The adsorption and desorption rates of 7 types of macroporous resins towards total saponins from the sea cucumber Pearsonothria graeffei were investigated. Among the studied macroporous resins, XAD761 resin was the most suitable to purify crude total flavonoid extract from Pearsonothria graeffei. When 9 BV of 2 mg/mL sample was flowed through XAD761 resin column at a speed of 0.8 mL/min, the adsorption reached dynamic equilibrium. The adsorbed saponins could be completely eluted with 5 BV of 70% (V/V) ethanol at 1 mL/min, with a desorption rate of 93.31%. After the purification, the purity of total saponins was increased from 21% to 65%.

High pressure carbon dioxide (HPCD) was applied to quick-freeze shiitake (Lentinus edodes) in order to reduce energy consumption and cost. After being blanched in boiling water, the mushroom was subjected to HPCD treatment. By using one-factor-at-a-time and orthogonal array design methods, operating parameters such as initial temperature and pressure of the reaction vessel and pressure-relieving time were optimized for maximum sensory evaluation of quick-frozen products. Results showed that the optimum HPCD conditions were as follows: 6 ℃ initial temperature, 7 MPa initial pressure and 4 min pressure-relieving time. In addition, pressure-relieving time had the most significant influence on the sensory quality of quick-frozen shiitake among the parameters.

Liquid-phase isoelectric focusing (LIEF) was applied to purify proteins extracted from edible bird s nest (EBN). After LIEF prefractionation, totally 10 fractions were collected and analyzed with SDS-polyacrylamide gel electrophoresis (PAGE). The results showed that gelationus materials mainly concentrated at the first four fractions, and there were also some impurities at the last two fractions. So fractions five through eight were pooled as purified protein sample for following two-dimensional electrophoresis (2-DE) analysis. By using LIEF combined with 2-DE, 4 proteins from EBNs were well separated, and about 30 to 60 2-DE spots were detected on the 2-DE gels. The findings confirmed that LIEF as a prefractionation prior to IPG-IEF can produce the best 2-DE patterns for EBN.

A non-thermal plasma/photocatalysis reactor, designed and fabricated in our laboratory, was used to decolorize water-soluble polysaccharides extracted from litchi flesh. Decolorization parameters such as the filling rate of alumina as a support for photocatalyst, voltage, polysaccharide concentration and treatment time were tested for their influence on decolorization efficiency. Meanwhile, a regression model was set up to describe decolorization efficiency as a function of the decolorization parameters by means of quadratic orthogonal rotary combination design. The results showed that when the filling rate of alumina, voltage, polysaccharide concentration and treatment time were 18.1%, 21.6 kV, 50.0 mg/mL and 33.8 min, respectively, the best decolorization results were achieved, with a decolorization efficiency of 91.2% and a polysaccharide retention rate of 87.4%.

In order to determine the optimum conditions for extraction of polysaccharides from fermented mycelia of Lentinus edodes by ultrasonic cell disruption and subsequent hot water extraction, a L9(34) orthogonal array design was employed to investigate the effects of the operating parameters material-to-solvent ratio, temperature, ultrasound intensity and extraction time on polysaccharide extraction. The optimum conditions for extracting polysaccharides from fermented mycelia of Lentinus edodes were material-to-solvent ratio1:15, extraction temperature 90 ℃, ultrasound intensity 400 W and extraction time 3 h. Under the optimum conditions, the extraction yield of polysaccharides was 3.38‰. Further, the obtained extract was purified/fractionated sequentially by DEAE-52 ion exchange column and Sephadex G-100 gel permeation column and as a result, a polysaccharide having DPPH free radical scavenging ability was obtained and named as LMP Ⅱ. UV spectral scanning and cellulose acetate membrane electrophoresis demonstrated the high purity of LMP Ⅱ. The fraction had the capability of scavenging superoxide anion and hydroxyl free radicals, and could inhibit the production of MAD in plasma and hydrogen peroxide-induced erythrocyte hemolysis in a dose-dependent fashion. Thus, LMP Ⅱ has a strong antioxidant potential.

The debittering of Gannan navel juice with magnesium silicate, macroporous resin or β-cyclodextrin was studied with respect to the effects of major process parameters on the contents of sugar, vitamin C and organic acids. The optimum conditions for debittering Gannan navel juice with magnesium silicate were activation temperature 120 ℃, magnesium silicate addition 1.0%, and adsorption at 20 ℃ for 1 h, and under these conditions, the debittering rate and the loss rates of sugar, vitamin C and organic acids were 64%, 11%, 4% and 61%, respectively. Among 6 investigated types of macroporous resin, HP-20 was best for debittering Gannan navel juice, and its optimum adsorption conditions for debittering Gannan navel juice were 1.0% HP-20 addition , 14 h adsorption time and 20 ℃ adsorption temperature, resulting in a debittering rate of 73% and respective loss rates of sugar, vitamin C and organic acids of 5%, 1% and 7%. The optimum conditions for debittering Gannan navel juice with β-cyclodextrin were 0.6%, 20 ℃ and 1 h for β-cyclodextrin addition, temperature and embedding time, respectively, and the resulting debettering rate was 52% and sugar, vitamin C and organic acids were little lost.

In this study, Small marine fish hydrolysates obtained by digestion respectively with flavor protease, neutral protease, trypsin and alkaline protease were comparatively determined for their hydroxyl free radical scavenging activity. It was found that small marine fish hydrolysate obtained with neutral protease exhibited the highest hydroxyl free radical scavenging activity and was rich in amino acids. By using a L9(34) orthogonal array design, the optimum conditions for hydrolyzing small marine fish with neutral protease to antioxidant peptides with the highest hydroxyl free radical scavenging activity were determined as follows: pH 7.0, liquid-to-material ratio 1:2, enzyme dose 500 U/g and reaction temperature 42 ℃, and the hydroxyl free radical scavenging rate of the resulting hydrolysate was over 95%. Sephadex G75 chromatographic separation showed that the obtained hydrolysate was mostly composed of peptides with molecular weight below 3000 D.

Response surface methodology was used to optimize the ultrasound-assisted extraction of total phenolic acids from Salvia miltiorrhiza bunge. Leaves. The extraction efficiency of total phenolic acids was investigated with respect to four variables including ethanol concentration, time, temperature and liquid-to-solid ratio. On the basis of a series of one-factor-at-a-time experiments, a polynomial regression model equation was fitted by the combined use of Box-Behnken experimental design and regression analysis. By analyzing the regression model using response surface analysis, the optimum extraction conditions of total phenolic acids from Salvia miltiorrhiza bunge. Leaves. were identified as follows: 63% ethanol concentration, 43 min extraction time, 50.00 ℃ extraction temperature and 33:1 (mL/g) liquid-to-solid ratio, and the extration efficiency of total phenolic acids was up to 7.78% under the optimized conditions. Confirmatory experiments indicated the good prediction ability of the established model.

The process for production of Sphauericepus gracilis yogurt by fermenting fresh cow milk supplemented with Sphauericepus gracilis pulp was optimized by response surface methodology based on one-factor-at-a-time experiments. The overall sensory score of Sphauericepus gracilis yogurt was studied with respect to four process parameters including fermentation time (x1), Sphauericepus gracilis pulp addition (x2), sucrose addition (x3) and inoculum size (x4). As a result, a regression model equation was fitted as follows: Y = 89.13333－2.39688x12－1.62188x22－1.62188x32－1.99688x42－2.99375x1x3－1.06875x1x4－1.25625x3x4. The optimum fermentation conditions for producing Sphauericepus gracilis yogurt with the highest sensory quality were fermentation time of 3.5 h, Sphauericepus gracilis pulp addition of 18%, sucrose addition of 6% and inoculum size of 4%. In terms of the importance in affecting the overall sensory score of Sphauericepus gracilis yogurt, the four factors ranked in the following order: Sphauericepus gracilis pulp addition, fermentation time, inoculum size and sucrose addition. The Sphauericepus gracilis yogurt obtained under the optimized fermentation conditions exhibited exquisite mouth feeling, homogeneous texture, unique flavor and elegant Sphauericepus gracilis aroma. The optimized process can provide a simple and feasible approach for production of Sphauericepus gracilis yogurt.

Small yellow croaker heads, chicken muscle, pork fat, egg white and carrots were blended to develop kamaboko gel. #br# Orthogonal array optimization showed that the optimum formula consisted of 20% small yellow croaker heads, 20% chicken, 15% concentrated carrot juice, 15% water, 12% egg white protein, 10% pig fat, 2% onion, 2% ginger, 2% salt, 1.5% garlic, 0.5% MSG. The resulting kamaboko gel exhibited yellowish-brown color, better gel-forming ability and water-holding capacity, #br# compact cross-section, improved springiness and chewiness, characteristic small yellow flavor and high nutritional value.

Headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled with mass spectrometry (GC-MS) were used for the qualitative determination of volatile compounds in white liquor samples. HS-SPME experimental conditions, such as sample volume in headspace glass vial, ionic strength, equilibrium temperature and time, desorption time were optimized. The best extraction performance was achieved under the following conditions: 40% sample volume in headspace glass vial with addition of 0.2 g/mL NaCl, 30 min equilibrium time at 50 ℃ with stirring speed of 200 r/min, 30 min headspace adsorption time, and 15 min desorption time in the GC inlet at 250 ℃. As a result, 42 aroma compounds were extracted out of the tested liquor sample (from Songhe Liquor Industry Co. Ltd.), including 26 esters, 6 fatty acids, 5 higher alcohols, 2 aldehydes, 2 ethers and 1 anhydride.

In order to achieve maximum degreasing rate, the hydrolysis of cultured large yellow croaker fillets by alkaline lipase was optimized by the combined use of single factor and orthogonal array design methods. The optimum hydrolysis conditions for degreasing large yellow croaker fillets were temperature 32 ℃, reaction pH 8.5, enzyme concentration 60 U/mL, reaction time 60 min, substrate-to-enzyme solution ratio 1:4 (by mass), respectively. Under these conditions, the degreasing rate was 67.32%.

Galactosyl-β-cyclodextrin (Gal-β-CD) was synthesized under the catalysis of α-D-galactosidase derived from germinated coffee beans using melibiose as a donor and β-cyclodextrin as an acceptor. The optimum synthesis parameters were enzyme dose 20 U/g melibiose, β-CD-to-melibiose molar ratio 1:2, pH 6.5 (50 mmol/L acetate buffer), reaction time 24 h and reaction temperature 40 ℃, respectively. The product obtained under the optimized conditions was purified by preparative HPLC, and the purified product was 6-O-α-D-galactosyl-β- cyclodextrin according to ESI-MS, IR, and NMR analyses.

The present study was conducted to optimize the extraction of gingerol oleoresin from ginger powder by enzymatic hydrolysis with both cellulase and hemicellulase. By using one-factor-at-a-time and orthogonal array design methods, the optimal extraction conditions of gingerol oleoresin for achieving maximum extraction efficiency were determined as follows: ellulase-to-hemicellulase ratio of 5:3 (m/m), total enzyme dose of 2.8 mg/100 mL, hydrolysis time of 2.5 h and hydrolysis temperature of 45 ℃. Under the optimum conditions, the extraction efficiency of gingerol oleoresin was 3.711%, 30% higher than the yield of ethanol extraction.

The response surface methodology was used to optimize the supercritical carbon dioxide extraction of antioxidant components from rosemary leaves. Three extraction parameters including pressure, length of extraction time and entrainer (absolute ethanol) amount were optimized based on total phenol content in extract. The optimum extraction conditions were extraction pressure 26.98 MPa, extraction time 2.28 h and entrainer concentration 0.48 mL/g, respectively, the resulting extract containing 12.70 mg/g total phenolic compounds. The extraction method can provide a simple, reliable and applicable method for the extraction antioxidant components from rosemary leaves.

Objectives: The preparation of antioxidant enzymatic hydrolysate (AEH) from Sepia esculenta by papain hydrolysis and the debittering of AEH by activated carbon adsorption were explored. Meanwhile, the nutritional value of AEH was also evaluated. Methods: The hydrolysis of Sepia esculenta and the debittering of AEH were optimized by orthogonal array design based on hydroxyl free radical scavenging rate and bitterness sensory score, respectively. The amino acid composition of AEH was determined by means of automatic amino acid analyzer. The nutrition value of AEH was analyzed based on its amino acid and chemical scores, calculated using egg protein as standard protein and the WHO/FAO reference model for essential amino acids as an appraisal criterion (EAA). Results: The optimal enzymatic hydrolysis conditions were hydrolysis temperature of 55 ℃, pH 7.0, enzymatic hydrolysis time of 5 h and enzyme amount of 1.0%; the optimal debittering conditions were activated carbon amount of 3.0%, debittering time of 120 min and debittering temperature of 40 ℃. The AEH obtained under these conditions with basically no bitterness had even higher hydroxyl free radical scavenging activity than crude protein extract from Sepia esculenta. The crude protein content of AEH was 18.07%. Meanwhile, AEH was rich in all kinds of amino acids with a total content of 95.95%. Moreover, essential amino acids (EAA) accounted for 42.00% of the total amino acids. The first limited amino acid was Val. The EAA index was 93.7 when compared with egg. The content of palatable and sweet taste amino acids like glutamic acid accounted for 38.68% of the total amino acids. Conclusion: The AEH has strong antioxidant capacity and high nutrition value and can therefore provide an ideal source of protein supplements.

In order to improve the color and functional properties of rice residue protein, response surface methodology was used to optimize parameters influencing its decolorization by hydrogen peroxide. The optimum decolorization conditions were hydrogen peroxide. concentration of 4.5%, pH 9.5, decolorization temperature of 55 ℃ and decolorization time of 45 min. Under these conditions, the whiteness of rice residue protein was improved from 20.5% to 48.2%. In addition, the lowest solubility (roughly 5%) of rice residue protein in pH 4－5 was observed. However, when pH was lower than 4 or higher than 6, the solubility of rice residue protein was significantly increased. The solubility of rice residue protein was 38.58% at pH 2 or 76.79% at pH 13. In neutral environment, the foaming capacity (FC), foam stability (FS), emulsifying activity index (EAI), emulsifying stability index (ESI), oil-holding capacity (OHC) and water-holding capacity (WHC) of rice residue protein after decolorization were 12%, 33.3%, 3.15 min, 24.84 min, 2.00 and 3.08, respectively. All of these values were much higher than those before decolorization. Therefore, hydrogen peroxide treatment can not only decolorize rice residue protein but also significantly improve its functional properties.

Response surface methodology was applied for the optimization of process conditions for the extraction of polyphenols from mango kernel. Temperature, extraction time and solid-to-liquid ratio were identified as main factors that affect polyphenol extraction by means of one-factor-at-a-time experiments. Based on a 20-run, three-level Box-Benhnken experimental design and multiple regression analysis, a mathematical model equation was fitted that describes the extraction rate of polyphenols as a function of temperature, extraction time and solid-to-liquid ratio, and the relationship between the function and the three variables was analyzed using response surface analysis. As a result, the optimal extraction conditions were extraction temperature of 56 ℃, extraction time of 2 h, 95% ethanol as extraction solvent with a solid-to-liquid ratio of 1:6.8. Under these conditions, the experimental extraction rate of polyphenols was 9.38%, which was close to the predicted value of 9.21% and obviously higher than the previously reported value of 6.86%. Therefore, the established extraction method has high reliability.

The anti-Saccharomyces cereviviae effect and notable medicinal value of Lycoris radiata alkaloids highlight the importance and necessity of total alkaloids extraction before ethanol fermentation from L. radiata bulbs. In the present study, one-factor-at-at-time experiments were conducted to explore the extraction efficiency of total alkaloids from L. radiata bulbs with respect to five operating parameters including extraction solvent type, temperature, extraction time, solid-to-liquid ratio and pH. The results showed that the extraction efficiency of total alkaloids was up to 28.70 mg/g under the following conditions: methanol as extraction solvent, solid-to-liquid ratio of 1:15 (g/mL), temperature of 60 ℃, pH 11.0 and extraction time of 1 h. Further, the fermentation performance of L. radiata bulbs for producing ethanol was compared before and after the removal of total alkaloids. As a result, the presence of total alkaloids had dramatic inhibitory effect on glucoamylase activity and the growth of S. cereviviae and little effect on α-amylase activity. This can preliminarily explain the inhibitory mechanism of Lycoris radiata alkaloids on ethanol fermentation.

As a novel fast food, rice burger was developed and its production process was optimized. The effects of japonica rice/glutinous rice ratio, rice/water ratio, soaking time and kind and amount of quality improvers on texture properties of rice burger were explored by one-factor-at-a-time method. The optimal processing conditions for producing rice burger with the highest sensory evaluation score was determined as follows: japonica rice-to-glutinous rice ratio of 3:7, rice-to-water ratio of 1:1 and water-soluble soybean polysaccharide (SSPS) as quality improver at 0.2% addition.

Objective: To optimize conditions for simultaneous microwave-ultrasonic assisted extraction of phenolic compounds from Senecio cannabifolius using ethanol as extraction solvent and to determine total phenol content in Senecio cannabifolius based on optimized microwave-ultrasonic assisted extraction process. Methods: Process conditions optimization was performed using one-factor-at-a-time and orthogonal array design methods. The extraction yield of phenolic compounds was investigated with respect to three process parameters such as microwave power, microwave treatment time and ethanol concentration. Determination of total phenol content was performed respectively using ultraviolet spectrophotometry and thin layer chromatography (TLC) scanning method. Results: The optimal extraction conditions were microwave treatment time of 120 s, microwave power of 90 W and ethanol concentration of 75%. In the ultraviolet spectrophotometeric determination, a mean spike recovery rate of 92.30%, a precision of 2.204% and a total phenol content of 0.1276% were observed, and those obtained by TLC scanning determination were 98.52%, 1.011% and 0.2044%, respectively. Conclusion: Both analytical methods above are applicable for the determination of phenolic compounds, and TLC scanning is a more accurate method.

Objective: To optimize the simultaneous extraction and purification of paeoniflorin and albiflorin from Radix Paeoniae Rubra. Methods: The optimal extraction conditions for achieving the highest total yield of paeoniflorin and albiflorin were determined using orthogonal array design. Further, the purification of paeoniflorin-albiflorin extract by microporous resin adsorption was explored. Results: The optimal extraction conditions were 70% ethanol as extraction solvent at a material-to-liquid ratio of 1:8 (g/mL) for reflux extraction repeated three times for 2 h each time. The optimal purification was achieved on AB-8 macroporous adsorption resin column with a diameter/height ratio of 1:8 under the following conditions: sample loading amount of 4.4 BV, washing with 3 BV water and eluting with 6 BV 40% ethanol at a flow rate of 1.5 BV/h. Conclusion: The optimized extraction process is simple and practical and can provide high purity of total paeony glycoside (TPG, mainly paeoniflorin and albiflorin).

One-factor-at-a-time and orthogonal array design methods were employed to optimize transesterification conditions for lipase catalyzed synthesis of scorbyl fatty acid esters from lard and ascorbic acid with ultrasound assistance. The optimum synthesis conditions of scorbyl fatty acid esters were tert-amyl alcohol as reaction medium, Novozym 435 lipase amount of 20% (calculated on the basis of the mass of ascorbic acid), molar ratio of ascorbic acid to lard of 1:3, ultrasound power of 350 W, ultrasound frequency of 59 kHz and reaction time of 9 h, and the resulting conversion rate of ascorbyl fatty acid esters was up to 88.00%. The ultrasonic treatment could improve scorbyl fatty acid ester yield from 71% to 88% and reduce the reaction time from 32 to 9 h. Novozym 435 exhibited excellent stability under the ultrasonic treatment condition and its activity remained at a relatively high level even after its sixth repeated use.

This study was undertaken to prepare medium-chain fatty acid (MCFA)-VC complex liposome using lecithin and cholesterol as membrane materials and optimize the preparation process. Four preparation methods including thin film method, high pressure-thin film method, double emulsification method and high pressure-double emulsification method were compared in terms of entrapment efficiency and liposomal particle size. As a result, high pressure-double emulsification method was found to be the best method. One-facto-at-a-time experiments were carried out to determine the optimal preparation conditions as follows: total lipid material cocentration of 5.0 g/100 mL, MCFAs concentration of 10.0 mg/mL, VC concentration of 3.0 mg/mL, lecithin/absolute ethanol ratio of 1:10 (g/mL), mass ratio of lecithin to cholesterol of 4:1, mass ratio of Tween to total lipid material of 3:10, mass ratio of VE to lecithin of 5:1, and twice repeated ultramicroemulsification at 120 MPa, respectively. <br /> Under these optimal conditions, the entrapment efficiencies of MCFA and VC were 49.01% and 54.19%, respectively and a mean particle size of 90.3 nm was achieved. The three indexes had little change during storage at 4 ℃ for 15 days, thus indicating excellent stability at low storage temperature.

Ten kinds of commonly used macroporous resin were compared for their effectiveness in purifying crude red pigment obtained from Parthenocissus tricuspidate fruits by fractional solvent extraction. It was found that LSA-7 resin had the best purification performance. Further, operating conditions for purifying red pigment from Parthenocissus tricuspidate fruits by dynamic adsorption onto LSA-7 resin column were optimized and UV spectrophotometry and HPLC were used to analyze red pigment samples. The adsorption of LSA-7 resin almost reached its saturation under the following conditions: temperature of 30 ℃, sample concentration of 30 mg/mL and sample loading amount of 2 BV. Elution at a flow rate of 3 BV/h resulted in a red pigment purity of more than 96.7%. Moreover, the resulting pigment composition was the same as that obtained by thin layer silica gel H separation. Therefore, LSA-7 resin is suitable for industrial dynamic production of red pigment from Parthenocissus tricuspidate fruits.

The enzymatic hydrolysis of grass carp scales with alcalase for the preparation of antioxidant peptides was optimized by one-factor-at-a-time and orthogonal array design methods. Peptide yield, hydrolysis of degree (DH) and hydroxyl free radical scavenging rate of grass carp scale hydrolysate were investigated with respect to temperature, enzyme dose, substrate concentration, reaction time. The optimal hydrolysis conditions were pH 9.0, hydrolysis temperature of 55 ℃, enzyme amount of 3%, hydrolysis time of 5 h and substrate concentration of 10%, respectively. Under these conditions, the yield of peptides was 55.2% and the resultant hydrolysate presented a hydroxyl free radical scavenging rate of 98.86%. High performance liquid chromatography analysis showed that 91.8% of peptides in the hydrolysate had a molecular weight below 1000 D. The hydrolysate had an isoelectric point of around 2.6 and a solubility of higher than 98 % in the range of pH 2－12 and could thus be extensively used in foods.

Colloidal gold particles with three different particle sizes of 20, 30 nm and 40 nm were prepared by the sodium citrate method. The colloidal gold particles with various particle sizes were then used to prepare test strips with colloidal gold-labeled anti-chloramphenicol (CAP) monoclonal antibodies. The preparation parameters of these test strips were optimized and their performance was compared. The test strip containing 30 nm colloidal gold particles exhibited a detection limit of 3 ng/mL. However, the detection limits of the test strips containing colloidal gold particles of 20 nm and 40 nm were only 7 ng/mL and 9 ng/mL, respectively. Moreover, the test strip containing 30 nm colloidal gold particles was more stable and sensitive than the other two and could therefore provide a more suitable marker for testing chloramphenicol.

Response surface methodology was used to optimize the ultrasonic-assisted extraction of total flavonoids from hovenia seeds. A regression model describing total flavonoid yield with respect to ultrasonic power, material-to-liquid ratio and ethanol concentration was established. Ethanol concentration was the most important affecting factor of the total flavonoid yield resulting from 60 min extraction at 65 ℃, followed by material-to-liquid ratio and ultrasonic power. The optimal extraction conditions for total flavonoids from hovenia seeds were ultrasonic power of 374.4 W, material-to-liquid ratio of 1:69.4 (g/mL), ethanol concentration of 64.5%, extraction temperature of 65 ℃ and extraction time of 60 min, and the resultant total flavonoid yield was (0.819± 0.003)%, which was close to the predicted value of 0.823%. Therefore, the established regression model is feasible and has good prediction capability.

Objective: To optimize the extraction of instant green tea powder from tea leaves. Methods: On the basis of one-factor-at-a-time experiments, orthogonal array design L16(43) was used to optimize the extraction of instant green tea powder and the yield of green tea powder was investigated with respect to three extraction parameters including extraction temperature, tea leaves-to-water ratio and extraction time. Results: The importance of the three extraction parameters in affecting the yield of green tea powder declined in the following order: extraction temperature, tea leaves-to-water ratio and extraction time. The optimal extraction conditions of instant green tea powder were extraction temperature of 80 ℃, tea leaves-to-water ratio of 1:20 and extraction time of 80 min. Under the optimal extraction conditions, the yield of instant green tea powder reached up to (25.1 ±0.1)%. Conclusion: Orthogonal array design is suitable for optimizing the extraction of instant green tea powder from tea leaves. The optimized extraction parameters are reliable.

The characteristics of adsorption and desorption of onion peel flavonoids on six kinds of macroporous resins were compared. Static adsorption and desorption experiments indicated that X-5 resin was the best resin for the separation and purification of flavonoids from onion peel. The optimal process parameters for purifying onion peel flavonoids with X-5 resin were sample loading flow rate of 0.5 mg/mL, sample pH 5.0 and 50 mL of 80% ethanol of as eluent at a flow rate of 1.0 mL/min. After the purification, the purity of flavonoids from onion peel was increased from 7.95% to 80.78% and could reach up to 94.5% after further triple recrystallization. The developed method is simple and feasible for industrialization.

Molecular distillation (MD) was used to purify essential oil from cumin oleoresin, obtained by supercritical carbon dioxide fluid extraction, and two important process parameters including temperature and pressure were optimized by response surface methodology for maximizing oil yield and cuminal content. Two quadratic regression model equations describing oil yield or cuminal content as a function of the two process parameters were established. Both parameters had a highly significant effect on oil yield and cuminal content. Based on numerical optimization and comprehensive considerations of oil yield and cuminal content, the optimal distillation conditions were temperature of 77 ℃and pressure of 122 Pa, resulting in an oil yield of 34.24% and a cuminal content of 30.43%.

In the present study, macroporous resin adsorption was used to probe the purification of total flavonoids from the crude extract of Actinidia arguta fruits, prepared by ultrasonic-assisted ethanol and reextraction with petroleum ether. Among the nine macroporous resins investigated, HPD 600 exhibited the best performance in adsorbing and desorbing total flavonoids from Actinidia arguta fruits and its optimum working parameters were sample solution pH 3－4, sample concentration of 0.5 mg/mL, sample loading amount of 3 BV, washing water amount of 3 BV, 4 BV of 80% ethanol as the eluent at a flow rate of 2 mL/min. After the purification, the average recovery rate and purity of total flavonoids was 86.5% and 37.2%, respectively. Therefore, HPD600 is suitable for the purification of total flavonoids from Actinidia arguta fruits.

In this work, hot air and microwave were combinedly used to dry yacon and its drying characteristics were explored under varying conditions of sample thickness, air temperature, and microwave power. Quadratic regression orthogonal rotary combination design was used to optimize total color change (δE) and drying time with respect to hot air temperature, water content at conversion point and microwave mass specific power. The results showed that the optimal process parameters of hot air drying were sample thickness of 2－4 mm, air temperature of 70 ℃ and those of microwave drying were sample thickness of 4 mm and microwave mass specific power of 2 W/g. The importance of factors affecting δE resulting from hot air combined with microwave treatment dropped in the following sequence: microwave mass specific power, hot air temperature and water content at conversion point, and water content at conversion point was the most important factor affecting drying time, followed by hot air temperature and microwave mass specific power. The optimal parameters for drying yacon by hot air combined with microwave treatment were sample thickness of 4 mm, hot air temperature of 68.1 ℃, water content at conversion point of 61.0% and microwave mass specific power of 2.6 W/g. Under the optimal process conditions, the color change δE was 21.53, the drying time t 172 min, the rehydration rate RR 4.12, and the shrinkage rate SR 84.35%.

The objective of this work to purify the crude pigment extracted from duck-blood glutinous rice by macroporous resin adsorption. Five types of macroporous resin were comparatively tested for their adsorption and desorption performance towards duck-blood glutinous rice pigment, and resin NKA-9 was considered best for purifying duck-blood glutinous rice pigment. Further, the effects of sample concentration, pH and loading flow rate and desorption flow rate on the adsorption and desorption rates of resin NKA-9 were investigated, and the results showed that the optimal purification parameters for duck-blood glutinous rice pigment was sample pH 1.0, sample loading flow rate of 1 mL/min, sample concentration of 1.0 mg/mL and desorption with 5 BV of 70% ethanol at a flow rate of 1.0 mL/min. In conclusion, NKA-9 resin is suitable to purify duck-blood glutinous rice pigment due to its advantages of large adsorption capacity, easy desorption and high resolution.

The extraction of pectin from persimmon peel with the aid of cellulase was optimized by orthogonal array design on the basis of one-factor-at-at-a-time. The optimum extraction parameters were identified as follows: extraction temperature of 45 ℃, enzyme dosage of 3.0 mg/g, pH 4.0, material-to-liquid ratio of 1:35 and extraction time of 2 h, and the resulting extraction rate of pectin was 8.87%. This method has the advantages of simplicity and convenience and can therefore be used for the extraction and determination of pectin.

The extraction and purification of inulin from Jerusalem artichoke grown in the saline-alkaline soil of Yancheng, Jiangsu province. The ash content of the botanic material was higher than those previously reported in the literature for Jerusalem artichoke samples from Fujiang province and Gan county, Jiangxi province. Twice repeated extraction for 40 min each time at 90 ℃ with a 15-fold volume of water proved optimal, and the resulting extraction efficiency was 89.56%. Ultrafiltration membrane separation with10 kD MWCO membrane could more effectively remove macromolecular substances such as protein and pectin from the obtained inulin extract when compared with the conventional phosphate-lime milk method, and the removal rate of protein and the retention ratio of inulin were improved by 27.12% and 13.41%, respectively. Polymerization degree analysis of different MWCO (10000, 5000, 2500 D and 340 D) fractions of the inulin extract showed that the polymerization degrees of inulin were varied from 16 to 60, which accounted for 76.1% of the total inulins. The optimal decoloration conditions for the inulin extract were activated carbon dosage of 5 g/L, decoloration temperature of 60 ℃ and decoloration time of 20 min. Under these conditions, the decoloration efficiency and the recovery of inulin were 92.87% and 91.63%, respectively. Therefore, ultrafiltration can greatly reduce the separation procedure due to convenience and rapidity and fewer procedures, thus showing a very promising prospect for industrial applications.

In order to establish a rapid sample pretreatment method for spectrometrically (based on Biuret reaction) determining peptides in rice hydrolysate prepared with alcalase, trichloroacetic acid (TCA) and ethanol were separately used as precipitants to remove high molecular weight proteins from the hydrolysate and three conditions including precipitant dosage and concentration, temperature and standing time were examined. The optimal conditions for TCA precipitation were adding a 3-fold volume of 150 g/L TCA solution to the hydrolysate and then standing at 35 ℃ for 10 min, and under these conditions, the peptide content in the hydrolysate was determined to be (54.2 ± 0.6)%. In the ethanol precipitation, a-fold volume of 75% ethanol solution was added to the hydrolysate and thoroughly mixed prior to standing at 25 ℃ for 10 min, and the resultant peptide content in the hydrolysate was (50.6 ± 0.1)%. Biuret reaction at 30 ℃ for 30 min proved optimal for stable color development. In summary, the TCA precipitation method has the advantages of wider linear range as well as higher sensitivity and repeatability compared with the ethanol precipitation method.

A HPLC method has been developed to determine sterigmatocystin in wheat. The residue of sterigmatocystin in wheat samples was extracted into n-hexane and cleaned up on silica-gel SPE column for removing fat and other impurities before injection into HPLC system connected with Nova-Pak C18 column. A mobile phase composed of methanol and water (70:30, V/V) was used at a flow rate of 0.7 mL/min. The detection was performed at 246 nm. There was a good linear relationship in the range from 0.08 to 4.00μg/mL (R2 = 0.9996). The average recovery was 86.59% with a RSD of 4.70%. The limit of detection was 0.017μg/kg. This method can provide a simple, rapid and accurate method for determining sterigmatocystin in wheat and other grains.

The aroma quality of Sichuan hot bean sauce samples of different fermentation periods, different fermentation methods and different manufacturing origins was analyzed with an electronic nose. The acquired experimental data were analyzed with principal component analysis (PCA) and statistical quality control (SQC). The aroma of Sichuan hot bean sauce varied with fermentation methods and fermentation period. PCA analysis could differentiate different samples. Hot bean sauce samples of Pixian and the other investigated manufacturing origins presented similarity and difference in odor fingerprint and could be distinctly differentiated by PCA and SQC.

In this study, a pair of specific primers was designed according to the polygalacturonase gene of Penicillium expansum to detect Penicillium expansum in rotten apples by polymerase chain reaction (PCR). The results showed that the specificity and sensitivity of the design primer pair were high and only Penicillium expansum DNAs were amplified. The detection limits of Penicillium expansum and DNA were 1.34 × 103 spores/mL and 2.40 × 10-2μg/mL, respectively. The optimal reaction condition was obtained as follows: anneal temperature of 54－59 ℃ and template concentration of 2.40－5.28μg/mL. Owing to its simplicity, rapidity and high specificity and sensitivity, this assay can be used for practical applications.

An ion-exclusion chromatographic method for the determination of lactic acid was developed using direct conductivity detection. Chromatographic separation was performed on a Shim-pack SCR-102H column using p-toluenesulfonic acid as eluent. The effects of eluent concentration, column temperature and flow rate on the retention time of lactic acid were investigated. The optimized chromatographic conditions for determining lactic acid were using 2.0 mmol/L p-toluenesulfonic acid as the eluent, column temperature 50 ℃ and flow rate 1.0 mL/min. The resulting retention time of lactic acid was about 8 min. Common organic acids (formic acid, acetic acid, citric acid and malic acid) did not interfere with the determination. The detection limit (RSN = 3) for lactic acid was 0.36 mg/L. The calibration curve of the method was linear in the range of 1.0－100.0 mg/L. The relative standard deviation for five replicate determinations of chromatographic peak area was 0.9%. The average spike recoveries of lactic acid from five brands of Chinese liquors ranged from 95.8% to 98.5% (n = 5).

The contents of protein and fat in liquid milk were determined by near infrared (NIR) spectroscopy combined with chemometric methods. Four training set and test set samples partitioning methods: random sampling (RS), kennard-stone (KS), Duplex, and sample set partitioning based on joint x-y distance (SPXY) were used and compared. Haaland’s criterion was employed for outlier detection. Eleven spectral pretreatments were used to eliminate the slope-background and noise. Under optimized conditions, the RMSECV, RMSEP, Rc2, and Rp2 of the established model for fat content were 2.434, 2.099, 0.958 and 0.964, respectively. These four parameters of the protein content prediction model were 2.270, 2.564, 0.942, and 0.940, respectively. The results show that this method can provide a useful strategy for quality of liquid milk owing to its accuracy and better generalization.

This study was designed to analyze phenolic compounds in different solvent (aqueous, ethyl acetate and 1-butanol) fractions of the ethanol extract of longan seeds by high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS) and to evaluate their antioxidant activity. A total of 11 compounds were identified in aqueous, ethyl acetate and 1-butanol fractions, including 6 phenolic compounds. Ethyl acetate fraction had the strongest antioxidant activity among the three fractions. Further separation of ethyl acetate fraction by macroporous resin AB-8 column chromatography resulted in 16 eluates. The measurement of DPPH free radical scavenging activity and reducing potential using ascorbic acid as a reference substance demonstrated that all the eluates had excellent antioxidant activity and eluates No. 7 and 8 had the strongest antioxidant activity. Highly pure gallic acid was obtained after repeatedly recrystallizing eluate No. 7, thus supporting the excellent antioxidant activity of the eluate. Meanwhile, the strongest antioxidant activity of ethyl acetate fraction as a low-polarity fraction indicated that longan seeds contained abundant amounts of phenolic compounds having small molecular weight.

A new microwave digestion-inhibition catalytic kinetic spectrophotometric method to determine trace nickel in food was developed based on the inhibition effect of nickel on the oxidation of bromcresol purplet by hydrogen peroxide in borax medium. The optimal microwave digestion condition was using 70% HNO3－30 % H2O2 (4:1, V/V) as digestion solution for 15 min digestion at 1.5 MPa. The fading reaction of bromocresol purple induced by hydrogen peroxide was inhibited in borax medium and PEG-200 could activate the reaction system. Reaction in boiling water for 14 min and detection at 590 nm proved optimal. The linear range for determination of nickel was 1.7 × 10-3－0.14 mg/L and the detection limit was 1.7 × 10-3 mg/L. This method has been satisfactorily applied to the determination of nickel in food with maximum relative standard deviation of 5.2%. The average spike recoveries of nickel from five kinds of botanic materials ranged from 94.4% to 107.1% (n = 5). Compared with the method of CB/T 5009 138－2003, the maximum relative error was lower than 6.3%.

Four methods, including modified CTAB, E.Z.N.A.TM Total RNA KitⅡ, EZ-10 Span Column Total RNA Isolation Kit and guanidine thiocyanate, were evaluated for their performance for isolating total RNA from mulberry fruit by comparing total RNA yield, purity and completeness as well as RT-PCR results. The results showed that modified CTAB method and E.Z.N.A.TM Total RNA KitⅡ were adequate for extracting total RNA from mulberry fruit. The acquired total RNA had a good quality and could be absolutely suitable for being used for further molecular biology experiments. Besides, the modified CTAB method was more economical and easier to operate than E.Z.N.A.TM Total RNA KitⅡ.

An ion chromatography method was presented to determine chlorine in hogwash oil and edible oil. Oil samples were ashed in muffle furnace at 550 ℃for 4 h with calcium oxide, cooled down, extracted with water in an ultrasonic field, and purified on an On Guard Na Ⅱ SPE column for eliminating metal ions before ion chromatographic analysis. The chromatographic separation was carried out on an IonPac AS19 (4 mm× 250 mm) column using 30.0 mmol/L KOH as mobile phase at a flow rate of 1.0 mL /min. The injection volume was 500μL. The external standard method was used to quantify chlorine. The detection limit of the method was 0.004 mg/L and a good linear relationship was observed over the range from 0.004 to 0.8 mg/L (r = 0.9992). The average recovery rate and RSD were 88% and 3.1%, respectively. This method proved easy to use, rapid, sensitive and accurate.

A method to determine the trace elements K, Mg, Ca, Fe and Cu in potato from three different cultivars grown in Henan region was proposed using microwave digestion and atomic absorption spectrometry. Three cultivars were all rich in K, Mg, Ca, Fe and Cu and varied in the contents of the trace elements. The relative standard deviations for determination of these elements ranged from 0.5% to 4.96%. The spike recovery rates from potato Zhongshu No.5 were from 94.9% to 102.2%. The limit of detection was 0.02μg/mL for Mg and 0.20μg/mL for the other four elements. This method can provide a reliable, sensitive, selective, simple and environmentally friendly approach for determination of trace elements in potato.

A pre-column derivatization method for separating and analyzing oligosaccharides by high performance liquid chromatography-electrospray ionization ion-trap mass spectrometry (HPLC-ESI-MS/MS) was established by using aniline as reductive amination reagent. Under the optimized HPLC-ESI-MS/MS conditions, HPLC separation was carried out on an Elite RP C18 column (4.6 mm × 250 mm, 5μm) with a mobile phase made up of acetonitrile and ammonium acetate (10 mmol/L, pH 4.5) under gradient elution mode and ultraviolet detection was performed at 239 nm. Maltodextrin derivatives were successfully separated and analyzed by HPLC-ESI-MS/MS in a positive ion mode. Stable maltodextrin derivatives and easy post-treatment could be achieved by this method. Hence, we conclude that it has potential application prospects in separation and analysis of oligosaccharides in food matrixes.

In this study, the content changes of saturated fatty aldehydes in lard, chicken fat and beef fat during the controlled oxidation process were first determined by online IR at the characteristic absorption wavelength of 1731 cm-1 using octanal as reference standard. The results indicated that the change trend of saturated fatty aldehydes during fat oxidation process was in agreement with that of determined peroxide value (P.V.) and acid value (A.V.). The content of saturated fatty aldehydes was correlated with the values of P.V. and A.V., respectively. Online IR is a convenient and rapid strategy due to avoidance of sampling and sample pretreatment.

Chemical modification method was employed to synthesize imidacloprid (IMI) hapten. The IMI hapten was then coupled with BSA and OVA to prepare immunogen (IMI-BSA) and coating antigen (IMI-OVA) by EDC method. Optimal coupling ratios between the IMI hapten and the two carrier proteins were eventually achieved. In order to define immunological characteristics of IMI, anti-IMI serum produced by immunized six-week-old Balb/c mice was tested by indirect ELISA and blocking ELISA. Meanwhile, spleen cells of immunized mice were hybridized with mouse myeloma cells by PEG-induced technique. Hybridoma cell strain 3C8 was obtained through positive screening and clonal culture. The experimental results indicated that the cell strain had high antibody titer, good affinity and high specificity. The optimal IMI-OVA concentration and IMI-mAb dilution were defined by square matrix titration. As a result of the above efforts, a blocking ELISA was developed for quantitative detection of IMI based on IMI-mAb with a linear range of 7.48 × 10-6 to 3.24×10-4 mg/mL (R2 = 0.9928) and a LOD of 8.00 × 10-6 mg/mL.

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous determination of five saccharides such as fructose, glucose, sucrose, maltose and lactose in foods. Samples were extracted with water under rotating vortex field, and protein was removed by using 100 mL of acetonitrile. The extract was separated on an ACQUITY BEH Amide HPLC column using acetonitrile-water (both containing 0.1% ammonia) as mobile phase. The electrospray ionization tandem quadrupole mass spectrometric analysis was carried out in the negative ion mode using selective reaction-monitoring (SIM) under the conditions: 10 MPa nebulizer pressure, 200 ℃ drying gas temperature, and 8 mL/min flow rate. The limits of detection were 32μg/kg for fructose, 32μg/kg for glucose, 9μg/kg for sucrose, 21μg/kg for maltose and 20μg/kg for lactose. The average recovery rates were 98.5%－102.2% at 10 g/kg and 2 g/kg spike levels with a relative standard deviation of 0.2%－1.4%. This developed method is characteristics of rapidity, high sensitivity, precision and convenient operation, thereby providing a promising approach for simultaneous determination of trace sugars in foods.

A simultaneous determination method for three sweeteners (sodium cyclamate, potassium acesulfame and sodium saccharin) and two preservatives (potassium sorbate and sodium benzoate) in food was established. Samples were directly diluted or extracted with water, followed by clean-up on Cleanert C18 column for removing organic impurities. The chromatographic separation of these additives was carried out on low hydrophobic IonPac AS17-C anion-exchange column using KOH solution as eluent by a two-step isocratic elution procedure. Detection was performed using a conductivity detector. Five kinds of additives could not be adsorbed by the clean-up column and high recovery rate was achieved when the pH of sample solution was adjusted to 9－10 prior to loading. This developed method is rapid, sensitive, accurate and reliable and therefore suitable for determining sweeteners and preservatives in foods.

Ursolic acid (UA) and oleanolic acid (OA) in Rosmarinus officinalis were separated and determined by RP-HPLC-PAD. HPLC assay was performed on Kromasil C18 column (4.6 mm×250 mm, 45μm) and the two compounds were detected at 210 nm using methanol-water-phosphoric acid (88:12:0.1) as mobile phase at a flow rate of 0.8 mL/min and the column temperature was set at 30 ℃. An average recovery of 100.6% was obtained with RSD of 1.6% in the sample injection volume range of 0.10－4.00μg for UA, and an average recovery of 98.7% was obtained with RSD of 1.2% in the sample injection volume range of 0.05－2.00μg for OA. The determination results of samples showed that the method was sensitive, repeatable and accurate, and could therefore be used for the determination of the two triterpene acids in Rosmarinus officinalis.

In order to explore the migration of biphenol A from polycarbonate milk bottles to foods, polycarbonate milk bottles were soaked in four food simulants such as distilled water, 3% acetic acid solution, 15% ethanol solution and olive oil for 3 days and the content change of biphenol A in the food simulants after 1, 2 and 3 days of soaking was detected by high performance liquid chromatography using an external standard method. The recovery rate, accuracy and linear relationship of the developed method were studied. At 0.1, 1 and 10 μg/mL spike levels, the recovery rates were 77.0%－98.7% with a variant coefficiant of 5%－9.8%. A good linear relationship was observed over the range of 0.1 to 10 μg/mL with a correlation coefficient of 0.99996. This method has been satisfactorily used to determine migration rates of biphenol A from polycarbonate milk bottles to different mimic foods at different contact peroids.

In order to explore a rapid determination method for vitamin C in healthcare products, colorless o-phenylenediamine (o-PD) solution was subjected to oxidation to form a soluble orange-red product by H2O2 as the oxidant and Fe (Ⅱ) as the catalyst in an acidic environment. The maximum absorbance of the product was located at 450 nm. However, ascorbic acid exhibited an obvious inhibitory effect on that reaction system and could result in the decreased absorbance of the product. The reduction of the absorbance was inversely proportional to the concentration of ascorbic acid in the linear range of 4.0 × 10-6－3.0 × 10-4 mol/L, which was suitable for the rapid determination of vitamin C in healthcare products with the advantages including convenient operation, low-cost reagents and instruments, high selectivity and high accuracy.

Two different analytical methods for determining aflatoxins in peanut, corn and rice were compared in this paper. Samples were extracted by 70% methanol supplemented with 4 g/mL NaCl and cleaned up by immunoaffinity columns. Half part of the eluent was derivated with hexane and trifluoroacetic acid, and detected by liquid chromatography with fluorescence detection (FLD), the rest part of the eluent was detected by liquid chromatography-electrospray ionization tandem linear ion trap mass spectrometer (LC-ESI-LTQ). Limits of detection (LOD) of AFB1, AFB2, AFG1 and AFG2 determined by LC-FLD were in the range of 0.5－1.5μg/kg, the correlation coefficients were in the range of 0.9979－0.9999, and the recovery rates of spiked samples were in the range of 50.29%－126.54%; LODs of AFB1, AFB2, AFG1 and AFG2 determined by LC-ESI-LTQ were in the range of 0.1－0.2μg/kg, the correlation coefficients were in the range of 0.9993－0.9998, and the recovery rates of spiked samples were in the range of 50.38%－121.27%. All results showed that liquid chromatography-electrospray ionization tandem linear ion trap mass spectrometric method was more selective and sensitive for the analysis and confirmation of aflatoxins in peanut, corn and rice than LC-FLD.

An indirect competitive ELISA method was established for determining chlorothalonil residues in vegetables through screening appropriate concentrations of antigen and antibody, exploring the effects of buffer system and pH on ELISA and evaluating the specificity and affinity of polyclonal antibodies. The results showed that the detection limit (IC20) of ELISA was 0.0123 ng/mL. The recovery rate of ELISA was 84.0%－89.8% with standard deviation of 3.0%－7.6%. The cross-reactivity (CR) with chlorothalonil analog was less than 0.01%.

The volatile components in grass carp surimi was extracted by headspace solid-phase microextraction (HP-SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). The effects of supplements such as salt, starch, egg white and ginger on volatile components in grass carp surimi were also explored. The results showed that major compounds in cooked grass carp surimi were aldehydes, alcohols, aromatic compounds and hydrocarbons. Salt, corn starch and egg white exhibited a small effect on the category of volatile compounds and a significant effect on relative content of volatile components. However, ginger had a significant impact on the category and relative content of volatile components in cooked grass carp surimi.

In order to evaluate the nutritional value of litchi (Litchi chinensis Sonn.), amino acid compositions of five kinds of litchi juice of Feizixiao from major production regions such as Guangdong, Guangxi, Hainan, and Fujian province in China were analyzed by using an automatic amino acid analyzer. The results showed that litchi juice was rich in amino acid components. The total content of amino acids in samples from Qinzhou in Guangxi province was the highest, which was up to 455.42 mg/100 mL; in contrast, the total content of amino acids in samples from Yangxi of Guangdong province was the lowest, which was 341.51 mg/100 mL. The average content of total amino acids in five juice samples was 396.38 mg/100 mL. Theγ-amino-n-butyric acid (GABA) and alanine were the major amino acids with an average content of 104.69 mg/100 mL for GABA and 67.37 mg/100 mL for alanine. Based on the analysis of GABA content in litchi juice, litchi is a potential material for the development of GABA-rich functional food products.

The molecular connectivity index (Xi), electrotopological state index (En) and molecular electrongativity distance vector (Mk) of 42 volatile compounds in nutmeg essential oil were calculated. A quantitative structure-retention relationship (QSRR) model for retention index (RI) of volatile compounds in nutmeg essential oil was deduced by leaps and bounds regression with the correlation coefficient of 0.980. The calculated values were in good agreement with experimental data with an average error of 2.71%. This model exhibited excellent stability and predictability through the evaluation by Jackknife method and LOO cross-validation procedure. The regression results showed that the Xi，En and Mk could characterize molecular structure and explain the nature of chromatographic retention index.

A real-time PCR method was developed for the rapid and specific detection of Escherichia coli O157:H7. A pair of primers was designed according to the conserved sequence of rfbE gene in Escherichia coli O157:H7. The SYBR Green I real-time PCR method for detecting Escherichia coli O157:H7 was established. The sensitivity and specificity of this method was analyzed through the comparison with traditional PCR methods. The results indicated that the developed SYBR Green I real-time PCR method had the characteristics of excellent specificity, sensitivity and repeatability. The sensitivity of this developed method was 2 × 101 CFU/mL in pure cultures and 1 × 102 CFU/mL in artificially contaminated meat samples. In addition, the established method was also used for the detection of clinical samples. The results showed that the detection rate of real-time PCR for Escherichia coli O157:H7 was significantly increased when compared with traditional PCR. Therefore, the established real-time PCR method is a rapid, specific and sensitive method for the detection of Escherichia coli O157:H7.

Objective: To establish an HPLC method for the simultaneous determination of 5 flavonoid components including hydroxysafflor yellow A (HSYA), 6-hydroxykaempferol-3,6-di-O-glucoside (6-HK3,6-O-G), 6-hydroxykaempferol-3-O-rutinoside-6-O-glucoside (6-HK3-R-6-G), 6-hydroxykaempferol-3-O-glucoside (6-HK3-O-G) and safflower yellow B (SYB) in the flowers of Carthamus tinctorius L. Methods: Venusil XBP-C18 (4.6 mm× 250 mm, 5μm) was used as the stationary phase. The mobile phase was composed of methanol and water (0.2 mol/L NaClO4-0.2‰ HClO4). The flow rate of mobile phase was 0.8 mL/min. The detection wavelength was 375 nm. Results: The standard curve revealed a good linear relationship over a range of 4.8－600μg/mL for HSYA, 4.08－510μg/mL for 6-HK3,6-O-G, 4.32－540μg/mL for 6-HK3-R-6-G, 4.24－530μg/mL for 6-HK3-O-G and 4.72－590μg/mL for SYB, respectively. The detection limits for HSYA, 6-HK3,6-O-G, 6-HK3-R-6-G, 6-HK3-O-G and SYB were 0.6, 0.3, 0.4, 1.3μg/mLand 0.5μg/mL, respectively. The average recovery rates were 97.1%, 93.6%, 95.6%, 99.7% and 102.3%. Conclusion: This established determination method for flavonoids is rapid and sensitive, which has a good reproducibility and stability and can be used for qualitative evaluation of Carthamus tinctorius L. and safflower yellow.

Solvent-thermal method was applied for extracting naringin from shaddock peel of Enshi Gongshui (Citrus grandis Osbeck) using ethanol-water mixture as extraction solvent, and the naringin was determined by ultraviolet spectrophotometry. The recovery rate of naringin was from 96.51% to 101.9% with the relative standard deviation of less than 0.16%. The effects of extraction temperature, extraction time, ethanol concentration, shaddock peel powder size and filling factor on extraction rate of naringin were explored. The antioxidant activity and stability of naringin were investigated by flow-injection chemiluminescence and spectrophotometry. The results showed that the optimal process conditions were ethanol concentration of 70%, shaddock peel powder size of 120 mesh, filling factor of 80%, extraction temperature of 60 ℃ and extraction time of 3 h. The strong antioxidant activity and stability of naringin were simultaneously observed.

In order to establish a method for determining triadimenol residues in banana by ultra-performance liquid-chromatography-mass spectrometry (UPLC-MS/MS), the triadimenol residues in samples were extracted with acetonitrile, cleaned up ony Florisil SPE column, separated on C18 reverse phase column using methanol-0.05% formic acid as mobile phase, and detected with positive ionization electrospray ionization-mass spectrometry under a multiple reaction monitoring (MRM) mode. An excellent linear relationship between triadimenol concentration in the range of 0－0.16 mg/L and peak area was achieved with a relative standard deviation of 4.8%－10%. The detection limit for triadimenol in banana was 1.0μg/mL and recovery rate of this method was in the range of 87.8%－97.8% with a relative standard deviation of 4.8%－10%. This developed method is simple, rapid, sensitive and can therefore be used for the determination of triadimenol in banana.

Multivariate statistical methods were used to establish a flavor model of fermented milk. The parameters of major flavor compounds such as carbonyl compounds (aldehyde and diacetyl), acids (volatile acid and total acidity), and fermented milk components (sugar, fat, protein and non-fat milk solids) were analyzed as independent variables, and sensory coordination of flavor as the dependent variable. In order to select the indices with great impact on dependent variable and little correlation with independent variables, multiple linear regression and principal components analysis (PCA) were conducted to analyze 8 flavor indices. Finally, the concentrations of aldehyde, volatile acid, sugar and fat were selected as the independent variables and sensory evaluation score of flavor coordination as dependent variable. The coefficients of variables in the established model revealed statistical significance and weak multicollinearity was observed. The adjusted R2 of the final model was 0.447. The determined values and the predicted values of the tested samples were fitted well with an average error of 7.18%.

A novel Ganoderma lucidum polysaccharide GLPS1a was purified sequentially by column chromatographies on DEAE-Sephadex A25 and Sepharose CL-6B gel. GLPS1a was eluted as a single symmetrical narrow peak on high-performance gel-permeation chromatography (HPGPC) and the average molgcular weight was 1.8×105 D. Das chromatographic analysis of absolute acid hydrolysate of GLPS1a suggested that its monosaccharide composition was composed of arabinose, galactose, glucose and xylose with a molar ratio of 4:2:10:1. Fourier-transform infrared (FT-IR), 1H and 13C NMR spectroscopy analyses revealed that GLPS1a had a backbone consisting ofβ-D-(1,3)-linked-D-glucosepyranosy1 residues with glycosy1 residues composed of β→(1,3) linked arabinoser,β-D-(1,4)-galcose,α-D-(1,2)-xylose and (1→6) linkedα-D-glucose residues.

Purified calcium based bentonite from Ningming, Guangxi autonomous region was used as coating material to keep mango fresh in light of its good water absorption capacity, bondability, adsorption capacity, stability, small mineral particles and high surface area. After diluted with water at liquid-to-solid ratio of 15:1, the bentonite was coated on the surface of mango fruits. Coated mango fruits were stored at ambient temperature and measured for their skin yellowing index, decay index, weight loss rate, firmness, respiration rate and total sugar, vitamin C and total acid contents. The results showed calcium based bentonite coating significantly decreased the skin yellowing, decay incidence and weight loss rate of mango fruits and alleviated the decrease of firmness and vitamin C content. Meanwhile, the occurrence of the respiration peak was inhibited, the accumulation of sugars and degradation of acids were retarded, thereby delaying the post-harvest ripening of mango fruits. After 2 weeks of storage, the weight loss rate, decay index, yellowing index of the treatment group were decreased by 43.7%, 51.7% and 42.1% and the firmness, total acid content, VC content were increased by 53.7%, 166.7% and 66.7% respectively, compared with the control group. In addition, neither respiration nor total sugar peaks were observed for the treated group.

Lipid peroxidation is an important factor that affects the quality and safety of traditional ham, and concerned by both companies and consumers. In this study, spraying dual antioxidants followed by chitosan coating and vacuum packaging in the presence of a special purpose deoxidant prepared by ourselves was used to treat diced traditional Jinhua ham before storage at normal temperature. The effects of deoxidant amount (calculated on the basis of the mass of Fe), chitosan coating concentration and different dual antioxidant combinations (0.05% tea ployphenols + 0.05% rosemary, 1% grape seed extract + 0.05% rosemary and 0.05% rosemary + 0.05% vitamin E) on the peroxidation value (POV), thiobarbituric acid reactive species (TBARs) value and color parameters (a* and b*) of the muscle and fat parts of Jinhua ham were evaluated based on orthogonal array design. After 6 months (from spring through autumn) of storage, the muscle POV and TBARs value of the sample sprayed with 0.05% rosemary + 0.05% vitamin E, coated with 2.5% chitosan and vacuum packaged at 2.0 g Fe deoxidation level were 3.15 meq/kg and 0.27 mg/kg, which revealed a significant decline (P ＜0.05) compared with the untreated control sample and were both within the national and internationally recognized limit ranges (POV ＜ 19.7 meq/kg, TBARs value ＜1 mg/kg). Meanwhile, the sensory quality of Jinhua ham was better maintained even after such a long period of storage due to the treatments.

Delaying quality deterioration and inhibiting the incidence of post-harvest diseases are key factors in reducing the loss of flat peaches during storage and transport. In the present study, fumigated with both 1.0 μL/L 1-MCP and 1.0 μL/L ClO2 was tested for the effect on post-harvest physiological parameters of Xinjiang flat peaches during storage at (23 ± 1) ℃ or (4 ±1 ) ℃. Compared with the control, combined treatment with 1-MCP and ClO2 remarkably suppressed ethylene release and respiration, postponed the accumulation of malondialdehyde (MDA), the reduction of total phenolic content and the increase of polyphenol oxidase (PPO) activity, and maintained a higher level of fruit firmness and superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities so as to decrease the percentage of decayed fruits, maintain fruit quality during storage and delay fruit senescence.

In order to evaluate the fresh-keeping effect of microvacuum storage on Laiyang pear, atmospheric storage was used as control to investigate physiological and biochemical changes of Laiyang Chili pear during microvacuum storage. The results showed that microvacuum storage significantly lowered the respiration intensity of Laiyang Chili pear and inhibited the occurrence of the respiration peak, reduced the loss of water, resulted in a weight loss rate of smaller than 3%, and alleviated the decrease of soluble solid and titratable acid (TA) contents (P ＜ 0.05) but did not significantly inhibit the decrease of vitamin C content (P＞ 0.05). It could therefore be concluded that microvacuum storage notably attenuates the metabolic intensity of Laiyang pear, thus erecting satisfactory fresh-keeping effect.

In order to provide experimental references for solving the problem of quality deterioration during the storage and fresh-keeping Capsella bursa-pastoris (L.) Medicus, the major phenols in the edible wild vegetable were extracted by grinding in the presence of methanol and analyzed by UV-visible spectrophotometry and high performance liquid chromatography (HPLC). Besides, crude peroxidase (POD) extracted from the edible wild vegetable was measured for its substrate specificity. The results showed that the maximum absorption wavelength of phenolic extract from Capsella bursa-pastoris (L.) Medicus was 213 nm. The major phenolic component was initially identified as pyrogallic acid. The preferred phenolic substrate of POD was identified as chorogenic acid with the optimal enzymatic reaction concentration of 8 mmol/L.

In this study, a milk beverage with ginger juice and brown sugar was developed and its formula was optimized. The results indicated that the best flavor, taste and stability were achieved when the beverage was composed of 10% ginger, 3% brown sugar and 70% milk and a stabilizer containing 0.02% carrageenan, 0.03% pectin and 0.05% sucrose.

The preparation of superfine ground eggshell powder was carried out using an adjustable planetary ball mill. Quadratic orthogonal rotary composite design combined with response surface methodology was used to optimize four operating parameters including grinding time, grinding speed, ball-to-material ratio and filling rate. The specific surface area of eggshell powder was investigated with regard to the four parameters. The optimal preparation conditions for superfine ground eggshell powder were filling rate of 21.46%, grinding time of 3.67 h, grinding speed of 421.83 r/min and ball-to-material ratio of 5.97 g/g. Under these conditions, the particle size d50 determined using a laser particle size analyzer was 3.49 μm, reaching micron-grade and the specific surface area was 1650.08 m2/kg.