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Table of Content

15 August 2010, Volume 31 Issue 15
Basic Research
pH and Thermal Stability of a Polysaccharide Fraction from Plantago asiatica L. Seeds
YIN Jun-yi,NIE Shao-ping*,LIN Hui-xia,LI Chang,XIE Ming-yong
2010, 31(15):  1-3.  doi:10.7506/spkx1002-6630-201015001
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In this study, the effect of acidic and alkaline treatments on the monosaccharide composition, apparent viscosity and granularity on a polysaccharide fraction (detected to contain a single component) purified from Plantago asiatica L. seeds. Meanwhile, the thermal stability of the polysaccharide fraction was analyzed using thermal gravity-differential thrermal analysis (TG-DTA). The results showed that acidic and alkaline treatments both had certain effect on the apparent viscosity and monosaccharide composition of the polysaccharide fraction. After acidic treatment (approximately pH 2.7), the apparent viscosity and average granularity diameter of the polysaccharide fraction both increased, but the xylose/arabinose molar ratio changed little. However, alkaline treatment (approximately pH 11.4) resulted in a decrease in apparent viscosity, average granularity diameter and xylose/arabinose molar ratio. Heating followed by cooling resulted in an increase in average granularity diameter. The TG-DSC analysis showed that the polysaccharide fraction began to degrade at 250 ℃ and the degradation ended at 550 ℃.

Purification and Activity of an Antifungal Peptide from the Seeds of Tartary Buckwheat (Fagopyrum tataricum)
BAI Cheng-zhi,WANG Zhuan-hua*,LI Yu-ying
2010, 31(15):  4-7.  doi:10.7506/spkx1002-6630-201015002
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An antifungal peptide (AFP) having the ability to protect organisms against fungal invasion was isolated from tartary buckwheat (Fagopyrum tataricum) seeds. The purification procedure involved extraction with 20 mmol/L Tris-HCl buffer, heating treatment, Resource S cation exchange column chromatography, and size exclusion chromatography (SEC) on Superdex peptide column. The apparent molecular weight of the purified peptide was approximately 8.0 kD evaluated by Tricine-SDS-PAGE, and its actual molecular weight was 3.909 kD determined by surface-enhanced laser desorption ionization- time of flight (SELDI-TOF). This peptide showed strong antifungal activity against Panus conchatus, Trichoderma reesei and Alternaria alternate and could cause swelling hyphal tips, hyphal distortion and condensed protoplasm in Trichoderma reesei. The easy preparation, high thermal stability and potent antifungal activity of this antifungal peptide demonstrate its great potential in food industry.

Effect of Thawing Methods on the Quality of Yellowfin Tuna Chunk
LIU Yan,WANG Xi-chang*,LIU Yuan
2010, 31(15):  8-12.  doi:10.7506/spkx1002-6630-201015003
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In order to ensure the quality of yellowfin tuna chunk after thawing, different thawing methods including air thawing at normal temperature, cold-storage thawing, warm salt-water thawing and static water thawing were used to explore their effect on the quality of yellowfin tuna chunk. Required times for thawing yellowfin tuna chunk by different methods and the changes in color, shearing force, pH, total bacterial count and sensory quality within 72 h after thawing were evaluated to address the relationships between thawing methods and the quality of tuna. Among 5 thawing methods, tuna warm salt-water thawing provided the best tuna quality. After warm salt-water thawing, the a* value, shearing force and sensory evaluation scores of the tuna were 12.30, 342.48 g and 12.80, respectively and the total viable count (TVC) within 48 h of storage was below the industrial standard threshold. Meanwhile, the color change and shearing force demonstrated better characterization of tuna quality change.

Properties of Sorghum Starches from Twenty Varieties in China
TIAN Xiao-hong,TAN Bin*,TAN Hong-zhuo,LIU Ming
2010, 31(15):  13-20.  doi:10.7506/spkx1002-6630-201015004
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Microstructure, physical, gelatinized and retrograded and thermal properties of sorghum starches from twenty varieties in China were investigated in this work. Most of the sorghum starches from twenty varieties selected in this study displayed irregular shape, concave surface and relatively bigger and uniform size of granules and some of them displayed honeycomb-like structure on the surface of granules; in contrast, the minority displayed spherical shape, smooth surface and relatively smaller size. Starch granular sizes from these varieties of sorghum ranged from 5 to 20μm. Physical, gelatinized and retrograded properties of sorghum starch exhibited remarkable differences among different varieties. Therefore, the choice of sorghum varieties should be different due to different processing purposes.

Effects of Heating Treatment and Glucono- δ-lactone-induced Acidification on the Gel Properties of Soybean Protein Isolate
YU Guo-ping,AN Jing,HAN Zong-yuan
2010, 31(15):  21-25.  doi:10.7506/spkx1002-6630-201015005
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Soybean protein isolate (SPI) was heated for different periods of time at different temperatures in order to investigate the effects of length of heating time and heating temperature on the gel strength, surface hydrophobicity, water-holding capacity of SPI. Length of heating time of 40 min and heating temperature of 90 ℃ were found optimum. Along with this, glucono-δ- lactone-induced acidification on SPI was investigated, and the optimum induction time was found to be 6 h. Also, the effect of acidification induced by different concentrations of glucono-δ-lactone followed by heating treatment under optimized conditions on the gel strength, surface hydrophobicity, water-holding capacity of SPI was explored, and the results obtained showed that glucono-δ-lactone-induced acidification resulted in significant changes in these three characteristics of heated SPI.

Application of Flaxseed Gum in Emulsion-type Sausages
WANG Hong-xia,XU Xing-lian*,ZHOU Guang-hong
2010, 31(15):  26-30.  doi:10.7506/spkx1002-6630-201015006
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Emulsion-type sausages were prepared by the use of different amounts of flaxseed gum. Cooking loss, water loss and the change in hardness of the products obtained during storage were measured. Added flaxseed gum could result in a lower cooking loss and slow down the change in hardness of emulsion-type sausages during storage; however, no obvious change in water loss was observed. The edible quality of emulsion-type sausages was significantly improved after adding 1 or 2 g/kg flaxseed gum; in contrast, added flaxseed gum at 3 g/kg exhibited a negative effect on their edible quality. Therefore, an appropriate amount of added flaxseed gum can enhance water- and oil-holding capacity, improve edible quality and attenuate the speed of starch aging. Amount of 1 g/kg was found optimum.

Relationships between Amylose Content and Gelatinization Characteristics of Different Varieties of Millet
LIU Hui,ZHANG Min*
2010, 31(15 ):  31-33.  doi:10.7506/spkx1002-6630-201015007
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Rapid visco analyzer was used to analyze the RVA spectra of 27 millet varieties and correlations among RVA eigenvalues were explored. The results showed that there was a significant difference in RVA eigenvalues among different millet varieties. The measurement of millet attenuation values provided an effective discrimination for 27 millet varieties. Amylose content was negatively correlated with attenuation values but positively correlated with retrogradation values. Therefore, RVA determination combined with amylose content provides a good approach for the identification of millet quality.

Effect of Heating Time on Starch Properties and Content of Resistant Starch in Rice
ZHAO Na,YANG Chao,TIAN Bin-qiang,SUN Zhi-da*,XIE Bi-jun
2010, 31(15):  34-38.  doi:10.7506/spkx1002-6630-201015008
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In this work, rice was subjected to heating treatment for different time periods. Rice starch was extracted from heated rice and used to explore the effect of heating time on its granular morphology, thermomechanical properties, gel characteristics and rheology behavior measured using SEM, DSC, texture analyzer and rheometer. Resistant starch content was determined by enzymatic hydrolysis method. With prolonged heating time, the swelling power and solubility of rice starch initially increased, followed by a decrease, and the content of resistant starch decreased by 18.01%-8.10% during 0-10 min. Starch granular morphology was converted to adhesive granules from single independent granules due to swelling. Gelatinization enthalpy value also decreased from 5.862 to 0.532 J/g. Different changes in the hardness and elongation of starch from heated rice were also observed. In addition, the shear stability of rice starch paste changed downward.

in vitro Antioxidant Activity of Ethanol Extract of Maca (Lepidium meyenii Walpers) Cultivated in Yunnan
HE Zhao,FENG Ying*,XU Long-feng,SUN Long,SHI Lei,CHEN Xiao-ming,ZHANG Zhong-he
2010, 31(15):  39-43.  doi:10.7506/spkx1002-6630-201015009
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The total antioxidant activity (TAC) of ethanol extracts of different color types (white, yellow and purple) of maca (Lepidium meyenii Walpers) cultivated at different altitude areas (2000, 2500, 3000 m and 3200 m) in Yunnan was measured by ferric reducing antioxidant power (FRAP) assay. Also, their scavenging activities against hydroxyl free radicals generated from Fenton reaction, DPPH free radicals and superoxide anion free radicals by a pyrogallol autooxidation system were evaluated. The results indicated that ethanol extracts of 3 color types of maca cultivated in Yunnan all had dose-dependent total antioxidant and free radical scavenging effects. Purple maca presented the highest TAC, followed by yellow and white macas. The DPPH free radical scavenging activity of white maca was lower than those of other two color types of maca. A higher TAC and a higher DPPH free radical scavenging activity were both observed in maca cultivated at 3200 m-altitude area than that from lower altitude areas. Three color types of maca were all able to remarkably scavenge hydroxyl radicals, with a scavenging ratio of more than 90% at a dose of 200 μL and yellow maca cultivated at 3000 m-altitude area had the best hydroxyl free radical scavenging activity. Three color types of maca all had only weak scavenging effect on superoxide anion free radicals.

Enzymatic Synthesis of Caprylic Caprylate in an Organic Solvent
ZHANG Feng-xiu1,ZHANG Guang-xian2,*
2010, 31(15):  44-49.  doi:10.7506/spkx1002-6630-201015010
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The synthesis of caprylic caprylate catalyzed by lipase from porcine pancreas in an organic solvent was carried out to explore the effects of organic solvent type, reaction temperature, amount of added water, reaction time, lipase amount, substrate concentration and caprylic acid-to-caprylic alcohol ratio on caprylic acid conversion. The optimum organic solvent for caprylic caprylate synthesis was n-hexane. Reaction temperature of 45 ℃, amount of added water of 29μL, caprylic acid-tocaprylic alcohol ratio of 1:1.2-1:1.5, caprylic acid concentration of 0.23-0.33 mol/L, lipase concentration of 2.314 g/L were found optimum. Under these optimized conditions, the conversion ratio of caprylic acid was 98.12%. In addition, the structure of synthesized product was characterized by IR, 1H NMR and 13C NMR. This synthesis method can yield a high conversion ratio of caprylic acid under mild reaction conditions.

Optimization of Square-wave Electroporation for Increasing the Permeability of Yeast Cells
JI Zhao-jun,SUN Bo*,CHI Yu-jie,XU Ning
2010, 31(15):  50-54.  doi:10.7506/spkx1002-6630-201015011
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Yeast (Saccharomyces cerevisiae CICC 1012) cells were statically cultured in YEPD medium at 30 ℃ for 24 h and then separated by centrifugation at 3000 r/min after the end of culture and suspended in an electric pulse medium (containing sucrose, Tris-HCl and MgCl2, at pH 7.5) at a cell concentration of 1×108 CFU/mL before square-wave electric pulse treatment under different operating conditions. Electric field strength of 7 kV/cm, pulse duration of 50μs, pulse number of 14, time interval of 2 s, and sucrose concentration of 0.6 mol/L were found optimum. The percentage survival of yeast cells was 81.16% and the percentage of electroporated yeast cells was 65.14% under these optimum conditions. This study suggests that the permeability of yeast cells can be increased by square-wave electroporation.

Kinetics and Optimization of Porcine Pancreatic Lipase-catalyzed Hydrolysis of Prickly Ash Seed Oil
XU Huai-de,TANG Ju,LIU Li-fang
2010, 31(15):  55-59.  doi:10.7506/spkx1002-6630-201015012
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In order to exploit α-linolenic acid from prickly ash seed oil, the hydrolysis characteristics of prickly ash seed oil by porcine pancreatic lipase were investigated and some key hydrolysis conditions were explored. The results indicated that an equation expressing oil-water interface (αt) with respect to reaction temperature (t), agitation speed (ω) and substrate concentration (S) was developed as follows: αt= 0.04ω 0.577t1.242S (1 + 0.02S). The change in hydrolysis reaction rate with varying reaction temperature obeyed Arrhenius equation. The activation energy was 21.891 kJ/mol. Based on Michaelis-Menten equation and the effect of αt on reaction rate, a kinetic model was established to describe the hydrolysis of prickly ash seed oil by porcine pancreatic lipase. The optimal hydrolysis conditions of prickly ash seed oil by porcine pancreatic lipase were reaction temperature of 50 ℃, oil concentration of 30%, enzyme concentration of 72.9 g/L and reaction time of 4 h. The dgree of hydrolysis reached up to 57.13% under these optimal conditions.

Methods for the Evaluation of Biscuit Crispy
JIANG Song,JIA Yu,SHI Ji-yong,LIU Rui-xia,ZHAO Jie-wen
2010, 31(15):  60-63.  doi:10.7506/spkx1002-6630-201015013
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The aim of this work was to establish a method for the evaluation of biscuit crispy. A texturometer (TA.XT2i, SMS, UK) was used to carry out puncturing tests and an optimum probe was screened out of P0.25S ball-shaped probe as well as P3 and P6 column-shaped probes. The relationship between the rupturing state and the number of spatial rupture (Nsr) of biscuits was analyzed. Meanwhile, comparison among puncturing, TPA and three-point bending tests used to  easure biscuits with varying moisture contents was made. The optimal puncturing probe was found to be P0.25S; the rupturing distance in the formula for calculating Nsr was the distance in the force versus distance curve at the force of zero; the correlation coefficient (R2) between Nsr and moisture content was 0.9763. Therefore, puncturing method is superior to other two methods and Nsr can used to characterize the crispy of biscuits.

An Optimum Protease for the Hydrolysis of the Residue Left after High Pressure Cooking of Chicken Bone
XIE Zheng-jun1,2,LIU Yan2,SHEN Jing2,CHI Mei-ling2,JIN Zheng-yu1,2
2010, 31(15):  64-67.  doi:10.7506/spkx1002-6630-201015014
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Four proteases, i.e, flavourzyme, neurase, alcalase and papain, were individually used to hydrolyze the residue left after high pressure cooking of chicken bone. The time courses of degree of hydrolysis (DH) of the residue by the proteases were plotted and the sensory characteristics and amino acid composition of the hydrolysates were analyzed. Flavourzyme had better hydrolysis effectiveness than other 3 proteases. The maximum DH of the residue by flavourzyme was measured to be 23.15%. The hydrolysate derived from flavourzyme hydrolysis was good in clarity and had strong chicken flavor. A total of 7 essential amino acids were detected in the hyrolysate, representing 68.90% of the total amino acids. The amino acids responsible for the chicken flavor of the hydrolysate were Glu, Gly, Asp and Arg, respresenting 5.09%, 1.40%, 2.59% and 10.45% of the total amino acids, respectively.

An Intellectual Rating System for Pork Freshness
GUO Pei-yuan,BI Song,YUAN Fang
2010, 31(15):  68-72.  doi:10.7506/spkx1002-6630-201015015
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Ammoniacal odor, hydrogen sulphide odor, hue, saturation and brightness in the collected image, the number of adipocytes and bacterial plaque of pork reflecting its freshness were measured. A backpropagation (BP) neural network structure, in which TVB-N value was the output and the above 7 non-coherent parameters composed the input was established. Based on this, a SOM network structure, in which TVB-N value was the input, was established for the cluster analysis of TVB-N values collected during pork spoilage and 5 TVB-N value based pork freshness rates were obtained. The rating results were in accordance with the national standard and those from sensory evaluation. This demonstrates high reliability of this rating method.

Anti-microbial Activity of Ethanol Extract from Asparagus officinalis Peel
FENG Cui-ping,ZHANG Pei-yi,ZHANG Shuai,LI Ling-ling
2010, 31(15):  73-75.  doi:10.7506/spkx1002-6630-201015016
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Oxford cup method was used to measure the anti-microbial activities of ethanol extract from Asparagus officinalis peel against Staphylococcu saureus, Eschrichia coli, Bacillus subtilis, Shigella, Salmonella and Penicillium, Mucor and Aspergillus niger. The results indicated that all these microorganisms were effectively inhibited by the extract and the antibacterial activity was much better than the anti-mold activity. The minimum inhibition concentration (MIC) was 1 g/100 mL for Staphylococcu saureus and 5 g/100 mL for other 4 bacterial species. The antibacterial effect was in a concentration-dependent manner. The MICs were 10, 30 g/100 mL and 40 g/100 mL for Penicillium, Mucor, and Aspergillus niger, respectively.

Purification and Identification of Peanut Allergen Ara h 6
LUO Chun-ping1,2,3,GAO Jin-yan4,HU Chun-qiu1,2,CHEN Hong-bing1,2,*,YAN Fei2,3
2010, 31(15):  76-80.  doi:10.7506/spkx1002-6630-201015017
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In order to effectively isolate and purify peanut allergen Ara h 6, peanut was subjected to a series of sequential treatments, namely de-fatting, protein extraction and anion-exchange chromatographic. Sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-PAGE), matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS) and Western blotting were used for the identification of target protein. The results indicated that the purified target protein was peanut allergen Ara h 6 with a molecular weight of 15 kD. The purity of Ara h 6 was more than 95%, and the recovery rate was 22.5%. Based on these investigations, a simple and efficient approach to purifying Ara h 6 is achieved, which will provide experimental materials for further research on peanut allergy.

Effect of Exogenous Enzymes on Shortening Ripening Period of Fermented Mutton Sausage
YANG Hua1,ZHANG Lin1,MA Li-zhen2,*,ZHU Ying-chun1
2010, 31(15):  81-86.  doi:10.7506/spkx1002-6630-201015018
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The effects of lipase, acidic protease and flavor protease on shortening ripening period of fermented mutton sausage were investigated. The optimal combination of enzymes was determined by using three-factor quadratic rotational composite design. Physicochemical index and sensory index of fermented mutton sausage with added exogenous enzymes were measured. The optimal amounts of three enzymes were found to be: 0.0022% lipase, 0.0011% acidic protease and 0.0027% flavor protease. On the 14th day of ripening, the contents of free fatty acids and non-protein nitrogen in the protease-treated group was 1.437% and 0.647%, respectively, which had no significant difference with those of the control group on the 35th day (P>0.05). Throughout the whole ripening period, TVB-N and thiobarbituric acid (TBA) exhibited no significant difference between the protease-treated group and the control group (P>0.05). In addition, similar sensory quality was observed in the proteasetreated group on the 21st day and the control group on the 35th day. Therefore, addition of exogenous enzymes can reduce the required ripening period of fermented mutton sausage by 40%.

Effects of Phytic Acid and Phenolic Compounds on the in vitro Digestibility of Milk Proteins
LIN Hai-wei1,ZHAO Yang-yang1,OU Shi-yi1,*,DU Shu-xia1,2,HUANG Cai-huan1
2010, 31(15):  87-90.  doi:10.7506/spkx1002-6630-201015019
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Pure milk samples with separately added phytic acid and phenolic compounds such as ferulic acid, tannin, salicylic acid and p-hydroxybenzoic acid at different levels were subjected to standing at normal temperature for 1 h or sterilization at 121 ℃ for 20 min followed by cooling to the normal temperature prior to pepsin hydrolysis in order to investigate the effects of phytic acid these phenolic compounds on the in vitro digestibility of milk proteins. The results indicated that all these compounds added alone resulted in a decrease in digestibility of milk proteins by 5%-27%. Prolonged length of standing time after cooling to the normal temperature (in the case of milk samples subjected to sterilization) resulted in a higher protein digestibility. Moreover, with increasing pepsin concentration, protein digestibility in vitro increase by 1%-9%.

Isolation, Purification and Anti-tumor Activity of a Polysaccharide, IOP3a from Inonotus obliquus
CHEN Yi-yong1,2,GU Xiao-hong1,TANG Jian1
2010, 31(15):  91-94.  doi:10.7506/spkx1002-6630-201015020
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Water extraction and deproteinization by Sevag method were carried out for the preparation of a crude polysaccharide extract from Inonotus obliquus, named IOP. IOP was subjected to sequential treatments with DEAE-Sepharose CL-6B anion exchange, Sepharose CL-6B and Sephadex G-200 columns for purification purpose and a polysaccharide fraction, named IOP3a, was obtained, which was identified to contain a single composition. The inhibitory effect of IOP3a on the proliferation of Jurkat and Daudi tumor cells in vitro was evaluated by MTT assay. It was found that IOP3a had an obvious anti-tumor activity in a dose-dependent manner in vitro (P < 0.01) and that the maximum inhibitory ratio of IOP3a on Jurkat and Daudi tumor cells were 71.84% and 75.14%, respectively.

Effect of Wall-free Cells of Yeast on Lipid Oxidation and Flavor of Silver Carp Surimi
FU Xiang-jin1,2,HE Hai-xiang3,XU Shi-ying2,LI Zhong-hai1, HU Ye-bi1, ZHANG Hui1
2010, 31(15):  95-99.  doi:10.7506/spkx1002-6630-201015021
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Suspension of wall-free cells of different types of yeast (brewers yeast, grape wine yeast, Saccharomyces cerevisiae and braker s yeast) prepared by snailase hydrolysis was used to treat silver carp surimi in order to examine its effect on lipid oxidation and flavor of silver carp surimi using chemical analysis, sensory evaluation and gas chromatography-mass chromatography. The results indicated that the suspension wall-free cells of grape wine yeast could more significantly inhibit lipid oxidation in silver scarp meat in comparison with brewers yeast, Saccharomyces cerevisiae and braker s yeast. The thiobartiburic acid reactive substance (TBARS) in silver scarp meat was quickly eliminated within 2 h period from 2.4 to 0.8 mg/kg with a rate of 0.8 mg/ (kg·h) at 25 ℃. Although traditional water-washed surimi retained severe fishy odor, it could be almost removed after treatment with the suspension. The contents of 2-decenal and 2, 4-decadenal as the major components responsible for fishy odor were under the detection limit (0.48 mg/kg) in surimi after treatment with the suspension. Therefore, wall-free cells of wine yeast have excellent effect on the removal of fishy odor from silver carp surimi.

Isolation, Purification and Monosaccharide Analysis of a Neutral Polysaccharide from Polygonatum odoratum (Mill) Druce
WANG Qiang1, LI Sheng-yu2,YANG Fan1,LIU Chun-ming1,*
2010, 31(15):  100-102.  doi:10.7506/spkx1002-6630-201015022
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Crude polysaccharides were obtained from Polygonatum odoratum (Mill) Druce by water extraction and ethanol precipitation, and were sequentially purified by ion exchange chromatography on DEAE-cellulose column and gel permeation chromatography on Sepharose CL-6B column and a neutral polysaccharide fraction was obtained. Its structure was determined using HPLC, FTIR and UV spectroscopy. The results showed that the polysaccharide fraction was mainly composed of mannose and glucose at a molar ratio of 5:1 and also contained a small amount of galactose and that its molecular weight was approximately 1.21 × 106 D.

Effect of Sequential Additions of Raw and Subsidiary Materials on the Quality of Emulsion-type Chicken Sausages
FU Qing-quan1,ZENG Hua1,XU Bao-cai2
2010, 31(15):  103-106.  doi:10.7506/spkx1002-6630-201015023
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In this work, chicken breast meat and chicken skin were used as raw materials to produce emulsion-type chicken sausages with the additions of some subsidiary materials. Five addition sequences for raw and subsidiary materials were designed for emulsion-type chicken sausage production and the products obtained were evaluated for their water-holding capacity, textural characteristics (analyzed by sensory evaluation and instrumental measurements, namely TPA compression and W-B shearing) and microstructural properties. Chicken sausages produced through the sequential steps of lean protein extraction, fat emulsification, chopping and mixing of seasonings, starch and ice water mixing has the best water-holding capacity, textural and microstructural characteristics. Multiple comparisons on TPA and W-B tests also exhibited a significant difference among chicken sausages produced based on different sequential additions of raw and subsidiary materials.

Microwave-assisted Extraction Kinetics and Thermodynamics of Pectin from Lemon Peel
ZHANG Kai,HUANG Guo-lin*,CHEN Zhong-sheng,HUANG De-juan,FU Na-na
2010, 31(15):  107-111.  doi:10.7506/spkx1002-6630-201015024
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The kinetic and thermodynamic mechanisms of the extraction process of pectin from lemon peel using 1-butyl-3- methylimidazolium chloride aqueous solution as extractant under microwave assistance were investigated. Based on the theory of Fick s second law, a dynamic model of pectin extraction was deduced by using the method of isolated variables and rate constantk, activation energy Ea, enthalpy change ΔH0, entropy change ΔS0 and free energy change ΔG0 were calculated. This model provides a valuable theory basis for the selection of optimum technological conditions for pectin extraction.

Nutritional Composition Analysis of Meat from Yak and Yellow Cattle in Sichuan
QIU Xiang1,ZHANG Lei1,WEN Yong-li1,*,WANG Jian-wen2, LIU Lu-shu1, MA Li1, WU Xian-zhi3,JIN Jie-ru1
2010, 31(15):  112-116.  doi:10.7506/spkx1002-6630-201015025
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Analysis of nutritional components including crude protein, crude fat, minerals and amino acids determined by relevant national standard methods was made for the meat from Xuanhan cattle, Pingwu cattle, Chuannan cattle, Ebian cattle, Jiulong yak and Maiwa yak of 3–4 years old in Sichuan. Multivariate analysis and LSD multiple comparisons were conducted using SPSS software. The results showed that nutrition components except Cu and histidine in the meat of different varieties of cattle and yak exhibited significant difference (P < 0.05) or extremely significant difference (P < 0.01). Maiwa yak, Jiulong yak and Xuanhan cattle had excellent quality characteristics of meat. Protein, Ca, P, Fe, Mn, Zn and four kinds of essential amino acids including Val, Leu, Ile and Arg and one kind of nonessential amino acid, Cys in Maiwa yak meat were relatively higher; Mn, Zn and three kinds of nonessential amino acids including Gly, Ala and two kinds of essential amino acids including Thr and Arg in Jiulong yak meat were also relatively higher; higher contents of fat, P, Zn, six nonessential amino acids including Asp, Glu, Ser, Tyr, Ala and Met, 3 essential amino acids including Lys, Phe and His, total essential amino acids and total amino acids were observed in Xuanhan cattle meat.

Emulsify Capacity and Stability of Cross-linked Casein with Polyphenol Oxidase from Agaricus bisporus
WU Jin-ju1,2,GAO Jin-yan1,3,LIU Xiao1,2,CHENG Wei1,2,CHEN Hong-bing1,2,*
2010, 31(15):  117-120.  doi:10.7506/spkx1002-6630-201015026
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Cross-linking of food proteins can modify their functional properties. Casein was cross-linked by polyphenol oxidase from Agaricus bisporus. The emulsifying capacity and emulsion stability of cross-linked casein were analyzed and SDS-PAGE was used to detect the amount of polymer formation. The emulsifying capacity and emulsion stability of cross-linked casein obtained after polyphenol oxidase treatment at 25 ℃ and an enzyme concentration of 400 U/mL for 4 h were 18.3 m2/g and 19.8 min, 17.3% and 37.5% higher than those of non-cross-linked casein, respectively. Such significant increments in both emulsifying properties might be tightly related to the amount of formed cross-linked casein.

Using ESR for Measuring DPPH Free Radical Scavenging Activity of Gingerol Oleoresin
GE Qing-feng,SONG Ming-jun,GU Lin*
2010, 31(15):  121-125.  doi:10.7506/spkx1002-6630-201015027
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This study investigated the use of ESR for measuring the scavenging effect of gingerol oleoresin on DPPH free radicals. DPPH free radicals could not be detected after 5 min exposure to half molar amount of gingerol, an antioxidant component contained in gingerol oleoresin. The percentage of scavenged DPPH free radicals was 50% when the molar ratio of gingerol to DPPH free radicals was 1:4.

Effect of a Combination of Polyphenolic Extracts from Herba Gei and Herba Lysimachiae on Antioxidant Stability of Kiwifruit Juice
OUYANG Yu-zhu1,WU Dao-hong1,HU Ming-hao1,CHEN Gong-xi2
2010, 31(15):  126-129.  doi:10.7506/spkx1002-6630-201015028
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Polyphenolic extracts from Herba Gei and Herba Lysimachiae were blended and added to kiwifruit juice in order to explore the effects of their presence on the peroxide value of kiwifruit juice exposed to ultraviolet light, temperature or hydrogen peroxide using BHT as control. In addition, the effect of volume ratio between the two polyphenolic extracts on the peroxide value of kiwifruit juice was also investigated, and the abilities of their blends at different ratios to scavenge hydroxyl free radicals were assessed. After thermal treatment at 90 ℃for 6 h, the peroxide value of kiwifruit juice added with a blend of polyphenolic extracts from the two species of plants at 1:1 was 8.55% and 24.57% lower than those of blank kiwifruit juice and kiwifruit juice added with BHT. When thermal treatment at 90℃ for 6 h was replaced by 0.5% hydrogen peroxide oxidation and ultraviolet light illumination for the same period of time, 9.08% and 1.83% decreases in the peroxide value of kiwifruit juice were achieved by replacing BHT with a blend of polyphenolic extracts from the two species of plants at 1:1 and the peroxide values of kiwifruit juice added with the blend were 17.55% and 3.57% when compared with blank kiwifruit juice. The blend of polyphenolic extracts from Herba Gei and Herba Lysimachiae at a volume ratio of 3:1 presented the highest antioxidant effect and its hydroxyl free radical scavenging ratio was 1.37 times higher than that of BHT. The presence of the blend with the highest antioxidant effect resulted in 56.27% decreases in the peroxide value of kiwifruit juice when compared with the presence of blank, respectively.

Optimum Mixing Ratio for Water Extract from Flos Sophorae Immaturus and Ethanol Extract from Radix Glycyrrhizae for Protection of Processed Foods against Lipid Oxidation and Antioxidant Properties of the Mixture
ZHANG Feng-qing1,HOU Jun1,LI Zi-yi2
2010, 31(15):  130-134.  doi:10.7506/spkx1002-6630-201015029
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Soybean oil was used to investigate the optimization of mixing ratio (m/m) for the water extract from Flos Sophorae Immaturus and the ethanol extract from Radix Glycyrrhizae for the protection of processed foods against lipid oxidation. Both the extracts were analyzed qualitatively by thin layer chromatography and IR spectroscopy and HPLC was employed for quantification. The antioxidant properties of a mixture of both the extracts having the best protective effect against lipid oxidation in soybean oil were evaluated by superoxide anion free radical scavenging assay and DPPH free radical scavenging assay and investigation of the protection of Cantonese-style moon cake against oxidation by the use of it was conducted. The optimum mixing ratio for both the extracts was 1:1. Rutin and glycyrrhizin were detected in the water extract from Flos Sophorae Immaturus and the ethanol extract from Radix Glycyrrhizae, respectively. IR spectroscopic analysis demonstrated that both the extracts contained molecules in which the phenolic hydroxyl group was associative type. The contents of rutin and glycyrrhizin in the mixture of both the extracts at 1:1 were determined by HPLC to be 76.8% and 0.46%, respectively. At a concentration of 1.5 g/L, the scavenging ratio of the mixture against superoxide anion free radicals was as high as 67.64%, and its DPPH free radical scavenging ratio at 10 mg/mL reached up to 62.88%. The shelf-life of Cantonese-style moon cake could be prolonged to around a month by the use of the mixture.

Stability of the Red Pigment from Brassica campestris L.
LI Wei1,2,ZHANG Yun1
2010, 31(15):  135-138.  doi:10.7506/spkx1002-6630-201015030
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Objective: The effects of different environmental conditions on the stability of the red pigment from Brassica campestris L. were studied. Methods: The stem bark of Brassica campestris L. was extracted with 75% acidic alcohol, pH 2. The red pigment obtained was scanned in the range of 400-700 nm and its stability under different environmental conditions was reflected by absorbance values at maximum absorption wavelengths. Results: The red pigment had good thermal stability and could endure high temperature. It was greatly affected by pH and presented good stability under low acidic conditions. H2O2 and VC could make the red pigment fade, but sugar could improve its stability. Fe3+ had hypochromic effect on the red pigment, while Na+, Cu2+, Ca2+, Mg2+ and Al3+ had hyperchromic effect.

Methylation of (-)-Epigallocatechin-3-gallate (EGCG)
LU Hai-peng,SUN Ye-liang,LIN Zhi*,TAN Jun-feng,GUO Li
2010, 31(15):  139-142.  doi:10.7506/spkx1002-6630-201015031
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For EGCG methylation via chemosynthesis, methyl iodide was used as methyl donor and two reaction systems (No.1 and No.2) were designed, in which the molar ratios between EGCG and methyl iodide were set at 1:80 and 1:1, respectively. Reaction products TRI-1 and TRI-2 obtained from reaction system No.1 and No.2, respectively were characterized by HPLCMS and NMR. The results showed that the molecular modification of EGCG could be successfully accomplished by the use of chemosynthesis, and five EGCG derivatives, namely 4″-Me-EGCG, 4′,4″-di-Me-EGCG, 5,3′,4′,5′,3″,4″,5″-hepta- Me- EGCG, 5,7,3′,4′,3″,4″,5″-hepta- Me-EGCG and 5,7,3′,4′,5′,3″,4″,5″-octa- Me-EGCG were identified in the two reaction products, of which, 3 were contained in reaction product TRI-1 and 2 in reaction product TRI-2.

in vitro Antioxidant Effect of Ethanol Extract from Gongshui White Pomelo Peel
WANG Wei1, ZUO Shuang-hai1,CHENG Chao1,2,*
2010, 31(15):  143-148.  doi:10.7506/spkx1002-6630-201015032
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In this study, the in vitro antioxidant effect of the 80% ethanol extract from Gongshui white pomelo peel was assessed and compared with those of the 80% ethanol extract from ponkan peel, VC, propyl gallate (PG). The results were showed that the scavenging abilities of the 80% ethanol extract (supernatant) from ponkan peel, VC and PG against hydroxyl free radicals trapped with salicylic acid were 5.515 and 1.320 times higher and 0.428 lower than that of the 80% ethanol extract (supernatant) from Gongshui white pomelo peel, while the freeze dried crystal of 80% ethanol extract from ponkan peel, VC and PG were 17.407 and 1.586 times higher and 0.514 times lower than that of the freeze dried crystal of 80% ethanol extract from Gongshui white pomelo peel, respectively. The scavenging abilities of the 80% ethanol extract from ponkan peel, PG and VC against hydroxyl free radicals generated in Fe2+/H2O2 reaction system were 18.416, 4.820 and 1.716 times higher than that of the 80% ethanol extract from Gongshui white pomelo peel, and the hydroxyl free radical scavenging abilities of the freeze dried crystal of 80% ethanol extract from ponkan peel, PG and VC were 6.589, 3.609 and 1.285 times higher than that of the freeze dried crystal of 80% ethanol extract from Gongshui white pomelo peel, respectively. In superoxide anion free radical scavenging ability, the 80% ethanol extract from ponkan peel, PG and VC were 13.941, 1.059 and 2.442 higher than the 80% ethanol extract from Gongshui white pomelo peel and the freeze dried crystal of 80% ethanol extract from ponkan peel, PG and VC were 5.908, 1.471 and 3.392 times higher than the freeze dried crystal of 80% ethanol extract from Gongshui white pomelo peel. The 80% ethanol extract from Gongshui white pomelo peel had the potential to reduce ferric ions, but its reducing power was weaker than those of 80% ethanol extract from ponkan peel, VC and PG.

Evaluation on the Proteolysis of a Surface Mucor-ripened Cheese during Ripening
ZHANG Na1,2,ZHAO Xin-huai1,*
2010, 31(15):  149-158.  doi:10.7506/spkx1002-6630-201015033
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A strain of Mucor was isolated from mao-tofu originated from in China and smeared on the surface of fresh cheese. The proteolysis occurring during cheese ripening was studied. The pH of the cheese was increased during 90 d ripening. The indexes of proteolysis, such as ratios of water-soluble nitrogen (WSN) fraction, pH 4.6-soluble nitrogen (pH 4.6-SN) fraction and 12 g/100 mL trichloroacetic acid-soluble nitrogen (12 g/100 mL TCA-SN) fraction to total nitrogen in the external zone of cheese, were elevated to be (23.68±1.07)%, (19.38±1.32)% and (8.61±0.85)%, respectively after 90 d of ripening, slightly higher than those in the central zone. SDS-PAGE and capillary electrophoresis were employed to analyze the pH 4.6-insoluble nitrogen (pH4.6-ISN) fraction of cheese and it was found that casein was degraded during ripening. Peptide profiles of the water-soluble nitrogen fraction separated from cheese were analyzed by reverse phase-high performance liquid chromatography (RP-HPLC) and the results also indicated that the proteolysis occurred and some new peptides were produced.

Effects ofβ-Conglycinin and Glycatedβ-Conglycinin on the Thermal Aggregation of Glycinin
SUN Wei-wei,YU Shu-juan*
2010, 31(15):  159-162.  doi:10.7506/spkx1002-6630-201015034
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The effects of β-conglycinin and glycated β-conglycinin on the thermal aggregation of glycinin was studied. Evidence was presented to suggest that β-conglycinin and glycated β-conglycinin could both prevent thermal aggregation of glycinin in 30 mmol/L Tris-HCl buffer solution (β-Me exsisted). Further, addition of glycatedβ-conglycinin prevented thermal aggregation of glycinin more obviously than β-conglycinin. The results also indicated that the inhibitory mechanism of glycated β-conglycinin on glycinin aggregation was not as same as that of β-conglycinin due to charge-charge interactions.

Preparation and Separation of ACE Inhibitory Hydrolysates from Rape Bee Pollen
LI Tian-jiao1,XU Xiang1,2,SUN Li-ping1,2,*,DONG Jie1,2
2010, 31(15):  163-166.  doi:10.7506/spkx1002-6630-201015035
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Four kinds of proteases were used for rape bee pollen protein enzymolysis to prepare ACE inhibitory activity hydrolysates. The ACE inhibitory activity (IC50) of enzymatic hydrolysates was determined by HPLC method. The results indicated that four hydrolysates prepared with different proteases had significantly different ACE inhibitory activities (P < 0.05). The strongest ACE inhibitory activity was observed in alkaline protease derived hydrolysate, with an IC50 of 0.35 mg/mL, followed by neutral protease, papain and acid protease derived hydrolysates. Furthermore, four rape bee pollen protein hydrolysates were applied to a Bio P-2 gel column for fractionization. Fractions with a retention time ranging from 70 to 120 min presented stronger ACE inhibitory activity and statistical analysis showed that their ACE inhibition inhibitory ratios were significantly different (P<0.05). All of the corresponding fractions separated from alkaline protease derived hydrolysate had more than 90% ACE inhibitory ratio, and their molecular weight distribution varied from 376.4 to 1355 D.

Division of Antioxidant Functional Regions of Flavonoids Based on Quantum Chemistry Analysis
LIU Ben-guo1,2,YANG Ji-guo2,GUO Ye1,NING Zheng-xiang2,GAO Jian-hua2
2010, 31(15):  167-170.  doi:10.7506/spkx1002-6630-201015036
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This study focused on the position of the most active hydroxyl group, the composition of highest occupied molecular orbital (HOMO) and their relationships with the antioxidant activity of flavonoids by quantum chemistry analysis. The results showed that B ring and the hydroxyl groups on B ring made a great contribution to the antioxidant activity of flavonoids. It was concluded that molecular structure of flavonoids could be divided into three functional regions: the crucial region of antioxidant activity (B ring), the accessorial region of antioxidant activity (C ring) and the adjustable region of solubility and affinity (A ring). The division of the antioxidant functional regions suggested that the solubility of flavonoids in either water- or oil-phase could be improved by introducing hydrophilic and hydrophobic groups to A ring, which could make flavonoids fully play their antioxidant activity.

Bioengineering
Cloning of Glucose Isomerase Gene from Actinoplanes missouriensis and Its Expression in Escherichia coli
WANG He1,2,YANG Rui-jin2,*,HUA Xiao2,QIAN Ting-ting1,ZHANG Wen-bin2,JIANG Xiao-yan2
2010, 31(15):  171-176.  doi:10.7506/spkx1002-6630-201015037
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The xylA gene encoded glucose isomerase (GI) was amplified from genomic DNA of A. missouriensis CICIM B0118 (A) by Slowdown PCR and subcloned into the expression vector pET-28a(+) to obtain an N-terminus His-tagged fusion expression plasmid pET-28a(+)-xylA. pET-28a(+)-xylA was then transformed into E. coli BL21 (DE3). The recombinant protein was actively expressed in E. coli BL21 (DE3) in the presence of isopropy-β-D-thiogalactoside (IPTG). SDS-PAGE analysis showed that the partially purified recombinant protein exhibited a major band with an apparent molecular weight of 45 kD in, which was consistent with the molecular weight calculated from the amino acid sequence. When the induction conditions were time 9h, IPTG 0.6mmol/L, temperature 30℃ and OD600nm 0.8, the enzyme activity of recombinant GI were 62.42 U/mL. These results can offer an experimental basis for the further investigation of directed evolution of GI into an artificial enzyme with the ability to isomerize lactose into lactulose.

Isolation, Purification and Solubility of Antibacterial Substances from Fermentation Supernatant of Marine Streptomyces parvus DY2741
LIU Wei1,2,XU Tao2,CAI Jing-min1,2,*,PAN Ren-rui2,WU Ying3
2010, 31(15):  177-180.  doi:10.7506/spkx1002-6630-201015038
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One aliquot of the fermentation supernatant of Streptomyces parvus DY2741 using soybean powder as substrate was vacuum dried and the residue was extracted with water or 5 different organic solvent alone. The ethyl acetate extract was found to have good inhibitory activity against both S. aureus and E. coli. Another aliquot of the fermentation supernatant was directly extracted with ethyl acetate 3 times and the extracts were then pooled and condensed in a rotation evaporator and blown to dryness under nitrogen. Finally, the residue was dissolved in methanol and filtrated before purification/fractionization on Sephadex LH-20 column. As a result, two antibacterial fractions were obtained and the second eluting peak presented stronger inhibitory activities against both bacterial species. Thin layer chromatography was used to further fractionize the fraction with higher antibacterial activity. The subfaraction displaying a clear single spot was demonstrated by gas chromatography-mass spectrometry to contain a single composition, which was preliminarily identified to be dibutyl phthalate (DBP) based on searching Wiley Registry of Mass Spectral Data and infrared spectral analysis. Therefore, DBP is one of the major antibacterial substances produced by Streptomyces parvus DY2741.

Optimization of Fermentation Conditions for Nattokinase Production in Solid-state Fermentation by Bacillus subtilis Natto Using Apple Pomace as Substrate
CANG Yi-peng1,ZHANG Hong-zhi2,DONG Ming-sheng2,*
2010, 31(15 ):  181-185.  doi:10.7506/spkx1002-6630-201015039
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On the basis of the results of one-factor-at-a-time experiments, urea concentration, water amount and calcium oxide concentration were determined to be the most important factors affecting on nattokinase production. Subsequently, response surface methodology was used to optimize these factors. The results showed that the optimal values of urea concentration, water amount and calcium oxide concentration were 2.58%, 84.06 mL and 2.65%, respectively. Under these conditions, the maximum nattokinase yield was 2150 IU/g, 27.98% higher than that obtained in one-factor-at-a-time experiments (only 1680 IU/g). The achievement of a high nattokinase activity using apple pomace, a low-cost industrial and agricultural waste as fermentation substrate demonstrates obvious economic advantages.

Production Comparison of Small Peptides in Milk Fermented by Different Strains of Lactobacillus helveticus
YIN Jie1,LU Shan-shan1,ZHANG Shao-hui1,2,GAO Yan-ling1,FU Li-na1,2,*
2010, 31(15):  186-189.  doi:10.7506/spkx1002-6630-201015040
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Three Lactobacillus helveticus strains (JCM1120, CICC6024 and L0906) were individually used to ferment fat-free milk powder. During 30 hours of fermentation, the changes in degree of hydrolysis (DH), pH and number of small peptides were examined periodically. The results indicated that CICC6024 strain had the strongest acid-producing ability and resulted in the highest maximum DH and the contents of small peptides in milk fermented by Lactobacillus helveticu CICC6024 and JCM1120 both reached their maximum amounts at 16 h; however, the fermentation activity of L0906 strain was relatively lower and still did not reach the peak at 28 h. In addition, 19 peaks with height of more than 20 mAU were observed in the RP-HPLC profile of the 16 h fermentation product of stain CICC6024. These investigations suggest that CICC6024 is an optimal strain for the production of small peptides derived from fermented milk and the optimal fermentation period is 16 h.

Identification of IgE-binding Epitopes on β-lactoglobulin
CONG Yan-jun1,REN Fa-zheng2,*,YUN Zhan-you3
2010, 31(15):  190-193.  doi:10.7506/spkx1002-6630-201015041
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A series of overlapping decapeptides (offset by five amino acids) were synthesized on the basis of the amino acid sequence of β-lactoglobulin. IgE-binding epitopes were identified using individual sera from cow milk allergic patients. In addition, we also identified critical amino acids (AAs) for IgE binding. The results showed that four IgE-binding epitopes were identified, which located in the sequences of AA 17 - 31, AA 72 - 86, AA 92 - 106 and AA 152 - 166, respectively. Threonine, methionine and aspartic acid were the critical amino acids for allergenicity of β-lactoglobulin.

Construction of Nisin-rbLF-N Fusion Gene and Its Expression in Escherichia coli
YUAN Xiao-yu1,XU Wen-tao2,HUANG Kun-lun2,LUO Yun-bo2,GU Xin-xi1,TIAN Hong-tao1,2,*
2010, 31(15):  194-197.  doi:10.7506/spkx1002-6630-201015042
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Considering that Nisin has a narrow antibacterial spectrum, rbLF-N with strong inhibitory activity against a wide range of bacteria was used to construct fusion gene Nisin-rbLF-N. The fusion gene was cloned into the expression vector pGEX- 4T1, followed by transformation into the E. coli BL21 prokaryotic expression system for protein expression under IPTG induction. The expressed protein encoded by Nisin- rbLF-N gene was detected by Tricine-SDS-PAGE protein electrophoresis and it inhibitory activities against Gram positive and negative bacteria were also assayed. A considerable amount of fusion protein was expressed in E. coli BL21 cells and the protein was mainly found in inclusion bodies. The product obtained from the inclusion bodies subjected to washing, dissolution in 8 mol/L urea and protein refolding had good inhibitory activity against Gram positive bacteria rather than their negative counterparts.

Isolation and Screening of a Gamma-Aminobutyric Acid-producing Lactic Acid Bacterial (LCB) Strain from Fresh Milk
LI Yuan-hong1,LU Feng-xia1,ZOU Xiao-kui1,LI Ying1,2,LU Zhao-xin1,*
2010, 31(15):  198-202.  doi:10.7506/spkx1002-6630-201015043
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A lactic acid bacterial strain with high γ-aminobutyric acid (γ-GABA)-producing ability, named fmbl12-4, was isolated from fresh milk. Based on the studies of morphological, physiological and biochemical characteristics and 16S rDNA sequence and phylogenic analyses, fmbl12-4 was identified as Lactococcus lactis subsp. lactis. After 24 h shake (100 r/min) incubation of the wet mycelia of fmbl12-4 in a 20-fold volume of 100 mmol/L L-monosodium glutamate solution at 30 ℃, aγ- GABA content of 82.36 mmol/L was obtained. Incubation in a MRS medium containing 25 g/L L-MSG for 6 days gave 4.68 g/L γ -GABA content.

Preliminary Investigation on the Biosynthesis of Recombinant Peanut Allergen Ara h 2
HU Chun-qiu1,2,GAO Jin-yan1,3,LUO Chun-ping1,2,CHEN Hong-bing1,2,*,ZHU Pan1,2
2010, 31(15):  203-207.  doi:10.7506/spkx1002-6630-201015044
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Ara h 2 is one of paramount allergens in peanut. The goal of the present study was to biosynthesize recombinant peanut allergen Ara h 2. Peanut cDNA was synthesized from total RNA using Oligo primers by RT-PCR in order to provide a template for the PCR amplification of Ara h 2 gene. The purified amplification products were cloned into the pMD19-T simple vector to construct a recombinant vector carrying Ara h 2 gene, named pMD19-T-Ara h 2. The recombinant plasmid was digested by Nco I and Hind III. The purified digestion products were then ligated to the pGEX-4T-1 expression vector and transformed into the BL21-codonPlus(DE3)-RIPL for 24 h expression under IPTG induction. The target product, GST-Ara h 2 fusion protein, was purified with Glutathione Sepharose 4B. The results of SDS-PAGE and western-blotting showed that GST-Ara h 2 fusion protein was 46 kD in size, with 90% purity and could specifically react with anti-Ara h 2 sera from rabbits, indicating that the recombinant protein has high specificity of immune reaction.

Contamination Pathways of Raw Chicken by Salmonella enteritidis in Slaughterhouses
LI Ji-xiang,GAO Ji-ye,TANG Yu,DING Meng-jian,ZHU Zhou-fu
2010, 31(15):  208-211.  doi:10.7506/spkx1002-6630-201015045
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Objective: To explore main contamination pathways of raw chicken by Salmonella enteritidis in slaughterhouses. Methods: The contamination of Salmonella enteritidis in raw chicken samples from different slaughterhouses was detected by polymerase chain reaction (PCR). The relationship between the contamination of raw chicken and the infection of broilers was investigated. Results: A total of 288 samples from 5 slaughterhouses were detected, and the results showed that 9.03% of them were contaminated by Salmonella enteritidis. No significant difference was observed among raw chicken samples from different slaughterhouses; however, the number of contaminated samples was positively correlated with the infection of Salmonella enteritidis during the nursery of broilers (the relative risk was 18.5). The experimental infected broilers harbored Salmonella enteritidis for 42 days and the length of bacteria excretion was approximately 56 days. Conclusion: Endogenous contamination is the predominant contamination pathway by Salmonella enteritidis in raw chicken from slaughterhouses.

Screening and Preliminary Identification of Dominant Bacteria in Chinese-style Cooked Salted Chicken
WANG Qin-dan1,LI Bai-lin1,OU Jie1,LUO Jing1,YAN Wei-ling2,*,CHEN Ping2
2010, 31(15):  212-215.  doi:10.7506/spkx1002-6630-201015046
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Based on morphological identification and gram staining, 6 microbe strains, numbered C1 through C6, were isolated from Chinese-style cooked salted chicken using Psychrophiles selective medium and the use of nutrient agar medium containing 3% NaCl allowed isolation of 4 microbe strains, numbered S1 through S4. Single colonies were separated for 16S rDNA gene amplification and sequencing. Based on the results of morphological, physiological and biochemical studies, strain C3 was identified as Staphylococcus sciuri, C6 as Klebsiella terrigena, C1, C2, C4 and C5 as Acinetobacter sp, S1 as Enterobacter gergoviae, S2 and S3 as Staphylococcus epidermidis, and S4 as Bacillus pseudomycoides.

Effects of Culture Conditions of Mycelial Pellet Formation and L-Lactic Acid Production by Rhizopus oryzae
JIANG Xue-wei1,2,LUO Xiao-ming2,SHENG Can-mei2,GAO Bi-da1,*
2010, 31(15 ):  216-220.  doi:10.7506/spkx1002-6630-201015047
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The effects of (NH4)2SO4 concentration, inoculum size, shake flask agitation speed and quantity of Tween-80 on the growht of Rhizopus oryzae mycelial pellets for L-lactic acid production were studied using shake flasks. Based on orthogonal array optimization, ammonium sulfate concentration of 4 g/L, inoculum size of 7% (V/V), shake flask agitation speed of 200 r/min and quantity of Tween-80 of 0.5 g/L were found optimum. The quantity of mycelial pelletswas up to 115 per milliliter after culture for 48 under these conditions, the average pellet diameter 1.2 mm and the yield of L-lactic acid 78.9 g/L. Our findings suggest that the grwoth of Rhizopus oryzae mycelial pellets is largely correlated with L-lactic acid production.

Preparation of Lyophilized Bifidobacterium bifidum Powder
ZHANG Fan1,2,ZHAO Min1,*,LI Lai-you1,LU Xiao-fei1,WANG Yan3,ZHANG Rui2
2010, 31(15):  221-224.  doi:10.7506/spkx1002-6630-201015048
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This study investigated the preparation of lyophilized powder of Bifidobacterium bifidum and assayed its tolerance to simulated human gastrointestinal environment and stability during storage at 37 ℃. Three methods used to prepare lyophilized powder of Bifidobacterium bifidum were described as follows: Method 1: B. bifidum strain was amplified by culturing in reconstituted milk based medium and mannitol was then added as cryoprotectant to prepare lyophilized powder; Method 2: B. bifidum strain was amplified by culturing in PTYG medium and a bacterial mud was then obtained after hypothermal centrifugation. Finally, mannitol as cryoprotectant was added to the bacterial mud to prepare lyophilized powder; Method 3: A bacterial mud obtained as described in Method 2 was added with mannitol as cryoprotectant, gelatin as embedding medium, skim milk powder as excipient to prepare lyophilized powder. The results indicated that a higher viable count was observed in the lyophilized powder prepared by Method 2, which was up to 1.31 × 1010 CFU/g and although exposed to simulated gastrointestinal environment, the lyophilized powder exhibited a viable count of up to 4.19 × 108 CFU/g, which suggests that the lyophilized powder has excellent tolerance to gastric acid and bile acid. The classic accelerated experiment proved that the lyophilized power obtained Method 2 had good stability during storage at 37 ℃ and the viable count still kept at a magnitude of 107 after storage for up to one year.

Preparation of Haptens by Two Different Methods for Immunoassay Determination of Florfenicol and Their Identification
ZHAO Peng-ling,ZHENG Hai-tao,JIANG Pan-pan,ZHU Xue-jia,HE Ji-guo*
2010, 31(15):  225-230.  doi:10.7506/spkx1002-6630-201015049
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Two hapaten synthesis methods, succinic anhydride method and alkaline hydrolysis were used for florfenicol deriviazation and the synthesized hapatens, named HP1 and HP2, were separately conjugated with BAS (bovine serum albumin) by active ester method and OVA (ovalbumin) by glutaraldehyde method to obtain two immunoagents, named HP1-BAS and HP2-BAS and two coating antigens, named HP1-OVA and HP2-OVA. HP1-BAS and HP2-BAS were separately used to immunize Balb/c mice for obtaining antisera. Antisera response to HP1-BAS and HP2-BAS were evaluated for their titers using HP1-OVA and HP2-OVA. The mass spectrometric and UV spectral characterization demonstrated that HP1 and HP2 were successfully synthesized. The coupling ratios between HP1 or HP2 and BAS or OVA were determined to be 12.4:1 (HP1-BSA), 8.5:1 (HP1-OVA), 21.8:1 (HP2-BSA) and 15.4:1 (HP2-OVA). The antiserum responses to HP1-BAS had the most specificity to HP2-OVA.

Purification and Thrombolytic Effect in vitro of a Novel Fibrinolytic Enzyme Produced by Endophytic Bacterium Paenibacillus polymyxa EJS-3
LU Feng-xia,YAO Zheng-ying,BIE Xiao-mei,ZHAO Hai-zhen,WANG Yu,GUO Yao,LU Zhao-xin*
2010, 31(15 ):  231-235.  doi:10.7506/spkx1002-6630-201015050
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Endophytes are a very important resource of microorganisms with potential application values. A novel fibrinolytic enzyme (PPFE-I) was purified from the fermentation supernatant of endophytic bacterium Paenibacillus polymyxa EJS-3 by the following procedure including ammonium sulfate precipitation, Hiprep phenyl FF hydrophobic chromatography, RESOURCEMQ ion exchange chromatography and Sephacryl S-300HR gel filtration. The apparent molecular mass of PPFE-I was estimated to be 63 kDa by SDS-PAGE analysis. The purity of PPFE-I was 94.1% determined by HPLC. Using the above procedure, 16 mg of active proteins were obtained from 1 L of the fermentation supernatant of Paenibacillus polymyxa EJS-3 and a 14.5-fold increase in the specific activity of PPFE-I was achieved and the activity recovery was 3.3%. Meanwhile, the final purified product had good thrombolytic activity in vitro.

Activity Determination and Characteristics of Malt Amylases
HE Yan-ke,HU Fei
2010, 31(15):  236-239.  doi:10.7506/spkx1002-6630-201015051
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The activities of alpha-amylase, beta-amylase and limit dextrinase in malt were measured by BPNPG7 method, PNP β-G3 method and pullulan method, respectively. Based on this investigation, the influences of temperature and pH value on the activity of the amylases were discussed and their thermal stability and hydrolysis performance were analyzed. The results showed the optimal reaction temperature for malt alpha-amylase, beta-amylase and limit dextrinase was 70, 60℃ and 55 ℃, and the optimal reaction pH values were 5.5, 5.5 and 5, respectively. The thermal stability of the alpha-amylase was better than that of two other amylases. Malt beta-amylase could retain good thermal stability at 50℃ and 55℃. Comparatively, malt limit dextrinase had poor thermal stability. In addition, these three amylases in malt presented certain relationships between activities at different reaction temperature and reducing sugar content in hydrolysis system.

Nutrition & Hygiene
Effect of Casein-glycomacropeptide on Intestinal Mucosal Immunity in Mice
LI Wei,CHEN Qing-sen*
2010, 31(15 ):  240-243.  doi:10.7506/spkx1002-6630-201015052
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In order to explore the effect of casein-glycomacropeptide (CGMP) on the intestinal mucosal immune response in normal mice, 28 female BALB/c mice were randomly divided into 4 groups for 7 mice in each group and by gavage given physiological saline (as control group) or CGMP at dosages of 30, 120μg/d and 300μg/d (low-, medium- and high-dosage groups) for 16 consecutive days. After treatment, all the mice were sacrificed and their spleen, peyer s patches and mesenteric lymph node (MLN) were collected to examine the change of CD3+, CD3+CD4+ and CD3+CD8+T lymphocytes subpopulations using flow cytometry. The results indicated that CGMP resulted in a significant increase in CD3+ and CD3+CD4+ lymphocytes in spleen and peyer s patches (P<0.05) in a dosage-dependent manner. Compared with the control group, high-dosage CGMP administration resulted in a higher percentage of CD3+CD8+ lymphocytes in spleen(P<0.05), and low-dosage CGMP administration made the CD3+CD4+/CD3+CD8+ ratio significantly (P < 0.05) increase but the percentage of CD3+CD8+ lymphocytes in MLN significantly decrease (P<0.01). The above results demonstrate that long-term gastric perfusion of CGMP can induce intestinal mucosal adaptive immune response without tolerance to its oral administration.

Anti-fatigue Effect of Sea Cucumber Stichopus japonicus in Mice
LI Bing,WANG Jing-feng,FU Jia,LI Xiao-lin,LI Hui,ZHAO Qin,XUE Chang-hu*
2010, 31(15):  244-247.  doi:10.7506/spkx1002-6630-201015053
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This paper describes the bioactive composition of cultured sea cucumber Stichopus japonicus and its anti-fatigue effect in mice. The results indicated that body wall of S. japonicus was rich in acidic mucopolysaccharides, collagen, bioactive amino acids and lipids. In comparison with the control group, administration of Stichopus japonicus for 30 consecutive days prolonged the duration of exhaustive swimming in mice weighted with weights (approximately 5% of body weight), promoted the synthesis of liver glycogen and hemoglobin and kept a level of hemoglobin 90 min post-swimming similar to that before swimming, significantly decreased the generation of blood lactic acid and accelerated the elimination of blood lactic acid and blood urea nitrogen in mice after swimming. Based on these investigations, S. japonicus has an obvious anti-fatigue effect and improves exercise endurance in mice.

Growth Inhibition Effect of Bog Bilberry Anthocyanin Extract on 3T3-L1 Preadipocytes
LIU Jia1,David G. Popovich2,JING Hao1,*
2010, 31(15):  248-252.  doi:10.7506/spkx1002-6630-201015054
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Objective: To study the inhibition effect and its mechanism of bog bilberry (Vaccinium uliginosum L.) anthocyanin extract (BBAE) on the growth of 3T3-L1 preadipocytes. Methods: MTT assay, LDH (lactate dehydrogenase) assay, flow cytometry and fluorescence microscope were used for measuring cell growth inhibition (IC50), membrane permeability, cell cycle and the morphological features of apoptotic cells, respectively. Results: BBAE effectively inhibited the growth of 3T3-L1 preadipocytes in a dosage-dependent way, with an IC50 of approximately 214μg/mL. 3T3-L1 preadipocytes showed a significant (P<0.05) lower LDH release (67.8%) after exposure to BBAE for 72 h than for 24h (89.0%) and 48 h (85.2%). No obvious improvement in the membrane permeability in 3T3-L1 preadipocytes was observed after BBAE treatment. BBAE effectively induced apoptosis of 3T3-L1 preadipocytes, significantly (P<0.05) increased cell population in the sub-G1 phase, had no significant effect in the G2/M phase and exhibited a block in the S and G0/G1 phases. After incubation for 72 h in the presence of BBAE, 3T3-L1 preadipocytes exhibited typical apoptosis features observed under fluorescence microscope.

Effect of Seven Lactobacilli Strains on the Proliferation of Mouse Spleen Lymphocytes in vitro
LI Ai-li,MA Dong-xue,MENG Xiang-chen*,WANG Jue
2010, 31(15):  253-256.  doi:10.7506/spkx1002-6630-201015055
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Objective: To evaluate the immunomodulation effect of seven Lactobacillus strains in vitro and to explore the application of mouse spleen lymphocytes in the selection of lactic acid bacteria with immunological activity. Methods: The effects of viable/heat-killed Lactobacillus strains belonging to different species at varying cell suspension concentrations on mouse lymphocyte proliferation were explored by MTT assay in vitro. Results: Either viable or heat-killed Lactobacilli alone could accelerate the proliferation of spleen cells in a dose-dependent manner. The most obvious immunomodulation effect was observed when vaiable/dead Lactobacillus strain suspension was at 107 CFU/mL (bacteria/cell ratio of 10:1) (P < 0.05). Meanwhile, the immunomodulation effect of living Lactobacillus strains was better than that of heat-killed Lactobacillus strains (P<0.05). The lymphocyte proliferation indexes (PI value) of Lactobacillus reuteri, Lactobacillus johnsoni and Lactobacillus fermentum were significantly higher than that of ConA-induced group (P<0.05). Conclusion: Spleen lymphocyte-based assay can be used as a useful primary indicator for the selection of candidate strains and an animal model for the evaluation of immunological activity.

Antioxidant Effect of Wheat Germ Oil Capsules in Mice
SONG Yu-qing1,WANG Shi-rang2,WEI Zhen-wei1,WANG Jun-guo1,YU Dian-yu2,*
2010, 31(15):  257-259.  doi:10.7506/spkx1002-6630-201015056
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Kunming healthy male mice were randomly divided into four groups, which were designated as low dose group, medium dose group, high dose group and blank control group to investigate the antioxidant effect of wheat germ oil capsules. MDA content, SOD and GSH-Px activities in liver homogenate were determined after administration of microencapsulated enzymetically extracted wheat germ oil for 30 consecutive days. The results indicated mice administered wheat germ oil capsules had a significant lower MDA content in liver homogenate and higher SOD and GSH-Px activities in comparison with those in the blank control group. Based on these investigations, wheat germ oil capsules are concluded to have in vivo antioxidant functions.

Effect of Apigenin on the Proliferation and Differentiation of 3T3-L1 Preadipocytes
YU Hua-qiang,JI Bao-ping*,LIU Jia,ZHOU Feng,GAO Feng-yi,SU Chun-yuan
2010, 31(15):  260-263.  doi:10.7506/spkx1002-6630-201015057
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Objective: To investigate the effect of apigenin on proliferation and differentiation of 3T3-L1 preadipocytes. Methods: 3T3-L1 preadipocytes were used as target cells to explore the effect of apigenin on their proliferation measured by MTT assay. Besides, cell differentiation using differentiation cocktail, oil red O staining and spectrometric determination were carried out for investigating the effect of apigenin on the differentiation of 3T3-L1 preadipocytes. Results: Apigenin at 30μg/mL and 50μg/mL concentrations could inhibit the proliferation and differentiation of 3T3-L1 preadipocytes in comparison with the blank group and the positive control group (established using Dulbecco s modified Eagle s medium containing 0.5 mmol/L IBXM, 1μmol/L dexamethasone and 10μmol/L insulin). Conclusion: Apigenin appear to have potential for the prevention of obesity.

Intervention Effect of Estrogen Combined with Pecan Oil on the Gene Expressions of Alzheimer gene -1 and Apolipoprotein E Gene in Ovariectomized Rat Hippocampus
CHEN Mo-ran1,ZHANG Wei2,SHEN Nan3,ZHAO Xing-yu4,*
2010, 31(15):  264-267.  doi:10.7506/spkx1002-6630-201015058
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Objective: To study the effect of pecan oil on the serum estrogen (E2) level and gene expressions of Alzheimer gene -1 (PS-1) and apolipoprotein E (aproE) gene and Aβ content in the hippocampus of ovariectomized rats subjected to E2 intervention. Methods: Ovariectomized female rats were used as animal model and divided into 8 groups for 8 rats in each group: groups given low dose (100 mg/kg) pecan oil alone or plus E2, separately named low-dose pecan oil group and low-dose pecan oil plus E2 group, middle-dose pecan oil group and middle-dose pecan oil plus E2 group and high-dose pecan oil group and high-dose pecan oil plus E2 group obtained similarly, control group (given only saline) and E2 group (given only E2). RT-PCR was used to detect the gene expressions of PS-1 and aproE in rat hippocampus, and radioimmunoassay to detect the level of Aβ in rat hippocampal and serum E2 level. Results: E2 intervention resulted in a significant (P<0.01) increase in serum E2 level in ovariectomized rats. The highest Aβ level was observed in the control group. Regardless of whether or not E2 intervention was adopted, Aβ level gradually decreased with increasing pecan oil dosage and a significant difference (P<0.05) was observed within both middle and high dose groups. The presence of E2 resulted in a large decrease in Aβ level in comparison with the control group, which exhibited the highest PS-1 gene expression but the lowest aproE gene expression. For rats both with and without E2 intervention, PS-1 gene expression showed only a slight decrease with increasing pecan oil dosage, while aproE gene expression markedly increased. However, at the same pecan oil dosages, E2 intervention resulted in a slight decrease in PS-1 gene expression but did not affect. The differences in aproE gene expression among these three pecan oil dosage groups disappeared. Conclusion: Both E2 and pecan oil PS-1 can attenuate PS-1 gene expression and elevate aproE gene expression so as to reduce Aβ level. Their regulatory effects on PS-1 gene might be achieved by different pathways; however, the same pathway seem to be used by them to regulate aproE gene.

Inhibitory Effect of Type II Collagen from Sheep Cartilage on Adjuvant Arthritis in Mice
LIU Yuan1,WANG Jian1,SHI Zhong-lin1,ZHANG Zhi-sheng2
2010, 31(15):  268-270.  doi:10.7506/spkx1002-6630-201015059
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Objective: To investigate the effect of intragastric administration of collagen II from sheep cartilage on the body weight and plantar thickness in mice with adjuvant arthritis. Methods: The optimal dosage of collagen II was screened using preliminary experiments. Mice were randomly divided into four groups, designated as control group (A), prevention group (B), treatment group (C) and model group (D). The body weight and plantar thickness in mice were measured at different time points before and after induction of inflammation. Results: The plantar thicknesses of groups B and C both began to markedly decrease from 12 and 14 days after inflammatory induction, respectively; the change trend of body weight initially decreased, followed by an increase. Group B was superior to group C in body weight recovery. However, body weight was inhibited but plantar thickness increased significantly after inflammatory induction in group D. Conclusion: Intragastric administration of collagen II can relieve inflammatory reaction in mice with adjuvant arthritis.

Inhibitory Effect of Triacylglycerols on Cultured Human Tumor Cells
FU Wei-chang1,2,GU Xiao-hong2,YU Hui-xin3,TANG Jian2,*,JIANG Zai-liang4
2010, 31(15):  271-277.  doi:10.7506/spkx1002-6630-201015060
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Six fractions of triacylglycerols (TGs) containing conjugated linolenic acids (CLns) were separated from the seed oil of Momordica charantia L. var. abbreviata Ser. (MCVO) and purified by non-aqueous reversed-phase (NARP)-HPLC. The cytotoxic effects of the fractions were further investigated on five human tumor cell lines: ECA-109 (esophageal carcinoma), SGC-7901 (carcinoma ventriculi), Bel-7402 (hepatoma), LS-174-T (colon carcinoma), KB (mouth epidermal carcinoma), and a human normal cell line: L02 (liver cell). α-Eleostearic acid (α-ESA) with a purity of 96% was used as a control. The results demonstrated that the inhibitory effects of the TG fractions on human tumor cell lines were more potent than that of α-ESA, and the effect of TG with three CLns was the weakest. These results suggest that the fatty acid compositions and molecular structures of the TG with more intense stability, which contain CLn, might affect the displayed cytotoxicity to human tumor cell lines.

Immunoregulatory Effects of Sulfurized, Desulfurized and Native Gracilaria lemaneiformis Polysaccharides in Immunosuppressive Mice
CHEN Mei-zhen,YU Jie,YANG La-wei,PAN Qun-wen
2010, 31(15):  278-282.  doi:10.7506/spkx1002-6630-201015061
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Improved chlorosulfonic acid/pyridine and HCl/methyl alcohol methods were used for sulfurizing and desulfurizing native Gracilaria lemaneiformis polysaccharides, respectively. The immunoregulatory effects of sulfurized, desulfurized and native Gracilaria lemaneiformis polysaccharides in mice with low immunity induced by cyclophosphamide were investigated. Compared with the model group, native Gracilaria lemaneiformis polysaccharides were the most effective in improving spleen index (P<0.05), phagocytic activity of macrophages (P<0.05), proliferation and transformation of spleen cells (P<0.05) and NK cell killing activity (P<0.01), followed by sulfurized and desulfurized ones. All three polysaccharides could significantly improve the formation of hemolysin and hemolytic plaque in immunosuppressive mice (P < 0.01), native and sulfurized Gracilaria lemaneiformis polysaccharides were superior to desulfurized ones. Based on these results, it can be concluded that Gracilaria lemaneiformis polysaccharides significantly increase the immune function in immunocompromised mice, that sulfate content in Gracilaria lemaneiformis polysaccharides is nonlinearly related to their immunoregulatory effect in immunocompromised mice, and that both sulfurization and desulfurization decrease the immunoregulatory effect of native Gracilaria lemaneiformis polysaccharides, especially desulfurization resulted in a significant decrease.

Reviews
Research Progress in Analysis of Factors Affecting Sensory Quality and Preservation Techniques for Post-harvested Agaricus bisporus
MENG De-mei1,SHEN Lin1,LU Jun2,SHENG Ji-ping1,*
2010, 31(15 ):  283-287.  doi:10.7506/spkx1002-6630-201015062
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Sensory quality is one of the primary factors determining commercial values of Agaricus bisporus. Influencing factors of four typical sensory quality changes including water loss, browning, cap opening and textural change during the storage of post-harvested Agaricus bisporus are analyzed in this paper. In addition, current storage techniques for Agaricus bisporus are also summarized. Finally, problems related to current storage techniques and potential application trends are proposed.

Research Advances in Antioxidant Composition of Botanical Extracts and Their Action Mechanisms
TAN Pin-xin1,YE Tao1,LIU Xiang-xin2,HE Jian-hua3,*
2010, 31(15):  288-292.  doi:10.7506/spkx1002-6630-201015063
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Oxidative damages to organisms caused by free radical might lead to the occurrence of many diseases, while many natural substances have the ability to scavenge free radicals. Plants are the most important source of human body exogenous antioxidants. This article summarizes previously reported studies on antioxidant composition of botanical extracts mainly consisting of polyphenols, vitamins, alkaloids, saponins, polysaccharides, bioactive peptides plants, and so on and their acition mechanisms.

Research Progress in Affecting Factors of Tea Aroma
WANG Li1,2,LIN Zhi1,*,LU Hai-peng1,TAN Jun-feng1,GUO Li1
2010, 31(15):  293-298.  doi:10.7506/spkx1002-6630-201015064
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Aroma, an important index of tea quality, is affected by tea varieties, natural environment, cultivation conditions, processing conditions and exogenous induction factors. In this paper, factors affecting tea aroma are discussed and the prospect of using exogenous inducers to regulate tea aroma is also proposed.

Research Progress of Antioxidant Properties and Applications of Chitosan and Its Derivatives
ZHAO Pan,WANG Li,MENG Xiang-hong*
2010, 31(15):  299-303.  doi:10.7506/spkx1002-6630-201015065
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The antioxidant properties and applications of chitosan and its derivatives are reviewed in this paper. The antioxidant properties of chitosan are mainly determined by its molecular weight and degree of deacetylation. In addition, etherification, esterification, acylation and chelation with metal elements all also influence the antioxidant properties of chitosan. Chitosan and its derivatives have broad application prospects in fresh-keeping of fruits and vegetables, juice clarification, browning prevention, aging delay, and so on.

Application and Analysis of Corn Silk as Food: A Review
WANG Cui-na,LIU Jing-bo*,WANG Er-lei,WANG Zuo-zhao,LIU Jun,LU Shuang,ZHANG Cheng
2010, 31(15):  304-307.  doi:10.7506/spkx1002-6630-201015066
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As a kind of traditional Chinese herb, corn silk has multiple functions. It has been widely used due to its characteristics of both medicine and food. Food industrialization and application of corn silk are summarized in this paper. Meanwhile, current problems in food industrialization of corn silk are also analyzed. Moreover, future application prospects of corn silk as food are proposed.

Current State of Applications of Preservation Techniques for Fruits and Vegetables Carried onboard Vessels
WANG Hong-yu
2010, 31(15):  308-311.  doi:10.7506/spkx1002-6630-201015067
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This article introduces principles of preservation techniques for fruits and vegetables carried onboard vessels and analyzes current state of their applications. Also, some proposals concerning further improvement of preservation effectiveness are put forward for further normalizing the preservation of fruits and vegetables carried onboard vessels and offering evidences for studies of prolongation of storage life of fruits and vegetables carried onboard vessels.

Application of High-Pressure Technology for the Modification of Dietary Fiber: A Review
LING Bo1,WU Hong-bin3,ZHENG Gang1,WU Hong3,ZHAO Guo-hua1,2,MING Jian1,2,*
2010, 31(15):  312-316.  doi:10.7506/spkx1002-6630-201015068
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A large number of studies have proved that modified dietary fiber is more favorable to human physiological functions than its native counterpart. High-pressure technology as an important food processing technology has unique advantages in the modification of dietary fiber. This paper reviews characteristics and classification of high-pressure technology as well as its applications for the modification of dietary fiber in order to offer references for further understanding and improvement of physiological functions of dietary fiber and its comprehensive ultilization and exploitation.