Selective precipitation of αs- and β-caseins from skimmed milk was achieved by the addition of calcium salt at alkaline pH. Effects of final concentration of CaCl2 (adding different volumes of 0.5 mol/L CaCl2 solution to skimmed milk), cooling temperature and repeated dissolution-precipitation procedure times on separation of αs-casein were analyzed by measuring purity of final products using SDS-PAGE followed by Coomassie brilliant blue staining, along with effects of the former two factors on separation of β -casein. The results showed that αs-casein with a purity of 83.33% and β -casein with a purity of 109.53% could obtained when the final concentration of CaCl2 was 0.065 mol/L, the cooling temperature 2 ℃, and the dissolutionprecipitation procedure repeated three times.

Compared to traditional column chromatography, high speed countercurrent chromatography (HSCCC) has many advantages such as rapid separation, low sample adsorption, good separation reproducibility, etc. Therefore, this study employed HSCCC to purify crude flavonoid extract from Rosa roxburghii Tratt fruit. The purification was performed using a twophase solvent system composed of chloroform, methanol and water (4:4:2, V/V) at a flow rate of 1.0 ml/min, when the rotation speed and the detection wavelength were set at 800 r/min and 254 nm, respectively. The results showed that five flavonoid compounds whose purities were 75.6%, 95.1%, 73.5%, 89.1% and 87.7%, respectively were obtained, and their masses were 21, 8, 11, 20 and 55 mg, respectively (obtained from 318 mg of dry crude flavonoid extract from Rosa roxburghii Tratt fruit).

The extraction of ginsenosides from Panax ginseng root using supercritical CO2 reverse microemulsion formed by bis(2-ethylhexyl) sodium sulfosuccinate (AOT), ethanol and water was studied, which was carried out in a 1 L supercritical CO2 extraction device. Single-factor and orthogonal array design methods were applied to optimize the extraction. The effects of 7 parameters on ginsenosides extraction were investigated by the single-factor method. A higher extraction yield of ginsenosides was achieved using ethanol as the cosufactant in comparison with butanol and n-pentanol, with the optimal added amount of 120 ml/ 100 g ginseng. Other 5 parameters such as amount of added water, amount of added AOT, extraction time, temperature and pressure were optimized using the orthogonal array design method. The optimal levels of the 5 parameters for improved ginsenosides extraction were determined as follows: amount of added water 36 ml/ 100 g ginseng, amount of added AOT 0.06 mol/100 g ginseng, extraction time 3 h, extraction temperature 55 ℃ and extraction pressure 30 MPa. An extraction yield of 0.757% was achieved under the optimized conditions. Moreover a dynamic model for ginsenosides yield as a function of extraction time was developed, which was E = 0.870 × (1－ e-0.618t). Compared to supercritical CO2 extraction (SCE), this extraction method yielded more ginsenosides.

One-factor-at-a-time (OFAT) experiments were conducted to analyze five factors affecting extraction yield of apple seed oil including grinding granularity of apple seeds, extraction pressure, duration and temperature. Based on the experimental results obtained, the influences of three key factors including extraction pressure, duration and temperature and their interactions on enzyme hydrolysis were evaluated by response surface methodology. The optimal levels for each variable to obtain the highest extraction yield of apple seed oil were as follows: pressure 41 MPa, temperature 56 ℃, and duration 110 min. Under such conditions as well as grinding granularity of material 60 mesh and CO2 flow rate 1.8 ml/min, the extraction yield of apple seed oil reached 24.36%.

Generally, the purity of crude polysaccharide extracted from Bletilla striata roots applied in Chinese traditional medicine is no higher than 80%, which seriously restricts its further utilization as an additive or a medicine material. In order to purify the crude polysaccharide extracted from Bletilla striata roots using 80% ethanol, this study employed the enzymatic hydrolysis technology to remove protein impurities from the crude polysaccharide extract. Papain was selected for further study because it presented the most outstanding efficiency of protein removal compared to neutral protease, chymocotrypsin, Amano protease, papain and alkaline protease. Four parameters affecting the efficiency of protein removal of papain including enzyme concentration, pH value, temperature and enzymolysis duration were investigated by one-factor-at-a-time (OFAT) experiments. The optimum ranges of the four parameters for protein removal were as follows: enzyme concentration 8 － 10 mg/g substrate, pH 7.0 － 7.5, temperature 45 － 50℃, and enzymolysis duration 120 － 150 min, and in verification experiments repeated three times a highest purity of 97.0% of the polysaccharide was observed, as well as a decrease of protein content in the crude polysaccharide from 0.91% to 0.32%. When papain was directly added to the extraction solution, a purity of 92.0% could be achieved at 4 h of extraction. The one-step extraction – purification procedure may be a more simple and rapid technique for the extraction and purification of polysaccharide from Bletilla striata roots.

Yellow pigment is traditionally extracted from corn bran with organic solvent in water bath. This extraction method, however, is reagent- and time- consuming, greatly toxicity-causing and lowly effective, and the yellow pigment extracted by the method is easily oxidized. This study aimed to set up a microwave-assisted organic solvent extraction method of yellow pigment from corn bran. The one-factor-at-a-time method was applied to investigate four parameters affecting the extraction of yellow pigment, and then the four parameters were optimized using orthogonal test design. Furthermore, stability of the yellow pigment under various environmental conditions was analyzed. The results showed that the optimal microwave-assisted extraction conditions were as follows: microwave power 400 W, ethanol concentration (extraction solvent) 80%, irradiation duration 60 s, and material/liquid ratio 1:8. Common food additives such as sugar, citrate acid and chloride sodium had little effects on stability of the yellow pigment, while sodium benzoate had some effect. The yellow pigment had good heat resistance, but poor light resistance. Good oxidation resistance was observed in it, but its reducing resistance was slightly poor. The yellow pigment was stable in acid, neutral and weakly alkaline media.

The brown rice, polished rice and rice bran of Oryza sativa L. subsp. japonica were analyzed for their proximate compositions and protein compositions. Soluble proteins were extracted from the brown rice, polished rice and defatted rice bran (our study indicated that removal of fat was favorable to dissolution of proteins) using deionized water (pH 8.5), respectively, and response surface methodology was adopted to optimize the extraction of water-soluble proteins from the three materials based on one-factor-at-a-time experiments. In addition, the water-soluble proteins from different sources were subjected to analyses of solubility and molecular weight distribution. Protein composition analysis showed that both the brown rice and polished rice contained mainly glutelin, and the glutelin content in the former was 4.78% lower than that in the latter, while the former contained more albumin than latter by 55.93%; the contents of globulin and albumin in the brown rice were lower than those in the rice bran by 77.22% and 44.59%, respectively, while the glutelin content in the former was higher than that in the latter. All extraction duration, temperature, material/liquid ratio influenced yields of water-soluble proteins from these three materials to different extents — among the three factors, material/liquid ratio was the most significant one influencing all the extraction of water-soluble proteins from the three rice materials; temperature was a significant factor that influenced the extraction of polished rice water-soluble proteins (p ＜ 0.05), and for the extraction of rice bran water-soluble proteins, it was a extremely significant factor (p ＜ 0.05), while no significant influence was observe on the extraction of brown rice water-soluble proteins; extraction duration only presented significant influence on the extraction of polished rice water-soluble proteins (p ＜ 0.05). Three quadratic polynomial models for the extraction of water-soluble proteins from the three different materials were set up by response surface regression analysis. Predicted and actual values of extraction yield of water-soluble proteins were well fitted, indicating their validity was good. Solubility and SDS-PAGE analyses revealed that the solubility and molecular weight distribution of water-soluble proteins from brown rice were between those from polished rice and rice bran proteins.

The study was conducted to remove impurities from inulin extract, which was extracted of Jerusalem artichoke Tubers using hot water, by the carbonation reaction between lime and carbon dioxide. The effects of amount of added lime, amount of introduced CO2 and temperature on protein reduction efficiency and Ca2+ concentraction in the inulin extract solution were investigated by single-factor method. Based on canonical analysis, the optimal conditions for maximizing protein reduction efficiency were determined as follows: adding lime to pH 13.4, introducing CO2 to pH 6.8, and reaction temperature 80 ℃. The optimized process resulted in over 81.6% protein reduction and only 3.4% inulin loss (especially, over 90% fructose was contained), indicating notable efficiency to remove reduced sugars with lower loss of inulin.

In order to explore the application feasibility of ultrasonic technique to the extraction of gynosaponins from Gynostemma pentaphyllum, one-factor-at-a-time experiments were conducted to investigate three factors (i.e., material/liquid ratio, temperature and extraction duration) influencing conventional water bath extraction and ultrasonic-enhanced extraction, and to compare efficiency of water bath extraction and ultrasonic-enhanced extraction at different frequencies (40 and 28 kHz) as well. Furthermore, the 28-kHz-frequency ultrasonic-enhanced extraction was optimized by orthogonal array design. Compared with the water bath extraction, the ultrasonic treatment at 40 kHz did not present marked enhancement effect on the extraction of gynosaponins, while the enhancement effect was obvious when ultrasonic frequency was decreased to 28 kHz. The optimal conditions for the 28-kHz-frequency ultrasonic-enhanced extraction were as follows: material/liquid ratio 1:30, temperature 70 ℃, and duration 60 min. The optimized extraction technique yielded 7.5934% of gynosaponins, and it also had good reproducibility and high reliability.

Apotransferrin was prepared from lactoferrin using acetic acid or citric acid, and the apotransferrin prepared using acetic acid was employed to prepare apotransferrin-chromium complex. The effects of acetic acid and citric acid on the apotransferrin preparation were compared by determining product yield and analyzing chemical structure by means of UV and IR absorption spectroscopy. The preparation conditions of apotransferrin-chromium complex were investigated by one-factorat- a-time experiments, and the product was characterized. Fe3+ could be effectively dissociated from lactoferrin by adjusting pH to 2.25 using acetic acid or to 2.50 using citric acid. Compared to citric acid, the use of acetic acid yielded more apotransferrin, but the apotransferrin products prepared using the two reagents had the same functional groups. The optimal complex conditions of apotransferrin with Cr3+ were as follows: 60－70 ℃, pH 7.0－7.6, molar ratio of apolactoferrin to chromium trichloride 1:2, and stirring duration more than 2 h.

The lipolysis-oxidation and its correlations with temperature, NaCl content and air-drying duration were investigated by comparing TBARs, POV and lipoxygenase activity in subcutaneous and intramuscular lipids of dry-cured duck (Cherry Valley variety) during high-temperature (18℃ for 24 h－21℃ for 48 h－24℃ for 72 h－26℃ for 96 h) and low-temperature (8℃ for 24 h－11℃ for 48 h－14℃ for 72 h－16℃ for 96 h) ripening. The results showed that in contrast with low-temperature processing, the POV in subcutaneous lipid was decreased by 30.77% after 72 h high-temperature ripening, and that in intramuscular lipid by 62.50% after 96 h drying; meanwhile, the activity of lipoxygenase was elevated by 7.26% while no significant changes were observed in TBARs. Additionally, the content of free fatty acid (FFA) was positively correlated with temperature during high-temperature processing; As well, NaCl content was significantly positively correlated with TBARs, suggesting that NaCl content and temperature were main factors responsible for lipolysis-oxidation.

Essential oil extracted from Ginkgo biloba fruits by supcritical CO2 fluid extraction technique was microcapsulated by means of spray drying taking β-cyclodextrin and Arabic gum as wall materials and glycerol monostearate as stabilizer. The microcapsule formula and the spray drying parameters were optimized by orthogonal array design. The best material compositions for microencapsulation were as follows: Arabic gum/β-cyclodextrin ratio (m/m) 1:1, core material/wall materials (m/m) 1:3, material concentration (mass-volume percentage, core material plus wall materials to mixed solution) 25%, and addition amount of glyceryl monostearate 0.1%; the optimum spray drying parameters were as follows: feeding speed 30 ml/min, outlet temperature 180 ℃, and inlet temperature 80 ℃. Under the optimal conditions, the microencapsulation efficiency was 90.66%. The microcapsule products were fine yellow or yellowish particles, and the content of moisture, density, solubility and content of flavonodis were 2.28%, 0.82 g/cm3, 98.10% and 5.73 %, respectively.

Ultrasonic technique, cellulose preparation and ion exchange resin were separately adopted to extract pectin from pumpkin flesh prepared into powder. The three extraction techniques were optimized by orthogonal array design, and validity of optimized conditions was verified triply. Additionally, effectiveness of these techniques was compared in terms of pectin yield. The optimal conditions for ultrasonic-assisted extraction were as follows: ultrasonic power 400 W, liquid/material ratio 10:1 (ml/g), extraction duration 35 min, and under these conditions a average pectin yield of 5.98% was achieved; the enzymatic extraction technique achieved an average yield of 9.56% under the optimized conditions as follows: enzymolysis duration 2.0 h, pH 4.5, temperature 55 ℃, and cellulase dose 0.5%; the optimal cation exchange resin (type 732) dose, material/liquid ratio (g/ml), pH, extraction duration, and temperature for extraction of pectin were 15%, 1:20, 2.5, 2.0 h, and 80 ℃, respectively, and under these conditions average yield of pectin was 7.62%. The results showed that compared to the other two extraction techniques cellulose-catalyzed hydrolysis is the most effective approach for preparing pectin from pumpkin.

Milk of white yaks grazing pastures in Tianzhu county, Gansu province was processed into hard cheese. The processing parameters were optimized using one-factor-at-a-time and orthogonal array design in which the interactions between the variables were neglected. In addition, cheese products in ripening period were subjected to analysis of proximate composition and microstructure observation under SEM. High hard cheese yield and good sensory quality both could be achieved when addition amounts of fermentation starter, rennet and CaCl2 were 3%, 30 μl/100 ml and 0.03%, respectively, temperature 40℃, and pH 6.1. The product on the 30th day of ripening contained 27.82 % protein and 36.43% fat, and the yield was 15.5%; no significant microstructure changes were founded during ripening (observed on the 30th, 60th and 90th day).

Microwave was applied to the extraction of oil from Paeonia suffruticosa Andr. seeds. The extraction technique was optimized using response surface methodology. n-Hexane was selected as a optimal extraction solvent because compared to other solvents including petroleum ether (boiling range 30－60℃ or 60－90℃), ethyl acetate and acetone it yielded the most oil and can be easily penetrated by microwave. Effects of three crucial factors (i.e., liquid/material ratio, microwave power and extraction duration) on extraction yield of oil were investigated using one-factor-at-a-time design. Response surface central composition design in which the interactions between the variables were considered was applied to optimize these factors. A quadratic polynomial regression model was developed. The optimal microwave-assisted extraction conditions were as follows: liquid/material ratio (ml/g) 9:1, microwave power 825 W and extraction duration 8 min. Under such conditions, the actual oil yield was 24.52%, between which and the predicted value a relative error of about 0.01% was found. GC-MS Analysis indicated that the oil from Paeonia suffruticosa Andr. seeds was abundant in unsaturated fatty acids, in which the contents of linoleic acid and linolenic acid were 24.57% and 67.13%, respectively.

Cheap and easily available Adinandra nitida leaves contain more than 20% flavonoid compounds that have numerous biological functions such as antioxidation, reducing blood lipid, lowering blood pressure, antimicrobial action, etc. Hot water was adopted to extract flavonoids from Adinandra nitida leaves in the present study. The extraction technique was optimized using response analysis methodology and antioxidant activities of the flavonoids extracted from Adinandra nitida leaves were evaluated by measuring DPPH and superoxide anion radical scavenging activity and reducing power. The optimal extraction conditions were as follows: extraction duration 36 min, water temperature 100 ℃, and ratio of water to material 20:1, and under such conditions the predicted and actual values (an average of three repeats) of flavonoids yield were 8.24% and 8.20%, suggesting that the validity of established regression model was good. HPLC Analysis indicated that the flavonoid extract contained 59.3% camellianin A. The flavonoid extract could significantly scavenge DPPH and superoxide anion free radicals in a dose-dependent manner, meanwhile a linear correlation between its concentration and reducing power was also observed (R2 = 0.9895).

Stir-frying in which oil-stirring procedure is of great importance is one of the most specific Chinese cooking techniques. Traditionally, oil-stirring procedure is accomplished manually. Empirical manual operation, however, cannot accurately control oil temperature, materials/oil ratio and dispersion degree of materials. Automatic stirrer was adopted instead of manual operation in the present study. In order to score the highest comprehensive sensory evaluation, four processing parameters [i.e., oil temperature, material (shredded pork fillet)/oil ratio, stirring frequency and stirring duration] were optimized using orthogonal array design. Three sensory indexes including tenderness, dispersion degree and color were weighed by paired comparison method and sensory evaluation scores were analyzed statistically by fuzzy math method. Range analysis for the comprehensive sensory score with various processing parameters indicated that their influences decreased in the following order: stirring duration > oil temperature > material/oil ratio = stirring frequency. Stirring duration and oil temperature were further optimized using quadratic orthogonal regression design. The best processing parameters were as follows: oil temperature 122.2 ℃, stirring duration 15.02 s, material/oil ratio 1:5 and stirring frequency 50 r/s; meanwhile water analysis indicated that the moisture loss was minimized when oil temperature and stirring duration were 125 ℃ and 14 s, respectively.

Except that few sweet potato leaves are taken as edible food or livestock feed, most of them that contain large amounts of bioactive flavonoids are discarded, which leads to a great waste of available resource. In the present study total flavonoids were extracted from sweet potato leaves using ethanol and purified using macroporous adsorption resin. The extraction and purification procedures were optimized by orthogonal array design and one-factor-at-a-time methods, respectively. Additionally, antioxidant properties of the purified total flavonoids were evaluated by assaying their ·OH and DPPH· scavenging activities. The optimal extraction conditions were as follows: ethanol concentration 60%, material/liquid 1:40, and temperature 90 ℃ for a thermal refluxing extraction duration of 60 min, and 1 g of the crude extract obtained under such conditions contained 101.3 mg of total flavonoids. The optimal purification parameters using macroporous resin HPD 500 whose adsorption and desorption performance was superior to those of other resins including AB-8, NKA-9, HPD 600 and HPD 450 were as follows: sample concentration 1.8 mg/ml, pH 3, and sample flow rate 3 BV/h; taking 50% ethanol as eluent, eluent flux 3 BV/h, and eluent quantity 4 BV, and the content of total flavonoids in the purified extract was 488.7 mg/g. Both of the crude extract and the purified product displayed a good scavenging activity to ·OH and DPPH·

Pork stuffing is prone to the risk of microbial outbreaks due to contamination by pathogenic microorganisms. Therefore, it is essential to treat raw fish to inactivate pathogenic microorganisms. The efficacy of electrolyzed oxidizing water (EOW) treatment for inactivating bacteria in pork stuffing was investigated in this study. EOW Treatment resulted in a reduction of bacteria population to 3 log10 (CFU/g) when fresh pork was immersed in acidic electrolyzed oxidizing (EO-A) water for 15 min at the pork/EO-A ratio (m/V) less than 1: 6 before stuffing preparation. However, the efficacy of EO-A was not affected significantly by fat tissue content in pork. The treatment of EO-A for less than 20 min with pork / EO-A ratio lower than 1:2 was needed for maintaining antimicrobial efficacy of EO-A. This study demonstrates that EOW treatment is a promising technique for decontamination of pork stuffing and extending shelf life of deep-frozen dumpling.

As a high quality protein resource that contains 18 amino acids including 8 essential ones accounting for 40% of total amino acids, silkworm pupa protein is more nutritional than soybean protein isolate. However, silkworm pupa protein is generally processed into powder with poor water solubility and unfavorable odor, which greatly retards its application in food industry. Silkworm pupa protein was hydrolyzed with five proteases (Alcalase, Flavourzyme, Protamex, Papain and Trypsin) respectively. Alcalase was confirmed as an optimal enzyme preparation to prepare silkworm pupa polypeptide in terms of degree of hydrolysis (DH) of material and DPPH· scavenging activity of hydrolysates. The enzymatic hydrolysis procedure was optimized using orthogonal array method and the corresponding product was subjected to further analysis of antioxidant activity such as reducing power and O2·, ·OH and DPPH·scavenging activities. The optimal Alcalase-catalyzed hydrolysis parameters were as follows: substrate concentration 4%, enzyme/substrate concentration ratio 2:100, temperature 60 ℃, pH 4, and hydrolysis duration 4 h, and under such conditions a DH of 28.2% was achieved. The hydrolysis product could effectively scavenge DPPH·, O2· and OH· radicals, suggesting its strong antioxidant activity.

Collagen fiber adsorbent can adsorb tea polyphenol monomers to various degrees but its molecule has no groups that can be bound with caffeine. So, based on this principle tea polyphenols can be purified using collagen fiber adsorbent. The adsorption properties of collagen fiber adsorbent for the purification of tea polyphenols were investigated. The results indicated that the adsorbent had strong adsorption selectivity, high adsorption capacity (850 mg/g) and good desorption efficiency. After being eluted using 50% ethanol aqueous solution, the yield of tea polyphenols was 85.46%, and the purity was over 99%. The adsorption isotherms of tea polyphenols could be well described by the Freundlich equation; and the adsorption kinetics data were well fitted to pseudo-second-order rate model.

Total flavonoids were extracted from dried Potentilla chinensis Ser. powder by ultrasonic-assisted extraction method and purified using macroporous adsorption resin. The ultrasonic-assisted extraction technique was optimized using orthogonal array design. Adsorption and desorption performance of 8 resins to total flavonoids from Potentilla chinensis Ser. were compared to select a optimal one and total flavonoids desorption efficiency of different concentration ethanol aqueous solutions was compared, moreover adsorption and desorption characteristics of the total flavonoids on HPD-600 type resin were investigated. The optimal extraction conditions of total flavonoids were as follows: using 60% ethanol as extraction solvent, material/liquid ratio (m/V) 1:40, extraction duration 75 min, and temperature 80 ℃, and these factors all had statistically significant effects (p ＜ 0.05) on yield of total flavonoids from Potentilla chinensis Ser. that reached 39.329 mg/g under such conditions. Compared to other 7 resins, HPD-600 type macroporous resin had better adsorption and desorption performance. The purification conditions of crude total flavonoid extract using this resin (quantity: 50 ml) were as follows: sample quantity 40 BV, sample flux 2 BV/ h, using 60% ethanol as eluent, and eluent quantity 5 BV, and after the purification, the purity of total flavonoids reached 60.28% and the yield of total flavonoid product was 2.29%.

Polyamides, D101 macroporous resin, powdered activated carbon and granular activated carbon were separately adopted to decolorize the crude polysaccharide from Ginkgo biloba pollen. Granular activated carbon had the best decolorization efficiency in terms of weighed score for retention rate of polysaccharide and decolorization rate. One-factor-at-a-time method was adopted to investigate the effects of three crucial factors (namely, decolorization duration, temperature and decolorant quantity) on decolorization of the crude polysaccharide. Subsequently, the three factors were optimized using orthogonal array design. The optimal decolorization duration, temperature and decolorant quantity were 50 ℃, 4 h and 0.15 g/ml, respectively. Under these conditions, the decolorization rate was over 72.84% and 88.19% of polysaccharide was recovered.

Ultrasonic technique was employed to extract total flavonoids from water chestnut hull with ethanol. Effects of four crucial factors including ethanol concentration, liquid/material ratio (V/m), extraction duration and repeated extraction times on extraction yield of total flavonoids were investigated by one-factor-at-a-time method. Subsequently, all these factors were optimized using orthogonal array design. The optimal parameters for extracting total flavonoids were as follows: ethanol concentration 50% and liquid/material ratio 10:1 for an extraction duration of 0.5 h repeated twice, and the yield of total flavonoids was up to 0.81% under these optimized conditions. The ultrasonic-assisted extraction for total flavonoids in water chestnut hull is a time- and cost-saving and highly efficient method.

The acid-catalyzed hydrolysis method was adopted to extract soluble dietary fiber from Chinese gooseberry skin residue, a by-product from juice or pulp processing. Effects of four crucial parameters (i.e., material/liquid ratio, pH adjustment of water as extraction solvent, temperature and extraction duration) on extraction yield of soluble dietary fiber were investigated by one-factor-at-a-time method. Subsequently, a central composition experimental design leading to a set of 30 experiments with different combinations of the four variables was performed to attain the maximum extraction yield of soluble dietary fiber. Under the optimized conditions as follows: material/liquid ratio (g/ml) 1:37, pH 2.5, and 80 ℃ for an extraction duration of 100 min, the yield of soluble dietary fiber was found to be 47.74%.

The preparative high-speed counter-current chromatography (HSCCC) method was applied to isolate and purify ricinine from the crude extract of Ricinus cammunis L. seeds, and the purity of purification product was measured by HPLC and its structure was analyzed by MS and NMR. After being defatted using a mixture of petroleum ether and ethyl ether (2:1, V/V) twice, caster bean seeds without shell was subjected to ricinine extraction using 95% ethanol in a Soxhlet extractor followed by vacuum concentration and freeze drying. The preparative HSCCC was performed using a two-phase solvent system composed of chloroform, methanol and water (2:1:1, V/V). A total amount of 70 mg of ricinine with over 99.62% purity was obtained from 100 mg of the crude extract. Ricinine was identified as the main component in the crude extract by MS and NMR. The preparative HSCCC is suitable for large-scale preparation of ricinine with high purity.

1,2-5,6-di-O-Isopropylidene-a-D-glucofuranose (DAG), a glucose derivative, was obtained by the reaction of Dglucose with acetone. Effects of various conditions such as temperature, D-glucose/iodine/acetone ratio (molar) and amount of added 4A molecular sieve on production yield of DAG were investigated. In the presence of iodine, heating for 5 h under reflux (at 62 ℃) allowed the generation of DAG from the reaction between D-glucose and acetone. However, the reaction time was greatly extended when the reaction temperature was below 62 ℃. At optimized D-glucose/iodine/acetone ratio of 1:0.15:122.5, the yield of DAG was found to be close to 75%. No obvious effect was found on the yield of DAG with the addition of 4A molecular sieve.

7S Globulin was extracted from soybean and hydrolyzed by alcalase. The 7S globulin hydrolysates at different degree of hydrolysis (DHs) were added into pork sausage to investigate their effects on textural and sensory properties of pork sausage as well as weight retention after water bathing, and effects of amounts of added different hydrolysates were investigated as well. A twovariable and three-level full factorial design was performed to attain the optimal chewness value. The pork sausage added with 1.5% of the hydrolysate at 11% DH has good textural and sensory properties and its weight retention after water bathing was high.

A high-yield Bacillus strain producing cyclodextrin glycosyltransferase (CGTase) has been screened and bred by our lab. In the present study, one-factor-at-a-time method was adopted to investigate the effects of medium components and fermentation conditions on CGTase production by the strain. The results showed that the optimal carbon source, nitrogen source and carbonate for the growth of the strain were 1% soluble starch, 0.1% yeast extract and 1% Na2CO3, respectively. And the optimal fermentation parameters were determined as follows: initial pH of fermentation medium 10, fermentation temperature 33 ℃, inoculation proportion 3%, rotation speed of shaker 180 r/min. A CGTase activity of 2842 U/ml was achieved under these conditions.

A simple, rapid and sensitive reversed-phase high-performance liquid chromatography method (RP-HPLC) was developed for the simultaneous determination of chlorogenic acid, epicatechin and rutin in hawthorn. The contents of these phenolic compounds in pulp and stone of dry fruit and pulp of fresh fruit were determined. The pulp of fresh hawthorn fruit had a highest epicatechin content of (1.661 ± 0.024) mg/g and the contents of chlorogenic acid and rutin in pulp of dry hawthorn fruit both were the highest, reaching (0.550 ± 0.002) mg/g and (0.498 ± 0.002) mg/g, respectively. The regression equations for the three analytes presented good linearity and all the correlation coefficients were over 0.999. This method had good precision and repeatability. The spike recoveries for chlorogenic acid, epicatechin and rutin ranged from 91.8% to 110.9%, 94.6% to 107.9% and 94.2% to 108.8%, respectively, and the detection limits were 0.14, 0.37 and 0.68 μg/ml, separately.

A robust and sensitive UPLC-MS-MS method was developed for the simultaneous determination of residues of 15 sulfonamides, 3 fluoroquinolones and 4 tetracylines in eel. The target compounds were extracted with acidic EDTA-Mcllvaine buffer solution, and enriched and cleared up using a hydrophilic-lipophilic balance (HLB) SPE cartridge. After seperation on UPLC BEH C18, the analytes were detected using a tandem mass spectrometry and quantified in multiple reaction monitoring (MRM) mode. At the spike levels of 5, 10 and 20 μg/kg respectively, the average recoveries for all the compounds were 72.4%－97.3%, and the variation coefficients were all under 14.4%. This method is simple, fast, sensitive, and particular for the simulaneous determination of sulfonamides, fluoroquinolones and tetracylines in eel.

A simple, rapid, accurate and sensitive method of solid-phase extraction and ion-pair RP-HPLC was developed for the determination of folic acid (FA) in health food products. Solid-phase extraction (SPE) was performed to enrich FA extracted using a Chromabond-SB cartridge with strong anion exchange material. The addition of tetra-n-butylammonium, as an ion-pairing reagent, from samples was found to significantly increase the retention time of FA, thus leading to a well shaped and clearly separated single peak. The analysis was performed on a Lu-Na C18 column (5 μm, 250 mm×4.6 mm) using a mobile phase composed of 0.05 mol/L KH2PO4 solution, 0.01mol/L tetra-n-butylammonium and acetonitrile (88:2:10, V/V, pH 5.5) at a flow rate of 1 ml/min, with the UV detection set at 284 nm. In the range of 0.06－2.40 μg/ml, a good linear relationship between peak area and FA concentration was found, and the correlation coefficient and the LOD were 0.9996 and 0.008 μg/ml, respectively. The spike recoveries for FA in three commercial health food products ranged from 95.14% to 102.87%.

This study developed a reverse phase HPLC method for determing β-phenylethanol in Chinese rice wine. Betaphenylethanol was separated on a Synergi Hrdro-RP C18 column (4.6 × 250 mm, 4 μm) using a mobile phase composed of CH3OH and H2O (50:50, V/V) at a flow rate of 1 ml/min and detected using a UV detector set at 210 nm. At the spike levels of 5.00, 15.00 and 30.00 mg/L, the average recoveries for β-phenylethanol were between 99.5% and 99.8% with the RSDs of less than 0.6% (n = 3); the limit of detection was 1.0 ng, and the linear range was from 0.5 to 50 mg/L (r = 0.9999). The results of β- phenylethanol determination in four different rice wine samples by this method were almost the same as those determined by gas chromatography method. Therefore, the method developed can be use to determine β-phenylethanol in Chinese rice wine.

A method of UPLC-MS-MS in multiple reaction monitoring (MRM) mode was developed for the qualitative and quantitative analysis of iodosulfuron-methyl-sodium in 9 substance including apple, spinach, shallot, wheat, bean, beef, chicken liver, fat and milk. The sample preparation was based on ultrasonic-assisted organic solvent extraction and GPC cleanup. The results showed that the method developed is easy, rapid and sensitive, and all of its linear range, recovery, precision and detection limit meet the requirement of residue analysis.

Tartary buckwheat rice and traditionally milled flour as well as the processing by-products were analyzed for their main nutritional and functional components and the utilization ratios of these components in the two tartary buckwheat products were evaluated. The results showed that in the milling processing, the nutritional and functional components were mainly concentrated in the tartary buckwheat bran, and the contents of protein and flavonoids were 23.88% and 6.58%, respectively, while their utilization ratios were only 34.57% and 13.65%, respectively. The tartary buckwheat rice obtained by producing technique of parboiled rice significantly contained more nutritional and functional components than tartary buckwheat flour (p ＜ 0.01), the utilization ratios of protein and flavonoids of which reached 78.95% － 89.58% and 66.44% － 77.78%, respectively, meanwhile a large amount of resistant starch was produced in the processing of two tartary buckwheat rices (water soaking and wetting were adopted in the processing respectively), accounting for 4.68% and 6.84%. These results demonstrate that tartary buckwheat rice is superior to tartary buckwheat flour in nutritional value and health care function.

A high performance liquid chromatographic method was developed for the determination of iprodione in fruits. Samples were extracted using acetonitrile, cleaned up by solid phase extraction using PSA and ODS (1:1, m/m) as dispersants. The chromatographic seperation was achieved on an ODS reverse-phase (RP) column. There was a good linear calibration curve in the range from 0.1 to 5.0 μg/ml with the correlation coefficient of 0.9994. The recoveries for iprodione in banana, orange and mango spiked at 0.5, 1.0 and 2.0 mg/kg ranged from 82.70% to 108.62%, with the RSDs of 1.8%－5.3%. The method detection limit was 0.036 mg/kg. This method is simple, sensitive, accurate and reproducible.

A headspace solid-phase microextraction (HS-SPME) method in combination with GC-MS was developed for the rapid determination of diazinon, fenitrothion, fenthion, parathion ethyl and ethion in strawberries. The operating conditions of HS-SPME and GC-MS were optimized. A good linear relationship was found to each of the organophosphorus pesticides and the correlation coefficients were in the range of 0.989－0.998. The precision for determining the organophosphorus pesticides by this method (n = 5) varied from 7.2% to 12.7% and the limits of detection were 5.2－10.7 μg/kg. The spike recoveries ranged 76%－ 94%. This method demonstrates many advantages including promptness, sensitivity, accuracy and low solvent consumption and therefore is able to meet the demand for determination of pesticide residues.

A method for the simultaneous determination of chrysoidine, auramine O and safranine T in food was developed by high performance liquid chromatography (HPLC). Samples were extracted using ammonia－methanol (1:50, V/V). Then the analytes were extracted from the extracts using CH2Cl2, concentrated and redissolved in formic acid－methanol (1:50, V/V), and cleaned up using n-hexane solution saturated with methanol prior to HPLC determination. The linear ranges of this method for determining the three pigments were 0.05－2.5 μg/ml and the correlation coefficients (r) all were higher than 0.9998. The recoveries for them in 6 kinds of foods spiked at two levels respectively ranged from 72.3% to 96.5%, and the RSDs were 0.3%－8.8% (n = 6). The limits of detection were about 0.02 mg/kg for chrysoidine, 0.03 mg/kg for auramine O and 0.004 mg/kg for safranine T.

The Englyst and Guraya methods developed for the determination of slowly digestible starch (SDS) have been reported frequently. However, compared to the former, the latter can be performed more simply and conveniently in that only pancreatic amylase is adopted in determination. The factors [including pretreatment (defatting or defatting plus protein removal), substrate concentration, heating duration, enzyme dose and hydrolysis duration] influencing the determination of SDS by the Guraya method were explored by one-factor-at-a-time design in this study. An actual SDS content could be obtained by the following determination procedure: incubating the mixture of 200 mg of starch that could be directly taken to determine without any pretreatment, 15 ml of 0.5 mol/L phosphate buffer at pH 6.9 and 4000 U of pancreatic amylase in 37 ℃ water bath, and then determining the maltose contents in 0.5 ml of 1-h and 10-h hydrolysates at 540 nm by DNS method respectively.

A model for citrus weight measuring was developed to realize online grading of citrus fruit with computer vision system. Four images from each of mid-maturing Lianhong Wenzhou citrus fruits (grown in the middle part of Hunan province) captured by computer vision system were processed by cutting, background removal, binary conversion and negative operation and finally the images of fruit part were extracted. The pixel ratios of fruit part/total image were used to construct partial least square (PLS) regression model to estimate fruit weight. Results showed that the absolute weight estimation error was －14.9092 －4.9981 g and the average error was －3.9278 g. The standard deviation was 4.5210 g, and the correctness for accuracy ±10 g was 93.3333% and for accuracy ± 8 g 76.6667%. It is feasible to estimate citrus fruit weight online and monitor the fruit weight during growing period by computer vision system.

A pre-treatment method was developed for determining residual clenbuterol in pork by ELISA and GC-MS. Samples were extracted with ethyl acetate under basic condition, and the extracts were further extracted using diluted hydrochloric acid to remove fat. The hydrochloric acid extracts were re-extracted using ethyl acetate following pH adjustment, and the final extract obtained was divided into two equal parts and each of them was dried by nitrogen blow. Water was added to one part prior to ELISA determination. After derivatization with bis(trimethylsilyl)trifluoroacetamide (BSTFA) another part was detected by GC-MS in selected ion monitoring mode (selected ions: 86, 212, 262, 277) and quantitatively analyzed by external standard method. The GC-MS detection limit was 0.30 μg/kg. The recoveries for clenbuterol determined by ELISA in pork spiked at the levels of 1.0 －5.0 μg/kg were 72.1%－105.6%, and by GC-MS 79.1%－95.7%, and the intra-day relative standard deviations for ELISA and GC-MS determination were 12.5%－ 16.8% and 4.6%－ 6.9%, respectively. There was a good linear correlation (the calibration coefficient was above 0. 999) between peak area and concentration of clenbuterol derivative in the range of 0.005 to 1.000 mg/L.

A reverse phase HPLC method was developed for the determination of tilmicosin residue in goat milk. Samples were extracted using methanol, and cleaned-up using SPE on a C18 cartridge with a mixture of acetonitrile and water (90:10, V/V) as the eluent [the washing with a mixture of acetonitrile and water (20:80, V/V) was carried out prior to elution]. The analysis was performed on a Symmetry column with a mobile phase composed of 0.1 mol/L ammonium acetate (adjusted to pH 5.0 with formic acid), acetonitrile and methanol (60:30:10, V/V) using a UV detector set at 280nm. The limit of quantification was 0.020 μg/ml and the linear range was 0.01－25 μg/ml, and the spike recoveries at three levels of 0.02－5 μg/ml were in the range of 90.3%－98.1% with a coefficients of variation ranging 4.1%－8.9%. The method can meet the requirement for tilmicosin residue analysis.

A HPLC method was developed for determining melamine in milk and dairy products. The analysis was carried out using the Waters HPLC system equipped with a C18 column (150 mm × 4. 6 mm, 5 μm) and a diode array detector set at 235.8 nm. The mobile phase consisted of 0.202% haptane sodium sulphate acetonitrile solution and 0.210% citric acid aqueous solution (10:90, V/V) with a flow rate of 1.0 ml/min, and the column temperature was set at 30 ℃. A good linear correlation (the regression equation: A = 59746C + 183.48) between the peak area and the melamine determination was found in the range between 0.1 and 1.6 μg/ml with a correlation coefficient of 0.9973. The recoveries for melamine in three spiked dairy products ranged 98.3%－ 99.2% with a RSD of less than 1.52 %.

Fresh royal jelly was analyzed for its fatty acid composition by GC-MS method. There were seven kinds of main fatty acids found in royal jelly. Among them were 10-hydroxy-2-decenoic acid (21.73%), decanedioic acid (20.64%), 2- dodecenedioic acid (19.87%), 10-hydroxydecanoic acid (10.85%), 3-hydroxy-decanoic acid (7.43%), 11-hydroxy-dodecanoic acid (2.37%) and 9,12,15-octadecatrienoic acid (5.00%).

This study developed a specific high-performance liquid chromatography-electrospray ionization ion trap mass spectrometric (HPLC-ESI-MS/MS) method that allowed simultaneous determination of 15 herbicide multi-residues in grain samples. Residues of the herbicides were extracted from grains with acetonitrile, cleaned up using florisil-SPE, and then determined by HPLC-ESI-MS/MS. The method showed high degree of linearity (the correlation coefficients were 0.9834－0.9997) over the range of 0.01－10 mg/kg for the analytes. The limit of quantifications ranged from 0.002 to 0.07 mg/kg. The average recoveries for the herbicides in spiked samples were between 74.44% and 115.56% with a relative standard deviations from 0.37% to 13.79%. The method developed was applied to detect the targets in real samples, and several herbicide residues were identified.

Based on the basic method and procedure for assessment of uncertainty, a mathematical model was established to assess the uncertainty of HPLC analysis of oxolinic acid residue in chicken. Factors contributing to the uncertainty were investigated by termwise analyzing and synthesizing the sources. The oxolinic acid residue in test portion of chicken was 78.0 μg/kg, and the expanded uncertainty was calculated as being 3.5μg/kg.

Hesperidin is one of the flavonoids existing in citrus fruit peel or physiologically fallen fruit before maturity, especially in the latter with over 3% content. Synephrine, an alkaloid, is mainly contained in immature citrus fruit as well, and the more mature the fruit becomes, the lower its content is. The physiologically fallen fruits of 7 citrus species were collected at two periods of pre-harvest fruit drop and dried by an up-draught drying fan or in natural air. These samples were analyzed for their hesperidin and synephrine contents by HPLC. The hesperidin analysis was carried out on a Hypercil ODS2 column (250 mm × 4.6 mm，5 μm) using a mobile phase composed of water, acetonitrile, THF and acetic acid (80:16:3:1, V/V) with UV detection set at 280 nm; the mobile phase (containing 0.2 g SDS/100 ml) for analyzing synephrine was an acetonitrile-water-phosphoric acid (32:68:0.2, V/V) system, and the detection wavelength was set at 225 nm. The results indicated that the contents of hesperidin in all the citrus species treated with 80 ℃ hot air were higher than those treated by natural air, 40 ℃ hot air, or 60 ℃ hot air. The contents of synephrine in all citrus species treated by 60 ℃ hot air were higher than those with other treatments. Moreover, the contents of hesperidin and synephrine were different greatly among different citrus species and between the periods of preharvest fruit drop. The hesperidin content in citrus fruits at the second period of physiologic drop was higher than that at the first period except for Guanxi honey pomelo and sour orange. The highest content of hesperidin was observed in Guanxi honey pomelo at the first period, reaching (199.28 ±0.7)μg/mg. While the synephrine content in the fallen fruits of all the citrus species at the first period were higher than that at the second period, especially satsuma mandarin fruit (Citrus unshiu Marcovitch, cv. Owari) had the maximum synephrine content of (20.50 ±0.89)μg/mg among all the species.

The RP-HPLC method for determining melamine in milk powder has been developed. However, the differences in chromatography instrument and column performance and status may lead to the occurrence of disagreement among determination results from different labs. To enhance the accuracy, reproducibility and efficiency of melamine detection by HPLC, sample preparation and chromatographic conditions were optimized in the present study. Milk powder samples were extracted using 1% trichloroacetic acid and 2% lead acetate solution in an ultrasonic field and cleaned up on an SCX solid phase extraction column which was activated and leached using 1% trichloroacetic acid instead of water. The optimization of chromatographic conditions was achieved by increasing the ion-pairing buffer containing 10 mmol citric acid and 10 mmol heptane-1-sulfonic acid sodium salt to pH 3 and adjusting the proportion of acetonitrile in the mobile phase consisting of it and the ion-pairing buffer to 28% (V/V). The external standard method was adopted for the quantitative analysis of melamine. The correlation coefficient of linear equation was 0.9997 and the limit of detection of melamine was 0.15 mg/kg by this method. The recoveries for melamine in blank milk powder spiked at five levels were within 95.8%－101.5%. The optimized method has high reproducibility and allows accurate detection and high recovery for melamine in milk powder.

The anthocyanin compositions in blackberry fruit were isolated using high performance liquid chromatography (HPLC) equipped with a lichrospher C18 column and a DAD detector and characterized by UV spectrometry, gas chromatography (GC) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). A total of 4 anthocyanins were found to be isolated on the C18 column. Among them were cyanidin (Cy) 3-O-glucoside (76.92%) , Cy 3-O-arabinoside (5.57%), Cy 3-Omalonylglucoside（ 2.76%）and Cy 3-O-dioxalylglucoside (14.75%).

A gas chromatograph-mass spectrometric (GC-MS) method was developed for the rapid determination of sodium cyclamate in foodstuffs. Samples were extracted with hexane in an ultrasonic field, and the extracts were analyzed by GC-MS after derivatization with a mixture of 50 g/L sodium nitrite solution and 100 g/L sulfuric acid (5:5, V/V). The detection limit was 40 mg/kg (signal/noise ratio = 3.0). The recoveries for cyclamate in six spiked samples ranged from 88.0 % to 108.0% and the relative standard deviations (RSDs) were less than 7.16%. This method has obvious advantages such as high sensitivity, specificity and simplicity versus other methods reported previously, therefore can be used to detect effectively low-level sodium cyclamate in foods

A rapid HPLC method was developed to determine 4-hexylresorcinol (4-HR) in shrimp meat. The sample was extracted with acetonitrile, filtrated through the 0.45μm membrane and then injected into the HPLC column. The analysis was performed on a reversed-phase C18 column using a mobile phase consisting of methanol and water (70:30, V/V) with fluorimetric detection (excitation: 280 nm, and emission: 320 nm). The analyte could be separated within 10 min by the procedure. The linear range was 0.02－50.0 mg/L (r = 0.99996) and the detection limit was 0.1 mg/kg. The average recovery ranged from 97.6% to 99.9% (n = 7), with a relative standard derivation from 2.1% to 4.6%. The method has the advantages of simplicity, repeatability and low detection limit, and can be used for analysis of shrimp samples in large quantity.

An analytical method using ion chromatography separation coupled with UV detection was developed for the determination of melamine in liquid milk. The procedure was based on extraction of test portions with acetonitrile, cleanup on an OnGuard II RP column to remove fat and filtration through 0.22 μm nylon membrane followed by ion chromatographic analysis of the extracts, using an IonPac CS17 column and UV detection at 240 nm. The calibration curve showed good linearity in the range of 0.02－5.0 mg/L, with a correlation coefficient of 0.99995. The recoveries for melamine spiked liquid milk ranged 82% －94%. The method has the advantages of easiness and quickness, and therefore can be applied for the determination of melamine in liquid milk.

This study investigated the feasibility of thermoluminescence (TL) method in the detection of irradiated food. Firstly, the silicate minerals were isolated from irradiated foods, then the energy in the silicate minerals, which is accumulated due to irradiation and released in the form of photon under heating condition, was detected to judge whether the foods were irradiated or not. Ten samples of black pepper, dehydrated capsicum, Chinese cinnamon bark, dehydrated mushroom, tea, dehydrated shallot, etc were analyzed. The results showed that the combination of silicate mineral isolation with TL method has a high reliability in the detection of irradiated foods.

A RP-HPLC method was established for the simultaneous determination of puerarin, daidzin and daidzein in roots, stems and leaves of Pueraria lobata (Wild) Ohwi. The procedure was based on extraction of test portions with 70% ethanol solution in an ultrasonic field for 20 min at 50 ℃ followed by direct HPLC analysis of the extracts. The chromatographic conditions were as follows: using a Hypersil ODS-2 column (4.6 mm × 250 mm, 5 μm) and a mobile phase composed of methanol and H2O, gradient elution [0－4 min 25:75 (methanol/water volume ratio), 4－7 min 25:75 → 32:78, 7－9min 32:68, 9－11 min 32:68 → 50:50, 11－24 min 50:50, 24－30 min 50:50 → 25:75], column temperature 35 ℃, detection wavelength 250 nm, and flow rate of the mobile phase 0.8 ml/min. A good linear relationship between peak area and concentration was found to puerarin, daidzin and daidzein in the ranges of 11.87－73.91 (r = 0.9998), 1.00－6.48 (r = 0.9997) and 0.28－1.53 μg/ml (r = 0.9994), respectively. The LODs were 0.43, 0.24 and 0.18μg/ml, respectively. Mean recoveries were 99.78%, 102.61% and 105.57% with the RSDs of 1.6%, 2.8% and 3.4% (n = 5), respectively. The precision, stability and reproducibility of the method all were good. The contents of puerain, daidzin, and daidzein in roots of Pueraria lobata (wild) Ohwi determined by this method were 3.98%, 0.36% and 0.039% respectively, higher than 3.28%, 0.26% and 0.028% of those analyzed according to the method stipulated in the Chinese Pharmacopoeia 2005 respectively, suggesting high efficiency of ultrasonic-assisted extraction of the three analytes. The contents of puerain, daidzin, and daidzein in stems of Pueraria lobata (wild) Ohwi were 0.004%, 0.0032% and 0.0007% respectively, while those in leaves were 0.0016%, 0.005% and 0.0012%, respectively. This method is accurate, fast and simple and therefore can be used for the simultaneous determination of puerain, daidzin, and daidzein in roots, stems and leaves of Pueraria lobata (wild) Ohwi. Our results demonstrate that the contents of puerain, daidzin, and daidzein in stems and leaves of Pueraria lobata (wild) Ohwi growned in Maoshan area of Jiangsu province are obviously lower than those in the roots.

Various configurations of glucose, fructose and sucrose in honey were determined by nuclear magnetic resonance (NMR) spectroscopy when dissolved in heavy water, their main characteristic peaks in the 1H-NMR spectrum were attributed, and their contents was measured with potussium biphthalate as an internal standard. The RSDs of determination of glucose, fructose and sucrose were 0.33%, 0.17% and 1.34%, respectively, and mean recoveries for them in spiked honey were 96.68%, 98.03% and 95.56%, respectively. This method can be applied to direct determination of small-amount samples with stable and repeatable results and high precision for study of quality standards of honey.

A HPLC coupled with diode-array detector (HPLC-DAD) method for the successful separation and determination of 6 synthetic pigments (tartrazine, amaranth, ponceau 4R, sunset yellow, allura red, and red 2G) was developed. Samples were extracted using a system consisting of 4 mol/L carbamide solution and methanol (1:1, V/V) and cleaned up on a solid phase extraction column using polyamide powder with the mesh from 100 to 200 mesh with a mixture of 25% ammonia and methanol (1:9, V/V) as the eluent. The extracts were adjusted to pH 5 － 6 and hold in 60 ℃ water bath for 20 min prior to polyamide adsorption. The chromatographic separation was achieved on an XDB-C18 column using a mobile phase consisting of methanol and 0.1 mol/L sodium acetate by gradient elution. The 6 synthetic pigments were detected with a diode-array detector whose wavelength was set according to the following procedure: 0－7 min, 440nm; and 7－35 min, 520 nm. The detection limits of tartrazine, amaranth, ponceau 4R, sunset yellow, red 2G and allura red were 0.03, 0.03, 0.03, 0.03, 0.04 and 50 mg/kg, respectively. The RSDs ranged from 0.47% (ponceau 4R) to 4.82% (sunset yellow), and the recoveries were in the range from 95.67% (allura red) to 99.55% (tartrazine).

The USA and the EU have legislated to require labeling of foods containing allergic ingredients. There are eight kinds of main allergic ingredients, including peanut and celery. A real-time fluorescent PCR assay was presented for the quantitative detection of peanut and celery ingredients in foods in the present study. When using the second pair of primer and probe (a total of two pairs were designed) of peanut for PCR amplification, among amplified DNA extracted from 27 samples only peanut produced fluorescent signal. Likewise, when using a pair of prime and probe designed using celery DNA for PCR amplification, only Chinese celery and western celery produced fluorescent signal in 18 samples after real-time PCR amplification. The sensitivity test indicated that 3.6 pg of peanut DNA could be detected, with a quantitative formula: y = －3.092261x + 21.216097 (R2 = 0.993068), where y was Ct, and x was natural logarithm of the DNA concentration (the same below); and 4.0 pg of celery DNA could be detected, with a quantitative formula: y = －4.0957441x + 23.412189 (R2 = 0.997039). The results demonstrate that these pairs of prime and probe have high sensitivity and amplification efficiency and therefore can meet the requirement of trace detection of peanut and celery ingredients in foods.

The contents of heavy metals such as Pb, total Hg, Cd, Se and total As in different parts of Pandalus borealis were analyzed by ICP-MS method and inorganic As by HG-AFS method. The results showed that Pb, total Hg, Cd, Se, total As and inorganic As all were detected in Pandalus borealis. The levels of heavy metals varied in the different parts of Pandalus borealis and high concentration of metals were found in head. Shrimp were sampled and analyzed based on NY5073－2001 (an agricultural standard issued by the Chinese ministry of agriculture). The contents of heavy metals were showed below the level of national sanitation limits. A standard procedure for measuring heavy metals in shrimps is proposed by cleaning, removing the head, shell and enteraden (if it is a large-sized shrimp) and keeping the muscle for analysis.

A sensitive HPLC method was developed for the rapid determination of chlorpromazine residue in animal-derived foods. Samples were extracted with acetonitrile and cleaned up on a solid phase extraction column filled with alkaline alumina. Quantitative analyses were performed using the HPLC system equipped with a C18 column and a PDA detector. The mobile phase consisted of acetonitrile and 0.1% phosphoric acid (7:3, V/V) at a flow rate of 1.0 ml/min, and the detection wavelength was set at 254 nm. The limit of detection was 4 μg/kg and mean recoveries ranged from 80% to 101%. This method is accurate and feasible with simple pre-treatment for the detection of chlorpromazine residue in animal-derived foods.

Porcine bone was treated by traditional cooking method, microwave method or enzymolysis method to obtain different hydrolysates. The hydrolysates obtained were analyzed for their nutrients including free amino acids, flavor nucleotide and minerals using amino acid autoanalyzer, UV-VIS spectrophotometer and microwave digestion-atomic absorption spectrometer, respectively. The enzymolysis method was found to obviously increase the content and quality of free amino acids, when compared with the other two methods. The content of flavor nucleotide (disodium 5'-ribonucleotide, I + G) in hydrolysate decreased in the following order: the enzymolysis method ＞ the microwave method ＞ the traditional cooking method. The contents of Ca, Zn, Fe and Mg in the hydrolysate obtained by the enzymolysis method all were the highest, while those in hydrolysate obtained by the traditional cooking method were the lowest.

A gas chromatography-mass spectrometry (GC-MS) method was developed for the simultaneous detection of 36 pesticide (including 9 kinds of pyrethroid pesticides, 12 kinds of organochlorine pesticides and 15 kinds of organophosphorus pesticides) residues in tea. The method was based on accelerated solvent extraction (ASE) with a mixture of acetonitrile and dichloromethane (1:1, V/V) and gel permeation chromatography (GPC) cleanup followed by GC-MS analysis of the extracts in selected ion monitoring (SIM) mode. The external standard method was adopted for quantitative analyses. At the three spike levels of 0.05, 0.2 and 1.0 mg/kg, mean recoveries for the 36 pesticides were between 67.8% and 110.2% with a relative standard deviation (RSD) ranging from 1.72% to 8.89%. The limits of detection were between 5 μg/kg and 55 μg/kg. This method is rapid, sensitive and accurate and can meet the demands for determining pesticides in tea samples.

A HPLC method was presented for the determination of theanine in tea. The sample preparation was achieved by extraction of samples with water (material/liquid ratio: 0.5 g/100 ml) in 80 ℃ water bath for 45 min, cleanup using solid phase extraction on a Sep-pak C18 column and derivatization with ortho-phthalaldehyde. The chromatographic conditions were as follows: XDB C18 column (4.6 × 250 mm, 5μm) used temperature, 40－50 ℃; mobile phase A, ammonium acetate solution containing 20 mmol and mobile phase B, ammonium acetate solution, methanol and acetonitrile (1:2:2, V/V, containing 20 mmol of ammonium acetate) for isocratic elution; flow rate, 1 ml/min; and detection wavelength, 338 nm. The limit of detection was 5 mg/kg. The average recoveries at two spike levels of 0.02 and 0.05 mg/ml (n = 6) were 98.6% and 101.1% and the relative standard deviations (RSDs) were 0.67% and 1.41%, respectively. Contents of theanine in various different varieties of tea such as green tea, flower petal tea, black tea, dark tea and oolong tea were determined by this method. Theanine content was the highest in green tea while was the lowest in red tea, however no obvious differences were observed among flower petal tea, black tea and oolong tea.

A LC-MS/MS method was developed for the detection of chloramphenicol residue in honey. Samples were extracted using ethyl acetate, and the extracts were separated on a ZORBAX XDB-C18 column (2.1 mm×150 mm, 5 μm) with a mobile phase composed of methanol and water (40:60, V/V). The analysis was carried out by MS/MS in an electrospray negative ion multiple reaction monitoring (MRM) mode. The limits of detection and quantification were 0.1 ng/ml and 0.1 g/kg, respectively. The linear range was between 0.1 ng/ml and 10.0 ng/ml. The average spike recovery was 88.2％, with an average RSD of 3.26%.

“Olinda” Valencia orange juice was stored for 6 months in a container filled with N2 or CO2 to 0.2 or 0.4 MPa at 15 ℃. Quality changes of four“ Olinda” valencia orange juice samples (sample P-1: N2, 0.4 MPa; sample P-2: CO2, 0.4 MPa; sample P-3: N2, 0.2 MPa; and sample P-4: CO2, 0.2 MPa) during the storage were investigated. A slight increase of L* value was observed in all the samples while the a* and b* values decreased dramatically. An obvious inhibition was found in color difference of the two orange juice samples stored under 0.4 MPa when compared to the control sample stored hermetically in a PET bottle at –5 ℃. Over 97% of soluble solids were preserved in the orange juice samples and the total bacterial count showed a changing trend of first increase and then decrease and the loss of vitamin C was less than 6 mg/100 g during the storage, which was the least in the sample P-1. The content of major aroma components in the sample P-1 was 1001 μg/ml. In general, the original quality and flavor of the orange juice can be preserved when stored under N2 or CO2 pressure environment.

The fresh-keeping effect of sodium hypochlorite or chlorine dioxide treatment on fruits and vegetables has been reported previously. The application of calcium hypochlorite, however, is confined to disinfection of plant seeds and egg products and control of bacteria in plant tissue culture. Up to now, no studies focusing on fresh-keeping effect of calcium hypochlorite have been reported. This study particularly focused on the effects of calcium hypochlorite, sodium hypochlorite and imazalil at two concentrations (300 mg/L and 500 mg/L) on relative conductivity (RC) of fruit peel of “Newhall” navel oranges and malondialdehude (MDA) content and activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in fruit pulp. The increases of RC and MDA content were inhibited and the activities of SOD, CAT and POD were enhanced by calcium hypochlorite treatment at 300 mg/L. However, significant inhibition effects of calcium hypochlorite treatment at 500 mg/L were observed on the increases in RC, MDA content and CAT activity and the decrease in SOD activity, whereas this treatment concentration was favorable to the increase in POD activity. In summary, calcium hypochlorite treatment shows better effects at 300 mg/L than at 500 mg/L.

Preliminary study of the fresh-keeping effect of modified atmosphere packaging on South America white prawns was conducted. Sensory evaluation and biochemical and biochemical analysis were performed on the prawns preserved in a modified atmosphere box with different proportions of mixed O2, CO2 and N2. The shelf life of fresh South America white prawns was extended by modified atmosphere packaging and better fresh-keeping effects were observed when pretreatment of the fresh prawns with 10% sorbitol followed by modified atmosphere preservation with the composition of 75% CO2 + 20% N2 + 5% O2.

The material of beef was treated by calcium propionate and vacuum-packaged, and then stored at 0 ℃ or room temperature. Through the measure of content of total volatile basic nitrogen (TVB-N), pH value, total bacterial count and sensory evaluation during storage, the fresh-keeping effects of different concentrations of calcium propionate on beef were investigated. The results showed that when the concentration of calcium propionate was 3%, the shelf lives of beef at 0 ℃ and room temperature reached 24 and 12 d, respectively. Furthermore, the calcium content and nutritional value in beef was promoted after the treatment of calcium propionate.

The effects of hot air treatment at 38 ℃ for 5 h on active oxygen metabolism and flesh lignification of loquat fruit (Eriobotrya japonica Lindl. cv. Jiefangzhong) during cold storage (1 ℃± 1 ℃, 90% relative humidity) were investigated. The heat treatment effectively inhibited the decreases of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities and the increase of peroxidase (POD) activity, maintained the low levels of superoxide anions (O2·) production and hydrogen peroxide (H2O2), inhibited the accumulation of malonaldehyde (MDA) and the increase in membrane permeability, mitigated the increase in fruit firmness and the decrease in juice percentage. These results suggest that heat treatment may maintain the balance between the formation and detoxification of active oxygen species and delay the lipid peroxidation process, thereby preventing the development of flesh lignification and maintaining the quality of cold-stored loquat fruits.

In order to find the relationship between chilling sensitivity and activities of antioxidant enzymes of postharvest tomato fruits, two cultivars of postharvest tomato fruits, Santiam (Solanum lycopersicum L. cv. Santiam) and Lichun (Solanum lycopersicum L. cv. Lichun), were treated with short-time (24 h) or long-time (20 d) chilling stress, and the changes in activities of antioxidant enzymes such as catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) during chilling stress were measured. It was found that chilling tolerance of tomato cultivars could be indicated obviously by activities of the four enzymes, and a positive relationship was observed between them. Activities of CAT, POD and SOD could distinctively reflect chilling tolerance diversity (p < 0.05) between the two cultivars within 4－24 h under chilling stress. Conclusively, cold tolerance of postharvest tomato fruits can be fast and effectively judged from activities of the antioxidant enzymes.

According to the specific formulation and processing technology, massive roots of Maoshan Pueraria lobata were made into particles and mixed with high-quality tea to produce an organic teabag which is easy to carry and clean and healthy. Via sensory evaluation, the optimum mass ratios of the particles of Pueraria lobata roots obtained to black tea, green tea and oolong tea were confirmed as being 5:1, 10:1 and 10:1, respectively. Especially, when the mass ratio of Pueraria lobata to black tea was 5:1, the taste was the best and the tea product could meet the requirement for consumers’ health. Meanwhile, effective components in roots of the product developed were determined as follows: puerarin 3.30%, daidzin 0.25% and daidzeint 0.17%.

A sports beverage was developed using silkworm pupa protein powder defatted by supercritical CO2 fluid extraction as the staring material by means of enzymolysis, debittering and desalination, and formulation. Five crucial factors affecting degree of hydrolysis (DH) of silkworm pupa protein by alkali protease were optimized to attain the maximum DH using orthogonal array design. Activated carbon and was used for debittering of the hydrolysate obtained followed by desalination using 717-type anion-exchange resin and 732-type cation-exchange resin. Subsequently, a certain amounts of water, sucrose and citric acid were blended with the debittered and desalined hydrolysate to produce sports beverage. To obtain a product with the highest sensory score, the hydrolysate/water ratio and amounts of added sucrose and citric acid were also optimized using orthogonal array design. Under optimized hydrolysis conditions [temperature 55 ℃, pH 9.0, solid/liquid ratio 1:7 (m/m), and enzyme/substrate ratio 7%], and the DH after 2.5 h was 29.97%. An optimal sports beverage product which can alleviate physical fatigue and has nice taste and special flavor of silkworm pupa could be obtained, when 5-fold volume of water was blended with the pretreated hydrolysate of silkworm pupa protein, with addition of 6% sucrose and 0.15% citric acid.