Loading...

Table of Content

25 July 2011, Volume 32 Issue 14
Processing Technology
Optimization of Ultrasound-assisted Extraction Process for Synephrine from Citrus aurantium Fruit by Response Surface Methodology
ZHANG Lu,FAN Jie-ping,CAO Jing,KONG Tao,TONG Sheng
2011, 32(14):  1-5.  doi:10.7506/spkx1002-6630-201114001
Asbtract ( 120 )   HTML ( 3)   PDF (373KB) ( 65 )  
Related Articles | Metrics
On the basis of one-factor-at-a-time experiments, response surface methodology was employed to the ultrasound-assisted extraction of synephrine from Citrus aurantium fruit. A quadratic regression model was established to investigate the extraction yield of synephrine with respect to three extraction parameters such as ethanol concentration, material particle size and ultrasound treatment time. The optimal extraction conditions determined were material particle size of 30 mesh, ethanol concentration of 67.90%, liquid-to-solid ratio of 12:1 (mL/g), extraction time of 16 min, and ultrasonic power of 420 W. Under these conditions, the extraction yield of synephrine was up to 5.87 mg/g, which was consistent with the predicted value of 5.77 mg/g. Thus, the established regression model had good feasibility.
Process Optimization for Acidic Water Extraction of Limonin from Citrus Peels by Response Surface Methodology
WU Jian,ZENG Fan-kun,CHEN Fei-ping
2011, 32(14):  6-10.  doi:10.7506/spkx1002-6630-201114002
Asbtract ( 140 )   HTML ( 2)   PDF (636KB) ( 81 )  
Related Articles | Metrics
The pH of pure water was adjusted with sulfuric acid to provide a solvent for the extraction of limonin from citrus peels. Limonin quantification was performed by HPLC. Based on one-factor-at-a-time experiments, a three-variable quadratic rotary unitization design combined with response surface methodology was used to optimize three conditions for acidic water extraction of limonin from citrus peels, and a mathematical model describing limonin yield versus the three extraction conditions was built. The optimal extraction conditions of limonin from citrus peels were 2.6 h extraction at 61.2 ℃, pH 4 and a solid-to-liquid ratio 1:19.2 (g/mL). Under the optimized conditions, a limonin yield of 0.117 mg/g was achieved.
Use of a Magnetic Ultrafiltration Membrane for the Separation of Angelica sinensis Root Polysaccharides
XIE Hui-ming,ZHU Ying-ying,ZHANG Shi-fa,WU Zhi-gang
2011, 32(14):  11-15.  doi:10.7506/spkx1002-6630-201114003
Asbtract ( 106 )   HTML ( 0)   PDF (595KB) ( 66 )  
Related Articles | Metrics
A magnetic ultrafiltration membrane whose molecular weight cut-off (MWCO) can be between 31000 and 73000 under 0.2 MPa pressure and varying magnetic field intensity was prepared by in situ synthesis on the basis of a polysulfone ultrafiltration membrane with a MWCO of 80000 and used sequentially separate Angelica sinensis root polysaccharides with a purity of 97.5%. As a result, three fractions were obtained under various magnetic filed intensities and named as A, B and C, respectively. Their respective weight average molecular weights (Mw) were determined by high performance gel permeation chromatography (HPGPC) to be 86317, 19989 and 62461. Polysaccharides with a relative molecular weight ranging from 70000 to 100000 was 70% in fraction A. Roughly 95% of fraction B consisted of polysaccharides with a relative molecular weight between 10000 and 30000. Fraction C contained approximately 80% of polysaccharides whose molecular weight was in the range of 50000-70000.
Optimization of Processing Technology for Scallop Hydrolysate Seasoning Powder
YANG Xiu-min,WANG Jie,LIU Ya-qiong
2011, 32(14):  16-20.  doi:10.7506/spkx1002-6630-201114004
Asbtract ( 141 )   HTML ( 0)   PDF (471KB) ( 86 )  
Related Articles | Metrics
In order to make full use of scallop and increase its added value, crushed scallop adductor muscle was processed into scallop hydrolysate seasoning powder by hydrolysis with flavourzyme and subsequent spray drying. The hydrolysis of scallop adductor muscle was optimized by orthogonal array design based on amino acid nitrogen content in its hydrolysate. On the basis of a three-variable, three-level Box-Benhnken experimental design, response surface methodology was used to optimize the spray drying conditions of scallop adductor muscle hydrolysate. The power yield of spray drying for scallop adductor muscle hydrolysate (Y) was investigated with respect to air inlet temperature (X1), air outlet temperature (X2) and ventilation rate (X3). The optimal hydrolysis conditions were determined as follows: flavourzyme dosage of 1200 U/g and solid-to-liquid of 1:4 (g/mL) for a hydrolysis duration of 5 h at 45 ℃ and under these conditions, the amino acid nitrogen content in scallop adductor muscle hydrolysate was (1.03 ± 0.01)%, which was increased by 0.12%-0.74% when compared with previously reported results. A regression model describing the effects of X1, X2 and X3 on Y was obtained as follows: Y = -2867.5825 +19.5670X1 +34.7780X2+779.4000X3-0.0761X12-0.2284X22-0.0433X32. The optimal conditions for spray drying of scallop adductor muscle hydrolysate were air inlet temperature 128.60 ℃, air outlet temperature 76.15 ℃, ventilation rate 0.9 m3/min, resulting in a power yield of 64.82%. A product that had a moisture content of 4.09% and was good in solubility, color and flavor was obtained.
A Comparative Investigation into Deproteinization Methods for Silkworm Pupa Polysaccharides
WU Shan-gang,LAI Tai-jun,SUN Jian-hua,LIU Xu-hui,TONG Zhang-fa,LIAO Dan-kui
2011, 32(14):  21-24.  doi:10.7506/spkx1002-6630-201114005
Asbtract ( 182 )   HTML ( 0)   PDF (397KB) ( 147 )  
Related Articles | Metrics
Protein removal rate and polysaccharide loss rate were used to evaluate and compare the effectiveness of Savag, s method, trichloroacetic acid (TCA) method, papain method and papain-TCA (papain hydrolysis followed by TCA precipitation) method in deproteinizing silkworm pupa polysaccharides. Papain-TCA method was found to be the best method for the deproteinization of silkworm pupa polysaccharides, and the optimal operating conditions were 1.5 h hydrolysis with papain at an enzyme-to-substrate of 2.0% and 50 ℃ followed by once treatment with TCA. A protein removal rate of 97.98% and a polysaccharide loss rate of 18.76% were achieved under such conditions. Only one absorption peak was observed in the UV-visible scanning spectrum of deporteinized silkworm pupa polysaccharides, indicating the removal of almost all proteins.
Employing Response Surface Methodology to Optimize Process Conditions for Enzymatic Extraction of Taurine from Oyster Meat with Neutral Protease
LIU Ya-nan,ZHANG Zhi-sheng,TONG Hai-ju,SUN Ke-yan,SONG Xin
2011, 32(14):  25-28.  doi:10.7506/spkx1002-6630-201114006
Asbtract ( 140 )   HTML ( 0)   PDF (422KB) ( 60 )  
Related Articles | Metrics
In this study, neutral protease hydrolysis was used to extract taurine from oyster meat and the extraction process was optimized. On the basis of one-factor-at-a-time experiments, a three-variable, three-level Box-Behnken experimental design coupled with response surface analysis was employed to explore the effects of enzyme dosage, pH and temperature on the extraction efficiency of taurine. The optimum hydrolysis conditions for taurine extraction were enzyme dosage 1300 U/g fresh meat, pH 7.5 and hydrolysis temperature 48 ℃, and the resulting extraction yield of taurine was 2.724 mg/g fresh meat.
Optimization for Ultrasonic-assisted Extraction of Polysaccharides from Panus giganteus Fruiting Bodies via Response Surface Analysis
YANG Run-ya,YANG Shu-de,DONG Hong-xin,YUAN Ru-yue
2011, 32(14):  29-33.  doi:10.7506/spkx1002-6630-201114007
Asbtract ( 183 )   HTML ( 0)   PDF (416KB) ( 58 )  
Related Articles | Metrics
The ultrasonic-assisted extraction of polysaccharides from the fruiting bodies of Panus giganteus was optimized by response surface analysis based on one-factor-at-a-time experiments. Under the optimal conditions: 72 ℃ extraction temperature, 1:44 material-to-water ratio and 57 min ultrasonic treatment time, the maximum extraction yield of polysaccharides was predicted to be 78.22 mg/g and observed to be 75.79 mg/g. Therefore, there was a good accordance between the predicted and observed values.
Conversion of High Fructose Corn Syrup F42 to F90 with Simulated Moving Bed by Safety Factor Method
CAO Long-kui,WANG Fei-fei,YU Ning
2011, 32(14):  34-39.  doi:10.7506/spkx1002-6630-201114008
Asbtract ( 102 )   HTML ( 0)   PDF (403KB) ( 70 )  
Related Articles | Metrics
Purpose :To prepare high fructose corn syrup F90 (with a fructose content of 90%) from F42 (with a fructose content of 42%) by simulated moving bed chromatography (SMB). Methods :The effects of resin type, feeding volume and rate, corn syrup concentration and operating temperature on separation degree were investigated by single-column pulse experiments. The theoretical SMB parameters were identified by the safety factor method and experimentally modified to be the optimal parameters. Results:The theoretically stimulated and experimental results showed good agreement. The optimal SMB parameters were switching time 469 s, feeding rate 1.574 L/h, elution solution flow rate 0.325 L/h, extraction solution flow rate 0.902 L/h, raffinate flow rate 0.951 L/h, and cycling flow rate 1.897 L/h. The yield and purity in the final product were 80.32% and 99.91% for fructose and 90.13% and 92.34% for glucose, respectively,
Optimization of Preparation Process of Oxidized Potato Starch Acetate by Response Surface Methodology
TAN Shu-qiong,LIU Li-ping,CHEN Hou-rong,LIU Xiong
2011, 32(14):  40-46.  doi:10.7506/spkx1002-6630-201114009
Asbtract ( 182 )   HTML ( 0)   PDF (797KB) ( 87 )  
Related Articles | Metrics
The response surface methodology (RSM) was used to optimize the preparation conditions of oxidized potato starch acetate. On the basis of one-factor-at-a-time experiments, a 29-run Box-Behnken experimental design involving 4 variables at 3 levels was used for mathematical modeling of substitution degree (SD) with respect to NaClO amount, acetic anhydride amount, pH and reaction time. The optimal reaction conditions for improved SD were NaClO amount 1.805%, starch/acetic anhydride ratio 5:1 (m/m), pH 8.06 and reaction time 1.5 h, resulting in an SD of 0.0975.
Use of Response Surface Methodology for Optimization of Ultrasound-assisted Extraction of Total Saponins from Asparagus officinalis L.
ZHANG Ruo-jie,WANG Lu-feng,MIAO Wen-hua,XU Xiao-yun,PAN Si-yi
2011, 32(14):  47-51.  doi:10.7506/spkx1002-6630-201114010
Asbtract ( 190 )   HTML ( 0)   PDF (415KB) ( 74 )  
Related Articles | Metrics
Response surface methodology based on a three-variable, three-level Box-Behnken experimental design was used to optimize ultrasound-assisted extraction of total saponins from Asparagus officinalis L. The extraction yield of total saponins was investigated with respect to temperature, extraction time and ultrasonic power. The optimal extraction conditions were found to be: ethanol concentration 95%, temperature 71 ℃, extraction time 23 min, ultrasound power 70 W, and number of extractions 2. Under these conditions, the extraction yield of total saponins was 23.96 mg/g.
Preparation of Cyclodextrin Inclusion Complex of Walnut Oil by Saturated Aqueous Solution Method
JI Jun-min,HUO Zong-e,ZHAO Jing-jing,HUO Xu-li,ZHANG Zhen-shan
2011, 32(14):  52-55.  doi:10.7506/spkx1002-6630-201114011
Asbtract ( 185 )   HTML ( 0)   PDF (342KB) ( 69 )  
Related Articles | Metrics
Walnut oil was encapsulated with β-cyclodextrin by saturated water solution. Based on a comprehensive evaluation of inclusion complex yield and inclusion efficiency, the optimal inclusion conditions were determined by one-factor-at-a-time and orthogonal array design methods to be: ratio of walnut oil and β-CD 1:4 (g/g), inclusion time 4.5 h, and inclusion temperature 65 ℃, under which, the inclusion efficiency was 81.6% and the inclusion complex yield 61.6%. UV spectrometric determination demonstrated the successful inclusion of walnut oil. The inclusion complex was a white powder-like solid and its solubility increased with increasing temperature. The storage stability of walnut oil was improved significantly after inclusion.
Preparation and Properties of Zein/Nano-TiO2 Composite Films
CHEN Ye,LI Peng,LUO Yin
2011, 32(14):  56-60.  doi:10.7506/spkx1002-6630-201114012
Asbtract ( 113 )   HTML ( 0)   PDF (578KB) ( 88 )  
Related Articles | Metrics
A method for preparation of zein/nano-TiO2 composite films was presented using hydrolysis of titanium isopropoxide (TTIP) by the sol-gel method to prepare Nano-TiO2 particles and subsequent casting. Zein/nano-TiO2 composite films with different TiO2 contents were tested for their properties. The largest tensile strength of 35.2 MPa, an elongation rate at break of 3.0% and a water vapor permeability of 169.9 g/(m2 ·24 h) were found at the TiO2 content of 14%. Photocatalytic experiments indicated that the composite film had strong antibiotic activity. Observations under scanning electron microscope (SEM) and atomic force microscope (AFM) revealed that TiO2 particles were evenly distributed in the composite film.
Preparation and Hydroxyl Free Radical Scavenging Activity of Tea Residue Polypeptides
LUO Hong-yu,YU Jun,YUE Peng-xiang,CHEN Xuan,WANG Li-pu,LI Xing-hui
2011, 32(14):  61-66.  doi:10.7506/spkx1002-6630-201114013
Asbtract ( 137 )   HTML ( 0)   PDF (300KB) ( 145 )  
Related Articles | Metrics
In order to establish an enzymatic method to hydrolyze crude tea residue protein to prepare tea residue polypeptides with higher hydroxyl free radical scavenging activity, the effects of enzymes (acidic protease, neutral protease, alkaline protease and protamex), substrate concentration, enzyme dosage, temperature, pH, hydrolysis time on hydroxyl free radical scavenging activity were studied. Protamex was the best enzyme for the preparation of tea residue polypeptides with hydroxyl free radical scavenging activity, followed by alkaline protease and the optimal substrate concentration, enzyme dosage, hydrolysis temperature, pH and hydrolysis time were 0.5%, 600 U/g, 55 ℃, 8.0 and 5 h for protamex hydrolysis, and 0.5%, 400 DU/g, 8.5, 50 ℃ and 1.0 h for alkaline protease hydrolysis, resulting in a hydroxyl free radical scavenging rate of 27.3% and 25.3%, respectively. Compared with protamex hydrolysis, alkaline protease hydrolysis resulted in a decrease in time consumption by 4 h despite showing no significant difference in hydroxyl free radical scavenging capacity. The polypeptide sample obtained by alkaline protease hydrolysis contained 28.4% protein, 11.0% polypeptide and 1.5% free amino acids and indicated an IC50 of 8.432 mg/mL against hydroxyl free radicals compared with 0.897 mg/mL for vitamin C.
Sterilization Process and Rheological Properties of Canned Abalone with Sauce
HUANG Ju-qing,FANG Ting,CHEN Jin-quan
2011, 32(14):  67-71.  doi:10.7506/spkx1002-6630-201114014
Asbtract ( 137 )   HTML ( 1)   PDF (344KB) ( 84 )  
Related Articles | Metrics
Objective: To explore the optimal sterilization process of canned abalone with sauce for ensuring its safety and maximizing its nutritional value, and then describe its rheological properties for providing a theoretical basis for quality assessment. Methods: The optimal sterilization process was explored by determining key quality indicators of canned abalone at various sterilization conditions. Meanwhile, the rheological properties of abalone were investigated by stress relaxation test and of sauce by static and dynamic rheological tests. Results: An obvious effect of different sterilization conditions on key quality indicators of canned abalone with sauce was observed. The optimal sterilization process was 12 min-12 min-12 min/121 ℃ (F121.1℃ = 3.6 min). The rheological properties of the canned abalone could be described by a dual Maxwell model during stress relaxation process. The sauce behaved as a kind of non-Newtonian fluid and revealed the properties of visco-elasticity and weak gel, and its rheological properties could be described by Cross equation. Conclusion: The determination of optimal sterilization process based on F-value for canned abalone can ensure its safety and maximize its nutritional value. The described rheological properties for this product can provide a theoretical basis for its quality assessment.
Optimization of Twin-screw Extrusion Technology of Defatted Corn Gluten Meal by Response Surface-Methodology
ZHANG Yan-rong,ZHOU Qing-tao,ZHANG Chuan-zhi,WANG Da-wei
2011, 32(14):  72-78.  doi:10.7506/spkx1002-6630-201114015
Asbtract ( 111 )   HTML ( 0)   PDF (611KB) ( 59 )  
Related Articles | Metrics
The objective of the present study was to optimize the process conditions for the modification of defatted corn gluten meal by two-screw extrusion by response surface methodology. The soluble protein content of extruded corn gluten meal was investigated with respect to water content before extrusion, extrusion temperature and screw rotation speed. The results indicated that the optimal twin-screw extrusion conditions were water content of 68%, extrusion temperature of 163 ℃ and rotation speed of 30 Hz (225 r/min). Under the optimal conditions, the soluble protein content of extruded corn gluten meal reached up to 3.43%. SDS-PAGE analysis demonstrated that the molecular weight distribution of soluble proteins in extruded corn gluten meal was in the range of 3500-14300 D, mainly consisting of polypeptides with a molecular weight between 3500 D and 6500 D. Modified corn gluten meal showed an obvious improvement in its physicochemical properties. Therefore, twin-screw extrusion is feasible to produce modified corn gluten meal.
Microwave-assisted Saponification for the Preparation of Aleuritic Acid from Lac Resin
LIU Shi-ping,ZHANG Hong,ZHOU Mei-cun,ZHENG Hua,LI Kai
2011, 32(14):  79-84.  doi:10.7506/spkx1002-6630-201114016
Asbtract ( 115 )   HTML ( 0)   PDF (618KB) ( 47 )  
Related Articles | Metrics
In order to prepare aleuritic acid, lac resin was saponified under microwave assistance, followed by salting out and crystallization. The effects of three major process conditions including microwave power, NaOH concentration and microwave treatment time on aleuritic acid yield were explored by one-factor-at-a-time experiments. Further, the three conditions were optimized by response surface methodology. The optimal saponification conditions were microwave treatment power of 200 W, NaOH concentration of 25.8% and microwave treatment time of 31 min. Under the optimal saponification conditions, the highest yield of aleuritic acid was achieved to be 21.90%. The aleuritic acid obtained was characterized by infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and scanning electron microscope (SEM) as even crystals with high purity. In summary, microwave-assisted saponification can provide a simple, time-saving and high-yield method for the preparation of aleuritic acid.
Optimization of Solvent-Free Microwave Extraction of Essential Oil from the Fruits of Schisandra chinensis and Its DPPH Radical Scavenging Activity
CHEN Xiao-qiang,ZHANG Ying,ZU Yuan-gang,YU Xue-ying,LI Jia-lei
2011, 32(14):  85-89.  doi:10.7506/spkx1002-6630-201114017
Asbtract ( 152 )   HTML ( 1)   PDF (133KB) ( 63 )  
Related Articles | Metrics
This study was undertaken to optimize the solvent-free microwave extraction conditions and DPPH radical-scavenging activity of essential oil from Schisandra chinesis fruits. The uniform design method was employed for process optimization. The optimal extraction conditions were determined as follows: extraction time, 50 min; microwave power, 800 W; and amount of water addition for pretreatment, 40%. Under these conditions, the extraction yield of essential oil was 0.92%. A total of 35 compounds were identified by GC-MS in the obtained essential oil with a total content of 91.06%, mostly consisting of ylangene (34.81%), β-himachalene (10.74%) and α-bergamotene (9.22%). The IC50 value of the essential oil against DPPH free radicals was determined as 3.01 mg/mL. In conclusion, solvent-free microwave extraction is a feasible method for essential oil extraction from Schisandra chinensis fruits.
Process Optimization for Preparation of Bovine Trypsin by Dual-factor Activation and Subsequent Chitosan Flocculation
LI Jun-lan,YU Qun-li,ZHANG Li,LIU Liang-liang,GUO Zhao-bin
2011, 32(14):  90-95.  doi:10.7506/spkx1002-6630-201114018
Asbtract ( 126 )   HTML ( 1)   PDF (201KB) ( 65 )  
Related Articles | Metrics
With the aim of developing a method to prepare bovine trypsin by dual-factor activation and subsequent chitosan flocculation, Plackett-Burman design was used to evaluate the effects of 13 process conditions on the activity and extraction rate of trypsin to screen out 4 most significant ones (P<0.05) including chtosan amount, ratio of bovine pancreas to duodenum and activation pH. Their optimal levels were optimized by the combined use of uniform design and partial least squares regression as follows: chtosan amount of 0.17%, CaCl2 amount of 0.06%, pancreas-duodenum ratio of 8.26:1, and activation pH 5.37, respectively. Under the optimized conditions, the activities of trypsin, lipase and amylopsin and the extraction rate of trypsin were observed to be 3408.71 U/g, 33.11 kU/g, 23.93 kU/g and 13.22%, respectively, which exhibited a relative error of 7.15%, 8.56%, 10.63% and 1.93% when compared with their predicted counterparts. Therefore, the combined use of Plackett-Burman design and uniform design is feasible to optimize the preparation of trypsin by dual-factor activation and subsequent chitosan flocculation.
Optimization of Pre-treatment Procedures for Canned Green Olive
SHENG Wen-jun,HAN Shun-yu,ZHU Xia,JIANG Yu-mei
2011, 32(14):  96-99.  doi:10.7506/spkx1002-6630-201114019
Asbtract ( 116 )   HTML ( 0)   PDF (149KB) ( 61 )  
Related Articles | Metrics
Orthogonal array design was employed to optimize two pre-treatment procedures including color protection and alkaline deastringency before fermentation in the production of canned green olive. The optimal color fixative formula was made up of 0.30 g/L magnesium chloride, 1.0 g/L kojic acid, 2.0 g/L vitamin C, 0.20 g/L zinc acetate and 0.02 g/L copper acetate. The optimal alkaline deastringency conditions were soaking at 33 ℃ for 13.5 h in 4.0 g/L NaOH solution. After the optimal deastringency treatment, the concentration of tannin in olive was decreased to 0.025%. Canned green olive processed based on the optimized pre-treatments revealed the best yellow-green color and mild taste.
Optimization of Ultrasound-assisted Extraction of Flavonoids from Actinidia arguta Fruits
LIU Chang-jiang,WANG Fei,LUAN Yun-feng,SUN Xiao-rong
2011, 32(14):  100-102.  doi:10.7506/spkx1002-6630-201114020
Asbtract ( 200 )   HTML ( 0)   PDF (335KB) ( 63 )  
Related Articles | Metrics
Objective: To explore the optimal extraction conditions of flavonoids from the fruits of Actinidia arguta. Methods: Flavonoids extraction was carried out using ethanol as the extraction solvent with the assistance of ultrasound. Response surface methodology based on Box-Behnken experimental design was used for process optimization. Results: The optimal extraction conditions were ethanol concentration of 70%, ultrasonic treatment time of 6 min and ultrasonic power of 270 W. Under these conditions, the experimental extraction rate of total flavonoids from Actinidia arguta fruits was 0.0297%, which was consistent with the prediction value. Conclusion: Ultrasound assistance is a suitable method for the extraction of total flavonoids from Actinidia arguta fruits.
Optimization of Ultrasonic-assisted Extraction for Pectin from Bergamot Residue
DENG Gang,JIAO Cong-cong,XU Hang-lin,XU Shuang-shuang
2011, 32(14):  103-107.  doi:10.7506/spkx1002-6630-201114021
Asbtract ( 137 )   HTML ( 0)   PDF (651KB) ( 76 )  
Related Articles | Metrics
Objective: To optimize pectin extraction from bergamot residue left after juice squeezing. Methods: Pectin extraction was achieved by ultrasonic-assisted acid extraction followed by ethanol precipitation. Response surface methodology and orthogonal array design were used to optimize the process conditions of ultrasonic-assisted acid extraction and ethanol precipitation. Results: The optimal ultrasonic-assisted acid extraction conditions were extraction at 63 ℃ and pH 1.6 for 37 min with an ultrasonic power of 395 W. The optimal ethanol precipitation conditions were precipitation at 15 ℃ and pH 2.0 for 1.5 h with a concentration ratio of 1:4. Conclusion: Under the optimal conditions, the extraction yield and precipitation recovery of pectin were 22.1% and 85.7%, respectively.
Effect of Extraction Conditions on Antioxidant Components and Antioxidant Activity of Strawberry Fruit Extracts
LUO Ya,WANG Xiao-rong,ZHANG Yong,LIU Ze-jing,REN Yun-nan,YANG Tao,TANG Hao-ru
2011, 32(14):  108-112.  doi:10.7506/spkx1002-6630-201114022
Asbtract ( 111 )   HTML ( 0)   PDF (161KB) ( 104 )  
Related Articles | Metrics
Strawberry fruits from Fragaria ananassa Toyonaka, picked at the green maturity stage were extracted with different solvents under varying conditions of temperature and extraction time and the extracts obtained were tested for their antioxidant components and antioxidant activity. The results showed that methanol-water-HCl (80:19.9:0.1, V/V) extract revealed a significant increase in the contents of total phenols, flavonoids and ascorbic acid, DPPH free radical scavenging activity and ferric ions reducing power when compared with methanol, ethanol, methanol: ethanol-acetone (1:1:1, V/V) and water extracts. The optimal extraction conditions (at 60 ℃ for 480 min) for achieving maximum extraction of antioxidant components did not accord with those (at 25 ℃ for 120 min) resulting in maximum antioxidant activity, indicating that the contents of antioxidant components did not necessarily represent the antioxidant activity of strawberry fruit extracts. Comprehensively considering the contents of antioxidant components and antioxidant activity of strawberry fruit extracts, we concluded that extraction with methanol-water-HCl mixture (80:19.9:0.1, V/V) for 120 min at 25 ℃ is more suitable for extracting antioxidant components from Strawberry fruits.
Optimization of Microwave-assisted Extraction of Polysaccharides from Isochrysis galbana
GUO Gan-lin,XU Shen-zhen,LI Wen-hao,SUN Ying-ying,WANG Chang-hai
2011, 32(14):  113-117.  doi:10.7506/spkx1002-6630-201114023
Asbtract ( 163 )   HTML ( 0)   PDF (277KB) ( 132 )  
Related Articles | Metrics
One-factor-at-a-time method and orthogonal array design were employed to optimize four process conditions for microwave-assisted extraction of polysaccharides from Isochrysis galbana such as pH, microwave power, temperature and extraction time. One-factor-at-a-time experiments showed that each of the four conditions had a marked effect on polysaccharide extraction, and their optimal levels were identified by orthogonal array design to be: pH 9, microwave power of 600 W, extraction temperature of 90 ℃ and extraction time of 20 min. Under these conditions, the extraction rate of crude polysaccharides was 96.8 mg/g compared with 47.7 mg/g for hot water extraction, and the contents of protein and polysaccharides were respectively 1.08% and 43.6% in the crude polysaccharide sample obtained compared with 1.18% and 22.1% for hot water extraction. The crude polysaccharides obtained by both extraction methods revealed similar IR spectra, demonstrating that microwave did not destroy the chemical structures of polysaccharides. In summary, microwave-assisted extraction is greatly superior to hot water extraction.
Optimization of Extraction Technology for Insoluble Dietary Fiber from Fortuneana pyracantha Fruits by Response Surface Methodology
LI Jia-xing,LIANG Xian-chang,HUANG Cheng,HUO Yong-peng,HU Ping-ping,HUANG Shou-en
2011, 32(14):  118-123.  doi:10.7506/spkx1002-6630-201114024
Asbtract ( 121 )   HTML ( 0)   PDF (792KB) ( 56 )  
Related Articles | Metrics
The alkali-catalyzed hydrolysis method was applied to extract insoluble dietary fiber (IDF) from the fruits of Fortuneana pyracantha and main process conditions were optimized by one-factor-at-at-a-time experiments and response surface methodology. The extraction rate and purity of IDF were investigated with respect to NaOH concentration, extraction time, extraction temperature and material-to-liquid ratio. The results showed that the optimal extraction conditions were NaOH concentration of 1.00% (g/g), extraction time of 3.00 h, extraction temperature of 77.8 ℃, and material-to-liquid ratio of 1:17 (g/mL). Under the optimal extraction conditions, the extraction rate and purity of IDF were 56.89% and 92.74%, respectively.
Process Parameter Optimization for Ultrasonic-assisted Osmotic Dehydration of Yacon
SHI Qi-long,ZHAO Ya,ZHENG Ya-qin
2011, 32(14):  124-129.  doi:10.7506/spkx1002-6630-201114025
Asbtract ( 175 )   HTML ( 0)   PDF (328KB) ( 64 )  
Related Articles | Metrics
The current study aimed to use response surface methodology to optimize process parameters for the osmotic dehydration of yacon under the assistance of ultrasonic. A series of one-factor-at-a-time experiments were conducted to investigate the effects of thosmotic dehydration time and temperature, ultrasonic power, sucrose concentration and ultrasonic treatment time on water loss (WL) and solid gain (SG). Further, quadratic regression orthogonal rotation combination design was used to model WL, SG and WL/SG ratio with respect to thosmotic dehydration time and temperature, sucrose concentration and ultrasonic treatment time, and the three models developed were analyzed by response surface methodology. Ultrasonic assistance was found capable of enhancing the smotic dehydration of yacon. In terms of the importance in affecting WL, the four investigated process parameters ranked in the following order: osmotic dehydration temperature, osmotic dehydration time, sucrose concentration, and ultrasonic treatment time, and the order for affecting SG was osmotic dehydration time, ultrasonic treatment time, osmotic dehydration temperature, and sucrose concentration, and for affecting WL/SG ratio osmotic dehydration time, sucrose concentration, ultrasonic treatment time, and osmotic dehydration temperature. The optimal ultrasonic-assisted osmotic dehydration parameters were osmotic dehydration temperature of 41 ℃, osmotic dehydration time of 1.7 h, sucrose concentration of 60.18 %, and ultrasonic treatment time of 35 min. Under the optimal process conditions, An average SG/WL ratio of 0.059 was achieved.
Optimization of Multi-enzyme Hydrolysis for Soybean Protein Extraction
LI Yang,JIANG Lian-zhou,SUI Xiao-nan,WANG Chen,WANG Zhong-jiang,LIU Wen
2011, 32(14):  130-133.  doi:10.7506/spkx1002-6630-201114026
Asbtract ( 241 )   HTML ( 0)   PDF (583KB) ( 77 )  
Related Articles | Metrics
A two-step enzymatic method was presented for soybean protein extraction by sequential hydrolysis with multiple enzymes (simultaneously added) and alcalase. The multiple-enzyme hydrolysis process was optimized by using mixed design to modeling the effects of cellulase amount, hemicellulase amount, pectin amount and hydrolysis time on total protein extraction efficiency. The optimal hydrolysis conditions for soybean protein extraction were hydrolysis at pH 5, 37 ℃ and a material/liquid ratio of 1:6 (g/mL) for 0.75 h with 0.64% cellulase and 0.56% hemicellulase and for another 3.6 h at 50 ℃ and pH 9.26 with 1.85% alcalase. Under these conditions, a maximum total protein extraction efficiency of 85.78% was observed. Multiple-enzyme hydrolysis caused an increase in total protein extraction efficiency by nearly 10% when compared with traditional heat-moisture treatment. We speculated that the reason for this was due to complete disruption of the soybean cellular structure after multiple-enzyme hydrolysis. However, the detailed mechanisms remain to be clarified.
Extraction and Antioxidant Activity of Polyphenols from Kuding Tea
LIU Jia,JIAO Shi-rong,TANG Yuan-mou,TANG Peng-cheng,FENG Hui
2011, 32(14):  134-138.  doi:10.7506/spkx1002-6630-201114027
Asbtract ( 189 )   HTML ( 0)   PDF (381KB) ( 86 )  
Related Articles | Metrics
The optimal conditions for the extraction of Kuding tea polyphenols for achieving maximum extraction yield were determined by response surface methodology to be ethanol concentration of 52%, material/liquid ratio of 1:24 (g/mL), microwave power of 291 W, and microwave treatment time of 62 s. The extraction rate of polyphenols was 114.82 mg/g under the optimal extraction conditions. The IC50 values of the obtained extract against DPPH, hydroxyl, superoxide anion ion free radicals and lipid peroxidation were 29.24, 34.14, 872.3 mg/L and 11.48 mg/L, respectively, suggesting that Kuding tea polyphenols have a remarkable antioxidant effect.
Characteristics of Two-stage Deodorizer and Optimization of Oil Deodorization
LI Zhen-lan,CHEN Xiao-hui,JIANG Wei,ZHANG Li-guo,YU Dian-yu
2011, 32(14):  139-143.  doi:10.7506/spkx1002-6630-201114028
Asbtract ( 184 )   HTML ( 0)   PDF (284KB) ( 133 )  
Related Articles | Metrics
In this study, tray type deodorizer was modified by external heating strategy to achieve two-stage deodorization. In this deodorization process, decolorized soybean oil was heated by double-helix heater to the optimal temperature of 170 ℃. After the oil entered the upper section of tray type column, primary gas stripping was carried out. Then, the oil was again transferred to double-helix heater where the residual pressure was set at 2 Torr and heated to 248 ℃ before distillation in the bottom section of tray type column. Steam amount in the upper section of tray type column represented 1% of total oil weight and in the bottom section 2%, and the total deodorization time was set at 45 min. As a result, oil retention time in deodorizer was largely shortened and the trans-fatty acids content in soybean oil was only 1.15%. Therefore, two-stage deodorizer reveals pollution-free and energy-saving properties.
Ultrasonic-assisted Extraction of Total Flavonoids from Gynura divaricata L. DC
LI Hui,BU Xiao-ying,CHEN Gong-xi,LI Ya-nan,LIANG Chun-feng,XIE Yi-zhen
2011, 32(14):  144-146.  doi:10.7506/spkx1002-6630-201114029
Asbtract ( 124 )   HTML ( 0)   PDF (343KB) ( 74 )  
Related Articles | Metrics
Objective: To optimize the ultrasonic-assisted extraction (UAE) of total flavonoids from dried and fresh leaves and stems of Gynura divaricata L. DC and explore the mechanisms by which ultrasonic can enhance the extraction of total flavonoids. Methods: The effects of material-to-liquid ratio, extraction time and ethanol concentration on extraction rate of total flavonoids were explored by single factor experiments. Scanning electron microscope (SEM) was utilized for examining the structural change of Gynura divaricata L. DC leaves after ultrasonic treatment. Results: The optimal UAE conditions were material-to-liquid ratio of 1: 30 (g/mL); extraction time of 15 min, ethanol concentration of 70%, and number of repeated extractions of 2. Under these conditions, the extraction rate of total flavonoids from the same parts of fresh Gynura divaricata L. DC was higher than that from dried Gynura divaricata L. DC. Conclusion: UAE method has many advantages over conventional solvent extraction such as higher extraction efficiency and shorter extraction time, which is possibly due to severe damage of Gynura divaricata L. DC cell wall by ultrasound.
Ultrasound-assisted Extraction and Antibacterial Activity of Polysaccharides from Rhizoma phragmitis
YAO Yi-cai,GENG Zhong-hua,WANG Nai-xin,ZHENG Yi,LI Chao
2011, 32(14):  147-151.  doi:10.7506/spkx1002-6630-201114030
Asbtract ( 115 )   HTML ( 0)   PDF (459KB) ( 75 )  
Related Articles | Metrics
On the basis of single factor experiments, the ultrasound-assisted extraction of polysaccharides from Rhizoma phragmitis was optimized by response surface methodology. The optimal conditions for polysaccharide extraction were liquid/material ratio of 9.9:1 (mL/g), temperature of 60 ℃ and ultrasonic treatment time of 52 min. Under the optimal extraction conditions, the extraction rate of polysaccharides from Rhizoma phragmitis was 9.06%. The extracted polysaccharide sample was extremely sensitive to Saccharmoyces cerevisiae, highly sensitive to Staphy lococcus aureus, and moderately sensitive to Aspergillumniger and Bacillus subtilis. Therefore, polysaccharides from Rhizoma phragmitis can be developed into a novel antibacterial product.
Ultrasonic-assisted Extraction of Saponins from Asparagus officinalis Scraps
SUN Jian,LI Man,WANG Li-wei,ZHAO Bing
2011, 32(14):  152-155.  doi:10.7506/spkx1002-6630-201114031
Asbtract ( 91 )   HTML ( 0)   PDF (199KB) ( 62 )  
Related Articles | Metrics
In order to improve the utilization rate of Asparagus officinalis L. scraps, ultrasonic assistance was applied for the extraction of saponins from the materials. After two rounds of uniform design, the optimal extraction conditions for achieving maximum extraction rate of saponins were material-to-liquid ratio of 1:1 (m/V), extraction temperature of 30 ℃, duty cycle of 0.4:1.6 (ratio of occupied to empty space), ultrasonic power of 200 W, extraction time of 30 min, extraction pH of 5.05 and ethanol concentration of 70%. Under the optimal conditions, the extraction rate of saponins was up to 7.5%, and the recovery rate was 98.78% after three rounds of extraction. The saponins could be fully recovered by three rounds of extractions in a 2 L circulated ultrasonic-assisted extraction device. Therefore, ultrasonic-assisted extraction is suitable for the extraction of saponins from Asparagus officinalis L. scraps.
Process Parameter Optimization for Extraction of Natural Extract from Mactra veneriformis
SHU Liu-quan,YI Xiao-lan,XU Wen-yuan,YAO Xing-cun
2011, 32(14):  156-160.  doi:10.7506/spkx1002-6630-201114032
Asbtract ( 107 )   HTML ( 3)   PDF (369KB) ( 45 )  
Related Articles | Metrics
The proximate chemical composition and amino acid composition of the soft part from Mactra veneriformis were analyzed. Based on dry weight, the contents of protein and lipid were 60.14% and 6.08%, respectively, and the content of 17 identified amino acids was determined to be 48.09%, and the content of essential amino acids (EAA) was 18.94% and of delicious amino acids (DAA) 22.73%, making up 39.38% and 47.27% of total amino acids, respectively. Natural extract (protein) extraction from the soft part from Mactra veneriformis was performed by homogenization with water, pH adjustment and extraction with NaCl. Based on one-factor-at-a-time experiments, response surface methodology (RSM) was employed to optimize the preparation process. The optimal extraction conditions were extraction temperature of 82.07 ℃, pH 7.87 and NaCl concentration of 1.75%. Under these conditions, the protein recovery reached up to 54.78%.
Enzymatic Extraction of Peptides from Extruded Soybean
JIANG Lian-zhou,SUI Xiao-nan,QI Bao-kun,WANG Sheng-nan
2011, 32(14):  161-164.  doi:10.7506/spkx1002-6630-201114033
Asbtract ( 167 )   HTML ( 0)   PDF (442KB) ( 59 )  
Related Articles | Metrics
Soybean extrusion before the aqueous enzymatic extraction of soybean oil can result in higher polypeptide yield. In this study, response surface methodology was employed to optimize process parameters for the aqueous enzymatic extraction of oil from extruded soybean in order to maximize soybean polypeptide yield. The optimal extraction conditions were alcalase amount of 1.6 %, temperature of 60 ℃, hydrolysis time of 3 h, material-to-liquid ratio of 1:5, and pH of 9.6. Under the optimal extraction conditions, the yield of soybean peptides was up to 41.36%, which revealed a significantly increase when compared with that obtained under the same extraction conditions without extrusion treatment.
Optimization Process Condition Using Response Surface Methodology for Two-step Enzymatic Hydrolysis of Crab Protein
WANG Fang-ying,DU Xian-feng,XU Min,LIU Jun
2011, 32(14):  165-170.  doi:10.7506/spkx1002-6630-201114034
Asbtract ( 123 )   HTML ( 0)   PDF (400KB) ( 48 )  
Related Articles | Metrics
The aim of the current study was to use response surface methodology to optimize process conditions for the sequential hydrolysis of crab protein with papain followed by flavourzyme to achieve maximum hydrolysis degree. On the basis of one-factor-at-a-time experiments, a four-factor, three-level quadratic general rotary unitization design was employed to establish a quadratic polynomial mathematical model that describes hydrolysis degree as a function of four process conditions, and the established model was analyzed by drawing response surface and contour plots. The optimal hydrolysis conditions were hydrolysis with 5500 U/g papain at pH 5 and 55 ℃ for 1.5 h followed by 4.5 h with 2 LAPU flavourzyme. Under these conditions, the DH of crab protein was predicted to 31.19% and observed to 30.08% with a relative error of 3.69%. Further, a seafood seasoning was formulated with the obtained hydrolysate. Therefore, this enzymatic hydrolysis method can be used to prepare seafood seasonings with strong flavor, bright yellow color and convenient cooking.
Preparation and Antioxidant Activity of Germ Peptides from Helongjiang Wheat Ⅱ: Optimization of Ultra-filtration Separation of Wheat Germ Peptides
ZHANG Hong-wei,,YANG Ming-duo,WU Ying-ying,ZHANG Ling,JIA Qing-sheng
2011, 32(14):  171-175.  doi:10.7506/spkx1002-6630-201114035
Asbtract ( 125 )   HTML ( 0)   PDF (285KB) ( 70 )  
Related Articles | Metrics
Wheat germ protein hydrolysate prepared by enzymatic hydrolysis was separated with ultra-filtration membranes with a molecular weight cutoff (MWCO) of 3 ku and 6 ku, respectively. Four ultra-filtration parameters such as pressure, time, pH and sample concentration were optimized by response surface methodology to be 0.08 MPa, 23 min, 6.83 and 2%, respectively. Under these conditions, the ultra-filtration membrane flux of was 4.85 L/(m2 ·h). The obtained fraction of less than 3 ku in molecular weight exhibited a DPPH free radical scavenging rate of 78.93% at the concentration of 11%.
Optimization of Ultrasonic-assisted Extraction Process for Water-soluble Soybean Polysaccharides from Soybean Residues
TIAN Rui-hong,JIANG Lian-zhou,LI Dan
2011, 32(14):  176-180.  doi:10.7506/spkx1002-6630-201114036
Asbtract ( 99 )   HTML ( 0)   PDF (503KB) ( 60 )  
Related Articles | Metrics
This study aimed at optimizing the ultrasonic-assisted hot water extraction conditions of water-soluble soybean polysaccharides (SSPS) from soybean residues left after the aqueous enzymatic extraction of soybean oil. On the basis of one-factor- at-a-time experiments, response surface methodology and central composite rotary design (CCRD) was employed to SSPS extraction yield with respect to ultrasonic power, ultrasonic treatment time, material-to-liquid ratio, extraction temperature and hexametaphosphate concentration, and a quadratic polynomial regression model was established. The optimal conditions for SSPS extraction were ultrasonic power of 150 W, extraction temperature of 88 ℃, ultrasonic treatment time of 17 min, material-to-liquid ratio of 1:28, and hexametaphosphate concentration of 2 g/100 mL. Under the optimal extraction conditions, the predicted and experimental extraction rates of SSPS were 12.06% and 11.52%, respectively.
Analysis & Detection
Determination of 3-Phenoxybenzoic Acid in Microbial Degradation Systems by HPLC-UV Detection
ZHAO Nan,LIU Shu-liang,LAI Wen,YUAN Huai-yu
2011, 32(14):  181-184.  doi:10.7506/spkx1002-6630-201114037
Asbtract ( 232 )   HTML ( 0)   PDF (220KB) ( 60 )  
Related Articles | Metrics
A HPLC method with UV detection was proposed to determine the concentration of 3-phenoxybenzoic acid (3-PBA) in microbial degradation systems. The chromatographic separation was performed on a Gemini 100A C18 column (5.0μm, 150 mm × 4.60 mm, i.d.) using a mobile phase made up of acetonitrile and water (70:30, V/V) at a flow rate of 0.7 mL/min, and 3-PBA was detected at 210 nm using a UV detector. The retention time of 3-PBA was 4.268 min. The linear range of the method was 0.5-50.0 mg/L. The average spike recovery for 3-PBA was 98.919%, with a relative standard deviation (RSD) of 2.78%. The residues of 3-PBA in 4 different microbial degradation systems were 24.467, 86.266, 2.633 mg/L and 1.921 mg/L, respectively. The developed method demonstrated the benefits of simplicity, rapidity, high accuracy and good separation.
Analysis of Carotenoids in Laying Duck Tissues Using High Performance Liquid Chromatography
XUE Feng,LI Chen,JIANG Pei,WANG Duo,REN Zhen-ming,PAN Si-yi,WANG Ke-xing
2011, 32(14):  185-189.  doi:10.7506/spkx1002-6630-201114038
Asbtract ( 151 )   HTML ( 0)   PDF (385KB) ( 55 )  
Related Articles | Metrics
With the aim of developing an optimal sample preparation method for the determination of carotenoids in laying duck liver tissues by high performance liquid chromatography, response surface methodology was employed to optimize the extraction recovery of carotenoids from laying duck liver tissues with respect to three extraction conditions such as temperature, extraction time and KOH concentration. The optimal extraction conditions were achieved as follows: extraction time 90 min, temperature 37 ℃ and KOH concentration 50 g/100 mL. The HPLC method established based on these extraction conditions exhibited a detection limit of 20 ng/mL for carotenoids in the liver and serum laying duck. The mean spike recovery rates for carotenoids in the liver tissues and serum laying duck were 95.21% and 105.50% with a relative standard deviation (RSD) of 5.71% and 6.73%, respectively.
Determination of Cadmium in Eel by Microwave Digestion Followed by Stripping Voltammetry on Bismuth/Nafion Modified Electrode
LI Jing,LI Hong-bo,FAN Da-he,WANG Wei
2011, 32(14):  190-193.  doi:10.7506/spkx1002-6630-201114039
Asbtract ( 127 )   HTML ( 0)   PDF (206KB) ( 137 )  
Related Articles | Metrics
A stripping voltammetric method based on microwave digestion was developed for determining cadmium in eel on a bismuth/nafion modified electrode. Oxidation yield a well-defined square wave peak for Cd2+ at about -0.85 V. Nafion concentration, bismuth film thickness, buffer solution pH, deposition potential accumulation time and other potential interference factors were investigated. A linear relationship was found between peak area and cadmium concentration over the range of 4.0 to 14.0μg/L with a correlation coefficient of 0.9964. The limit of detection of the method was 0.2μg/L. The sensor was highly sensitive and effective to detect cadmium even in the presence of several excess potential interference ions.
Simultaneous Determination of Four Aflatoxins in Peanut Oil by Liquid Chromatography-Tandem Mass Spectrometry
ZHAO Xiao-juan,XIAN Yan-ping,LUO Hai-ying,QIAN Min,BAI Wei-dong
2011, 32(14):  194-197.  doi:10.7506/spkx1002-6630-201114040
Asbtract ( 131 )   HTML ( 0)   PDF (313KB) ( 56 )  
Related Articles | Metrics
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for simultaneous determination of 4 aflatoxins in peanut oil including aflatoxins B1, B2, G1 and G2. The sample preparation was achieved by sequential extraction with aqueous methanol solution and chloroform. The analytes were separated on a C18 column using a mobile phase composed of acetonitrile and 0.1% aqueous formic acid solution and detected using electrospray ionisation (ESI)-MS/MS in positive ion mode with multiple reaction monitoring (MRM). The linear range of aflatoxins determination was from 0.0 to 20.0μg/kg. The recovery rates for four aflatoxins were from 70.8% to 108.0% at 1.0μg/kg and from 82.4% to 104.5% at 10.0 and 20.0μg/kg, and the relative standard deviations from 5.7% to 9.7%. The developed method proved highly selective and sensitive in determining 19 commercial peanut oil samples, thus being suitable for qualitative and quantitative analysis of four aflatoxins in peanut oil.
Determination of Phosphorylated Oligosaccharides Prepared from Potato Starch
YANG Li,YANG Wen-jun,LIU Xia,DU Xian-feng
2011, 32(14):  198-201.  doi:10.7506/spkx1002-6630-201114041
Asbtract ( 168 )   HTML ( 1)   PDF (315KB) ( 124 )  
Related Articles | Metrics
The current study was carried out to quantitatively and qualitatively analyze phosphorylated sligosaccharides prepared from potato starch by totally enzymatic method. The phosphorylated sligosaccharide composition was determined by thin layer chromatography (TLC) and high performance anionic exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Infrared spectroscopy (IR) was used for structure elucidation. The analytes were identified as a mixture of maltooligosaccharides containing phosphate groups and having a degree of polymerization between 3 and 7, in which maltotriose, maltotetraose, maltopentaose and maltohexaose were the dominant components.
Construction of an in vitro Allergy Reaction Evaluation Method for Cow Milk and Its Substitutes Using Human Leukemia Cell Line KU812F
CONG Yan-jun,REN Fa-zheng
2011, 32(14):  202-205.  doi:10.7506/spkx1002-6630-201114042
Asbtract ( 125 )   HTML ( 1)   PDF (212KB) ( 96 )  
Related Articles | Metrics
This study aimed to construct an in vitro cellular assay for suspected allergenic components of cow milk and its substitutes using human leukemia cell line KU812F, an immature prebasophillic cell line based on their histamine release ability. KU812F was differentiated into basophils by incubation with serum from cow milk allergic people. The release of histamine from differentiated KU812F cells was monitored after sensitization with either cow milk or its substitutes. The results showed that this in vitro assay was highly reliable and reproducible in determining histamine release from KU812F cells after respective sensitization with cow milk and its products. Cow milk and its substitutes differed in their histamine release ability. Cow milk allergen induced histamine release in a dose-dependent manner. Specifically, a positive relationship was observed in a defined range of allergen dose, followed by a negative relationship after maximum histamine release.
Determination of 6 Tetracycline Antibiotics in Milk by Matrix Solid-Phase Dispersion Extraction Using Multiwalled Carbon Nanotubes Coupled with HPLC
WANG Xue-cui,LIU Bing,ZHANG Lu-xin,JI Jing-jing,SHI Jin-qiu,ZHANG Hang,YANG Zong-hui,WU Hong
2011, 32(14):  206-209.  doi:10.7506/spkx1002-6630-201114043
Asbtract ( 156 )   HTML ( 4)   PDF (241KB) ( 30 )  
Related Articles | Metrics
A matrix solid-phase dispersion extraction (MSPDE) method was developed to extract 6 tetracycline antibiotics (TCs) from milk samples using multiwalled carbon nanotubes (MWCNTs) as adsorbent prior to high performance liquid chromatography (HPLC) determination. Milk samples, MWCNTs, oxalic acid, and EDTA were evenly ground and then packed into a glass syringe as dispersion column. The analytes were eluted with methanol containing formic acid, and detected by HPLC with variable wavelength detector at 365 nm. The limits of detection (LODs) for 6 TCs ranged from 0.01 to 0.03μg/mL. Their recoveries in spiked milk samples were in the range of 78.7%-105.2% with relative standard deviations of less than 12%. #br# MSPD exhibited higher recovery in extracting 6 TCs as compared to C18 column extraction, suggesting that the developed MSPD procedure can be applied for the multiresidues analysis of pesticides and veterinary drugs in foods.
Folin-Ciocalteu colorimetric Determination of Total Polyphenol Content in Hovenia acerba Fruit
XIANG Jin-le,LI Zhi-xi,GUO Xiang-feng,LI-Huan,ZHENG Shu-yan
2011, 32(14):  210-214.  doi:10.7506/spkx1002-6630-201114044
Asbtract ( 118 )   HTML ( 0)   PDF (288KB) ( 174 )  
Related Articles | Metrics
A quantitative Folin-Ciocalteu colorimetry method to determine total polyphenols in Hovenia acerba fruit was developed. The color reaction was carried out with 0.6 mL of Folin-Ciocalteu reagent and 1.5 mL of 20 g/100 mL aqueous Na2CO3 solution in darkness at 30 ℃ for 60 min. The detection wavelength was set as 750 nm. The linear range of the established standard curve was 0-8.47 mg/L. The relative standard deviations of stability, reproducibility, precision, and spike recovery rate of this method were all satisfactory. Thus, this method can be applicable to determine the total polyphenols of Hovenia acerba fruit.
Changes of Volatile Components in Nile Tilapia during Purging Process
DU Wei-guang,LI Xiao-ding,WANG Shu-e,XIONG Shan-bai,FU Na,WANG Hong-mei,HU Fen,YANG Xiao-bo,GONG Xia
2011, 32(14):  215-218.  doi:10.7506/spkx1002-6630-201114045
Asbtract ( 132 )   HTML ( 0)   PDF (167KB) ( 40 )  
Related Articles | Metrics
The volatile compounds in the muscle of Tilapia nilotica during 12 days of purging in autumn were extracted by solid phase micro-extraction (SPME) and analyzed by gas chromatography-mass spectroscopy (GC-MS). Totally 31 kinds of volatile compounds were isolated and identified including aldehydes, hydrocarbons, Kwai alkenes, aromatic hydrocarbons, alcohols, esters, terpenes, and others, in which aldehydes, aromatic hydrocarbons and hydrocarbons were the top three most abundant compounds, with a relative level to total volatile compounds of 36.97%, 17.85%, 20.70% at the beginning of the purging period and 44.49%, 34.65%, 8.66% at the end of the purging period, respectively. After 8 days of purging, the contents of octanal and nonanal significantly decreased, and neither octatriene nor cyclohexene were detected, which is desirable for the elimination of undesirable odor. Meanwhile, the contents of benzaldehyde and aromatic benzene ring increased, which was helpful in promoting the formation of desirable flavor in tilapia.
Simultaneous Determination of 7 Preservatives in Soy Sauce by High Performance Liquid Chromatography
XIA Jing,ZHANG Jing-xuan,LI Hui,YANG Lan,WU Chun-min
2011, 32(14):  219-222.  doi:10.7506/spkx1002-6630-201114046
Asbtract ( 185 )   HTML ( 1)   PDF (188KB) ( 59 )  
Related Articles | Metrics
An analytical method to simultaneously determine 7 preservatives in soy sauce such as benzoic acid, sorbic acid, dehydroacetic acid and p-hydroxybenzoic acid esters (methyl paraben, ethyl paraben, propyl paraben and butyl paraben) was established using high performance liquid chromatography. The analytes were cleaned up on Oasis HLB column and detected at 230 nm and 260 nm. Their chromatographic separation was performed on Warters-C18 column (4.6 mm × 250 mm, 5μm) using acetonitrile and ammonium acetate as mobile phase for gradient elution. All the 7 preservatives displayed a linear concentration-peak area relationship over the concentration range of 0.4-100 mg/L, with a correlation coefficient of larger than 0.9994. The limits of detection of the method were from 0.28 to 0.55μg/mL. Average spike recovery rates for the 7 preservatives in a blank sample were from 84.4% to 102.3% (n = 3). This method can be used to detect preservatives in soy sauce rapidly and conveniently.
Multiresidue Determination of Pesticides and Polychlorinated Biphenyls in Tea by Solid-phase Extraction and Gas Chromatography
WU Lin,WU Xiao-bo,ZHANG Cheng-cong,MA Li-li,LIN Shi-yun,LU Guang-qiu,TANG Na
2011, 32(14):  223-226.  doi:10.7506/spkx1002-6630-201114047
Asbtract ( 583 )   HTML ( 0)   PDF (243KB) ( 97 )  
Related Articles | Metrics
A solid-phase extraction and gas chromatographic method was established to simultaneously determine 21 organochlorines, pyrethroids and polychlorinated biphenyls (PCBs) in tea. Tea samples were extracted with hexane-acetone (1:1, V/V) in an ultrasonic bath and cleaned up on an Envi-Carb/NH2 SPE column. The analytes were separated on a RTX-5 capillary column and detected in 63Ni-ECD (electron capture detector). The recoveries for the analytes were from 68.64% to 125.62% with a relative standard deviation (RSD) from 1.05% to 12.78% at the spike levels of 0.02, 0.05 mg/kg and 0.3 mg/kg. The limits of detection (LOD) of the method ranged from 0.0022 to 0.0129 mg/kg. In conclusion, this method can be suitable for the determination of organic contaminants in tea samples.
Development of Enzyme-linked Immunosorbent Assay for Neomycin
LIU Sha-zhou,SANG Xiao-xue,OUYANG Hua-xue,LEI Shao-rong,BAI Lin-han
2011, 32(14):  227-231.  doi:10.7506/spkx1002-6630-201114048
Asbtract ( 244 )   HTML ( 1)   PDF (225KB) ( 109 )  
Related Articles | Metrics
In this study, we describe the advantages and disadvantages of direct competitive enzyme-linked immunosorbent assay (dc-ELISA) and indirect competitive ELISA (idc-ELISA) and ELISA methods for the detection of neomycin. Anti-neomycin polyclonal antibodies were prepared and used to detect neomycin by dc-ELISA and idc-ELISA. The cross-reaction rates of prepared anti-neomycin polyclonal antibodies with gentamincin and kanamycin were 2.04% and 0.02%, respectively, and with ampicillin, erythromycin and tetracycline all less than 0.01%. The accuracy and recovery of idc-ELISA were tested with an intra-plate error of less than 4%, an inter-plate error of less than 11% and a recovery between 135.5% and 191.3%. The detection limits of dc-ELISA and idc-ELISA were 28.58 ng/mL and 51.74 ng/mL, respectively, both of which were below the national maximum residue limit (MRL) of 500μg/kg. Therefore, a dc-ELISA method and an idc-ELISA method to detect neomycin have successfully established. Further, the idc-ELISA method where the working conditions were better optimized can be used for the development of neomycin test kit.
Determination of 3-Monochloropropane-1,2-diol in Soy Sauce and Oyster Sauce by Solid Phase Extraction Combined with Gas Chromatography-Mass Spectrometry
XIONG Jun,GONG Liang,LAI Yi-dong
2011, 32(14):  232-236.  doi:10.7506/spkx1002-6630-201114049
Asbtract ( 161 )   HTML ( 0)   PDF (315KB) ( 35 )  
Related Articles | Metrics
A simple and sensitive method for determination of 3-monochloropropane-1,2-diol (3-MCPD) in sauce samples by solid phase extraction (SPE) with gas chromatography-mass spectrometry (GC-MS) is described. In this work, type of elution solvent, volume of elution solvent and sample were investigated to optimize SPE conditions. 5.0 g sample was mixed and homogenised with 5 mol/L sodium chloride solution, then adsorbed on the SPE column. The target analyte was extracted and derivatised, finally analyzed by GC-MS. The relative standard deviation (RSD, n=5) for the studied target analyte was 8.8% and the coefficient of determination for calibration curve was 0.9998. The method detection limit was 0.15 μg/kg, which is adequate for practical samples. The method was applied to soy sauce and oyster sauce samples and the recovery of 87.2%-109.4% with RSDs (n=3) of 5.6%-10.2% were obtained.
Effects of Dp368 Glycosidase Treatment on Volatiles in Semillon Grape Juice
JIANG Yu-mei,HAN Shun-yu,ZHU Xia,BI Yang
2011, 32(14):  237-240.  doi:10.7506/spkx1002-6630-201114050
Asbtract ( 111 )   HTML ( 1)   PDF (209KB) ( 38 )  
Related Articles | Metrics
The volatiles of Semillon grape juice before and after 36 h of hydrolysis with Dp368 glycosidase were analyzed by headspace solid-phase micro-extraction (HS-SPME) and GC-MS. A total of 64 volatile compounds were isolated and identified, mostly including components with chain lengths of less than 10 carbon atoms and alcohols were the most abundant volatiles. Compared with untreated control, Dp368 treatment caused a 3.12% increase in the release of total volatile compounds and a considerable increase in the release of acids, terpene, some benzene derivatives and C5-C7 compounds.
A Rapid Spectrometric Method for Detecting Alicyclobacillus acidoterrestris in Fruit Juice
YE Jian-fang,LI Wen-jun,ZHAO Wen-chao,MO Xiao-jing,JIA Cai-feng
2011, 32(14):  241-244.  doi:10.7506/spkx1002-6630-201114051
Asbtract ( 134 )   HTML ( 0)   PDF (561KB) ( 78 )  
Related Articles | Metrics
In the presence of Alicyclobacillus acidoterrestris, vanillic acid and vanillin can be converted into guaiacol, which can be further converted into a reddish-brown product by peroxidase. Based on this color reaction, a method was developed to spectrometrically detect the presence of Alicyclobacillus acidoterrestris in real systems. In static culture, BAM medium with the addition of 100μg/kg vanillic acid was the most favorable for guaiacol formation. The peak value of guaiacol concentration was delayed along with the decrease of bacteria concentration. A visible color was formed in medium and its OD470 could reach up to 1.0 or even more after 21 hours of culture at the initial spore density of 3 spores/mL. And the same result also was obtained in an apple juice system. Thus, this method can allow rapid, simple and sensitive detection of Alicyclobacillus acidoterrestris in fruit juice.
Analysis of Amino Acid Composition and Se Content in Different Species of Termitomyces Grown in Sichuan
ZOU Li-kou,PAN Xin,,YUE Ai-ling,LUO Yan,LI Bei,ZHANG Yue,YAO Qiong,WU Qi,ZHENG Lin-yong
2011, 32(14):  245-248.  doi:10.7506/spkx1002-6630-201114052
Asbtract ( 173 )   HTML ( 1)   PDF (260KB) ( 54 )  
Related Articles | Metrics
Fruiting body samples of 10 species of Termitomyces grown in different regions of Sichuan province were analyzed for their amino acid composition using amino acid auto analyzer and Se content using atomic fluorescence spectrometer. The results showed that the contents of total amino acids and essential amino acids were 15.92%-28.86% and 7.08%-10.20%, respectively in the fruiting bodies of the investigated species of the genus Termitomyces. The fruiting bodies of T.albuminosus, T. robustus, T. badius, T. microcarpus, T. schimperi and T. heimi exhibited a total amino acid content of more than 20% and the contents of total amino acids and essential amino acids in T. heimii fruiting bodies were 28.86% and 10.20%, respectively. Besides, Se content of Termitomyces fruiting bodies was 3-18 times higher than that of Xerula radicata, and the Se content of T. badius was (1.2286 ± 0.0340)μg/g. It could be concluded that the 10 investigated species of Termitomyces grown in Sichuan province are rich in a variety of amino acids and Se and are highly nutritious.
Determination of Fructose, Glucose, and Maltose in Honey by HPLC-FLD
ZHANG Qi-an,WANG Juan,DAI Jian-xiao,DU Pei-fen,WANG Su-qing,LU De-mei,YANG Shao-bo
2011, 32(14):  249-252.  doi:10.7506/spkx1002-6630-201114053
Asbtract ( 256 )   HTML ( 2)   PDF (297KB) ( 125 )  
Related Articles | Metrics
An ion-pair reversed-phase high performance liquid chromatographic method was developed to simultaneous determine fructose, glucose, and maltose in honey using p-aminobenzoic acid (p-AMBA) for pre-column derivatization. The chromatographic separation was achieved on an ODS column using a mobile phase made up of 0.1 mol/L phosphate buffer solution (20 mmol/L tetrabutylammoniumhydrogen sulfate, pH 2.5) and acetonitrile (95:5, V/V). The analytes were detected using a fluorescence detector and quantified by external standard method. The results showed that the detection limits of fructose, glucose and maltose were 210, 96μg/kg and 240μg/kg, respectively, and the linear ranges were 130 -140, 52-98 mg/kg, and 154-98 mg/kg (r > 0.9988). The spike recoveries ranged from 98.2% to 101.2%, with RSDs between 3.4% and 5.4%.
Evaluation of Pork Freshness by HS-SPME-GC-MS
MA Yu-lu,ZHU Bin,ZHANG Lei,XU Xin-rong
2011, 32(14):  253-256.  doi:10.7506/spkx1002-6630-201114054
Asbtract ( 177 )   HTML ( 0)   PDF (173KB) ( 81 )  
Related Articles | Metrics
A method to evaluate pork freshness was proposed based on the use of headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) to analyze changes in the volatile composition of pork with different freshness. Pork samples with different freshness showed a big difference in their volatile composition. Along with the decrease in freshness, some toxic sulfides and amines were detected including methanethiol, disulfide dimethyl, dimethyl trisulfide, tetrasulfide dimethyl, indole and so on. Our results indicated that HS-SPME-GC-MS could changes in these compounds in pork, therefore providing an applicable approach to evaluate pork freshness.
Comparison of Volatile Components in Pork from Feedlot-raised and Pasture-raised Tibetan Miniature Pigs
SUN Zhi-chang,HAN Ling,LI Yong-peng,YANG Qin
2011, 32(14):  257-260.  doi:10.7506/spkx1002-6630-201114055
Asbtract ( 113 )   HTML ( 0)   PDF (151KB) ( 36 )  
Related Articles | Metrics
The volatile compounds in longissimus dorsi muscles from 6 month-old Tibetan miniature pigs raised in feedlot with cereal and on natural pasture from Gannan Tibetan Autonomous Prefecture, Gansu province were investigated by gas chromatography-mass spectrometry (GC-MS). Feedlot-raised and pasture-raised Tibetan miniature pigs mostly varied in their aldehyde contents (38.33% and 25.19%, respectively). Methylthiopropanal (meaty flavor) and benzothiazole (gravy flavor) that can be derived from Mailard reaction in feedlot-raised pork were 23% and 122% more than that in pasture-raised pork, respectively. Lipid oxidation products showed a significant increase in feedlot-raised pork as compared with their pasture-raised pork (P <0.05), and a significant difference in the types of lipid oxidation products was also found. Pasture-raised pork exhibited significantly higher terpene content than feedlot-raised pork (P <0.05). From these results, we concluded that raising methods can affect volatile compounds in pork from Tibetan miniature pig and therefore might affect pork flavor.
Determination of DHA and Linoleic Acid Contents in Infant Formula Milk Powder by GC-MS
PENG Fei-jin,YANG Wei-hua
2011, 32(14):  261-263.  doi:10.7506/spkx1002-6630-201114056
Asbtract ( 145 )   HTML ( 0)   PDF (229KB) ( 127 )  
Related Articles | Metrics
A method to determine docosahexaenoic acid (DHA) and linoleic acid contents in infant formula milk powder by gas chromatography-mass spectrometry (GC-MS) was developed. Samples were methylesterized with acetyl chloride-MeOH, followed by extraction with toluene before GC-MS analysis. The external standard method was used for quantification. The average spike recoveries for DHA and linoleic acid in a commercial sample were 96%-110%. The developed method proved simple, precise, accurate and reliable, thereby being suitable for the determination of DHA and linoleic acid contents in infant formula milk powder.
Composition Analysis of Phenols in Vitis ficifolia Bge and Vitis davidii Foex Fruit Skins
ZHANG Ming-xia,LIU Chong-huai,ZHANG Jing,FAN Xiu-cai
2011, 32(14):  264-267.  doi:10.7506/spkx1002-6630-201114057
Asbtract ( 119 )   HTML ( 0)   PDF (155KB) ( 81 )  
Related Articles | Metrics
Phenols are the most important components for maintaining high quality of grapes. The anthocyanins and non-anthocyanin phenolic compounds in the fruit skins of Vitis ficifolia Bge and Vitis davidii Foex were extracted with methanol and ethyl acetate under the assistance of ultrasonic respectively and their composition was qualitatively and quantitatively analyzed by high performance liquid chromatography mass spectrometry (HPLC-MS). As a result, 20 anthocyanins and 6 non-anthocyanin phenolic compounds were identified in Vitis ficifolia Bge fruit skin, and 6 anthocyanins and 15 non-anthocyanin phenolic compounds in Vitis davidii Foex fruit skin. The major anthocyanins in Vitis davidii Foex fruit skin were elphinidin-3,5-O-di-glucoside and malvidin-3,5-O-di-glucoside, and in Vitis ficifolia Bge malvidin-3,5-O-di-glucoside and petunidin-3,5-O-di-glucoside. Feruloytartaric acid and its derivatives, ferulic acid hexose ester and quercetin-O-rhamnoside were the major non-anthocyanin phenolic compounds in both species of wild grapes. The content of non-anthocyanin phenolic compounds in Vitis davidii Foex was much higher than that in Vitis ficifolia Bge.
Determination of 4,6-Dinitro-O-Cresol (DNOC) Residue in Animal-origin Foods by Solid-phase Extraction and Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectrometry
WU Yan,KANG Qing-he,LIU Yong,HU Shen,YANG Chang-zhi,GAO Kai-yang
2011, 32(14):  268-272.  doi:10.7506/spkx1002-6630-201114058
Asbtract ( 141 )   HTML ( 0)   PDF (280KB) ( 41 )  
Related Articles | Metrics
A solid-phase extraction and ultrahigh performance liquid chromatography-tandem mass spectrometry method has been developed for the determination of DNOC residue in animal-origin foods. Samples were extracted with acetone-hexane (1:2, V/V) after high-speed homogenization. The crude extract was purified on Oasis HLB solid phase extraction column to remove fat and inorganic salts, which could effectively reduce the background interference generated by complex matrix in samples. The DNOC residue was separated on BEH C18 (50 mm × 2.1 mm, 1.7μm) column using acetonitrile-water as the mobile phase by gradient elution and detected using a tandem mass analyzer in the multi-reaction monitoring (MRM) mode. The developed method exhibited an excellent linear relationship (r>0.999) and a detection limit of 0.005 mg/kg. At the spiked levels of 0.005, 0.01 mg/kg and 0.02 mg/kg, the average recovery rates for DNOC were in the range of 82.6%-108% with a relative standard deviation (RSD) of less than 10% (n = 6). This method proved rapid, accurate and highly sensitive and can therefore be used for the determination of DNOC residue in animal-origin foods.
Biogenic Amines in Salted Duck Analyzed by TLC Combined with HPLC
WANG Feng-qin,LIU Fang,MENG Yong,WANG Dao-ying,ZHU Yong-zhi,XU Wei-min
2011, 32(14):  273-276.  doi:10.7506/spkx1002-6630-201114059
Asbtract ( 106 )   HTML ( 0)   PDF (353KB) ( 96 )  
Related Articles | Metrics
The composition and contents of biogenic amines in salted duck were analyzed by thin layer chromatography (TLC) combined with high performance liquid chromatography (HPLC). Six biogenic amines including putrescine, cadaverine, spermidine, spermine, tyramine and 2-phenylethylamine were detected in salted duck samples by TLC. Similarly, six biogenic amines were also detected by HPLC, and the concentration of each biogenic amine was less than 204μg/g. The analytical results obtained by both methods were consistent. Therefore, TLC can be used as an economic and rapid method for the qualitative analysis of biogenic amines in meat products.
Spectrometric Determination of Trace Copper in Foods by BCA (2,2'-Biquinoline-4,4'-dicarboxylic acid disodium salt) Method
LIU Xuan,FENG Zhi-ming
2011, 32(14):  277-280.  doi:10.7506/spkx1002-6630-201114060
Asbtract ( 185 )   HTML ( 2)   PDF (219KB) ( 62 )  
Related Articles | Metrics
The colour reaction between BCA (2,2'-biquinoline-4,4'-dicarboxylic acid disodium salt) and copper was developed for determining trace copper in foods. In the presence of pH 11.0 buffer solution and hydroxylamine hydrochloride, BCA could react with copper (II) to form a purple complex with a ratio of 2:1. The molar absorbance constant was 7.72 × 103 L/(mol ·cm) at 562 nm. The absorbance obeyed Beer s law in the range of 0-4.8μg/mL Cu (Ⅱ). The established method was used for the determination of trace copper in tea and kelp. The determination results are consistent with the results from atomic absorption spectrometry (AAS) method. In conclusion, this method has the advantages of good accuracy, stability and can therefore be applied to the determination of trace copper in foods.
Determination of Soybean Protein Isolate in Emulsion-type Pork Sausages
YANG Yong,ZHOU Xiao-ping,QIN Dan,CHENG Yan
2011, 32(14):  281-284.  doi:10.7506/spkx1002-6630-201114061
Asbtract ( 182 )   HTML ( 0)   PDF (328KB) ( 69 )  
Related Articles | Metrics
sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used for the qualitative and quantitative analysis of soybean protein isolate (SPI) in emulsion-type pork sausages. Results showed that SPI displayed five major bands including β-conglycinin d1, α', β and d2 subunits and glycinin d3 subunit in SDS-PAGE, which could be distinguished from pork protein. A linear regression equation with band intensity as a function of SPI concentration of α' subunit in the range of 0.5%-10% was obtained for determining SPI in emulsion-type pork sausages. The prediction values of samples containing SPI at various amounts of 7%, 3%, 1.5%, 0.8% and 0.5% exhibited a high reproducibility with variation coefficients between 1.90% and 7.01%. The successful application of SDS-PAGE was also demonstrated by a high correlation coefficient of 0.98 obtained from regression analysis between the predicted and actual values of SPI in spiked emulsion-type pork sausages.
Uncertainty Evaluation for the Determination of Cadmium in Peanuts by ICP-MS
LIU Tong-ying,WU Shan-feng,ZHANG Li-dong
2011, 32(14):  285-288.  doi:10.7506/spkx1002-6630-201114062
Asbtract ( 119 )   HTML ( 0)   PDF (157KB) ( 58 )  
Related Articles | Metrics
Objective: To establish a determination method of cadmium in peanuts by inductively coupled plasma-mass spectroscopy (ICP-MS) and evaluate the uncertainty of determination results. Methods: A mathematic model was established by analyzing the uncertainty sources from different parts. The final uncertainty degree was calculated by standard uncertainty and extended uncertainty during measurements. Results: The cadmium content in peanuts was determined to be (162 ±5)μg/kg with a k value of 2, which met the national standard. The major uncertainty was attributed to four sources such as repeatability of measurement, calibration of standard solution, volume and sampling. Conclusion: This method is applicable to the evaluation of uncertainty during component determination in foods by ICP-MS.
Effects of Extraction Methods on Nutritional Components in Millet Bran Oil
ZHAO Chen-yong,WANG Chang-qing,XU Jie,FAN Ying,WANG Fei
2011, 32(14):  289-292.  doi:10.7506/spkx1002-6630-201114063
Asbtract ( 150 )   HTML ( 0)   PDF (242KB) ( 82 )  
Related Articles | Metrics
Supercritical carbon dioxide extraction (SCDE) and isopropanol solvent extraction (ISE) were employed to extract millet bran oil. The fatty acid composition and the contents of sterol, vitamin E and phospholipid as well as the color change of the obtained samples were determined by gas chromatography and fluorescence spectrometry. The results showed that the content of linoleic acid in millet bran oil was even higher than other edible oils, which was up to 71.82%. The contents of unsaturated fatty acids and phospholipid in SCDE-derived millet bran oil exhibited a decrease by 0.11% and 99.60% respectively when compared with ISE-derived millet bran oil, but the contents of saturated fatty acids of C14-C22, vitamin E and sterol were higher than those of ISE, which were up to 0.93%, 20.64% and 34.82%, respectively. Moreover, SCDE-derived millet bran oil revealed a lighter color.
Changes of Aroma Components in Loquat Wine during Aging Process
PU Biao,ZHANG Yao,LIU Yun
2011, 32(14):  293-297.  doi:10.7506/spkx1002-6630-201114064
Asbtract ( 154 )   HTML ( 0)   PDF (331KB) ( 154 )  
Related Articles | Metrics
In order to explore the effect of natural aging process on aroma components in loquat wine, headspace solid phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the aroma components in original and naturally aged samples of loquat wine. Quantification was performed by the area normalization method. The results indicated that 27 aroma components were identified in wine samples aged for 0, 3, 6, 9 months, of which 19 such as 1-hexanol, n-heptanol, 1-octanol and so on were found in all of the four samples and 8 such as 1-nonanol, amyl acetate, ethyl caprylate and otherwise were the predominant compounds. At the four aging stages, esters were the most predominant aroma components, followed by alcohols, acids, terpenoids and aldehydes, and the types of aroma components and major aroma components and their relative contents revealed differences. The relative contents of alcohols and aldehydes exhibited a downward trend, and of esters, acids and terpenoids an upward trend. Difference aroma composition provided loquat wine with different aroma performance at different aging stages.
Determination of Ochratoxin A in Edible and Medicinal Foods by HPLC-Fluorescence Technology
FU Wu-sheng,QIU Wen-qian,ZHENG Kui-cheng,LU Hua-dong,GUO Bin,YAN Xiao-bo
2011, 32(14):  298-302.  doi:10.7506/spkx1002-6630-201114065
Asbtract ( 119 )   HTML ( 1)   PDF (224KB) ( 52 )  
Related Articles | Metrics
Objective: To develop a method to determine ochratoxin A (OTA) in edible and medicinal foods using immunoaffinity column purification and high performance liquid chromatography (HPLC). Methods: Powdered samples were extracted with methanol-water (8:2, V/V) sequentially by vortex mixing, ultrasonic treatment and shaking. The resulting extract was diluted with phosphate buffer solution, filtrated and cleaned up on immunoaffinity column (IAC) containing antibodies specific to OTA . The pooled eluate was separated on a C18 column (4.6 mm × 150 mm, 3μm) and detected by fluorescence detector (FLD). Results: The limit of detection (LOD, RSN = 3) was 1.0μg/kg for OTA. An excellent linear relationship between peak area and OTA concentration was observed in the OTA concentration range of 0.5-100 ng/mL with correlation coefficient of 0.9995. The average recovery rates for OTA in prince ginseng root, lotus seed, coix seed, Radix Ophiopgonis, dried longan pulp and oriental water plantain rhizome spiked with OTA standard at a level of 1-8μg/kg were varied from 81.8%-107% with a relative standard deviation (RSD) of 1.66%-15.0% (n = 3). Conclusion: This method has the advantages of satisfactory results and high accuracy and precision and can meet the requirements of the Europe Union for the determination of OTA in food and feed, thus providing a suitable method for determining OTA edible and medicinal foods rich in starch or sugar.
Optimization of Total Flavonoids Extraction from Radix Puerariae and HPLC Determination of Puerarin
YANG Shu-ping,HAN Li-jun,ZHU Jin-wei,XU Rui-bo,JIANG Ying-dao
2011, 32(14):  303-306.  doi:10.7506/spkx1002-6630-201114066
Asbtract ( 141 )   HTML ( 7)   PDF (183KB) ( 82 )  
Related Articles | Metrics
In this paper, orthogonal array design L9(34) was employed to optimize the extraction conditions of total flavonoids from Radix Puerariae residue left after pueraria root powder extraction. The effects of extraction temperature, ethanol concentration, extraction time and material-to-liquid ratio on extraction rate of total flavonoids were probed. Meanwhile, a HPLC method to determine puerarin content in Radix Puerariae was presented based on optimized extraction process. The optimal extraction conditions were determined as follows: ethanol concentration 70%, reflux time 150 min, reflux temperature 80 ℃, and material-to-liquid ratio 1:40, under which, the contents of total flavonoids in Radix Puerariae, Radix Puerariae residue and pueraria root powder were 46.11, 32.41 mg/g and 11.23 mg/g, and of puerarin 40.63, 21.24 mg/g and 4.71 mg/g, respectively. From these results, we drew the conclusion that Radix Puerariae residue is rich in total flavonoids and puerarin and that the optimized extraction process can be used for the extraction of total flavonoids and puerarin from Radix Puerariae residue.
Detection of Pure Milk with Different Packages by Electronic Nose
XIAO Tao,YIN Yong,YU Hui-chun,ZHOU Qiu-xiang
2011, 32(14):  307-310.  doi:10.7506/spkx1002-6630-201114067
Asbtract ( 122 )   HTML ( 0)   PDF (301KB) ( 38 )  
Related Articles | Metrics
Dairy quality can be affected by different packages, which has received more attention recently. Pure milk samples with three kinds of packages including PrePak, Tetra Pillow and Tetra Brik were measured by an array composed of 13 gas sensors. Mean differential coefficients were used for feature extraction. Pure milk samples with three kinds of packages was discriminated by Fisher discriminant analysis (FDA) and Back-Propagation network (BPN). The results showed that pure milk with three kinds of packages could be discriminated well using electronic nose according to quality changes during storage.
Packaging & Storage
Effect of Enhanced Freshness Formulation on Postharvest Physiological Properties of Oriental Sweet Melons (Cucumis melo var. makuwa Makino) during Storage
QI Hong-yan,TENG Lu-hua,LI Yan,XIAO Ya-nan
2011, 32(14):  311-317.  doi:10.7506/spkx1002-6630-201114068
Asbtract ( 109 )   HTML ( 0)   PDF (508KB) ( 56 )  
Related Articles | Metrics
Oriental sweet melons Jinheng No. 2 were immersed in enhanced freshness formulation (1% or 2% EFF solution) or plain water (as control) for 3 min before storage in incubators for 20 d at 10 ℃ and a relative humidity of 85%. Postharvest physiological properties of oriental sweet melons were determined at 7-day intervals during storage. EFF treatment alleviated the decrease of weight, firmness, water content and soluble solid, delayed the appearance of the ethylene peak and extremely significantly reduced the ethylene peak height (P <0.01). Meanwhile, EFF treatment significantly promoted the activities of superoxide dismutase (SOD) and catalase (CAT) (P < 0.05), and extremely significantly inhibited the activities of polyphenol oxidase (PPO) and peroxide (POD) (P <0.01). Therefore, EFF treatment delayed the maturation and the following senescence of sweet melons, and thus prolonged their storage life. During the early part of the storage period, 2% EFF treated sweet melons had significantly higher aldehydes content than those in the control group and 1% EFF treated sweet melons (P <0.05). During the later part, 2% EFF treated sweet melons revealed a significantly increase in the contents of total aroma compounds, esters, acetic and oxalates, and the appearance of the aroma peak was delayed for 3 days, thus reducing the loss of aroma compounds and maintaining the quality of sweet melons. Collectively, these results indicate that 2% EFF treatment is more beneficial to delay the senescence of oriental sweet melons and maintain their quality.
Effect of 1-Methylcyclopropene Treatment on Metabolism and Qualities of Fresh-cut Watermelon
JIAO Yan, LI Wu,ZHANG Chao,MA Yue,LI Xi-hong,ZHAO Xiao-yan
2011, 32(14):  318-322.  doi:10.7506/spkx1002-6630-201114069
Asbtract ( 159 )   HTML ( 0)   PDF (533KB) ( 47 )  
Related Articles | Metrics
Watermelon was treated with 1-methylcyclopropene (1-MCP) before and/or after being cut up before storage at 5 ℃ in plastic boxes to investigate the effect of 1-MCP treatment on the respiratory rate, ethylene production, firmness, and color of fresh-cut watermelon. Cutting-up followed by treatment with 1 mg/L 1-MCP for 24 h proved optimal. As a result, the respiratory rate and ethylene production of watermelon were effectively reduced, and the color and firmness were well maintained during 7 days of storage
Effect of Essential Oils on Postharvest Decay and Quality of Strawberry Fruits
WU Xin,JIN Peng,KONG Fan-yuan,DUAN Yang-feng,ZHAO Jing,SHEN Jie,DING Yan,ZHENG Yong-hua
2011, 32(14):  323-327.  doi:10.7506/spkx1002-6630-201114070
Asbtract ( 212 )   HTML ( 0)   PDF (619KB) ( 74 )  
Related Articles | Metrics
Freshly harvested strawberries (Fragaria ananassa Duch. cv. Fengxiang) were used to explore the preservation effect of 5 essential oils including carvacrol, cinnamaldehyde, perillaldehyde, linalool and allyl isothiocyanate at various concentrations (0.5, 1, 5,10μL/L) during storage at 20 or 5 ℃. The results showed that all of the 5 essential oils could significantly inhibit the incidence of fruit decay at both 5 ℃ and 20 ℃ of which, allyl isothiocyanate revealed the most obvious inhibitory effect. However, high concentrations of essential oil such as allyl isothiocyanate and perillaldehyde at 5μL/L and the other three essential oils at 10μL/L could result in chemical injury of strawberry fruits. Treatments with each essential oils at appropriate concentrations significantly inhibited the increase of weight loss and the decrease of firmness, retained higher levels of titratable acidity, total soluble solids, vitamin C, total sugar and reducing sugar, thereby maintaining better fruit quality. These results suggested that essential oil treatment might be a promising method to control fruit decay and maintain high quality for postharvest strawberries.
Effect of Storage Temperature on Quality and Preservation of Fresh Tumorous Stem Mustard
WU Ri-zhang,LIU Li-dan,ZENG Kai-fang
2011, 32(14):  328-332.  doi:10.7506/spkx1002-6630-201114071
Asbtract ( 117 )   HTML ( 0)   PDF (450KB) ( 31 )  
Related Articles | Metrics
The effect of different storage temperatures on postharvest quality and preservation of fresh tumorous stem mustard was investigated. Fresh tumorous stem mustards were packaged with 0.03 mm thick polyene bag after pretreatment prior to storage in cooling incubators at 85%-95% relative humidity (RH) and different temperatures (0, 5, 10, 15 ℃), respectively. During the storage period of 22 days, germination rate, decay degree and commodity rate were recorded and the contents of ascorbic acid, total soluble solids (TSS) and soluble protein were measured every other 5 days. The results indicated that tumorous stem mustard showed significantly reduced germination rate, decay degree and weight loss rate and increased commodity rate during storage at 0 ℃ and 5 ℃ when compared with storage at 10 ℃ and 15 ℃, and the decrease of ascorbic acid, total soluble solids (TSS) and soluble proteins in tumorous stem mustard was delayed during storage at 0 ℃ and 5 ℃, but the contents of total phenols and flavonoids in tumorous stem mustard at different storage temperatures revealed an un-regular change. The best preservation effect with 100% commodity rate and 0% decay degree was observed during storage at 0 ℃. The storage life could reach up to 50 days under the optimal storage conditions. The ascorbic acid content in samples stored at 0 ℃ was increased by 109% and 208% when compared with those stored at 10 ℃ and 15 ℃, respectively. The level of soluble proteins in samples stored at 0 ℃ was increased by 16.7%, 59% and 89.6% when compared with those stored at 5, 10 ℃ and 15 ℃, respectively. In conclusion, storage at 0 ℃ and 5 ℃ is more beneficial to maintain postharvest quality of tumorous stem mustard than storage at 10 ℃ and 15 ℃. The most appropriate storage temperature is 0 ℃ for fresh tumorous stem mustard.
Technology Application
Optimization of Enzymatic Hydrolysis Rabbit Meat and Formulation and Vacuum Freeze-drying of Rabbit Meat Floss
WANG Wei,LI Xiang,ZHANG Jia-min,LIU Da-yu,ZHANG Yin
2011, 32(14):  333-336.  doi:10.7506/spkx1002-6630-201114072
Asbtract ( 126 )   HTML ( 0)   PDF (156KB) ( 49 )  
Related Articles | Metrics
Rabbit meat was hydrolyzed with papain and the hydrolysate was used to develop nutritional and healthcare floss with the addition of carrot rich in vitamins and other ingredients. In order to maximize hydrolysis degree, the optimization of the hydrolysis conditions of rabbit meat were performed using one-factor-at-a-time combined with orthogonal array design method, and this method was also used to optimize process conditions for the vacuum freeze-drying of rabbit meat floss for achieving maximum comprehensive sensory score. The optimal hydrolysis conditions were found as follows: temperature 50 ℃, hydrolysis time 6 h, pH 7.0, enzyme dosage 2%, and solid-to-liquid ratio 1:4. Rabbit meat floss formulated with the hydrolysate obtained under the optimal hydrolysis conditions and 4% soybean protein isolate and 50% compound fruit puree showed the best quality. The optimal vacuum freeze-drying conditions were filling thickness of 3 mm, pre-freeze temperature between -25 and -30 ℃, dry container pressure of 40 Pa, sublimation temperature of 60 ℃, analytical temperature of 20 ℃, and analytical pressure 40 Pa.
Emulsification Properties of Alpha-Amylase Hydrolysates of Octenyl Succinic Anhydride Modified Maize Starch and Their Applications in Ice Cream
ZOU Jian,LIU Ya-wei
2011, 32(14):  337-340.  doi:10.7506/spkx1002-6630-201114073
Asbtract ( 116 )   HTML ( 0)   PDF (213KB) ( 76 )  
Related Articles | Metrics
Enzymatic hydrolysates of octenyl succinic anhydride modified maize starch with different DE (dextrose equivalent) values were prepared with α-amylase and their emulsifying capacity and emulsion stability were tested. After modification with octenyl succinic anhydride and hydrolysis with α-amylase, the emulsifying capacity of starch was substantially improved. HLB values of more than 10 could be achieved under all the tested substitution degree (SD), and the corresponding samples could be applied in oil-in-water emulsion. The combined use of the sample with a SD of 0.019 and commercial emulsion S-60 (6:4) resulted in the highest expandability of 144% and a sensory score of 20, thus providing a better ice cream emulsifier.
Application of Membrane Separation Technology Integration in Separation and Concentration of Hibiscus sabdariffa Pigments
GUO Hong,PENG Yi-jiao,LU Xiao-lian,JIA Jian-hui,TIAN Xu
2011, 32(14):  341-345.  doi:10.7506/spkx1002-6630-201114074
Asbtract ( 144 )   HTML ( 0)   PDF (333KB) ( 33 )  
Related Articles | Metrics
The integration of ultra-filtration and reverse osmosis membrane technology can provide a protection effect on Hibiscus sabdariffa pigments and improve their quality during purification and condensation process at room temperature. The optimal separation process conditions were ultra-filtration pressure of 0.3 MPa, filtration temperature of 30 ℃, flow rate of 1.375 m/s and material/liquid ratio of 1:4. Under the optimal separation conditions, the separation rates of pectin and pigment were over 96% and 90%, respectively. The permeate was condensed to 20 °Bx by reverse osmosis at 4.5 MPa and 30 ℃. The membrane cleaning method discussed in this paper can provide a promising method for separating and concentrating Hibiscus sabdariffa pigments and other natural pigments.
Optimization of Preparation Process for Peanut-milk Fresh Cheese
YOU Li-xin,YANG Liu,MA Jing-xi,CHEN Hai-yan,MA Hong,ZHANG Feng-kuan
2011, 32(14):  346-349.  doi:10.7506/spkx1002-6630-201114075
Asbtract ( 125 )   HTML ( 0)   PDF (161KB) ( 47 )  
Related Articles | Metrics
In this study, peanut milk was used to partially substitute milk during the preparation process of fresh cheese. Effects of three factors including peanut milk amount, calcium amount and curd enzyme amount were explored by o one-factor-at-a-time combined with orthogonal array design method. The results indicated that the optimal formula was peanut milk 20%, calcium chloride 0.06% and curd enzyme of 0.002%. The resultant fresh peanut-milk cheese revealed milk-white color, soft and elastic texture and peanut flavor, and the yield is 16.33%.
Processing Technology of K+ Type Lead-free Preserved Chicken Eggs
ZHANG Xian-wei,GUO Shan-guang,JIANG Ai-min,LI Yuan-zhi
2011, 32(14):  350-355.  doi:10.7506/spkx1002-6630-201114076
Asbtract ( 108 )   HTML ( 0)   PDF (852KB) ( 76 )  
Related Articles | Metrics
Fresh chicken eggs were used to prepare lead-free preserved eggs. The effect and mechanisms of KOH on pH and color of albumen and yolk as well as the texture profile analysis (TPA) of preserved chicken eggs were investigated. The results indicated that adding 5.5% KOH during the pickling process could provide excellent sensory quality and texture properties for preserved chicken eggs. This investigation can provide theoretical guidance for the manufacturing of K+ type lead-free preserved eggs.
Development of Compound Preservatives for Western-style Ham-sausages
XU Xin,HUANG Qin,YAN Yong-zhen,ZHOU Xu-xia,CHEN You-liang,LI Wei-fen
2011, 32(14):  356-360.  doi:10.7506/spkx1002-6630-201114077
Asbtract ( 166 )   HTML ( 0)   PDF (435KB) ( 51 )  
Related Articles | Metrics
Objective: To develop compound preservatives for western-style ham-sausages. Methods: A total of 10 kinds of compound preservatives were screened by bacteriostasis tests on three major spoilage bacteria in western-style ham-sausages based on pH, total volatile basic nitrogen (TVB-N) and total bacteria number. Results: The formula of compound preservative with the best fresh-keeping capacity was 0.225% Nisin, 0.225% citric acid and 0.195% lysozyme, followed by 0.375% Nisin + 0.375% citric acid and 0.375% Nisin + 1.125% potassium sorbate or 0.375% Nisin + 0.075% EDTA. Conclusion: The optimal compound preservative formula was 0.225% Nisin, 0.225% citric acid and 0.195% lysozyme.