In order to increase the solubility of soybean protein concentrate (SPC) at the isoelectric point, SPC was hydrolyzed by papain to form soluble protein and then glycosylated with dextran to form a hydrophilic protein-polysaccharide complex. The best hydrolysis conditions of SPC were determined as follows: SPC concentration 5%, papain concentration 10000 U/g, and temperature 55－60 ℃. The best glycosylation was achieved after 3.5 h of reaction at a dextran/SPC ratio 1:1. As a result, the nitrogen solubility index of SPC near the isoelectric point increased from 9.53% to 39.12%. The obtained soybean protein soluble at the isoelectric point can have more applications in moderately acidic foods.

The purpose of this study was to develop a macroporous resin adsorption method for the decolorization of Ganoderma lucidum polysaccharides. Ganoderma lucidum polysaccharides with a molecular weight between 10 kD and 500 kD were obtained by extracting Ganoderma lucidum fruiting bodies twice with boiling water, concentrating and ultrafiltrating with different MWCO (10 kD and 500 kD) membranes. Ten types of macroporous resin were compared for their effectiveness in decolorizing the polysaccharides. Based on decolorization rate and polysaccharide retention rate, type D303 macroporous resin had the best decolorization performance. Process parameter optimization for the decolorization of Ganoderma lucidum polysaccharides by static adsorption of type D303 macroporous resin were performed using one-factor-at-a-time combined with orthogonal array design method. The optimum conditions for static decoloration of resin D303 were as follows: sample concentration 15 mg/mL, pH 6, decoloration temperature 50 ℃, and decoloration time 7 h. Under the optimal conditions, a decoloration rate of 91.89% and a polysaccharide retention rate of 75.28% were obtained. The optimum conditions for dynamic decoloration of resin D303 were as follows: flow rate 3 BV/h (1 BV=10 mL), and sample loading amount 150 mg/mL resin, resulting in a decoloration rate of 92.01% and a polysaccharide retention rate of 71.85%. These findings collectively indicated that the resin D303 was more suitable for the decoloration of Ganoderma lucidum polysaccharides.

Rice dregs glutelin (RDG) was glycosylated with carrageenan (Car) by dry-heated Maillard reaction. The effects of mass ratio of RDG to Car and reaction time on degree of graft reaction and functional properties of RDG-Car conjugates were investigated. The results showed that the degree of graft reaction was 28.84% under the optimal conditions: RDG-to-Car mass ratio 1:2, temperature 60 ℃, relative humidity 79% and reaction time 24 h. The solubility, emulsifying property and emulsion stability of the resulting RDG-Car conjugate were improved obviously, which were increased by 2.04, 4.84 and 0.63 times, respectively when compared with those of RDG. Meanwhile, we found that the surface hydrophobicity of glutelin was reduced dramatically after glycosylation with Car. Compared with RDG, its conjugate with Car exhibited much higher solubility, emulsifying capacity and emulsion stability in a wide pH range.

One-factor-at-a-time combined with orthogonal array design method was employed to optimize the microencapslation condition of athocyanins extracted from the fruits of Berberis kaschgarica Rupr with 80% acidified aqueous ethanol solution three times for 15 min each time under the assistance of ultrasonic. The optimal microencapslation conditions for maximizing the microencapsulation efficiency of athocyanins from the fruits of Berberis kaschgarica Rupr were core-to-wall material ratio 1:5, maltodextrin-to-β-cyclodextrin ratio 1:6, solid content 30%, gum acacia amount 1.0%, inlet air temperature 160 ℃, and outlet air temperature 80 ℃. Athocyanins from the fruits of Berberis kaschgarica Rupr showed an increase in the stability towards light, temperature, carbohydrates, reducing agents, oxidants and metal ions after microencapsulation.

One-factor-at-a-time combined with orthogonal array design method was used to optimize process conditions for pectin extraction from mulberry stalk bark by ammonium oxalate-oxalic acid hydrolysis and subsequent ethanol precipitation. The effects of solid-to-liquid ratio, pH, temperature and time on pectin extraction rate were investigated. Pectin extraction rates from the bark of different stalk positions of mulberry cultivars Husang 32, Yu 711, Nongsang 8 and Nongsang 14 at different growth stages were compared. The optimal conditions for extracting pectin from mulberry stalk bark were solid-to-liquid ratio (g/mL) 1:14, pH 2.0, temperature 90 ℃, and extraction time 120 min, and the addition of activated carbon at 1 g/100 mL for decolorization at 60 ℃ for 30 min resulted in the best decolorization. Under these conditions, the pectin extraction rate was roughly 12%. Cultivars, harvest periods and stalk bark positions showed a difference in the extraction rate of pectin. Among the four cultivars investigated, Husang 32 revealed the highest pectin extraction rate. In summer a higher pectin extraction rate from mulberry stalk bark was observed than in spring and autumn. In spring and autumn, the bark of the middle position of mulberry stalk exhibited a higher pectin extraction rate than that of the top and bottom. In summer, the pectin extraction rate from the bark of one-year-old mulberry stalk was higher than that of newly grown mulberry stalk. In addition, an increase in pectin extraction rate was found from fresh mulberry stalk bark as compared with its dried counterpart.

Dried soybean powder was defatted with either petroleum ether, n-hexane or ethyl ether before the extraction of anticancer peptides with PBS buffer (pH 7.4) under ultrasonic assistance. In order to maximize the inhibitory rate of anticancer peptides against human gastric cancer cell line SGC-7901, a three-factor, three-level orthogonal array design was used to optimize three operating conditions including material particle size, solid-to-liquid ratio and ultrasonic treatment time. Anticancer activity evaluation of anticancer peptides extracted from defatted soybean was carried out using MTT assay. The optimal extraction conditions were determined as follows: material particle size 80 mesh, solid-to-liquid ratio 1:5 (g/mL) and ultrasonic treatment time 80 min. The inhibitory rate of the extract under these conditions against the proliferation of human gastric cancer cell line SGC-7901 was 39.03%.

Objective: To establish optimal parameters for the separation and purification of total flavonoids from the whole plant of Stenoloma chusana (L.) Ching using AB-8 macroporous adsorption resin. Methods: Static and dynamic adsorption and desorption behaviors of AB-8 macroporous adsorption resin were evaluated for achieving the best purification of total flavonoids. Results: The optimum adsorption and desorption parameters were found to be: sample pH 4.5, sample concentration 1.00 mg/mL, sample loading flow rate 80 mL/h, 70% ethanol as the eluent, desorption flow rate 40 mL/h and eluent amount 60 mL, resulting in a total flavonoid purity of 66.16%. Conclusion: AB-8 macroporous adsorption resin is safe, economical and easy to use and can therefore be promisingly applied to separate and purify total flavonoids from the whole plant of Stenoloma chusana (L.) Ching.

In order to accelerate the dissolution of intracellular anthocyanins into grape juice, Cabernet Cauvignon grapes were mechanically crushed and subjected to pectinase hydrolysis followed by microwave treatment. The conditions of pectinase hydrolysis and microwave treatment were optimized by Box-Behnken experimental design combined with response surface methodology for maximizing anthocyanin content in grape juice. Based on Box-Behnken experimental design, two regression models describing pectinase hydrolysis and microwave treatment were established. The optimal pectinase hydrolysis conditions were pectinase amount 1.1‰, hydrolysis temperature 40 ℃, and hydrolysis time 3.15 h, and the optimal microwave treatment conditions were grape amount 129.5 g, treatment time 19 s, and number of repeated treatments 3. Analysis of variance indicated that the two mathematical models were highly statistically significant (P＜0.0001), the lack of fit of each of which was not significant (P＞0.1), thereby being applicable to analyze and predict the dissolution of anthocyanins during grape juice processing. Grape juice with a higher anthocyanin content and a brilliant color can be obtained by the combined use of pectinase hydrolysis and microwave treatment.

On the basis of one-factor-at-a-time experiments, an L16(43) orthogonal array design was performed to optimize process conditions for aqueous two-phase extraction of R-phycoerythrin from Porphyra yezoensi. The effects of PEGs of different molecular weights, PEG 4000 dosage, the concentration of Na2SO4 as the phase-forming salt and ionic strength on the extraction of R-phycoerythrin were examined. The results indicated that the optimal aqueous two-phase extraction conditions were PEG 4000 as the phase-forming polymer at 6%, Na2SO4 concentration 13%, NaCl concentration 1.5%. After the optimized aqueous two-phase extraction, the purity of R-phycoerythrin was increased to 0.727 from 0.187, showing a 2.25-fold increase. Therefore, aqueous two-phase extraction is more suitable for R-phycoerythrin extraction than ammonium sulfate precipitation.

Cell wall disruption followed by organic solvent extraction was used to extract lycopene from Rhodotorula glutins. The optimal cell wall disruption method and extraction solvent were found to be hot acid treatment and acetone-ethyl acetate (1:1), respectively. Three extraction conditions such as material-to-liquid ratio, temperature and time were optimized by orthogonal array design to be 1:60 (g/mL), 30 ℃ and 3 h, respectively. Under these conditions, the extraction rate of lycopene was 4.55 mg/g, 41.30% higher than before optimization.

Pepino puree was treated with pectinase and centrifuged and the supernatant (fruit juice) was fermented for 10 days to make pepino fruit wine. Response surface methodology was used to optimize four pectinase treatment conditions such as pectinase dosage, time, temperature and pH for achieving the best colorization of pepino juice and fruit wine. On the basis of one-factor-at-a-time experiments, a three-level quadratic rotation-orthogonal composite design was used to set up regression models that describe the effects of these treatment conditions on the absorbance at 680 nm of pepino juice and fruit wine. Hydrolysis temperature and time had a significant effect on the absorbance at 680 nm of pepino juice (P＜0.05), and pectinase dosage significantly affected the absorbance at 680 nm of pepino juice (P＜0.05), but neither of them was significantly affected by pH (P＞0.05). The optimal pectinase treatment conditions determined by ridge analysis for pepino juice and fruit wine were pH 4.6 and 4.0, treatment temperature 32 ℃ and 30 ℃, treatment time 63 min and 55 min, and pectinase dosage 0.3 g/kg and 0.316 g/kg, respectively. The multiple regression analysis indicated the established regression models could fit the relationship between various pectinase treatment conditions and the absorbance at 680 nm of pepino juice and fruit wine very well.

Objective: To separate and purify nattokinase by fibrin affinity chromatography. Methods: The fermentation supernatant of Bacillus subtilis subsp. natto was fractionally salted out with ammonium sulfate and dialyzed, and the crude nattokinase obtained was purified by affinity chromatographic column chromatography at 4 ℃. The purity of purified nattokinase was analyzed by SDS-PAGE. Results: Nattokinase of electrophoretical purity was obtained, with a purify fold of 8.3 and a recovery of 43.9%. The optimum reaction pH and temperature pf purified nattokinase were 7.0－9.0 and 50 ℃, respectively. The enzyme activity exhibited a sharp drop at temperatures above 60 ℃ and good stability in the pH range of 6.0－10.0. The enzyme was slightly activated by Mg2+ but dramatically inhibited by Cu2+. Conclusion: Affinity chromatography on fibrin-agarose is applicable to fast purify nattokinase.

Objective: To optimize the process parameters of solvent reflux extraction of catalpol from Radix Rehmannia glutinosa. Methods: On the basis of one-factor-at-a-time experiments, response surface methodology (RSM) was used for process parameter optimization. A regression model was established describing catalpol extraction yield as a response to various process parameters. Results: The optimal extraction conditions were 72.94% methanol aqueous solution as the extraction solvent, extraction temperature 54.8 ℃, extraction time 3.0 h and number of repeated extractions 2. Under these conditions, the catalpol extraction yield was 3.513%. Conclusion: The established regression model can accurately and conveniently predict catalpol extraction yield. The optimal extraction process obtained is efficient and feasible.

Ganoderma lucidum spore powder was subjected to twin-screw extrusion before polysaccharide extraction. The effects of material moisture content, screw rotary speed, temperature and feeding speed on the cell wall disruption rate of Ganoderma lucidum spore and polysaccharide yield were explored. The four process conditions were optimized by orthogonal array design method as follows: material moisture content 15%, screw rotary speed 223 r/min, temperature 125 ℃ and feeding speed 155 g/min. The resulting cell wall disruption rate and polysaccharide yield were 78.6% and 2.219%, respectively, which were increased to 83.48% and 2.37% after the second twin-screw extrusion.

One-factor-at-a-time and orthogonal array design methods were used to optimize the conditions for ultrasonic-assisted ethanol extraction of total flavonoids from the dried shoot of Equisetum ramosissimum Desf. grown in west Hunan province, China. The extraction yield of total flavonoids was 1.16% under the optimal extraction conditions: 45% ethanol aqueous solution as the extraction solvent, material-to-liquid ratio 1:30 (g/mL), ultrasonic treatment time 30 min, and extraction temperature 60 ℃. The total flavonoids could scavenge hydroxyl free radicals in a concentration-dependent fashion and had stronger inhibitory effect against lipid peroxidation in tea seed oil than in lard.

The conditions for ultrasonic extraction of polysaccharides from Salvia officinalis L. leaves were optimized by one-factor-at-a-time and orthogonal array design methods. A material-to-liquid ratio of 1:40 for 7 min extractions performed twice proved optimal. The resultant polysaccharide yield was 3.27%. The polysaccharide extract obtained had excellent DPPH free radical scavenging effect, revealing a scavenging rate of 82% at the concentration of 160μg/mL and an IC50 of 112μg/mL.

Objective: To optimize the conditions for ultrasonic-assisted extraction of aucubin from Eucommia ulmoides Oliv. key fruits. Methods: One-factor-at-a-time method and response surface methodology based on Box-Behnken experimental design were used for process conditions optimization. Results: The optimal extraction conditions were 72.1% aqueous ethanol solution as the extraction solvent, ultrasonic power of 300 W, extraction time of 20.5 min and solid/liquid ratio of 12.3:1 (mL/g). Under these conditions, the extraction yield of aucubin was observed to be 5.91%. Ethanol concentration had the largest impact on the extraction yield of aucubin, followed by solid/liquid ratio and extraction time. Conclusion: Ultrasonic assistance can enhance the extraction of aucubin from Eucommia ulmoides Oliv. key fruits.

In this study, one-factor-at-a-time and orthogonal array design methods were used to optimize the conditions for hot reflux extraction of total flavonoids from the shoot of Salicornia europaea L. The determination of total flavonoids was spectrometrically carried out using rutin as the reference standard. The optimal conditions for extracting total flavonoids from the shoot of Salicornia europaea L. were 80% ethanol as the extraction solvent, solid/liquid ratio 1:50, extraction temperature 70 ℃, and extraction time 4 h, resulting in a total flavonoid yield of 25.172 mg/g.

The shoot of Geum japonicum Thunb. var. chinense F. Bolle was ultrasonified in ethanol-ammonium salt two-phase aqueous system to accelerate the extraction of total polyphenols. Operating parameters such as solid-to-liquid ratio, volume ratio of initial ethanol to initial water, temperature and extraction time were optimized by one-factor-at-a-time and orthogonal array design methods for maximizing the extraction yield of total polyphenols. Solid-to-liquid ratio of 1:20 (g/mL), volume ratio of initial ethanol to initial water of 0.8, ammonium sulfate concentration of 0.27g/mL, extraction temperature of 60 ℃ and extraction time of 60 min were found optimal. Under the optimal extraction conditions, the extraction yield of total polyphenols was 3.04%. This method can provide a novel approach for the extraction of total polyphenols with highly efficient, time-saving and energy-saving benefits and no impact on the biological activity of extracts.

Nitrosohemoglobin was prepared from porcine hemoglobin and glycosylated with chitosan, which was selected in consideration of thermal stability. The effects of mass ratio of nitrosohemoglobin to chitosan, pH, temperature and reaction time on the glycosylation of nitrosohemoglobin were probed by one-factor-at-a-time method. Subsequently, response surface methodology, based on Box-Benhnken experimental design, was used to optimize pH, temperature and reaction time for achieving maximum absorbance at 450 nm of reaction products. The optimal glycosylation conditions of nitrosohemoglobin were determined as follows: mass ratio of nitrosohemoglobin to chitosan, 4.16:1, pH 5.6, temperature 50.5 ℃ and 15.7 min.

Solvent extraction and purification by macroporous resin adsorption were used to acquire DPPH free radical scavenging components from Chinese date honey. Extraction solvent type, macroporous resin type, sample loading amount, sample loading flow rate, eluent type, elution flow rate and elution volume were optimized. Acidified ultrapure water (adjusted to pH 2 with HCl) was better solvent for DPPH free radical scavenging components in Chinese date honey than ultrapure water. Among four types of macroporous resin investigated, XDA-2 resin was found to be the most suitable choice. The optimal adsorption and desorption parameters of XDA-2 resin for purifying DPPH free radical scavenging components extracted from Chinese date honey of the same weight were sample loading flow rate of 1.0 mL/min, 80% ethanol aqueous solution as the eluent, elution flow rate of 4.0 mL/min and elution volume of 2 BV.

Objective: To optimize the alkali extraction and acid precipitation of total flavonoids from Cyclocarya paliurus callus. Methods: The effects of pH, material/liquid ratio, borax amount and extraction time on the extraction rate of total flavonoids from Cyclocarya paliurus callus. Results: The optimal extraction conditions were extraction solvent pH of 9.0, borax amount of 2.5%, extraction time of 60 min, and acid precipitation pH of 4.5. Conclusion: Under the optimal conditions, the extraction rate of total flavonoids was up to 4.01%.

The effects of 5 drying methods including hot air drying, vacuum microwave drying, extrusion drying with variable temperature and pressure difference, vacuum freeze drying and vacuum drying on physical properties, nutritional composition and microstructure of sweet potato products were investigated. Hot air drying resulted in the largest harness followed by extrusion drying with variable temperature and pressure difference, vacuum microwave drying, vacuum drying and vacuum freeze drying. Hot air-dried sweet potato products exhibited the largest δE* followed by those dried by vacuum drying, extrusion drying with variable temperature and pressure difference, vacuum microwave drying and vacuum freeze drying. Sweet potato products showed no remarkable change in their crude protein or crude fiber contents before and after drying. All of the five drying methods could result in a decrease in the crude starch content and an increase in the reducing sugar content of sweet potato products, and moreover, β-carotene and VC contents were both substantially decreased. After vacuum freeze drying and extrusion drying with variable temperature and pressure difference, the excellent honeycomb structure of sweet potato products was observed with evenly widened intercellular spaces. Hot air dried and vacuum dried sweet potato products displayed a compact structure. The structure of vacuum microwave dried sweet potato products was very compact. The results collectively indicate that extrusion drying with variable temperature and pressure difference can result in both better product quality and lower production cost and is therefore suitable for industrial-scale production of dried sweet potato products.

In this paper, a kind of natural nutritional jelly sweets with Lingnan flavor was studied. First, gelatin and pectin were mixed to achieve better gel performance and higher gel melting point; then Pericarpium citri reticulatae oleoresin, Amomum villosum oleoresin and wampee pulp sludge with Lingnan flavor were added to obtain unique flavor and appearance; in addition, emulsifiers such as sucrose ester with different HLB values were used to resolve the problems related to foaming, transparency and wall stickiness. The optimal formula wascomposed of 2.3% gelatin, 1.3% pectin, 0.77% Pericarpium citri reticulatae oleoresin, 0.39% Amomum villosum oleoresin, 5.8% wampee pulp sludge, 0.08% sucrose ester s170 and 0.19% sucrose ester s1570. The jelly candy prepared using this formula revealed high melting point, unique flavor, moderate elasticity and flexibility and crystal clear appearance.

Solvent extraction was used to extract polyphenols from persimmon fruits in this study. Among three organic solvent investigated, ethanol was found to be the most suitable solvent for extracting total polyphenols and condensed polyphenols from persimmon fruits. The following investigations were carried out to explore the effects of ethanol concentration, material-to-liquid ratio, extraction time and extraction temperature on total polyphenol yield and to optimize the four process conditions by one-factor-at-a-time and orthogonal array design methods. Ethanol concentration was identified as the most important factor that affects total polyphenol yield followed by material-to-liquid ratio, extraction time and extraction temperature. The optimal extraction conditions for achieving both higher yields of total polyphenols and condensed polyphenols from persimmon fruits were ethanol concentration of 90%, material-to-liquid ratio of 1:40, extraction time of 30 min and extraction temperature of 40 ℃. Under the optimal extraction conditions, the extraction rate of total polyphenols was up to 2.061%.

In this study, the optimal extraction conditions of total polyphenols from the flowers of Chinese chestnut cultivar Yanlong were investigated. The traditional heating reflux method was used for the extraction of total polyphenols. Four different extraction solvents were applied for the extraction of polyphenols. The results indicated that methanol was the best extraction solvent, and microwave was superior to ultrasonic in enhancing the extraction of total polyphenols. The optimal process parameters for microwave-assisted extraction of total polyphenols were determined by orthogonal array design to be 40% methanol as the extraction solvent, microwave treatment time of 60 s, microwave power of 480 W and material-to-liquid ratio of 1:25 (g/mL). Under the optimal extraction conditions, the extraction rate of total polyphenols from chestnut flowers was up to 6.69%.

In this work, urea adduction fractionation was used to purify linoleic acid from Pyracantha fortuneana seed oil and the purified product was further separated by silica column chromatography to obtain squalene. The effects of adduction time, adduction temperature and oil-urea-ethanol ratio on the purity and recovery rate of linoleic acid were probed by one-factor-at-a-time and orthogonal array design methods. The analysis of linoleic acid and squalene was performed by GC-MS. The results showed the optimal adduction parameters were adduction time of 12 h, adduction temperature of －5 ℃, and oil-urea-alcohol ratio of 1:2:6 (g/g/mL). Under the optimal adduction conditions, the purity of linoleic acid was increased from 38.40% to 68.55%, and the recovery rate of linoleic acid reached up to 72.23%. After separation by silica column chromatography, a squalene sample with 98.16% purity was obtained .

Pectinase was used for enzymatic extraction of allicin from wastes from the processing of pickled Allium chinense G. Don bulbs. On the basis of one-factor-at-a-time experiments, response surface methodology was employed to optimize the conditions for enzymatic extraction of allicin. The optimal extraction conditions were extraction temperature of 37 ℃, extraction time of 3 h and enzyme amount of 0.8%. Under the optimal extraction conditions, the yield of allicin was up to 0.1763 g/g, which was close to the predicted value of 0.1761 g/g.

A new type of yacon (Smallanthus sonchifolius) juice microencapsulated oil powder was prepared by spray drying using evening primrose oil as the core material and Yacon juice as the wall material. The results showed that the optimal formula was 30% evening primrose oil, 1.7% polyglycerol ester, 14% self-made octenyl succinic anhydride-modified maize starch, 0.5% propylene glycol alginate (PGA), 0.5% xanthan gum, 0.5% sodium carboxymethyl cellulose (CMC), 25% yacon juice (dry matter basis), and 27.8% maltodextrin. The oil content on the surface of microencapsulated evening primrose oil powder was 1.20% and the embedding efficiency of evening primrose oil 96.0%. Meanwhile, microencapsulated evening primrose oil powder was rich in fructo-oligosaccharide (FOS). After dissolved, microencapsulated evening primrose oil powder became an emulsion with good stability and yacon flavor.

In the present study, the extraction of Undaria pinnatifida polysaccharides by ultrasonic treatment alone and in combination with cellulase hydrolysis was optimized by orthogonal array designs L16 (45) and L9 (34), respectively. The optimal ultrasonic-cellulase treatment conditions for simultaneously improved polysaccharide yield and scavenging activity of polysaccharide extracts against hydroxyl radicals generated in Fenton system were treatment time of 15 min, cellulase amount of 2.8 × 104 U/g algae power, treatment temperature of 70 ℃ and solid-to-liquid ratio of 1:80. Under the optimal extraction conditions, the extraction rate of Undaria pinnatifida polysaccharides was (4.522 ± 0.028)%. The hydroxyl radical scavenging rate of the obtained extract was up to (51.70 ±0.47)%. In addition, each of the four process conditions showed a significant effect on the extraction rate of Undaria pinnatifida polysaccharides (P＜0.01) and no significant effect on the scavenging activity of polysaccharide extracts against hydroxyl radicals (P＞0.05). The combination of ultrasonic and cellulase could significantly increase the extraction rate of Undaria pinnatifida polysaccharides and the scavenging activity of polysaccharide extracts against hydroxyl radicals as compared with ultrasonic alone (P＜0.01).

Intact Chinese chestnut kernels were enzymatically hydrolyzed to develop functional products with antihypertensive and antioxidant activities. Enzyme screening was investigated for different purposes. Papain could result in higher short-chain peptide yield and degree of hydrolysis (DH) than other five proteases investigated. A higher short-chain peptide yield was obtained by papain + α-amylase than papain + pullulanase and papain alone. Compared with papain alone, the combination of papain and each of the other five proteases increased the DH of Chinese chestnut kernels, especially in combination with Flowryme. Improper protease amount was unfavorable for the hydrolysis of Chinese chestnut kernels. The appropriate amount of α-amylase was 0.35 g/100 mL hydrolysate. The appropriate ratio of papain to Flowryme was 2:1 (m/m). The DH of Chinese chestnut kernels was 26.27% and the short-chain peptide yield was 43.62% under the following hydrolysis conditions: protease amount of 8000 U/g protein, hydrolysis temperature of 55 ℃ and hydrolysis time of l5 h. The resultant hydrolysate exhibited excellent ACE inhibitory activity with an IC50 of 4.70 mg/mL and antioxidant activity. The IC50 vales for inhibiting linoleic acid oxidation and scavenging superoxide anion, hydroxyl, DPPH free radicals were 4.26, 2.77, 7.78 mg/mL and 4.30 mg/mL, respectively.

Canna edulis Ker starch-acrylic acid graft copolymer was prepared by an inverse microemulsion method using ammonium persulfate as the initiator and N, N＇-meyhylene-bisacrylamide as cross-linking agent under nitrogen protection. An inverse emulsion system containing Canna edulis Ker starch was formed under an oil-to-water ratio of 1.2:1, complex emulsifier amount of 30%, and emulsifier HLB (hydrophilic-lipophilic balance) of 7.36. The optimal copolymerization conditions of Canna edulis Ker starch and acrylic acid were acrylic acid amount of 16 mL, initiator amount of 3.5%, cross-linking agent amount of 0.8%, and neutralization degree of acrylic acid of 70%. The water-absorbing capacity of graft copolymers prepared under the optimal conditions was 1340 g/g. Meanwhile, infrared spectral analysis revealed that acrylic acid was successfully grafted onto Canna edulis Ker starch.

Dialyzed deaminated wheat gluten was subjected to ultrasonic treatment under varying conditions of ultrasonic power, treatment time and ultrasonic field temperature with the aim of studying the effect of ultrasonic treatment on functional properties of deamidated wheat gluten. The optimal conditions of ultrasonic power, treatment time and ultrasonic field temperature for maximizing nitrogen soluble index (NSI) were determined by response surface methodology to be 100 W, 10 min and 44 ℃, respectively. Under the optimal conditions, the NSI was up to 77.28%. The foaming capacity and foam stability of deaminated wheat gluten were increased by 11% and 20% respectively after ultrasonic treatment. In addition, ultrasonic treatment could also improve the emulsifying capacity and emulsion stability of deaminated wheat gluten.

In order to optimize the extraction of anthocyanins from blackcurrants, the effects of solvent type, ethanol concentration, material/liquid ratio, extraction time, HCl concentration on the extraction yield of anthocyanins and the DPPH free radical scavenging rate and reducing power of blackcurrant extracts were explored. Extraction for 2 h at a material/liquid ratio of 1:10 (g/mL) using acidified aqueous ethanol (containing 40% ethanol and 0.5% HCl) as the extraction solvent provided optimum extraction of anthocyanins from blackcurrants. The resultant extraction yield of anthocyanins and the anthocyanin content, DPPH free radical scavenging rate and reducing power of the obtained blackcurrant extract were 172.29 mg/100 g of fruit, 86.15 mg/L, 71.64% and 1.64 (A700), respectively. Blackcurrant anthocyanins at the concentration of 0.1 mg/mL revealed stronger DPPH free radical scavenging rate and reducing power than BHA and ascorbic acid of the same concentration (P ＜ 0.05). Thus, blackcurrant, rich in highly antioxidant anthocyanins, has a promising prospect for development and application.

An aqueous two-phase system composed of 24% PEG400 and 15% Na2SO4 was used to extract total flavonoids from the crude ethanol extract of Actinidia kolomikta leaves. The effects of crude extract concentration, KCl amount, pH and extraction temperature on the extraction efficiency of total flavonoids were explored by one-factor-at-a-time and orthogonal array design methods. The results showed that crude extract concentration and pH were major affecting factors and KCl, and extraction temperature exhibited less effect on the extraction efficiency of total flavonoids. The optimal aqueous two-phase extraction conditions were crude extract concentration of C0, KCl amount of 2%, pH of 9 and extraction temperature of 25 ℃. Under the optimal extraction conditions, total flavonoids from Actinidia kolomikta leaves was mainly distributed in the upper phase with a distribution coefficient of 24.31 and an extraction rate of 96.90%. Therefore, this method can provide a simple, convenient, economical and highly efficient strategy for the extraction of total flavonoids.

Cassava starch was modified with epichlorohydrin (ECH) and octenyl succinic anhydride (OSA) by a semi-dry process to synthesize hydrophobic lipophilic crosslinked octenyl succinic anhydride-modified starch (COSAS). The synthesis process was optimized by one-factor-at-a-time and orthogonal array design methods. The reaction mechanisms were elucidated. The whiteness of COSAS was determined and structural analysis was carried out using Fourier transform infrared spectrometry and scanning electron microscope (SEM). The results indicates that the optimal synthesis process parameters of COSAS were starch water content of 15%－18%, OSA amount of 3% (based on the dry weight of starch), esterification time of 90 min, pH 9.0, and reaction temperature of 100 ℃. The average degree of substitution (DS) of COSAS prepared using the optimized process parameters was 0.0175, and its whiteness was slightly lower than that of native starch. FTIR spectral analysis revealed that crosslinked bonds and groups in octenylsuccinate were introduced into starch after esterification. SEM observations also showed that the surface of COSAS was rougher than that of native starch although some particles with concaves, gaps and cracks were observed.

In this study, orthogonal array design was employed to optimize the conditions for ultrasonic-assisted extraction of flavonoids from apple peel. Along with this, the stability of flavonoids extracted from apple peel was evaluated. The optimal extraction conditions were extraction temperature of 60 ℃, ethanol concentration of 60%, extraction duration of 20 min, and material-to-liquid ratio of 1:25. Under the optimal extraction conditions, the extraction rate of flavonoids was 27.56 mg/g. Meanwhile, the extracted flavonoids were stable at pH 6.0 and unstable at a temperature over 40 ℃. Light illumination could result in a decrease of stability. In addition, H2O2, Na2SO3, NaNO2, Pb2+, Cu2+, and Fe3+ could obviously reduce the absorbance of flavonoids; on the other hand, Mg2+ and Ca2+ could result in an increase in the absorbance of apple peel flavonoids. Vitamin C, Zn2+, Al3+, and K+ did not reveal obvious effect on the absorbance of apple peel flavonoids. Therefore, ultrasonic-assisted extraction reveals high efficiency and reproducibility with RSD of 0.55% in extracting apple peel flavonoids. Flavonoids from apple peel have weak tolerance to high temperature as well as strong acid and alkali. Although VC, Zn2+, Al3+, and K+ exhibit less effect on the stability of apple peel flavonoids, H2O2, Na2SO3, NaNO2, Mg2+, Ca2+, Pb2+, Cu2+ and Fe3+ have obvious impact on the stability of apple peel flavonoids.

Lactobacillus casei and Staphylococcus xylosus were used as the mixed fermentation starter for fermented beef sausages. The optimal fermentation process parameters of fermented beef sausages were determined by orthogonal array design method to be: fermentation time of 16 h, pH 5.0, fermentation temperature of 30 ℃, mixed fermentation starter amount of 107 CFU/g with a Lactobacillus casei-to-Staphylococcus xylosus ratio of 3:1 and relative humidity of 90%. In addition, the addition of mixed fermentation starter in a slow fermentation method could produce fermented beef sausages with excellent texture and taste as well as soft flavor, which is suitable for Chinese consumption habits.

In this study, three types of macroporous resin were assessed for their adsorption and desorption capacity towards antioxidant peptides in the maize protein hydrolysate, prepared by alcalase hydrolysis, and XAD-7HP resin was found to be the most suitable resin among them. The static adsorption of XAD-7HP resin and the static desportion of antioxidant peptides with different desorption solvents were performed under different pH conditions. As a result, the optimal process parameters for the separation of antioxidant peptides were sample pH 7.0 and 70% aqueous ethanol as the desorption solvent. Antioxidant maize peptides were successfully separated by the dynamic adsorption of XAD-7HP resin, resulting in a 2-fold increase in DPPH free radical scavenging activity.

Anthraquinone is one of the major functional components in Cassia obtusifolia L. seeds. Response surface methodology was employed to optimize the ultrasonic-assisted extraction of free anthraquinone from Semen Cassiae. The extraction efficiency of free anthraquinone was investigated with respect to four process conditions including ethanol concentration, extraction temperature, ultrasonic treatment time and material-to-liquid ratio. The optimal conditions for anthraquinone extraction were 80% aqueous ethanol as the extraction solvent, material-to-liquid ratio of 15:1 (mL/g), extraction temperature of 65 ℃, ultrasonic treatment time of 30 min and ultrasonic power of 100 W. Under the optimal extraction conditions, the extraction rate of free anthraquinone from Semen Cassiae. was 28.32%.

In order to improve the comprehensive utilization of walnut resource, the extraction of brown pigment from walnut shell was explored. On the basis of one-factor-at-a-time experiments, a three-variable quadratic equation was established by orthogonal regression design to describe the effects of ethanol concentration, temperature, extraction time and material-to-liquid ratio on the extraction rate of brown pigment. Through resolving the equation, the optimal conditions for extracting brown pigment from walnut shell were identified to be ethanol concentration of 52%, extraction time of 4.8 h, extraction temperature of 70 ℃, and material-to-liquid ratio of 1:5. Under the optimal conditions, the extraction rate of brown pigment was 5.0496%.

Response surface analysis was used for optimizing the microwave-assisted extraction of chlorophyll from filter mud in sugar cane mill factories. The results showed that the optimal conditions for microwave-assisted extraction of chlorophyll were microwave irradiation time of 60 s, extraction temperature of 34 ℃ and material-to-liquid ratio of 1:7 (g/mL). Under these conditions, the predicted chlorophyll yield was 0.280 mg/g, which was close to the actual chlorophyll yield of 0.277 mg/g. Compared with the traditional extraction, microwave-assisted extraction revealed an enhanced yield of chlorophyll by 6.95% with considerably time-saving benefits.

An electrochemical signal inhibition method coupled with microwave digestion was developed for ultra-sensitive determination of chromium(Ⅵ) in ell. Cr(Ⅵ) could be oxidized and the oxidation peak current was therefore inhibited. Factors affecting Cr(Ⅵ) determination such as buffer solution pH, enrichment potential, accumulation time and possible interferences were investigated. The developed method revealed excellent linearity over the Cr(Ⅵ) concentration of 0.2 to 2.6 nmol/L with a correlation coefficient 0.9977. The limit of detection was 60.2 pmol/L. This method proved ultra-sensitive and effective despite the presence of excess interference ions, thereby being applicable for the determination of Cr(Ⅵ) in eel.

A safranine O (SO) polymer film was formed by cyclic voltammetry on the surface of a pretreated pencil electrode (PGE) in SO-containing phosphate buffered saline (PBS). The effects of buffer pH and potential scan range on the modification process were investigated. The polymer film formed in an acidic solution (pH 6.01) and a potential scan range between－1.0 V and 0.0 V (vs SCE) showed high electrochemical activity and good stability in blank PBS solutions, and a good linearity between the voltammetric peak potential and the buffer pH was obtained in the pH range of 1.5－7.5. This modified electrode could be used for determining the acidity of oranges, tomatoes and juice with satisfying results.

A rapid assay was developed for the detection of mecA and spa gene present in methicillin-resistant Staphylococcus aureus (MRSA) using loop-mediated isothermal amplification (LAMP). Staphylococcus aureus and other relevant bacteria were detected for their mecA and spa genes by both polymerase chain reaction (PCR) and LAMP methods. Gene amplification was successfully achieved by LAMP within 60 min when the temperature was held at 64 ℃, and the results were consistent results with those of the conventional PCR methods. The limits of detection of the LAMP method for mecA and spa genes were identified by agarose gel electrophoresis to be 102 and 10 cells per tube and observed by naked eyes to be 103 and 10 cells per tube respectively. The LAMP method was then applied to artificially polluted raw milk, and gave identical results with the traditional PCR methods. LAMP can rapidly detect mecA and spa genes, thus providing an applicable assay for detecting MRSA in raw milk.

Nonlinear chemical fingerprint based on chemical oscillatory reaction is a novel technology to analyze samples from the nonlinear chemical viewpoint. Different kinds of tea beverages from different manufacturers were added to the steady system sodium bromate-manganese sulphate-sulphuric acid-acetone to obtain their nonlinear chemical fingerprints, and the similarity was calculated. Uni-President ice black tea could be differentiated from other tea beverages by the intuitionistic information, quantitative information, and similarity calculation. And the function between oscillatory life and determining dosage was good. The quality of the tea beverage was evaluated by comparing the nonlinear chemical fingerprint parameter information of the ice black tea with different amounts of adulterated water. Therefore, nonlinear chemical fingerprint can provide a novel strategy to identify and evaluate tea beverages.

A gas chromatography-mass spectrometry (GC-MS) method was developed for determining metaldehyde residue in various food matrixes including rice, soybean, spinach, tomato, onion, tea, apple and Chinese chestnut. Metaldehyde residue in samples was extracted with acetone-methylene mixture, and then the extracts were purified with LC-NH2/Envi-carb solid phase extraction (SPE) cartridge. The limit of quantification (LOD) of the developed method was 0.01 mg/kg, and the average recoveries and relative standard deviation (RSD) for metaldehyde in samples spiked in the range of 0.01 to 0.5 mg/kg were in the range of 70.5%－111.7% and 4.4%－11.0%, respectively.

A new rapid method was established to determine metal elements in medlar fruit by microwave digestion and continuum source atomic absorption spectrometry. Samples were subjected to microwave digestion before simultaneous determination of six metal elements, including iron, zinc, copper, manganese, cadmium and lead. The established method presented a limit of detection ranging from 0.006070 to 0.04975 μg/L. The precision RSDs were between 1.5% and 5.0% (n = 12). The mean spike recoveries for the six metal elements ranged from 86.68% to 111.7% (n = 6). This method has been used to simultaneously determine iron, zinc, copper, manganese, cadmium and lead in medlar fruit with the benefits of rapidity, simplicity and low cost and satisfying results.

Steam distillation extraction followed by GC-MS was used to analyze the chemical composition of volatile oil from the flowers of Elaeagnus angustifolia L. Peak area normalization method was used for quantification. Totally 64 compounds were separated, of which 54 were identified and accounted for 96.89% of the total volatile oil, mostly including ethyl trans-cinnamate (77.36%), (E)-2-methoxy-4-(1-propenyl) phenol (3.03%), acetal (2.70%), ethyl cis-cinnamate (1.09%), ethyl benzenacetate (1.06%), ethyl benzoate (1.03%) and trans-nerolidol (1.03%).

Objective: To develop a rapid multiplex polymerase chain reaction (m-PCR) assay for simultaneous detection of Salmonella spp., Staphylococcus aureus and Listeria monocytogenes in food. Methods: The genomic alignment method was used to identify specific PCR target sequences. Three pairs of specific primers were designed with Primer Premier 5.0 according to the invasive protein gene (invA) of Salmonella, the nuc gene of Staphylococcus aureus and the prs gene of Listeria monocytogen. Multiplex PCR was established by optimizing the reaction system. Results: The sensitivity of the multiplex PCR method was 7.6 pg/μL for Salmonellla spp., 3.8 pg/μL for Staphylococcus aureus, and 5.1 pg/μL for Listeria monocytogenes. All specific primers were amplified, and their corresponding strips were observed in validation experiments without cross reactivity. Conclusions: A triple PCR assay has been established for the simultaneous, sample, rapid and sensitive detection of Salmonella spp., Staphylococcus aureus and Listeria monocytogenes in food.

The volatile oils of different parts of Microtoena insuavis (Hance) Prain ex Dunn were extracted by headspace solid-phase micro-extraction (HS-SPME) method. Their chemical composition was qualitatively analyzed by GC-MS based on Kovats retention indices and was quantified by peak area normalization method. Totally 74 volatile constituents in the stems ,105 in the leaves and 85 in the flowers of M. insuavis (Hance) Prain ex Dunn were separated and identified, accounting for 97.34%, 98.80% and 97.96% of the total peak area, respectively. The main components in the stems were neryl acetate (5.63%), β-caryophyllene (17.32%), α-bergamotoilene (7.56%), trans-β-farnesene (10.2%) and caryophyllene oxide (5.21%), and in the leaves Z-citral (11.64%), geranial (16.35%), neryl acetate (8.44%), β-caryophyllene (13.08%), trans-β-farnesene (10.88 %) and caryophyllene oxide (8.34%), and in the flowers Z-citral (21.49%), geranial (27.5%), neryl acetate (9.99%), β-caryophyllene (5.47%) and trans-β-farnesene (10.11%). It was also observed that there were significant differences in the relative contents of chemical components in the three parts of M. insuavis (Hance) Prain ex Dunn.

A high performance liquid chromatography method for the determination of the artificial sweetener acesulfame K in food was developed. Ultrasonic-assisted aqueous extraction followed by the removal of protein impurities by adding zinc acetate and potassium ferrocyanide was used for sample preparation. Acesulfame K was separated on a C18 column using methanol-0.02 mol/L ammonium acetate (5.5:94.5, V/V) as mobile phase at a flow rate of 0.8 mL/min and detected using a diode array detector (DAD) at 230 nm. The column temperature was set at 30 ℃ and the injection volume 5μL. The retention time of acesulfame K was about 4.6 min. The detection limit of the developed method was 1.7 mg/kg, and the linear range was between 1.0 and 50.0μg/mL. The mean spike recoveries for acesulfame K in a blank juice sample exceeded 90%, with a relative standard deviation below 2% (n=6). In this method, acesulfame K was extracted using water as solvent with the assistance of ultrasound, and purified by precipitation. The method proved to be simple, rapid, accurate and practical.

An AccQ ·tag precolumn derivatization and reversed phase HPLC method was presented to determine the contents of 17 free amino acids in litchi fruits from 5 different cultivars, Ziniangxi, Dadingxiang, Heiye, Lanzhu and Tianyan. The method proved highly reproducible and precise. The ratio of essential amino acids to total amino acids was 36.4% and to non-essential amino acids 0.57 in Tianyan, indicating good agreement with the ideal human protein requirements. The five litchi cultivars were all rich in medicinal, umami and sweet amino acids with a difference in their contents and small amounts of several aromatic amino acids were also found. Therefore, different litchi cultivars distinctly differ in taste and flavor.

Micellar electrokinetic capillary chromatography (MECC) coupled with the addition of methanol to the running buffer was used for the separation and determination of five β-lactam antibiotics, ceftiofur, cephazoline, cephalexin, ampicillin and penicillin G. The running buffer was optimized to consist of 20 mmol/L Na2HPO4, 20 mmol/L NaH2PO4 (pH 8.5), 20 mmol/L SDS and 0.25 (V/V) methanol. Under the voltage of 18 kV, baseline separation was achieved for the five antibiotics within 15 min, and their concentrations and peak areas exhibited a good linear relationship. The detection limits for these antibiotics were between 5.3 and 8.1 mg/L. The precision of the method was found to be 3.8%－5.5%. The results indicate that the combination of micellar pseudostationary phase and organic additives enables highly efficient chromatographic separation of antibiotics of very similar structures.

An electronic nose system PEN3 was used to discriminate the storage time of raw goat milk at 4 ℃ and 25 ℃. The volatile composition of goat milk was sampled by PEN3, and the obtained data were analyzed using principal component analysis (PCA) and linear discrimination analysis (LDA). The results showed that PCA method could discriminate the storage temperature and time of raw goat milk except for the variation of volatiles during storage. On the contrary, LDA method could not discriminate the storage temperature and time effectively although it could discriminate the variation in volatiles during storage. These findings collectively indicate that electronic nose can effectively discriminate the storage time of raw goat milk at 4℃ and 25 ℃ and the variation in volatiles during storage.

Objective: To establish a colorimetric method to determine the antioxidant capacity of water-soluble compounds in functional food based on the reaction between 1,10-2 phenanthroline and Fe3+ to form yellow complexes. Methods: The hydrophilic antioxidants in functional foods were extracted with pH 7.4 PBS buffer solution (75 mmol/L) and allowed to reduce Fe3+ to Fe2+. Fe2+ was exposed to 1,10-2 phenanthroline to form a stable Fe2+-phenanthroline complex. The absorbance of the complex was determined on a spectrophotometer at 536 nm and used to calculate the antioxidant capacity of water-soluble compounds in functional food using Trolox, a water soluble vitamin E analog, as the reference standard. The accuracy, linearity, repeatability, recovery rate and limit of detection (LOD) of this method were studied, and its feasibility was also verified. Results: This method showed a good linearity over the Trolox concentration of 0.66－10.53 μmol/L (R2 = 0.9999). The LOD was 0.54 μmol/L. The replicability and repeatability was 2.7% and 3.3% relative standard deviation (RSD), respectively. The mean spike recovery was (99.9±4.6)% (n = 5). Conclusion: This method is applicable to determine the antioxidant capacity of water-soluble compounds in functional food.

Objective: To establish a HPLC method to determine the contents of oleanolic acid (OA) and ursolic acid (UA) in different organs of Paeonia lactiflora Pall.. Method: Oleanolic and ursolic acids were extracted from samples with ethanol under the assistance of ultrasonic. The chromatographic separation was conducted on a Lichrospher C18 column (250 mm × 4.6 mm, 5μm) using a mobile phase made up of methanol and 0.1% phosphoric acid solution (85:15, V/V) at a flow rate of 1 mL/min. The column temperature and the detection wavelength were set as 30 ℃ and 210 nm, respectively. Results: The linearity of OA and UA was in the range of 25－100μg/mL with a correlation coefficient over 0.998 (n = 5). The overall intra-day and inter-day variation coefficients were 1.46%－2.84% and 1.33%－3.32% for OA and 1.27%－2.96% and 1.97%－3.64% for UA, respectively. The accuracy of determination of OA and UA was 1.28%－3.52% and 0.96%－2.88%, respectively. Conclusion: The method is convenient, rapid and accurate, and can thus be used to separate and quantify OA and UA in different organs of Paeonia lactiflora Pall..

The volatile flavor components in different parts of rainbow trout were analyzed by headspace solid phase microextraction combined with gas chromatgraphy-mass spectrometry (HS-SPME/GC-MS). A total of 38 compounds were identified in the raw ventral, tergal and tail muscles of rainbow trout, and 22 in their cooked counterparts. After being cooked, the ventral region of rainbow trout showed the best flavor followed by the ventral and trail regions, while the evaluation of umami taste of the tail region was superior to that of the ventral and tergal regions. Furthermore, the contents of ketones, compounds containing sulfur, nitrogen and/or oxygen and heterocyclic compounds were distinctly higher in the raw ventral region compared to the raw tergal and tail regions, alcohols and aldehydes revealed the highest content in the tail region, and the total hydrocarbon content of the tergal region showed an over 2-fold increase compared to that of the ventral and tail regions. The results of comprehensive evaluation that cooked rainbow trout muscles had a higher relative content of total volatile flavor components than raw samples, suggesting that cooking promotes the formation of volatile flavor compounds.

The aim of this study was to develop a rapid and simple method for the determination of lactoferrin from fresh bovine milk, transgenic bovine milk and human milk. After removing fat by centrifugation and precipitating caseins by adjusting pH, the lactoferrin contents were separated by SDS-PAGE (100 V, 12 g/mL gel, comb:1.0 × 10 teeth, 5μL injection, staining for 3 h and destaining for 2 h); and then the target fractions in the gel were examined by thin layer chromatography scanner (transmission, zigzag scan, dual wavelength, swing width: 8 mm, delta Y: 0.1 mm). The results showed that good separation was achieved for lactoferrin (LF), α-lactalbumin (α-La) and β-lactoglobulin (β-Lg) from three different sources. The recoveries for LFI (LF standard obtained from fresh bovine milk) in fresh bovine milk and LFII (LF standard obtained from transgenic bovine milk) in transgenic bovine milk across three spike levels were 104.53% and 108.37%, respectively. The intra-plate assay precision RSDs for LFI and LFII were 3.1003% and 1.8151%, respectively. The calibration curves of LFI and LFII displayed a good linearity within the range of 100 to 2000μg/mL, with a correlation coefficient of respectively 0.9988 and 0.9990.

Head-space solid phase micro-extraction method (HS-SPME) and simultaneous distillation extraction method (SDE) were compared for their sampling effectiveness in GS-MS analysis of volatile components in chestnut rose juice. Totally 52 compounds were identified, including 17 hydrocarbons, 12 esters, 7 alcohols, 5 acids, 3 phenols, 3 ketones, 3 aldehydes and 2 heterocycles. Thirty-seven volatile components were identified by HS-SPME method and 19 by SDE method. Compared to SDE method, HS-SPME method has the advantages of rapidity, simplicity, avoidance of organic solvents, more kinds of identified components, non-destructive sampling and is therefore more suitable for the analysis of volatile components in chestnut rose juice.

The volatile flavor compounds in Hangzhou Longjing tea, Huangshan Maofeng tea, Shandong Laoshan Mountain tea and Fujian oolong tea were extracted by solid-phase micro-extraction (SPME), purge and trap-thermal desorption (P&T-TD), stir bar sorptive extraction (SBSE), headspace sorptive extraction (HSSE) and analyzed by GC-MS. The major aromatic constituents of tea consisted of vinyls, aldehydes, alcohols, ketones, esters, acids, aromatic compounds, nitrogen-containing compounds, heterocyclic compounds, sulfur-containing compounds, and phenolic compounds. The four varieties of tea were all rich in vinyls, aldehydes, alcohols, and ketones. Although these compounds indicated the largest content in Fujian oolong tea, Hangzhou Longjing tea, Huangshan Maofeng tea and Shandong Laoshan Mountain tea, belonging to the green tea family, contained higher contents of esters and heterocyclic, aromatic and phenolic compounds. The comparison between HSSE-1 and HSSE-2, where nitrogen purging was carried out over tea and below the liquid level of tea infusion, respectively, indicated that the composition and contents of aromatic compounds in tea presented a slight difference before and after being infused. Therefore, tea can reveal dramatic differences in their aromatic components according to different geographic origins and different varieties.

An orthogonal signal correction-wavelet packet transform-partial least squares (OSC-WPT-PLS) method was proposed for simultaneous detection of tryptophan, tyrosine and phenylalanine with overlapped fluorescent spectra. A program (POSCWPTPLS) was designed to execute relevant calculations and three chemometric methods (OSC-WPT-PLS, WPT-PLS and PLS) were compared in this study. The relative standard errors of prediction (RSEP) were achieved for all components by using OSC-WPT-PLS, WPT-PLS and PLS were 2.80%, 4.35% and 5.14%, respectively. The OSC-WPT-PLS method revealed the best detection efficiency among three methods, which could be successfully applied to determine the contents of tryptophan, tyrosine and phenylalanine in water, Gold-Camel wine and Hetao wine made in Inner Mongolia with a recovery rate of respectively 96.9%－103.2%, 94.1%－105.4% and 95.3%－107.8%.

In order to establish a simple and rapid method for the polarographic analysis of manganese, manganese-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP)-octyl polyethylene glycol phenyl ether (OP) system was studied by linear sweep polarography. The results showed that in Na2B4O7-NaOH (pH 11.0) buffer solution, manganese-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol(5-Br-PADAP)-octyl polyethylene glycol phenyl ether (OP) complex at －0.73 V (vs. SCE) could produce a sensitive adsorption wave. The second-order derivative peak current of the wave revealed a linear relationship with manganese over the concentration range of 0.10－0.32μg/mL (r = 0.9989, n = 10). The detection limit was 0.05μg/mL. Meanwhile, this adsorption wave was an irreversible electrode process, which could be verified by various electrochemical methods. The electron transfer number was 2 and the effects of ions on peak current were also validated. This proposed method was used for the determination of manganese content in rice with a recovery rate ranging from 94.1% to 101.0% and a relative standard deviation of 1.9%.

In order to clarify the contribution of flavor components to the overall flavor of button mushroom (Agaricus bisporus), the flavor compounds in mushroom were analyzed by headspace-solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Two kinds of SPME fibers with different coatings and two columns with different polarities were used for the extraction and separation of flavor compounds. The results indicated that the SPME fiber (DVB/CAR/PDMS) with three phases could separate more flavor compounds than the fiber (CAR/PDMS) with two phases; similarly, the polar column (DB-WAX) could separate more flavor compounds than the weak-polar column (HP-5), especially octane and octene derivatives. Nevertheless, more pyrazine compounds could be separated by non-polar column (HP-5). The major flavor compounds in button mushroom were 1-octen-3-one (mushroom-like flavor), 1-octen-3-ol (mushroom-like flavor), 3-octen-2-one (cooked mushroom-like flavor), benzeneacetaldehyde (floral flavor), 2,5-dimethyl pyrazine (popcorn flavor), 2,6-dimethyl pyrazine (roasted nut flavor), hexanal (grass flavor), 3-methylbutanal (fruity flavor) and 2-acetylthiazole (meat flavor).

A gas chromatography-mass spectrometry (GC-MS) method has been established for the determination of methyl carbamate and ethyl carbamate in white liquor. The GC-MS conditions were column HP-55% phenylmethyl Siloxane (30.0 m × 0.25 mm, 0.25μm) as the chromatography column, injection volume of 1μL (split ratio, 50:1), column temperature of 170 ℃, ion source temperature of 230 ℃, quadrupole temperature of 150 ℃, mass scanning range (m/z) of 30－500 and solvent delay time of 3 min. The samples were purified by amino solid phase extraction column and then the eluent was evaporated to dryness using nitrogen blow. The results showed that the standard curves of methyl carbamate and ethyl carbamate revealed an excellent linear relationship in the concentration range of 2－30μg/mL with a correlation coefficient of respectively 0.9923 and 0.9811. The average recovery rates of this determination method for methyl carbamate and ethyl carbamate were 76.10% and #br# 75.43% with a RSD of 4.48% and 4.00%, respectively.

An analytical method was developed for determining total content of sialic acids including N-acetylneuraminic acid (Neu5Ac) and N-glycolyl neuraminic acid (Neu5Gc) in human milk. Sialic acid in human milk was released by acid hydrolysis, and derivatized with 4,5-methylenedioxy-1,2-phenylenediamine dihydrochloride at 50 ℃ for 150 min in a dark environment. The separation of sialic acid was achieved on LiChrosorb RP-18 column (250 mm × 4 mm, 5μm) using methanol-acetonitrile-water (7:8:85) as the mobile phase at a flow rate of 0.9 mL/min. Injection volume and column temperature were set at 10μL and 30 ℃, respectively. The fluorescence excitation and emission wavelengths were 373 nm and 448 nm, respectively. The results showed that the linear range of sialic acid was 50－400μmol/L. The average recovery rate was 94.0%. The precision, stability and repeatability RSDs were 0.4%, 1.0% and 0.8%, respectively. The limits of detection were 0.02μmol/L for Neu5Ac and 0.03μmol/L for Neu5Gc. Therefore, this developed method is characteristics of simple operation, and high reproducibility and sensitivity. It can be widely applied to determine total content of sialic acid in infant formula, cow milk and human milk.

A high performance liquid chromatography method was developed for determining three fungicides including thiabendazole (TBZ), o-phenylphenol (OPP) and diphenyl (DP) residues in chopsticks. The residues were extracted with methanol by Soxhlet extraction, separated on Cosmosil C18 column by using a mixture of methanol and water (70:30) as the mobile phase at a flow rate of 1.0 mL/min and detected at 247 nm. The correlation coefficient and detection limit of this method were 0.999μg/mL and 0.01μg/mL, respectively. The recovery rates and relative standard deviations for TBZ, OPP and DP in a blank sample across three spike levels were 95.8%－97.1% and 1.4%－2.6%, respectively. This method proved simple, fast, highly efficient and accurate.

A gas chromatography-mass spectrometry (GC-MS) method is presented for determining trifluralin residues in aquatic products in this paper. In the method, extraction with acetone, partition with n-hexane and cleanup on a Florisil solid-phase extraction column were used for sample preparation, and quantification was performed by the external standard method. Trifluralin concentration exhibited a good linearity over the range of 5－100μg/L, with a correlation coefficient of 0.99996. The detection limit of this method was 1.0μg/kg for trifluralin. The recovery rates of trifluralin in eel, corvine, India shrimp, clams and swimming crab across the spike levels of 1.0, 2.0μg/kg and 4.0μg/kg were 82.0%－93.6%. This simple and sensitive method can be applied for the determination of trifluralin residues in aquatic products.

In order to explore the contents and distribution of metal elements in buckwheat, the contents of nine metal elements (Fe, Mn, Zn, Cu, Ca, Mg, Mo, Cd and Se) were determined by atomic absorption spectrometry, and the distribution of these metal elements was analyzed by principal component analysis and cluster analysis. Four principal factors accounted for 73.64% of total variances. The cumulative contribution rate of the first factor and the second factor to total variances was 44.41%, which suggested that copper, magnesium, molybdenum and cadmium were the characteristic elements in buckwheat. Cluster analysis showed that twenty-eight buckwheat samples could be classified as two groups, which could identify the genuineness of Fagopyrum Mill to some extent. Therefore, buckwheat was a good dietary source of essential trace metals for humans as well as trace metals such as Mg and Mo. The results of cluster analysis based on the contents of metal elements in buckwheat also can provide a reference for the classification of buckwheat species.

A method has been established for the determination of calcium in protein power using microwave digestion-flame atomic absorption spectrophotometry with La(NO3)3 as the releasing agent. Digestion efficiency was investigated with respect to four variables including digestion system, digestion pressure, digestion time and pressurization style. The effect of La(NO3)3 concentration on the release of calcium was discussed. Under optimal conditions, the linear range of this method for calcium was 1－20μg/mL and the detection limit was 0.15μg/mL. The average calcium content in a commercial protein powder sample determined by this method was 0.46% with a relative standard deviation of 1.63% (n = 6). The average recovery rate of calcium in a protein powder sample with a calcium content of 9.10μg/mL across the spike levels of 0.5, 1.5μg/mL and 2.0μg/mL was 96.8% with a relative standard deviation of 2.34%. Therefore, this method has a wide linear dynamic range, good correlation, high accuracy and precision, and high practical application value.

The microwave-assisted extraction of volatile oil from the residue left over after lutein extraction Tagetes erecta L. was optimized by one-factor-at-a-time and orthogonal array design methods. Oil yield was investigated with respect to solvent-to-material ratio, extraction time and microwave power (low, medium and high fire). The optimal extraction conditions were petroleum ether as the extraction solvent at a solvent-to-material ratio of 6:1 for 60 s extraction under the assistance of high-fire microwave power. Under the optimal extraction conditions, an oil yield of 1.575% was achieved. The chemical composition of the volatile oil was analyzed by gas chromatography-mass spectrometry (GC-MC) and 19 compounds were identified.

A mathematical model was established to evaluate the uncertainty of determining nicotinamide in infant formula milk powder by high performance liquid chromatography with diode-array detection. According to the relevant regulations given in JJF 1135-2005 Evaluation of Uncertainty in Chemical Analysis Measurement and JJF 1059－1999 Evaluation and Expression of Uncertainty in Measurement, the sources of uncertainty for determining nicotinamide in infant formula milk powder were explored. Finally, the standard uncertainty and the expanded uncertainty were achieved. The content of nicotinamide in infant formula milk powder determined by HPLC was (63.01 ± 3.50) mg/kg. The major sources of uncertainty affecting determination results were pre-treatment, standard solution and standard curve fitting.

According to JJG1059-1999 Measurement Uncertainty and Results Indication, a mathematic model of uncertainty evaluation for the determination of polychorinated biphenyls (PCBs) in river crab by gas chromatography (GC) was established. The whole determination procedure was systematically investigated to analyze the sources of determination uncertainty. Meanwhile, the uncertainty of each variable was also evaluated and synthesized. The major affecting factors of GC determination uncertainty for PCBs in river crab were achieved.

The composition and contents of fatty acids in four kinds of honey such as chaste tree honey, clover honey, citrus honey and rape honey collected from Hubei province were comparatively analyzed. Fatty acids were extracted by ether and esterified with 1% sulfuric acid-methanol, and then analyzed by gas chromatography-mass spectrometry (GC-MS). Totally 14 fatty acids were identified in four kinds of honey, of which 8 were isolated from chaste tree honey, clover honey and rape honey, and 7 were isolated from citrus honey. Moreover, the content of unsaturated fatty acids accounted for 45.53%－79.31% of total fatty acids, while saturated fatty acids accounted for 16.68%－40.77 %. Palmitic acid and oleic acid were detected in each kind of honey.

To prepare a compound preservative for chilled pork, black pepper extract, prepared by soaking in 80% aqueous ethanol followed by reflux extraction, chitosan and glacial acetic acid were formulated to be mixed with water, and the effect of the compound preservative on total bacterial count in chilled pork was evaluated after 12 days of storage at 0－4 ℃. In order to minimize total bacterial count in chilled pork, response surface methodology based on quadratic general rotary unitized design were used to optimize the final concentrations of black pepper extract, chitosan and glacial acetic acid in aqueous solution. The compound preservative could dramatically inhibit microbial growth in pork during cold storage, and its optimal formula was 0.95% black pepper extract, 0.99% chitosan and 0.80% acetic acid, resulting in a total bacterial count of 5.2214 lg (CFU/g) after 12 days of storage.

Fresh-cut Huangguan pear was immersed in ethanol extract (100 mg/mL) of Fructus Mume for 5 min, air-dried, packaged with clear plastic wrap and stored at 4 ℃. During the storage, the total bacterial count, texture, content of vitamin C, weight lose, relative conductivity, phenol oxidase (PPO) activity, soluble solid content of Huangguan pear were determined every three days. Results showed that Fructus Mume extract could prolong the shelf life of fresh-cut Huangguan pear to 9 d, of which the fruit quality and water content remained good.

The fresh-keeping effect and mechanisms of pre-harvest chlorine dioxide (ClO2) treatment on ‘Red Fuji’ apple were studied. Red Fuji apples were sprayed with 0, 20, 50 mg/L and 80 mg/L ClO2 before harvest. Physiological indicators were measured regularly during storage and decay index was counted in the end. Pre-harvest ClO2 treatment could considerably scavenge colonies on fruit surface, inhibit the decrease in fruit hardness and titratable acid content, reduce respiration rate, ethylene release and decay index and increase the activities of POD and PAL, but have no obvious inhibitory effect on fruit weight loss. The appropriate concentration of ClO2 was 50 mg/L, resulting in an obvious fresh-keeping effect and a considerable prolongation of the shelf life.

In this paper, the stability of seven kinds of Japanese and Korean pear purees (Housui, Nansui, Sydney, Crystal, Yuanhuangli, Whangkeumbae and Bretschncideri) during storage was studied. Their pH, reducing sugar, contents of amino acid, 5-HMF and soluble phenols and total chromatism were determined. The results showed that the stability order of seven kinds of pear purees during storage was Yuanhuan, Sydney, Crystal, Housui, Nansui, Bretschncideri and Whangkeumbae. Reducing sugar (9.6%～7.2%) and amino acid (4.2～3.5 mg/100 mL) contents were higher in Yuanhuanli compared to other six varieties, but 5-HMF (0.6～1.1 mg/100 g) and soluble phenols (3.3～2.1 mg/g) in Yuanhuanli were less, and the pH (3.3～3.4) and chromatism (22.7～39.9) was the lowest. Therefore, Yuanhuang pear puree reveals the highest storage stability among seven species.

In this paper, the effect of ozone water treatment coupled with bag package on the preservation of Chinese chestnut fruits during storage was investigated. Fengkai Chinese chestnut fruits were immersed in ozone water solution of various concentrations (1.0, 0.5 mg/mL and 0.25 mg/mL). After ozone water treatment, the Chinese chestnut fruits were packaged with plastic bags and stored in an environment at (0 ± 1) ℃ and 90%－95% relative humidity (RH) for 180 days. The changes of quality and physiological indices of Chinese chestnut fruits during the storage period were examined. The results indicated that ozone water treatment coupled with bag package could effectively inhibit the respiration intensity and amylase activity, postpone the change of starch and sugar, reduce the weight loss and decay rate, and improve the catalase activity of Chinese chestnut fruits. Meanwhile, Chinese chestnut fruits treated with 1 mg/mL ozone water coupled with bag package had a decay rate of 3% and a weight loss of 1.1%. Therefore, ozone water treatment coupled with bag package can greatly improve the quality of Chinese chestnut fruits.

The respective effects of post-harvest citrus oil induction and vibration stress treatment on oleocellosis in Jincheng orange peel were studied based on collapse index and color index. Oleocellosis in Jincheng orange peel showed a gradual increase as the concentration of citrus oil increased. The most serious oleocellosis in citrus peel could arise from 100% citrus oil treatment. In addition, mechanical vibration stress also could induce oleocellosis in Jincheng orange peel. Mechanical vibration stress at 500 r/min revealed the most obvious effect on oleocellosis formation. Moreover, Jincheng oranges treated with citrus oil or mechanical vibration stress were also used to explore the effect of storage temperature on oleocellosis in their peels. As a result, Jincheng oranges stored at 20 or 5 ℃had the severest change in oleocellosis. However, Jincheng oranges had the slightest change in oleocellosis during 5 ℃ storage. Therefore, these results can provide a theoretical reference for exploring the mechanisms and control strategies of oleocellosis.

In this study, the content of total phenols, the activities of polyphenol oxdise (PPO) and peroxidase (POD) and browning degree of persimmon vinegar during storage were spectrometically assayed. Meanwhile, the effects of selected inhibitors such as NaCl, citric acid and L-ascorbic acid on the browning of persimmon vinegar were also investigated. The results indicated that the browning of persimmon vinegar during storage was enzymatic browning due to the oxidation of total phenols by PPO and POD in the presence of oxygen. Browning inhibitors such as NaCl, citric acid and L-ascorbic acid could maintain the content of total phenols, significantly inhibit the activities of PPO and POD, and delay the browning of persimmon vinegar during storage. In addition, 0.24 g/100 mL NaCl, 1.2 g/100 mL citric acid and 0.48 g/100 mL L-ascorbic acid revealed better inhibitory effect.

Mono-cyclohexyl fumarate (MCHF) was synthesized from cyclohexanol and maleic anhydride under microwave radiation using anhydrous aluminum chloride as the catalyst. The reaction products were structurally identified by means of melting point measurement, Infrared (IR) spectral analysis and elemental analysis. The effects of molar ratio of substrates, esterification temperature and time, isomerization temperature and time, microwave radiation power and isomerization catalyst dosage on MCHF yield were studied. The optimal reaction conditions were determined as follows: cyclohexanol/maleic anhydride/anhydrous aluminum chloride molar ratio 1:1.2:0.0225, microwave irradiaton power 700 W, esterification temperature 55 ℃, esterification time 30 min, isomerization temperature 100 ℃, and isomerization time 25 min. Under such conditions, the yield of MCHF reached 78.84%.

A current-type nano-immunosensor was developed for the specific determination of immunoglobulin G (IgG) content in colostrum products and bovine IgG-containing products. The chitosan with excellent film-forming capability and biocompatibility was used as the medium to connect nano-gold and glassy carbon electrode. Due to its large surface area, strong adsorption capacity and good biocompatibility, nano-gold was used to immobilize rabbit anti-bovine IgG-HRP. Electrochemical properties of electrode surface during each fabrication procedure were characterized by cyclic voltammetry and alternating current impedance method and standard bovine IgG in phosphate buffer was determined by chronoamperometry. The results revealed that the current-type nano-immuosensor had an excellent linear relationship between the concentration of bovine IgG in the range of 0.1－10000 ng/mL and the change rate of stable current before and after immunization with a correlation coefficient of 0.9976. Moreover, this immunosensor proved stable, reproducible, easy to use and inexpensive, thus being applicable for the quality control of bovine IgG products.