects of substrate concentration, mixing ratio for papain and neutral protease, hydrolysis pH and hydrolysis temperature on hydrolysis degree, protein recovery rate and heme content were investigated. The results indicated that substrate concentration was the most important factor that affects hydrolysis degree and protein recovery rate. pH was the most important factor that affects heme content. The optimal hydrolysis conditions for the preparation of heme-rich polypeptide products were substrate concentration of 6%, pH 8, hydrolysis temperature of 55 ℃ and papain-to-neutral protease ratio of 5:5. Under the optimal preparation conditions, relatively high protein recovery rate and heme content for the hydrolysis of porcine hemoglobin were achieved.

β-conglycinin and glycinin were separated by large-capacity (250 × 4 mL) low-speed (5300 × g) centrifugation at the condition of alkali dissolution and acid precipitation. Results indicated that better centrifugation efficiency of soybean protein was in pH 8.5 Tris-HCl solution; The optimal pH values for precipitating glycinin andβ-conglycinin were 6.4 and 4.8, respectively. Meanwhile, the optimal pH for removing the impure proteins was 5.0. The enhancement of entrifugation efficiency was achieved by keeping turbid liquid at 4 ℃ for more than 2 h before centrifugation. Under the optimal conditions, the yields of glycinin andβ-conglycinin were 6.8% and 2.2%, respectively. The purities of separated proteins determined by SDS-PAGE were 89.1% and 78.9%. Low-speed centrifugation is suitable for separatingβ-conglycinin and glycinin.

Ultrasonic extraction conditions for total flavonoids from Humulus lupulus L. were optimized by single factor experiments and orthogonal design with the aim of establishing a sample preparation method for determination of the content of total flavonoids in Humulus lupulus L. by NaNO2-Al(NO3)3-NaOH colorimetric method using rutin as the reference. The optimal extraction process parameters were material-to-liquid ratio of 1:50, extraction duration of 1 h and repeated extraction number of 2. The content of total flavonoids from Humulus lupulus L. was 69.98 mg/g under the optimal extraction conditions, which was much higher than that of residues and beer. The linear range was between 10.2μg/mL and 40.8μg/mL with a correlation coefficient of 0.9985. The average recovery rate was 99.33% with a relative standard deviation of 3.60%. The extraction and determination methods were simple and feasible, which is suitable for the preparation and quality control of flavonoids extracted from Humulus lupulus L.

Heat pump drying device was used for the drying of whole litchi. The drying curves and dry curve rates of litchi in steady condition were determined. The conversion rate of water content during combinatorial drying processing of heat pump and microwave drying was analyzed. The effects of heat pump drying temperature, the conversion rate of water content, and microwave drying time on the quality of litchi during combinatorial drying processing were investigated. Orthogonal test results indicated that the order of drying efficiency on the quality of litchi were heat pump drying temperature, conversion rate of water content and microwave drying time. The optimal drying parameters were heat pump drying temperature of 50 ℃, conversion rate of water content of 100% and microwave drying time of 2.5 min. Under the optimal processing conditions, the score of comprehensive sensory evaluation was 27.

Objective: To explore the microwave-assisted extraction of procyanidins from raspberry seeds and screen the optimal extraction parameters. Methods: The response surface design was used to investigate the effects of ethanol concentration, microwave power, material-liquid ratio and microwave time on extraction rate of procyanidins from raspberry seeds. Results: The optimal extraction conditions were ethanol concentration of 60%, ultrasonic power of 300 W, material/liquid ratio of 1:10 (g/mL) and microwave extraction time of 3 min. Under the optimal extraction conditions, the extraction rate of procyanidins from raspberry seeds was up to 7.19 mg/g, which exhibited a 3-fold enhancement compared with traditional water extraction. Conclusion: The optimized microwave extraction process for procyanidins from raspberry seeds is highly efficient and less time consumption.

In order to optimize extraction process parameters for terpenoids from Sorbus tianschanica Ruper, the content of terpenoids in Sorbus tianschanica Ruper as the raw material was determined to evaluate the effects of soaking time, methanol/water ratio in extraction liquid, material/extraction liquid ratio, extraction temperature and particle size on extraction rate of terpenoids. Results indicated that the optimal extraction conditions for terpenoids from Sorbus tianschanica Ruper were methanol/water ratio of 20:80, material/liquid ratio of 1.5:10 (g/ml); extraction temperature of 60 ℃ and extraction time of 4 h. Under the optimal extraction conditions, the extraction rates of terpenoids from the leaves and branches of Sorbus tianschanica Ruper were 1.59% and 1.45%, respectively. Therefore, the optimal extraction process is simple and reliable, which is suitable for the extraction of medicinal herbs in bulk.

In order to explore the effect of transglutaminase (TGase) on the characteristics of soybean protein isolate (SPI), 7S and 11S protein gels, the parameters of these TGase-treated protein gels were determined by TA-XT plus SEM (scanning electron microscope) and fluorescence spectrophotometer. Results indicated that gel hardness of TGase-treated SPI gels was significantly increased compared with that of the control. The optimal conditions of TGase treatment for SPI were TGase addition amount of 40 U/g, treatment temperature of 40 ℃, treatment pH of 7.5 and treatment time of 2.5 h. After treatment with TGase, the surface hydrophobicity and water-holding capacity of soy protein isolate gels exhibited a decrease. Meanwhile, heating treatment also resulted in a significant increase in the hardness of TGase-treated protein gels, and TGase-treated SPI gels had the largest gel intensity, followed by 7S and 11S in turn.

Microencapsulation is an effective method to protect biologically active materials from the damage by environmental factors. Yeast cells are natural and edible microencapsules. In the present study, yeast cells were pre-treated by alcohol, 3% sodium chloride, alkaline protease and sodium hydroxide to obtain ACY, AEY, AY and AWGP, respectively. The treated yeast cells were used to adsorb tea polyphenols in aqueous solution. The results indicated that the absorption rates of tea polyphenols in 4 kinds of pre-treated yeast cells such as ACY, AEY, AY and AWGP with the addition of 2.00 g tea polyphenols were 98.1%, 94.3%, 93.2%, and 73.2% under the conditions with absorption time of 4 h, absorption temperature of 40℃, and tea polyphenol solution at pH 4.0. The adsorption capacities of ACY, AEY, AY and AWGP on tea polyphenols were 319.8, 307.4, 303.8 mg/g and 238.5 mg/g, respectively. Adsorption kinetics analysis showed that four kinds of pre-treated yeast cells were in accordance with Langmuir and Freundlich isotherm models. Antioxidant experiments confirmed that yeast cells could function as the role of microencapsules.

In order to explore spray drying conditions of sweet potato leave extract (SPLE), orthogonal tests were used to optimize the spray drying conditions of SPLE on the basis of single factor tests. The results indicated that the optimal spray drying conditions were inlet air temperature of 190 ℃, flux rate of 300 mL/h and total solid content of 25%. Under the optimal spray drying conditions, the yield of the product, water content and activity loss rate were 53.78%, 5.29% and 11.13%, respectively.

Water can be changed from liquid to saturated steam by heating method, which results in the destroy of hydrogen bonds among H2O molecules and the exposure of hydrogen atomic nuclei to function as the protons for attacking metal ions in non-hydrated phospholipids. The non-hydrated phospholipids can be removed from crude oil through the separation between phosphatidic acids and divalent metal ions. The optimal removal process of non-hydrated phospholipids was based on hydration degumming of crude oil for the removal of hydrated phospholipids, heating of hydrated degummed oil to 110 ℃, stirring at 90 r/min, introduction of 2% (on the basis of oil amount) saturated steam pressure at 0.14 MPa allowed to proceed for 50 min. Under the optimal conditions, the phosphorus content in degummed oil was 17.9 mg/kg. This method can provide a theoretical basis for industrial production.

Supercritical fluid CO2 extraction was applied to extract oil from Allium mongolicum seeds. Based on single factor experiments, the effects of extraction pressure, extraction temperature, extraction time and CO2 flow rate on extraction rate of Allium mongolicum seed oil were explored by orthogonal design. The results indicated that the optimal extraction conditions were extraction pressure of 35 MPa, extraction temperature of 45 ℃, extraction time of 120 min and CO2 flow rate of 35 kg/h. Under the optimal extraction conditions, the extraction rate of Allium mongolicum seed oil was 15.00%. GC-MS analysis showed that fatty acids in Allium mongolicum seed oil were composed of 86.65% unsaturated fatty acids and 13.35% saturated fatty acids. Furthermore, linoleic acid (63.24%), oleic acid (15.99%) and palmitic acid (7.93%) were major fatty acids in Allium mongolicum seed oil. Therefore, supercritical fluid CO2 extraction can provide excellent physico-chemical properties, high purity and quality for Allium mongolicum seed oil.

Objective: To explore the extraction and antibacterial activity of colchicine from lily root powder. Methods: Colchicine was extracted from the dry powder of lily roots. The content of colchicine in the extract was determined by using high performance liquid chromatography (HPLC). The optimal extraction conditions were explored by single factor and orthogonal array design methods. Minimal inhibitory concentration (MIC) and antibacterial rate of colchicine were measured by bacteriostasis tests in vitro. Results: The optimal extraction conditions were extraction temperature of 80 ℃, ethanol concentration of 95%, material-liquid ratio of 1:6 and extraction time of 8 h. The MICs of colchicine against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Albicans bacteria and Sarcina lutea were 0.20, 0.20, 0.24, 0.16 mg/mL and 0.20 mg/mL, respectively. Conclusion: The colchicine in lily roots has significant inhibition effect on five species of bacteria in vitro.

In order to obtain triterpenoids with high purity from Cyclocarya paliurus leaves, macro-porous resin was used for purification. Results indicated that macro-porous resin revealed a static absorption mode. AB-8 resin had good adsorption capability on triterpenoids from Cyclocarya paliurus leaves, and its adsorption capacity, desorption rate and total recovery rate were 77.49 mg/g, 85.44% and 72.01%, respectively. Dynamic adsorption and desorption experiments of AB-8 resin suggested that the increasing flow rate of sample solution could result in the decrease of adsorption rate, and the increasing sample amount in resin could result in a pattern of initial increase and final decline for adsorption rate. A better elution efficiency was observed at the concentration of 95% ethanol, and 10 BV was reasonable dosage. Both peak concentration and desorption rate were declined with the increasing flow rate of eluent. The best flow rate was 1.5 mL/min. The purity of triterpenoids purified by AB-8 macro-porous resin was 44.30%.

Cellulose, hemicellulase and were simultaneously used for the aqueous enzymatic extraction of soybean oil by in the present study, and the extraction process was optimized by mixed design. It was found that the optimal hydrolysis process for soybean oil extraction consisted of suspending of soybean powder in a 6-fold volume of water, adding 0.84% cellulose and 0.56% hemi-cellulase for hydrolysis at 37 ℃ for 0.75 h, and further hydrolysis with Alcalase added at a concentration of 1.85% for 3.6 h at 50 ℃with an initial pH of 9.26, and provided an oil extraction efficiency of 81.04%, which was higher than that of wet-heating treatment extraction.

In order to optimize the microwave-assisted extraction process for anthocyanins from bilberry using 1% HCl ethanol as the solvent, response surface methodology was used to explore the effects of microwave power, microwave treatment time, solvent concentration and extraction temperature on extraction rate of anthocyanins on the basis of single-factor investigations. Results indicated that the optimal extraction conditions for anthocyanins from bilberry was microwave powder of 500 W, microwave treatment time of 7 min, solvent concentration of 55%, and extraction temperature of 51 ℃. Under the optimal extraction conditions, their extraction efficienc of anthocyanins from bilberry was (1.47 ± 0.15) mg/g.

Bifidobacterium adolescentis ys01 and Lactobacillus casei ys05 were used as the materials to prepare a selenium-enriched yogurt starter. The optimal conditions for selenium enrichment with Bifidobacterium adolescentis ys01 and Lactobacillus casei ys05 were explored by single-factor and Box-Behnken design methods. The optimal conditions for selenium enrichment were fructooligosaccharide of 1%, Se4+ concentration of 6.83μg/mL, initial pH 6.0, inoculation ratio between Bifidobacterium adolescentis ys01 and Lactobacillus casei ys05 of 2:1, inoculation amount of 3.8%, incubation temperature of 42 ℃, selenium addition time point at the 24 h of cultivation, and cultivation period of 60 h. Under the optimal conditions, the content of selenium in the mixture of Bifidobacterium adolescentis ys01 and Lactobacillus casei ys05 was (551 ± 4.6)μg/g and the conversion rate of selenium was (42.2 ± 3.6)%. In addition, an excellent fermentation performance of selenium-enriched yogurt starter prepared by Bifidobacterium adolescentis ys01 and Lactobacillus casei ys05 was achieved. The content of organic selenium in the yogurt prepared by this starter was (17 ± 4.5)μg/kg.

Objective: To optimize the ultrasound-assisted extraction of ursolic acid from Plantago asiatica L.. Methods: On the basis of single-factor experiments, response surface methodology (RSM) was used to explore the optimal conditions for extracting ursolic acid from Plantago asiatica L. following regression analysis of the relationship between extraction parameters and extraction rate of ursolic acid. Results: The optimal extraction conditions were extraction temperature of 75 ℃, ethanol concentration of 90%, ultrasound power of 480 W, liquid/material ratio of 5:1, and extraction time of 25 min. Under the optimal extraction conditions, the extraction rate of ursolic acid was 0.144%. Conclusion: The optimal extraction conditions are reasonable and effective.

In this paper, ultra-high pressure technique was applied for the extraction of tea polyphenols. On the basis of single factor experiments, the optimal extraction process for tea was investigated to explore the effects of solvent concentration, material/liquid ratio, extraction pressure and pressure treatment time on the extraction rate of tea polyphenols. Meanwhile, the extraction rates of tea polyphenols, caffeine, soluble sugars and amino acids between ultra-high pressure extraction and normal high temperature extraction were compared. The results indicated that the optimal extraction processing parameters were 70% ethanol, material/liquid ratio of 1: 40, extraction pressure of 200 MPa, and pressure treatment time of 10 min. Under the optimal extraction conditions, the extraction rates of tea polyphenols, amino acids, soluble sugars and caffeine were 26.61%, 3.87%, 4.76% and 2.95%, respectively, which were higher than those of hot water extraction. Therefore, ultra-high pressure extraction has the advantages of clear supernatant as well as short time and non-thermal extraction.

Corn starch was used as the raw material to prepare corn amylose by diluted alkaline dispersion method. The optimum conditions for preparing and separating corn amylose for improved amylose yield and blue value were determined by orthogonal array design to be NaOH concentration of 0.35－0.45 mol/L, NaCl concentration of 5% and centrifugation speed of 7000－8000 r/min. In addition, according to comparison on blue value, intrinsic viscosity and molecular weight, texture properties and molecular weight distribution, diluted alkaline dispersion derived corn amylose was more pure than n-butyl alcohol derived corn amylose and corn amylose obtained by ethanol method. The gelatinization properties and molecular weight distribution of diluted alkaline dispersion derived corn amylose were found to be as similar as those of the amylose standard.

Chayote (Sechium edule) Juice was used as the basal fermentation medium to prepare bacterial cellulose through the fermentation of Acetobacter xylinus. Plackett-Burman factorial design was used to determine the effects of sugar concentration and pH on productivity of bacterial cellulose. Steepest ascent method was used to determine the central point of both factors. Central composite design was used to build the experimental model and the optimal processing conditions were fermentation temperature of 28 ℃, (NH4)2SO4 concentration of 0.3 g/100 mL, Schehium edule juice concentration of 100 %, sugar concentration of 6.54 g/100 mL and pH 4.19. Under the optimal processing conditions, the yield of bacterial cellulose was up to 4.18 g/L (dry weight).

In order to establish a clean production process of fish gelatin, the ultra-high pressure-assisted extraction of gelatin from fish skin was investigated to explore the effects of ultra-high pressure treatment pressure, ultra-high pressure treatment time, extraction temperature and extraction time on gel strength and yield of gelatin. Results indicated that the optimal extraction processing conditions were ultra-high pressure treatment pressure of 300 MPa, ultra pressure treatment time of 10 min, extraction temperature of 50－60 ℃ and extraction time of 4 h. Under the optimal extraction conditions, the gel strength and the yield of gelatin were 274 g and 75.03%, respectively. The melting and gelling temperatures were 23.6 ℃ and 16.4 ℃, respectively.

In order to make full utilization of Rehmannia glutinosa Libosch leaf resource, improve its added value and provide optimal drying method for Rehmannia glutinosa Libosch leaves extract, single-factor design was used to explore the effects of microwave power and drying time on water content of dried products, followed by process optimization for the microwave vacuum drying of the extract by orthogonal array design based on multi-index comprehensive evaluation. Results indicated that the optimal microwave vacuum drying parameters were initial water content in extract of 45%, microwave power of 2 kW, heating time of 18 min, rotating speed for loading tray of 90 r/min, intermittent ratio of 3:1 and loading amount of 110 g. Under the optimal drying conditions, water content, retention rate of verbascoside and retention rate of total glycosides were 2.89%, 95.98% and 89.41%, respectively. Compared with vacuum oven drying, vacuum belt drying and freeze drying, microwave vacuum drying has the remarkable advantages of low water content, less loss rate of bioactive components, short drying time, high retention rate of bioactive components and simple operation, which exhibits promising application value in the field of industry due to its stability and reliability.

In order to develop a kind of calcium supplement with high bioavailability, and improve added value of egg white protein, egg white was enzymatically modified and then chelated with calcium. Enzyme screening for the modification of egg white showed that the optimum hydrolysis mode for egg white was sequential hydrolysis with alcalase and neutrase. After this, process optimization for the enzymatic modification of egg white and chelating reaction between modified egg white and calcium was conducted using orthogonal array design. The optimal conditions for the stepwise double enzymatic hydrolysis of egg white were substrate concentration of 6%, alcalase/substrate ratio of 1:100, hydrolysis pH of 8.0 and hydrolysis time of 3 h; neutrase/substrate ratio of 1:25, hydrolysis pH of 7.0 and hydrolysis time of 3 h. In addition, the optimal preparation conditions for calcium-chelating egg white peptide were the ratio between peptide and CaCl2 (m/m) of 2.5:1, reaction pH of 9.5, substrate concentration of 4%, and reaction temperature of 55 ℃. Under the optimal conditions, the yield of soluble calcium and degree of hydrolysis were 21.15 mg/L and 8.66%, respectively. Therefore, sequential dual-enzyme hydrolysis method is better than single-enzyme hydrolysis method for the preparation of egg white peptide. The obtained egg white peptides can form a kind of bridging bidentate complex with calcium. The calcium content in the calcium-chelating egg white peptide was up to 8.75%.

In this study, Schisandra chinesnsis (Turcz) Baill was used as the raw material to extractγ-schizandrin by ultrasound-assisted enzymatic hydrolysis. Single-factor experiments indicated that extraction rate ofγ-schizandrin was greatly affected by hydrolysis temperature, hydrolysis time and enzyme dosage. The optimal extraction conditions were explored by response surface analysis to be hydrolysis temperature of 52.89 ℃, extraction time of 4.04 h, and enzyme dosage of 0.96%. Under the optimal extraction conditions, the extraction rate of γ-schizandrin was up to 0.262%. 

Objective: To explore the optimal ultrasonic extraction processing and antioxidant activity of total flavonoids from Cirsium japonicum. Methods: The total flavonoids in Cirsium japonicum were extracted by ultrasound-assisted alcohol extraction method and the content of total flavonoids was determined by UV spectrophotometry. The antioxidant activity of total flavonoids from Cirsium japonicum was evaluated by the scavenging capability for superoxide anion and hydroxyl free radicals. Results: The optimal extraction conditions for total flavonoids from Cirsium japonicum were ethanol concentration of 75%; material/liquid ratio of 1:30 and ultrasonic treatment time of 45 min. Under the optimal extraction conditions, the extraction rate of total flavonoids was 0.289%. The total flavonoids from Cirsium japonicum exhibited an obvious scavenging effect on free radicals. The antioxidant activity of total flavonoids was a dose-dependent in the certain concentration range.

The objective of this study was to optimize the supercritical fluid CO2 extraction of volatile oil from Perilla frutescens leaves. Single factor and orthogonal design methods were used to investigate the effects of pressure, temperature, extraction time and CO2 flow rate on extraction rate of volatile oil. Pressure of 20 MPa, temperature of 35 ℃, CO2 flow rate of 10 kg/h and extraction time of 150 min were found optimum. Under the optimal extraction conditions, the extraction rate of volatile oil was up to 3.2%.

The extraction and antioxidant activity of total polyphenols from Ampelopsis grossedendata were studied in this paper. The optimal extraction conditions were achieved to be extraction at 75 ℃ for 1.5 h with a 25-fole volume of 50% acetone aqueous solution as the extraction solvent. Under the optimal extraction conditions, the yield of total polyphenols was 21.82%. Total polyphenols from Ampelopsis grossedendata showed high reducing power and excellent scavenging effect on hydroxyl, superoxide anion and DPPH free radicals in a dose-dependent manner.

The residue of purple sweet potato after pigment extraction was used as the main raw material to produce wine. A fuzzy comprehensive evaluation model was adopted to evaluate the sensory quality of the prepared wine product. The results indicated that fermentation temperature, material-to-liquid ratio, sugar addition amount, fermentation time were key factors during the fermentation process of wine. Orthogonal array design was used to determine optimal fermentation processing parameters. The optimal processing parameters were fermentation temperature of 25 ℃, material-to-liquid ratio of 1:25, sugar addition amount of 22%, and fermentation time of 12 days. Fuzzy comprehensive evaluation showed that the sensory quality for 9 kinds of wine was ordered as follows: 6#＞3#＞5#＞4#＞7#＞9#＞2#＞1#＞ 8#. This evaluation method was accurate and scientific.

Objective: To make good use of onion and prepare palatable and healthy onion wine. Methods: Onion was used as the raw material and three pre-treatment methods were applied to treat onion. Response surface methodology was used to optimize fermentation parameters for the production of onion wine. Results: Onion wine was palatable when onion was subjected to microwave treatment at 539 W power for 20 min. The optimal fermentation parameters were fermentation temperature of 25.3 ℃, yeast bacillus inoculation amount of 0.84% and fermentation time of 48.36 h. Under the optimal conditions, the alcohol content of onion wine was 9.7% and the extraction rate of flavonoids from onion wine was 65.12%. Multivariate regression analysis showed that established regression models for alcohol content or extraction rate of flavonoids  as a function of fermentation temperature, yeast bacillus inoculation amount and fermentation time were both remarkable, which could be used for practical prediction. Conclusion: Microwave pre-treatment can effectively remove the unpleasant aroma in onion and the optimized fermentation conditions for producing onion wine are reliable.

Skimmed extruded soybean dregs were used as the raw material to prepare water-soluble polysaccharides through the steps of ultrasonic-assisted extraction and purification by Sevag s method. The optimal ultrasonic-assisted extraction parameters were found to be extraction pH of 4.5, temperature of 90 ℃, material/liquid ratio of 1:20 (g/mL), ultrasonic power of 200 W, and ultrasonic extraction time of 40 min. Under these optimal extraction conditions, the extraction rate of water-soluble soybean polysaccharides was up to 8.82%. The purification of crude polysaccharides was achieved by treating with a Sevag reagent composed of CHCl3 and n-butanol (3:1, V/V) 3 times. The recovery rate of purified polysaccharides was up to 60.30%.

Supercritical CO2 fluid extraction technique  was explored to extract total flavonoids from praecox leaves in northern areas of China. Single-factor design was used to determine main variables that influence extraction rate of total flavonoids. The optimal extraction conditions were achieved to be extraction temperature of 36 ℃, ethanol concentration of 50%, extraction pressure of 35 MPa, entrainer (absolute ethanol) amount of 1:15, entrainer amount 9% and extraction time of 40 min. Under the optimal extraction conditions, the extraction rate of total flavonoids was 23.24 mg/g. The supercritical fluid CO2 extraction can be used for the extraction of total flavonoids from praecox leaves with high extraction efficiency.

In order to improve process and edible quality, the effects of different pressure, holding time and corn flour concentration on gelatinization degree of corn flour were studied with corn flour as raw material by single factor experiment and orthogonal experiment, in order to improve the processing quality and food quality of corn flour. The results showed that with the increment of pressure and prolongation of holding time, the gelatinization degree enhanced. With the concentration of corn flour increasing, gelatinization degree enhanced firstly and then decreased. The results of orthogonal experiment showed that the corn flour which concentration is 15g/100 mL was gelatinized 98.66 % under pressure of 500 MPa for 20 min.

Objective: To investigate the determination of soluble solids and total acidity in Gannan navel orange by using near infrared (NIR) diffuse reflection spectroscopy. Methods: NIR spectroscopy was used to determine the contents of soluble solids and total acidity in 150 Gannan navel oranges, including 120 navel oranges for model establishment and 30 navel oranges for model validation. The NIR spectra ranged at 350－1800 nm of navel oranges were collected. After the moving of the spectra, the first-order differential D1log (1/R) and the second-order differential D2log (1/R) pre-treatments were used to process. Principal component regression (PCR) and partial least square (PLS) regression were used to establish a mathematical prediction model. Results: The PLS model with D1log (1/R) data treatment could exhibit better prediction efficiency. The correlation coefficients of soluble solids and total acidity using this prediction model were 0.9263 and 0.9562 and the root mean standard errors of soluble solids and total acidity were 0.4102 °Brix and 0.018%, respectively. Conclusion: NIR spectroscopy can provide an accurate, reliable and nondestructive method for evaluating internal quality index through soluble solids and total acidity of Gannan navel orange.

Objective: To establish a determination method of ferulic acid in wheat bran by derivatization combined with spectrophotometry. Methods: Ferulic acid was analyzed spectrophotometrically at 720 nm. The color-developing agent was the mixture of 0.6 g/100 mL FeCl3 and 0.9 g/100 mL K3Fe(CN)6] (1:0.9). Results: A good linear relationship in the concentration range of 2.36－14.16μg/mL for ferulic acid (r = 0.9996) was observed, and the detection limit of this developed method was 0.022μg/mL. The average recovery rate of this method was 103.1%. Conclusion: This developed method is characteristics of simple operation, accurate results and high average recovery rate, which is suitable for the determination of ferulic acid in wheat bran.

A gas chromatography-mass spectrometry (GC-MS) method was developed for the simultaneous determination of 72 pesticides and their isomers including organochlorine, pyrethriod, organophosphorus and other pesticides in tea. After moistened by water, the samples were subjected to extraction by acetonetrile, preliminary clean up by 5 g/100 mL sodium chloride, and further purification on carbon/NH2 column through the elution using 25 mL of ethyl acetate-acetone (1:1). The MS detection was performed in the selected ion-monitoring mode under the optimal chromatographic conditions. The recovery rates were determined in samples spiked at 0.1 mg/kg and 1.0 mg/kg. The overall recovery rates were 65.3%－142.3%, with a relative standard deviation (RSD) between 3.0% and 20.6%. The detection limit of this method was 0.01－0.08 mg/kg with a signal/noise ratio of 3. This developed method is characteristics of high sensitivity and accuracy, which is suitable for the simultaneous determination of pesticide residues.

A reversed-phase high performance liquid chromatography (RP-HPLC) method was established to simultaneously determine six artificial sweeteners including aspartame (ASP), sodium saccharin (SA), sodium cyclamate (SC), acesulfame potassium (AK), neotame (NTM) and stevioside. The separation was carried out on a Platicil ODS (250 mm × 4.6 mm, 5μm) column through gradient elution using 20 mmol/L (NH4)2SO4-acetonitrile (pH 4.4) as mobile phase. The whole separation process was completed in 30 min before diode array detection. An excellent linear relationship between peak area and sweetener concentration in the range of 0.4－120 mg/L with a correlation coefficient varying from 0.99967 to 0.99998 was observed. The recovery rates of spiked samples in the range of 4.0－10.0 mg/kg ranged from 85% to 107% with a relative standard deviation less than 3.2%. Therefore, this method is characteristics of simple operation, rapid detection and excellent purification efficiency so that it can be used for the routine analysis of these sweet additives in foods and beverages.

A reverse phase high performance liquid chromatography (RP-HPLC) method has been developed for determining dinotefuran, clothianidin, imidacloprid and acetamiprid residues in rice. Neonicotinoid residues were extracted from the sample by acetonitrile, and then cleaned up with ENVI-Florisil and carb SPE tube. The HPLC detection was performed using a DAD detector in the external standard mode. Results indicated that average recovery rates in spiked samples were in the range of 75.5%－96.0%, the relative standard deviations varied between 0.49% and 4.36% and the detection limit was 0.004 mg/kg. A good linear correlation between peak areas and the concentrations of four neonicotinoid residues was observed in the range of 0.1－1000μg/mL with a calibration coefficient of 0.9996.

An ultra-high performance liquid chromatography-quadrupole tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of cyanuric acid residues in milk powder. Samples were thoroughly suspended in 60 ℃ water and dialyzed against deionized water for 3 h in 60 ℃ water bath before analysis on reversed-phase high performance liquid chromatography-quadrupole tandem mass spectrometry. Mass spectral acquisition was applied with a multiple reaction-monitoring (MRM) mode. Qualitative analysis was achieved on the basis of the retention time and information about parent ions and two daughter ions. Quantitative determination was carried out on the basis of the characteristic ion of m/z 42.0. The linear range for cyanuric acid was between 5μg/L and100μg/L with a correlation coefficients (r2) of larger than 0.9999. The average recovery rate for cyanuric acid ranged between 87.5% and 98.8% in milk powder samples spiked at the levels of 100.0, 500.0 μg/kg and 1000.0μg/kg. The relative standard deviation (RSD) was less than 9%. The detection limit of this method was 100.0μg/kg. Therefore, this method is simple and suitable for routine analysis of milk powder.

A graphite furnace atomic absorption spectrometry (GFAAS) method was established to determine the amount of tin in foods under the condition of closed vessel digestion. Samples were subjected to determination at ashing temperature of 1000 ℃ and atomization temperature of 1800 ℃ using PdCl2 and Mg(NO3)2 as the matrix modifiers. Under the optimal determination conditions, an excellent linear relationship was observed in the concentration range of 0.05－0.20 mg/L. The detection limit, recovery rate and accuracy of this developed method were 6.7μg/L, 99.2%－104.4% and 4.3%, respectively. Therefore, this developed method is characteristics of simple operation, high accuracy and excellent sensitivity so that it can meet the requirement for the determination of tin in foods with low concentration.

Selenium contents with different chemical states and valences in two kinds of Se-enriched s.pirulina tablets were determined by atomic fluorescence spectrometry generated from hydride. The effects of atomizer height, HCl concentration and KBH4 concentration on Se fluorescence signal were investigated. The microwave digestion and wet digestion were also compared. In addition, the effects of ultrasonic cell-break method and repeated freezing-thaw method on the extraction rate of protein were explored. Results indicated that two digestion methods had no significant difference (P = 0.6900), and selenium content in samples treated by repeated freezing-thaw method was only 25%－30% of that treated by ultrasonic cell-break method, which suggested that ultrasonic cell-break method was better than repeated freezing-thaw method. Under the optimal conditions, selenium contents in Se-enriched s.pirulina tablets were significant difference (P < 0.0001). Although both inorganic Se and organic Se co-existed, the organic Se in the states of Se (IV) and Se (VI) was still prominent, which was up to 60%. The contents of Se in both states in sample 1 revealed a significant difference (P = 0.0094), but the contents of Se in both states in sample 2 had no significant difference (P = 0.2269). The detection limit of this method was 0.64 ng/g, and the recovery rate of spiked samples was in the range of 93.0%－98.8%. Therefore, this method is characteristics of simple operation, high sensitivity and low detection limit, and provides a theoretical reference for determining the content of Se in different states and valences from Se-enriched s.pirulina tablets.

The aromatic composition of fresh glorious orange juice was analyzed by solid phase microextraction (SPME) coupled with gas chromatography-mass spectroscopy (GC-MS). The difference in aromatic component among fresh orange juices extracted by different SPME fibers was compared. Results indicated that 53 kinds of aromatic components including hydrocarbons, esters, alcohols, aldehydes and ketones were identified. The major aromatic components in fresh orange juice were limonene, β-myrcene, linalool, α-terpineol, terpinen-4-ol, ethyl butyrate, octanal, α-pinene and β-phellandrene.

Objective: A reverse-phase high performance liquid chromatography (RP-HPLC) coupled with micelle-mediated extraction method was developed for the simultaneous determination of five isoflavonoids such as puerarin, daidzin, daidzein, genistin and genistein from kudzu powder. Methods: The non-ionic surfactant Triton X-114 was used as the extraction solvent. The chromatographic separation of samples was performed on a Phenomenex C18 column using methanol-0.25% glacial acetic acid as the mobile phase by means of gradient elution and a UV detector set at 250 nm was used for detection. The chromatographic conditions were explored to optimize the micelle-mediated extraction and enrichment of cloud points. Results: The highest extraction rate of isoflavonoids was achieved using 3 g/100 mL Triton X-114 as the surfactant for ultrasonic-assisted extraction at 40 ℃ for 30 min with a material/liquid ratio of 1: 100 (g/mL). Sodium chloride was added to the extract to improve extraction rate and cloud point enrichment. The limit of detection (LOD) of this developed method was in the range of 0.016－0.079μg/mL (RSN=3) with average recovery rates ranging between 93.7% and 98.86%. The enrichment factor was approximately 12.5. Conclusion: This developed method is characteristics of simple operation, low cost, high extraction efficiency and less pollution to environment, which is suitable for the quality control of five isoflavonoids in kudzu powder.

The method of visible and near-infrared diffuse reflection (VIS/NIR) spectroscopy was used to rapidly determine soluble solid content (SSC) of intact Mopan persimmon fruits. In spectral region between 570 nm and 1848 nm, calibration results for the SSC of fruits were compared with different regression techniques, different derivative treatments and different scatter and standard treatments. The results indicated that the modified partial least squares (MPLS) model with the first derivative D1 log(1/R) processing and disscattering treatment provided better prediction performance for the SSC in fruits. The correlation coefficient of cross validation (Rcv), correlation coefficient of prediction (Rp2), root-mean-square error of cross-validation (RMSECV) and root-mean-square error of prediction (RMSEP) were 0.8076, 0.8085, 0.4546 °Brix and 0.4482 °Brix, respectively. These results confirmed that it is feasible to use the established VIS/NIR spectroscopy model for the nondestructive determination of the SSC in Mopan persimmon fruits.

The solvent extraction-differential pulse stripping voltammetry method was developed to determine O-phenlyphenol (OPP) in orange peel. In order to avoid the influence of ascorbic acid and essential oil, OPP was extracted by toluene from orange peel. Under the optimal conditions, differential pulse stripping voltammetry was used to determine OPP in orange peel. The results demonstrated that the oxidative peak current of OPP was linearly correlated with the OPP concentrations in the range of 2.0 × 10-9 －4.0 × 10-6 mol/L. The detection limit and recovery rate of this developed method were 8.1 × 10-10 mol/L and 106.7%－112.2%, respectively. Therefore, this developed method is characteristics of simple operation, fast detection, high sensitivity and accuracy. 

In order to establish a gas chromatography method for 11 kinds of pesticide residues in vegetables, the pre-treatment method for vegetables according to the standard of NY/T 761－2008 entitled   Determination of organic phosphorus, organic nitrogen, pyrethroid and carbamate pesticide residues in fruits and vegetables   was modified. Meanwhile, the effect of vegetable matrix on determination efficiency of pesticide residues was explored. During the determination of pesticide residues, DB-17 capillary separation column and flame photometric detector (FPD) were used. The results indicated that 11 organophosphorus pesticide residues could be effectively separated. The recovery rates of 11 pesticides in cucumber, tomato and ginger with three spiked levels were in the range of 71.2%－117.9%. The relative standard deviation (RSD) was in the range of 2.1% to 11.2%. The detection limit of this method was 0.005－0.060 mg/kg for DB-17 column, and the retention time was 6.396－19.400 min. The calibration curves revealed a good linear relationship with correlation coefficients of more than 0.999. Under the heating at 40 ℃ by N2, the recovery rates of dichlorovos and phorate could be enhanced up to 95.00%－103.3%, respectively. A small amount of impure peaks in cabbage, baby vegetables and Shanghai green, and a large number of matrix peaks in garlic chive could interfere with the detection of pesticide residues.

Volatile oils extracted from the fruits of Schisandra spenanthera Rehd. et Wils. and Schisandra chinensis (Turcz) Baill. with supercritical CO2 fluid were analyzed for their chemical composition by gas chromatography-mass spectrometry (GC-MS) based on area normalization. Results indicated that the major components in volatile oils were terpendids with relative contents of 62.97% and 73.05%. The major compounds in volatile oil extracted from Schisandra spenanthera β-himachalene (7.88%), 2,6-dimethyl-6-(4-methyl-3-pentenyl) bicyclo [3,1,1] hep-2-ene (6.44%), and δ-elemene (6.39%). The major compounds in volatile oil extracted from Schisandra chinensis were α-ylangene (19.09%), α-curcumene (16.03%) and β-himachalene (7.71%).

A rapid and sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of gibberellin residue in vegetables and fruits was developed. The gibberellin in samples was primarily extracted by methanol solution and further extracted by ethyl acetate after pH adjustment from 3 to 4. The extract was purified by C18 column and detected by HPLC-MS/MS with quantification through an external standard method. Linear range of gibberellin in this determination method was between 0.01μg/mL and 10.0μg/mL, and the detection limit was 0.01 μg/mL. The recovery rates of gibberellin in all samples at a spiked level ranging from 0.02 to 1.0 mg/kg were in the range of 77.0% to 100.0% with a CV of 3.39%－10.05%. The results indicated that this developed method was characteristics of high sensitivity and accuracy as wall as low detection limit, which could meet the requirement of MRL determination.

Objective: To establish a multiplex PCR for simultaneously detecting Staphylococcus aureus, Shigella spp., Salmonella spp. and Listeria monocytogenes in meat. Methods: The primers were designed according to Staphylococcus aureus nuc gene, Shigella spp. ipaH gene, Salmonella spp. invA gene and Listeria monocytogenes inlA gene. The target genes were amplified by multiplex PCR under optimized reaction conditions. Results: Four bacterial pathogens could be amplified, which revealed the special bands at the corresponding locations. When the meat samples were contaminated with four pathogens, the detection limits of Staphylococcus aureus and Salmonella spp. were 102 CFU/mL, and the detection limits of Shigella spp. and Listeria monocytogenes were 101 CFU/mL. Conclusion: The established multiplex PCR method is more specific, rapid, and sensitive than traditional detection methods, which is suitable for the rapid detection of Staphylococcus aureus, Shigella spp., Salmonella spp. and Listeria monocytogenes in meat.

The volatile components and fatty acids in tiger frog meat were analyzed by headspace-solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). Results indicated that 36 volatile compounds were isolated and identified, which included 15 aldehydes with the highest content and were accounted for 68.76% of total volatile components. Hexanal, (Z)-4-heptenal, (E,Z)-2,4-decadienal, (E,E)-2,4-decadienal, 1-octen-3-ol and 2,3-pentanedione made the great contribution to the total flavor of tiger frog meat. The fatty acids of tiger frog meat were dominated by unsaturated fatty acids (UFA), which was accounted for 72.89% of total fatty acids. Tiger frog meat was an n-3 PUFA-rich food source in daily diet. Linolenic acid (C18:3 n-3, ALA), eicosapentaenoic acid (C20:5 n-3, EPA) and docosaheraenoic acid (C22:6 n-3, DHA) were the major n-3 PUFA. UFA was the important aromatic precursor of tiger frog meat.

A simultaneous determination method for 7 kinds of carbamate residues in vegetables was developed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples was extracted with acetonitrile and cleaned-up by NH2 solid phase extraction (SPE) cartridges. The analytes were quantified by UPLC-MS/MS in a positive ion multiple reaction mode (MRM). An excellent linear relationship for 7 carbamate residues was observed in the concentration range of 5－200μg/L with the regression coefficients of 0.9977－0.9999. The average recovery rate of 7 carbamate residues in vegetables at the spiked level of 0.01－0.10 mg/kg was in the range of 72.1%－110.2% with relative standard deviation of 1.7%－9.4%. This developed method revealed a detection limit range of 0.5－8.0μg/kg (RSN = 10). Therefore, this developed method is characteristics of simple operation, high sensitivity and precision, which can meet the requirements for simultaneous determination of carbamate pesticide residues in vegetables for inspection and confirmation.

The aroma components in Cabernet Gernischt, Cabernet Sauvignon, Cabernet Franc and Merlot were identified by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). The aroma components in grapes were extracted by vibrating extraction at constant temperature, and the non-volatile components were removed by solvent-assisted flavor evaporation (SAFE). The volatile components were condensed by N2 and analyzed by GC-MS and GC-O methods. A total of 67 aroma compounds were detected and 60 aroma compounds were identified in four kinds of grapes. The major aroma compounds were hexanal, 1-hexanol, (Z)-3-hexen-1-ol, acetic acid, (E,Z)-2,6-nonadienal, 3-methylbutanoic acid, anethole, hexanoic acid, benzyl alcohol, β-phenylethyl alcohol, β-ionone, 2-hexenoic acid, 4-methoxy benzaldehyde, and an unknown herb-like compound. Although similar aroma components were observed in four kinds of grapes, the aroma intensities of these aroma components were different. These aroma components were classified into seven categories including fruit aroma, plant flavor, chemical flavor, microbiological flavor, floral flavor, caramel flavor and other flavors according to wine aroma wheel. Among 4 kinds of grapes, the chemical flavor exhibited the highest aroma intensity, which was followed by floral flavor, plant flavor and fruit flavor. The aroma characters of four winemaking grapes were closely correlated with the contents of volatile aroma compounds.

A high performance liquid chromatography (HPLC) method was developed to determine imidaclprid residue in fruits. Samples were extracted by the improved QuEChERS method using acetonitrile as the solvent and purified on C18/PSA column. The detection limit of this developed HPLC method was 0.05 mg/kg and the linear correlation coefficient of standard curve was 0.9988. Recovery rates for imidaclprid in spiked samples at 0.05, 0.1 mg/kg and 0.20 mg/kg was in the range of 92%－102% with a relative standard deviation varying from 5% to 11%. Therefore, this developed method is characteristics of rapid determination, high accuracy and sensitivity so that it is suitable for the detection of imidaclprid residue in fruits.

A novel method for the analysis of isoflavonoids in soybean was established by rapid resolution liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (RRLC-Q-TOF-MS). Samples were extracted with methanol under ultrasound assistance, and then a Welch Materials C18 column was applied in the RRLC separation using acetonitrile and water (0.1% formic acid) as the mobile phase. Elutes were detected by Q-TOF to obtain MS spectra with a positive ion mode. Nine isoflavonoids were identified. Therefore, this method can be used to rapidly determine isoflavonoids of soybean.

In order to minimize the interference in xanthine oxidase method for the determination of superoxide dismutase (SOD) activity in animal and plant tissues, the xanthine oxidase method was modified. The optimal experimental conditions for preparing bank samples were explored by measuring the activity and circular dichroism spectrum of SOD. A heated sample was designed as the experimental blank. Subtraction rule was used to eliminate the interference of other substances in xanthine oxidase system. Standard addition recovery experiments and actual determination of SOD activity in animal and plant tissues were used to compare the method with and without modification. Results indicated that the improved xanthine oxidase method could result in more accurate determination of SOD activity in animal and plant tissues.

Objective: To establish a method for the extraction and determination of five volatile halogenerated hydrocarbons (VHHs) in edible oil by headspace solid-phase microextraction (HS-SPME) and gas chromatography-electron capture detector (GC-ECD). Methods: Samples were subjected to headspace extraction with 5 types of fiber (Supelco Inc.). Extraction efficiencies of different fibers were compared, and the effects of extraction temperature, extraction time, and solvent volume were investigated. The chromatographic separation was carried out on a capillary column equipped to a gas chromatography system with electron capture detector. Results: CAR/PDMS fiber of 75μm was the selected fiber. After pouring 9 mL of edible oil in a 15 mL vial, the extraction was conducted at the equilibrium temperature of 60 ℃ and extraction time of 30 min. The desorption of fiber was performed at 290 ℃ for 3 min. The detection limit of the established method ranged from 0.02 (tetrachloroethylene) to 1.4 ng/mL (trichloro ethane). The average recovery rate was in the range of 89%－105% with a relative standard derivation (RSD) of less than 8.5%. Conclusion: This method is simple, practical, and sensitive, which is suitable for the determination of VHHs in edible oil.

Purple potato was used as the raw material to extract pigment by microwave and ultrasonic methods. Both methods were compared and optimal extraction parameters of both methods were also explored. The results showed that the optimal microwave extraction conditions were using a 10-fold volume of a mixture of HCl and C2H5OH at a ratio of 50:50 as the extraction solvent to extract the raw material for 12 min at 75 ℃ in a microwave field. The optimal solvent composition for  ultrasonic extraction consisted of HCl and C2H5OH at a ratio of 40:60, and material/liquid ratio of 1:30 (g/mL), ultrasonic treatment time of 30 min and extraction temperature of 60 ℃. Microwave extraction derived purple sweet potato pigment had higher hydroxyl free radical scavenging capacity than purple sweet potato pigment obtained by ultrasonic extraction. Overall, microwave extraction is superior to ultrasonic extraction.

The content of reduced glutathione (GSH) in Lycium barbarum L fruits was determined by mass spectroscopy and UV-visible spectroscopy using 5,5＇-dithio-bis-nitrobenzoic acid (DTNB) as the simultaneous derivatizing agent. GSH in Lycium barbarum L fruits was significantly affected by extracellular chemical environment during sample treatment. Extraction  with DTNB as the simultaneous derivatizing agent inhibited the transformation or decomposition of GSH due to immediate derivatization during sample treatment. Quantitative determination results indicated that Lycium barbarum L fruits contained GSH in the range of (6.56±0.54) mg/g, which was one of the most GSH-abundant plant species.

Objective: To analyze the contents of saccharides, the molecular weights of polysaccharides and monosaccharide composition of Abelmoschus manihot gum (AMG) from four different sources. Methods: The contents of reducing sugars, total saccharides and polysaccharides in four kinds of AMG samples were determined by 3,5-dinitros-alicylic acid (DNS) colorimetric method. Infrared spectra (IR) of AMG samples were also analyzed. The molecular weights of polysaccharides in purified AMG samples were characterized by gel permeation chromatography (GPC), and the monosaccharide composition of AMG samples were analyzed by gas chromatography (GC). Results: The contents of reducing sugars were 51.07%, 9.00%, 53.94% and 11.46%, respectively; the contents of total saccharides were 79.95%, 78.99%, 91.98% and 61.13%, respectively; and the contents of polysaccharides were 28.88%, 69.99%, 38.04% and 49.67%, respectivly, in four kinds of AMG samples. Infrared spectra indicated that AMG-1 and AMG-3 were mainly composed of α-D-glucopyranose, while AMG-2 and AMG-4 were mainly composed of mannose. The peak molecular weights of AMG polysaccharides were 3.91 × 103, 5.36 × 105, 3.87 × 103 and 5.12 × 105, respectivly. All four kinds of AMG samples contained mannose, glucose and galactose; and their molar ratios were 0.42:1.00:0.27, 1.00:0.15:0.54, 0.27:1.00:0.15 and 1.00:0.12:0.48, respectivly. Conclusion: The contents of reducing sugars, total saccharides and polysaccharides, the molecular weights of polysaccharides and monosaccharide composition apparently differ among AMG gums from different sources.

The effect of yeast mannan treatment on the growth of Monilinia fructicola in potato dextrose agar (PDA) medium and the brown rot disease of plum fruits was studied. In vitro experiments showed that yeast mannan treatment with different concentrations (5, 25, 50 g/L and 100 g/L) could obviously inhibit the growth of Monilinia fructicola hypha, and the inhibitory effect of yeast mannan treatment on the growth of fungi was in a concentration-dependent manner. In vivo tests showed that yeast mannan treatment could effectively inhibit brown rot disease of plum fruits inoculated with Monilinia fructicola before/after yeast mannan dipping. Yeast mannan treatment could also reduce the respiration intensity and weight-loss rate, and delay the color change of plum fruits stored at 23 ℃, which could maintain better storage quality of plum fruits.

The effects of hot water treatment and/or β-aminobutyric acid (BABA) treatment on the incidence of blue mold rot disease in postharvest apple fruits were studied. Combined hot water and BABA treatment conditions were also optimized by orthogonal array design. The results showed that hot water and BABA treatment alone could effectively reduce lesion diameter of apple inoculated with Penicillium expansum. The lesion diameters of apple fruits treated with 45 ℃ hot water alone for 8 min and with 50 mmol/L BABA alone for 5 min were 82.86% and 80.76%, respectively, when compared with the control. In addition, the combined order of hot water and BABA had no significant effect on disease control; however, the interval time had an obvious effect on disease control. The optimal conditions for combined hot water and BABA treatment were hot water treatment at 45 ℃ for 6 min and then 50 mmol/L BABA treatment for 5 min with an interval of 10 min. Validation experiments also indicated that combined treatment with hot water and BABA can effectively shorten duration time of heat treatment and significantly improve disease control capability for blue mold rot in postharvest apple fruits.

In this study, the effect of storage temperature on the respiratory intensity and quality of eggs was investigated. Results indicated that the respiratory intensity of eggs was increased with increasing storage temperature and was inhibited effectively during storage at 4 ℃. The respiratory peak occurred at 4 ℃ and 25 ℃, respectively, during 30 days of storage. The respiratory peak of eggs stored at 4 ℃ was reduced by 40% and had a 3 day delayed occurrence when compared with those stored at 25 ℃. Increased weight loss rate and air cell diameter in eggs were observed during the extension of storage time. Haugh unit exhibited a slow decrease at 4 ℃ and the eggs still remained at AA grade until the 30th day of storage. In contrast, Haugh unit revealed a dramatic decrease at 25 ℃ and the grade of the eggs was decreased to A until the 6th day of storage period.

Cross-linked cassava starch was used as the major material to coat mandarin oranges. Coated mandarin oranges during the storage for 36 days at room temperature were subjected to the determination of changes in weight loss rate, decay rate, soluble sugar content, respiration intensity and vitamin C content. The results indicated that cross-linked cassava starch, especially highly cross-linked starch, could efficiently prolong the storage life of oranges. Compared with the control group, weight loss rate, decay rate, soluble sugar consumption amount, respiration intensity and vitamin C loss rate of the film-coated oranges were lower.  

In order to improve the quality of tomatoes during storage,   Liaoyuanduoli   tomatoes were chosen as the experimental materials to explore the effect of calcium-spraying treatment on the quality of tomatoes during cold storage period. The results indicated that spraying treatment of tomatoes with calcium agents resulted in the decrease of the firmness, soluble solid contents, reducing sugar content, titratable acid content and free amino acids in tomatoes during cold storage. The treatment with calcium pantothenate could result in the slowest decrease of tomato firmness, which was 14.33 kg/cm2 for tomato firmness at the end of storage period. The decline of other indices revealed the slowest decline in the tomatoes treated by humic acid calcium. The red-converting index showed an increasing trend and the best red-converting efficiency resulted from the treatment of humic acid calcium, which revealed 19% higher than the control. The lycopene was up to 4.55 mg/100 g in the humic acid-treated tomatoes. In general, humic acid calcium treatment has multiple obvious advantages.

Chilled chicken was subjected to immersion treatment with a compound natural preservative composed of Nisin, tea polyphenols, spice extract and vitamin C and then chill storage at 4 ℃. On the basis of total microorganism counts and TBARS in treated chicken, the optimal compound preservative formula was determined by orthogonal array design to consist of 0.025% Nisin, 0.05% tea polyphenols, 2.0% spice extract and 0.02% vitamin C. The total viable count, sensory score, TVB-N and TBARS of preservative-treated chicken were 4.21 lg(CFU/g), 9, 7.57 mg/100 g and 0.229 mg/mL on the 7th day of storage; and 6.07, 5.8, 30.54 mg/100 g and 0.693 mg/mL on the 22nd days of storage, respectively. Every index on the 21st day of storage was in the ranges allowed by national standards. Therefore, the shelf life time of chicken treated by optimal compound natural preservative is 21 days.

The screening of compound browning inhibitors for fresh-cut potatoes was explored by quadratic rotation composite design. The effect of screened compound browning inhibitor on polyphenol oxidase (PPO) activity and browning degree of fresh-cut potatoes during storage period was also analyzed. The results indicated that the optimal formula of compound inhibitor for controlling the browning of fresh-cut potatoes based on orthogonal design was 0.005% kojic acid, 0.045% isoascorbic acid, 0.045% L-Cys, 0.01% CaCl2 and 0.2992% EDTA-2Na. This compound inhibitor could obviously inhibit PPO activity, delay PPO activity peak for more than 6 days, and attenuate the browning degree of fresh-cut potatoes. The sensory quality of fresh-cut potatoes treated with this compound inhibitor was much better than that of fresh-cut potatoes treated with NaHSO3 and distilled water control group. Therefore, this screened browning inhibitor for fresh-cut potatoes is highly effective and has the potential to be an alternative to NaHSO3 as a browning inhibitor and be used for the manufacturing and circulation of potatoes.

In this study, the effects of different fertilizer treatments during growth period on storage quality of Dongzao jujube were investigated. Three kinds of fertilizers (amino acid fertilizer, mineral fertilizer and rare earth fertilizer) were used to treat Dongzao jujube during the development periods from blooms to young fruits. Dongzao jujube trees submitted to normal management were used as the control. All fruits were harvested after 110 days of blooms and the samples were analyzed at six different stages during 105 days of storage. The results showed that the mature degree and the total sugar content of treated fruits were higher than those of the control. During storage, all treated fruits exhibited an earlier stage for turning red, weak and rot than that of the control fruits. A significant increase of total sugar content in amino acid fertilizer treated fruits during the whole storage period was observed, followed by the treatment of mineral fertilizer, rare earth fertilizer and the control. Mineral fertilizer could obviously increase the content of vitamin C during storage, but did not result in a significant difference of total acid content and fruit firmness. Therefore, all fertilizer treatments could increase fruit quality of Dongzao jujube in a certain extent, and also result in negative impact during storage.

Friar plum (Prunus salicina Lindl.) was used as the raw material to explore the effect of gas composition on fruit quality and preservation of fruits during modified atmosphere cold storage. The results showed that the optimal gas composition for the storage of Friar plum was composed of O2 ≥ 2% and CO2 ≤ 5%. Under the optimal gas conditions, the storage life of plum fruits at 0－1 ℃ exceeded 3 months. After the storage, fruit firmness and the contents of titratable acids in fruits were declined. The conductivity of pulp was increased when compared with pre-storage. The percentage of good fruits was higher than 85% and the rotting rate was less than 10%. In addition, the color and flavor of fruits were normal. 

Twin-screw extruder processing was used to prepare textured soybean protein (TSP). The effects of protein, fat and starch amounts and water content on TSP quality were explored by orthogonal tests coupled with principal component analysis. In addition, TSP was used as the raw material to prepare meatballs. The effects of salt, sugar, beef perfume and monosodium glutamate on the flavor and texture parameters of meatballs were investigated. The results showed that the descending order of material components for affecting TSP quality was fat, protein, water content and starch, respectively. Meanwhile, the optimal material system was composed of 30% water, 20% soybean protein isolate, 25% potato starch, and 6% soybean oil. Moreover, the optimal flavor formula of meatballs was 4% salt, 1% sugar, 1.5% beef perfume and 1% monosodium glutamate. Texture property analysis showed that texture parameters of meatballs at the compression ratio of 50% were 6.111 kg of hardness, 0.765 of cohesion, 0.869 of elasticity, 4.113 kg of chewiness and 0.429 of resilience.

 Objective: To develop a fruit vinegar beverage using pepino fruits as the raw material. Methods: Alcohol fermentation, acetic acid fermentation and beverage formulation were studied for the development of pepino fruit vinegar beverage. Results: The optimal acetic acid fermentation conditions were determined by orthogonal array design to be pH of 4.0, fermentation temperature of 30 ℃, fermentation time of 6 days, and acetic acid bacteria inoculation amount of 7%. The optimal formula of pepino fruit vinegar beverage consisted of fruit vinegar fluid of 10%, fruit vinegar sugar content of 12%, and salt addition amount of 0.4%. Conclusion: The developed fruit vinegar beverage is rich nutrients and has a balanced sweet-and-sour taste.

Nano-Fe2O3-modified graphite electrode was prepared and used as a new potentiometric sensor for the detection of ascorbic acid. The properties, determination conditions and factors of this potentiometric sensor were explored. Results indicated that the linear range of this sensor in phosphate buffer solution with pH 6.5 ranged from 1.0 × 10-6 to 1.0 × 10-3 mol/L (r = －0.9969) with－30.2 mV/pC slope and 8.9 × 10-7 mol/L detection limit. This sensor has been used for determining ascorbic acid in orange juice and vitamin C tablets with satisfactory results. 

Agaricus bisporus is a natural healthy food. In order to improve the nutritional value of dried noodles, the optimal preparation process for dried noodles with Agaricus bisporus was explored by orthogonal array design. The optimal preparation parameters were Agaricus bisporus powder addition amount of 5%, sodium alginate addition amount of 0.3% and salt amount of 3% and water 40－50 mL/100 g. The final product has an appetizing appearance, unique flavor and healthcare function.