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15 January 2012, Volume 33 Issue 1
Invited Papers
Metabolism of Lactate and Its Critical Role in Health
PANG Guang-chang,CHEN Qing-sen,HU Zhi-he
2012, 33(1):  1-15.  doi:10.7506/spkx1002-6630-201201001
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The reason why lactic acid bacteria and its fermented food are helpful for health in most situations may be due to the production of lactate. The metabolic role of lactate has gained extensive attentions from physiologists and biochemists. However, during the first half of the last century, lactate has been designated as a waste product, especially for the controversial role in muscle fatigue. Currently, more and more publications are exploring and unveiling the critical roles of lactate in multicellular organisms. Lactate has been described as modulation enzymes with catalytic properties to affect hormonal release and responsiveness, and control body homeostasis. Moreover, these properties are directly related to the genesis and sustainability of pathological conditions such as diabetes and cancer. Lactate should not be regarded simply as an anaerobic metabolite, but should be considered as a regulatory molecule that modulates the integration of metabolism. Although lactate is not a redox product, it is an important intermediate metabolite for glycolysis, biological oxidation and biosynthesis. Lactate is produced in the cytosol by the fermentative branch of glycolytic pathway through the reduction of pyruvate with the concomitant oxidation of NADH to NAD+, a reaction catalyzed by lactate dehydrogenase (LDH). Therefore, lactate plays key roles in maintaining the dynamic equilibrium of NADH/NAD+, pH, ATP and biological oxidation/biosynthesis. Due to its multiple bioactivities, lactate is widely used in fermented and functional food, meat quality and color protection, and cancer prevention and resistance so that it is an ideal marker for evaluating physiological alteration, stress and pathology.

Basic Research
Rapid Analysis of Antioxidant Constituents from Taxillus delavayi, a Yi Ethnomedicinal Material
PIAO Xiang-lan, DENG Zhang-qin,CHEN Hu-biao,WANG Jin
2012, 33(1):  16-19.  doi:10.7506/spkx1002-6630-201201002
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Objectives: To rapidly separate and identify antioxidant constituents from the whole plant of Taxillus delavayi, a Yi ethnomedicinal material, and assess their antioxidant activity. Methods: The antioxidant activity of the methanol extract of the medicinal material and its different solvent fractions obtained by repeated extractions sequentially with dichloromethane, n-butanol and water was assessed by DPPH free radical scavenging assay. The dichloromethane-soluble fraction was further separated by silica gel column chromatography, and a high antioxidant component named as TDD8 was obtained and analyzed by bioassay-linked HPLC and 1H-NMR. Results: An individual compound named as TDD8-2 was separated from TDD8 by semi-preparative HPLC and identified by 1H-NMR as pinoresinol. Conclusion: The bioassay-linked HPLC method allows the rapid separation and identification of antioxidant components from medicinal materials.

Antioxidant Activity of Polyphenol Extracts from Leaves of E. grandis × E. urophylla Guanglin No. 9
WANG Jun-liang,XIAO Su-yao,CHEN Yun-jiao,CHEN Xue-xiang,TANG Jie,CAO Yong
2012, 33(1):  20-24.  doi:10.7506/spkx1002-6630-201201003
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Crude ethanol extract from the leaves of E. grandis×E. urophylla Guanglin No. 9 was fractionated by repeated extractions sequentially with solvents of different polarity into petroleum ether-soluble, chloroform-soluble, ethyl acetate-soluble, n-butanol-soluble fractions and residue. Total phenolic contents in the six samples were determined by Folin-Ciocalteu method. Meanwhile, their antioxidant activity was tested by in vitro ABTS, DPPH and FRAP assays. The results indicated that among the samples, the ethyl acetate-soluble fraction showed the highest total phenolic content, 502.67 mg/g, and the strongest ABTS and DPPH scavenging activity and reducing power activity, which were better than those of VC. The IC50 values of the fraction against DPPH and ABTS radicals were 0.097 mg/mL and 0.034 mg/mL, respectively. Moreover, a positive correlation between total phenolic content and antioxidant activity was observed for all the samples. This indicates that polypehnolics are mainly responsible for their antioxidant activity. The crude ethanol extract exhibited a total phenloic content (over 30%) similar to that of its counterpart from tea. This study demonstrates that the crude ethanol extract has a high exploitation potential.

Effect of Lipid Oxidation on Protein Structure
ZHANG Yin-liang,AN Qiao-yun,YANG Hui
2012, 33(1):  25-30.  doi:10.7506/spkx1002-6630-201201004
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This paper deals with the effect of lipid oxidation on protein structure. Oxidized lipid products were prepared by oxidizing linoleic acid under different conditions and allowed to react with bovine serum albumin (BSA) under the same conditions (25 ℃, 4 h). Changes in various properties of BSA were determined during the reaction with oxidized lipid products. The results showed that oxidized lipid products revealed a decrease in thiobarbituric acid value (TBA) after reaction with BSA, while the oxidation value (carbonyl group content) and surface hydrophobicity of BSA increased. Meanwhile, the maximum emission wavelength of the protein showed a red shift and the secondary structure varied obviously. Therefore, lipid oxidation has a significant impact on protein structure.

Antioxidant Activity of Polyphenolic Extract from Shanxi Aged Vinegar
CHEN Shu-jun,FENG Bin,LIU Cheng,SU Jing,ZHANG Hai-ying,LIU Ya-bin, WU Xia-hua
2012, 33(1):  31-34.  doi:10.7506/spkx1002-6630-201201005
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The in vitro antioxidant activity of polyphenolic extract from Shanxi aged vinegar was investigated using different antioxidant evaluation systems and compared with that of gallic acid and vitamin C. The results showed that the polyphenolic extract possessed antioxidant activity in a dosage-dependent manner which varied with the type of model systems. The reducing power and hydroxyl free radical scavenging activity of the samples under investigation were found to decrease in the following order: the polyphenolic extract > gallic acid > vitamin C. The decreasing order of superoxide anion radical scavenging activity among the samples was the polyphenolic extract > vitamin C >gallic acid. The DPPH radial scavenging activity was in the decreasing order of gallic acid > the polyphenolic extract > vitamin C. The nitrite scavenging activity of the extract was poorer than that of vitamin C. The samples decreased in total antioxidant capacity (at the same concentration) in the order of gallic acid > vitamin C > the polyphenolic extract.

Antioxidant and Moisture Retention Properties of Hyaluronic Acid and Its Degradation Products from Squid Eyes
DAI Qiong,YANG Wen-ge,CHEN Xiao-fang,ZHAO Yue-yue,XIONG Shu-li, LU Jia-fang
2012, 33(1):  35-38.  doi:10.7506/spkx1002-6630-201201006
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Two hyaluronic acid fractions with different relative molecular mass isolated from squid eyes, named as HA-1 and HA-2, respectively and the degradation products of HA-2 separated by ultrafiltration were determined for their moisture retention capacity and antioxidant properties such as ferric ion reducing power and scavenging activity against DPPH and hydroxyl radicals. The results showed that the moisture retention capacity of hyaluronic acid and its degradation products was superior to that of glycerol and increased with increasing relative molecular mass. Fraction HA-2 exhibited the highest water retention rate, 92.66%. All the HA samples investigated possessed antioxidant activity, which increased with decreasing relative molecular mass. Stronger free radical scavenging activity was observed for hyaluronic acid with relative molecular mass below 6000, while HA-1 and HA-2 had weaker antioxidant activity.

Synergistic Degradation of Acephate Aqueous Solution by Ultrasonic and Titanium Dioxide
LEI Lei,WANG Xin,YIN Xiao-mei
2012, 33(1):  39-43.  doi:10.7506/spkx1002-6630-201201007
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Titanium dioxide was prepared and used to explore its synergistic effect with ultrasonic on degradation of acephate aqueous solution at low concentration. The degradation rate of acephate was investigated with respect to temperature, pH, ultrasonic intensity, titanium dioxide amount and various combinations of ultrasonic intensity and titanium dioxide amount. The degradation rate of acephate increased as the ultrasonic treatment time increased up to 1 h and the temperature increased from 5 ℃ to 20 ℃. An acidic environment of pH 3 was favorable to the degradation of acephate. Within a certain range, titanium dioxide amount was positively related to the degradation rate of acephate. An ultrasonic intensity of 40 W/cm2 was conducive to increasing the degradation rate of acephate. Moreover, ultrasonic and titanium dioxide could synergistically degrade acephate. A degradation rate of 78.3% was observed for 2 mg/L acephate aqueous solution at 20 ℃ and pH 3.0 with the addition of titanium dioxide at 0.6 g/L after 50 min ultrasonic treatment at a frequency of 25 kHz and an intensity of 40 W/cm2.

Physico-chemical Properties and Stability of Pigments from Spine and Shell of Sea Urchin Glyptocidaris crenularis
WANG Xiao-dong,ZHOU Da-yong,ZHU Bei-wei,LU Yan-hong
2012, 33(1):  44-48.  doi:10.7506/spkx1002-6630-201201008
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The present study aimed to characterize physicochemical properties and stability of pigments extracted from the spine and shell of sea urchin (Glyptocidaris crenularis). Our results showed that the pigments had relatively high solubility in polar solvents such as water and methanol but had relatively low solubility in non-polar solvents such as light petroleum and hexane. The pigments showed orange color in acidic conditions but yellowish brown color in basic conditions. The pigments were relatively stable to heat but unstable to light. Na2SO3 and potassium sorbate could not only cause changes in the color but also decrease the stability of the pigments. H2O2 and NaCl could not cause any changes in the color but decrease the stability of the pigments. High concentrations of cane sugar could enhance the stability of the pigments. Vitamin C could protect and enhance the color of the pigments.

Application of Oat Starch-based Fat Substitutes in High-Ratio Cake
XING Ming,WANG Zhan,SHU Teng-fei,HU Zhong-ze,LIU Ying
2012, 33(1):  49-53.  doi:10.7506/spkx1002-6630-201201009
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In this study, the effects of oat starch-based fat substitutes (OSFS) as a partial substitute for fat on texture and the physico-chemical characteristics of high-ratio cake were investigated. OSFS could well simulate the role of fat in high-ratio cake. The additions of 25% OSFS with a DE value of 2.39, 2.93 and 3.73, respectively were all good substitutes for fat and OSFS with a DE value of 2.39 was the best among them. A fat content below 40% in high-ratio cake was successfully replaced by adding the best fat substitute at a concentration of 25%. When 20% of fat was substituted by OSFS, OSFS brought no detectable changes in texture and physico-chemical properties of high-ratio cake, suggesting that the optimum level of fat substitution in high-ratio cake was 20%.

Spectroscopic Characteristics and Antioxidant Properties of Xyl-Gly Maillard Reaction System
YU Peng-wei,LIU Deng-yong,ZHOU Guang-hong
2012, 33(1):  54-58.  doi:10.7506/spkx1002-6630-201201010
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Maillard reaction products (MRPs) were prepared using xylose and glycine by model Maillard reaction. The pH value, absorbance and color parameters of the MRPs were determined. Meanwhile, the antioxidant effect was evaluated in terms of DPPH free radical scavenging activity, ferrous ion-chelating activity and lipid peroxidation inhibitory activity. The results showed that the colorless reaction system became blue and finally showed brown color as the reaction proceeded. Moreover, the pH and L* value gradually decreased. The a* value increased, while the b* value revealed an opposite change. However, the two color parameters changed little during the later part of the reaction. The MRPs exhibited good ferrous ion-chelating activity, and resulted in a lower peroxide value, but possessed weak DPPH free radical scavenging activity. In general, the products had strong antioxidant properties.

Coloring Kinetics of Rice Tea Infusion
LI Sha-sha,SHEN Shuo,XIONG Shan-bai,ZHAO Si-ming
2012, 33(1):  59-63.  doi:10.7506/spkx1002-6630-201201011
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Broken rice was used to make rice tea after soaking and roasting. In the process, the occurrence of Maillard reaction and caramelization could produce pigment materials that make rice tea infusion colorful. The effects of making parameters and infusing time on the color parameters of rice tea: lightness (L*), redness (a*), yellowness (b*) and chroma (c*) were investigated. The results showed that the orange color turned to pure yellowness and tea lightness decreased with prolonged infusing time. The process of color formation followed an exponential model. Furthermore, rice soaking could influence the color of rice tea. Rice tea resulting from 10 min soaking at a material-to-water ratio of 1:20 (m/V) could quickly show stable color with high lightness, yellowness and chroma.

Structural Characterization and Antibacterial Activity of Carboxymethyl Thiourea Chitosan
LI Xiao-fang,MA Jin-man,FENG Xiao-qiang,WANG Ting-pu,YANG Sheng,ZHANG Hong-juan,KONG Xu-e
2012, 33(1):  64-67.  doi:10.7506/spkx1002-6630-201201012
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Carboxymethyl thiourea chitosan (CMTCS) was prepared and characterized by infrared spectrometry (FT-IR), ultraviolet spectrometry (UV) and differential thermal and thermogravimetry analysis (TG-DTA) methods. The antibacterial activity of CMTCS against E.coli and St.aureus were investigated in vitro. The results showed that the antibacterial activity of CMTCS was obviously higher than that of chitosan with an MIC of 0.20 mg/mL against both E.coli and St.aureus.

Isolation, Purification and Structural Analysis of Fucoidan from Kelp
ZHANG Wen-qing,ZUO Ping-ping,XU Chen,YANG Lei,ZHANG Yu-long,XIA Wei
2012, 33(1):  68-71.  doi:10.7506/spkx1002-6630-201201013
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A homogeneous polysaccharide named as TC-1 was obtained from kelp by DEAE-cellulose and gel filtration chromatography. Its chemical structure was characterized by means of monosaccharide composition analysis, methylation analysis and IR spectroscopic analysis. TC-1 was a complex sulfated polysaccharide with a weight-average molecular weight of 3.7 × 105. TC-1 mainly consisted of fucose and small amounts of xylose, mannose, glucose and galactose were also found. The chain of TC-1 included 1,4-linked or 1,3-linked fucose, 1,3-linked xylose, 1,3-linked or 1,6-linked mannose, 1,3,4-linked or 1,2,4,6-linked glucose, and 1,6- linked,1,3,6- linked, or 1,3,4,6- linked galactose.

Analysis of Phenols, Flavonoids and Oxygen Radical Absorbance Capacity (ORAC) of Three Varieties of Adlay
WANG Li-feng,HE Rong,YUAN Jian,JU Xing-rong
2012, 33(1):  72-76.  doi:10.7506/spkx1002-6630-201201014
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In order to explore the phytochemical profile of three adlay varieties, the levels of total, free and bound phenols and flavonoids were determined using a microplate reader. Meanwhile, the oxygen radical absorbance capacity (ORAC) was measured as an indicator for total antioxidant capacity using a multifunctional fluorescence microplate reader. The contents of free ((45.19 ± 0.91) mg of gallic acid equivalent/100 g of dried samples) and bound ((30.86 ± 1.18) mg of gallic acid equivalent/100 g samples) phenols in Longyi I were significantly higher than those in Liaoning V and Guizhou Heigu (P < 0.05). For all these adlay varieties, bound phenols averagely accounted for 45.28% of total phenols. The content of free flavonoids in Liaoning V showed a significant increase as compared with Longyi I and Guizhou Heigu, and the content of bound flavonoids in Longyi I was higher than that of Liaoning V and Guizhou Heigu. The highest content of total flavonoids was found in Liaoning V. The adlay varieties were ranked in decreasing order of ORAC as follows: Longyi I  ((668.0 ± 32.7) mg of Trolox equivalent/100 g of dried samples), Liaoning V and Guizhou Heigu. The average percentage of bound ORAC in total ORAC was 48.08%. A correlation coefficient (r2) of 0.933 was observed for the significant correlation  (P < 0.05) between the total phenol content and total antioxidant capacity of each adlay variety.

Purification and Identification of Proline-rich Polypeptides from Bovine Colostrum
YU Fang,LI De-long,ZHANG Bo,GAO Yan-ling,ZHANG Shao-hui
2012, 33(1):  77-80.  doi:10.7506/spkx1002-6630-201201015
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Bovine colostrum was extracted to obtain bioactive proline-rich polypeptides (PRP). The molecular weight and amino acid composition of PRP were analyzed by means of SDS-PAGE and an automated amino acid analyzer, respectively. Reversed-phase high performance liquid chromatography (RP-HPLC) was employed to purify PRP. The results showed that the proline content in PRP was as high as 20%. The molecular weights of principal components were in the range of 5-25 kD as determined by SDS-PAGE. RP-HPLC showed that major spectral peaks were eluted by 37%-45% acetonitrile. As a result, PRP with a purity of 96.7% was obtained.

Changes in Structure and Characteristics of Intramuscular Connective Tissues during the Development of Wuzhumuqin Sheep
SU Ya-la,HOU Xiao-wei,BORJIGIN Gerelt
2012, 33(1):  81-86.  doi:10.7506/spkx1002-6630-201201016
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Wuzhumuqin sheep aged 1-18 months were tested for the structural change of intramuscular connective tissues by a histological method. Meanwhile, the contents of pyridinoline and proteglycans in intramuscular connective tissues were determined during the development of Wuzhumuqin sheep. The thickness of endomysium increased with increased age and no significant difference was observed between 6 and 9 months and between 12 and 18 months (P> 0.05). The thickness of perimysium showed an obvious increase during the first 6 months and then a significant decrease (P < 0.05). The diameter of endomysial honeycomb structure gradually increased, and collagen fibrils in endomysium became more tightly bounded to each other. Moreover, the wavy pattern of collagen fibres in perimysium became more regular during the growth of sheep. Furthermore, the contents of pyridinoline and uronic acid in connective tissue revealed a significant increase during the growth process of sheep (P < 0.05).

Intermittent Microwave Drying Properties and Kinetic Model of Lees
ZHANG Li-hua,ZHANG Wen,LU Zhen-zhen,XU Zhong-ming
2012, 33(1):  87-91.  doi:10.7506/spkx1002-6630-201201017
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A self-made online testing device for microwave drying was used to dry lees for exploring its batch drying properties. The effects of microwave power, lees layer thickness and intermittent time on moisture content, drying rate and temperature were investigated. The dehydrating law of lees was achieved during intermittent microwave drying. A kinetic model for intermittent microwave drying was established based on experimental data as follows: ln (-lnMR)= -3.9977+0.0038P-0.6427H- 0.4118R +(1.7216 + 0.0001P +0.0200H-0.0403R) lnt. The kinetic model could accurately describe drying process of lees and predict water content and drying rate.

Effect of Binding Conditions on Quality of Restructured Beef
KONG Bao-hua,MA Fu-jun,DIAO Ya-kun
2012, 33(1):  92-97.  doi:10.7506/spkx1002-6630-201201018
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Restructured beef is made from smaller pieces of beef fused together by a binding agent. In order to improve the quality of restructured beef, a mixture of transglutaminase (TG) and sodium caseinate (SC) at a ratio of 1:4 (m/m) was used to bind beef pieces. The effects of time (1, 2, 3, 4, 5 or 6 h), temperature (1, 4, 7 or 10 ℃) and pressure (2, 3, 4, 5 or 6 N/m2) on physical properties of restructured beef were studied by one-factor-at-a-time method. The results showed that the optimal time, temperature and pressure were 3 h, 4 ℃ and 4 N/m2, respectively. Under these conditions, the binding strength of restructured beef was reinforced, the thawing loss and cooking loss were decreased, and the texture and color were improved.

Identification of Water Buffalo Caseins by Liquid Chromatography and LTQ-Orbitrap Mass Spectroscopy
WANG Li-na,XU Ming-fang,CHENG Xi-fei,XIANG Ming-xia,LI Zi-chao,LI Yun-kai
2012, 33(1):  98-102.  doi:10.7506/spkx1002-6630-201201019
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A rapid and efficient method to analyze the amino acid sequence of casein was presented using LTQ-Orbitrap mass spectroscopy coupled with liquid chromatography. In order to understand the amino acid sequence and substitution of cow, water buffalo and goat caseins, LTQ-Orbitrap mass spectroscopy coupled with liquid chromatography was used to analyze 4 major casein components, and their complete amino acid sequences were acquired by database searching. The amino acid substitutions of cow milk caseins were markedly lower than those of goat milk caseins. Thus, this study demonstrates that the amino acid sequences of cow milk caseins are more stable than those of goat milk caseins.

Basic Research
Anti-Bacillus cereus Mechanisms of Fructus Mume Extract
LIU Meng-yin,LIU Fang,ZHOU Tao,ZHU Yong-zhi,XU Wei-min
2012, 33(1):  103-105.  doi:10.7506/spkx1002-6630-201201020
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The objective of the present study was to investigate the mechanisms for the inhibition of Bacillus cereus by Fructus Mume extract. The effect of Fructus Mume extract on the integrity of cell wall was studied by determining the content of alkaline phosphatase (AKP). The contents of extracellular proteins were assayed by Bradford method. Cell membrane permeability was examined based on changes in electrical conductivity. The effect of Fructus Mume extract on the synthesis of bacterial proteins was analyzed by SDS-PAGE. The results indicated that Fructus Mume extract could damage the structures of cell wall and cell membrane, causing an increase in cell membrane permeability and the release of intracellular contents. Fructus Mume extract could also affect the synthesis of bacterial proteins and block protein expression in bacteria.

Bioengineering
Cultivation of Selenium-Enriched Spirulina maxima
YANG Ying-ying,GUAN Bin,KONG Qing,YOU Yong,GAO Yan-yan,ZHANG Rui-qin,LI Xiao,ZUO Tao,LIU Jin-chang,HOU Qing-yun
2012, 33(1):  106-110.  doi:10.7506/spkx1002-6630-201201021
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 In order to achieve selenium enrichment in Spirulina maxima, the effects of different amounts and strategies for selenium addition on the growth of S. maxima as indicated by biomass and selenium concentration were explored. The addition of 100μL of 100 μg/mL Na2SeO3 at the same time each day for 8 consecutive days after 1 day of growth in Se-free environment was found optimal, resulting in a biomass of 0.903g/L and an organic Se content of 1413.168 μg/g dry S . maxima.

PCR-DGGE Analysis of Microbial Community Structure of Bozaa, a Traditional Kyrgyz Fermented Beverage
Nurgul RAHMAN,HUA Chang-chun,ZHU Xiao-ying,Gulsum TOHSUN,DONG Ming-sheng
2012, 33(1):  111-114.  doi:10.7506/spkx1002-6630-201201022
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The microbial community structure of Bozaa, a traditional Kyrgyz fermented beverage, was analyzed by the PCRDGGE
technique. PCR amplification of 16S rRNA gene V6-V8 region and 26S rDNA D1 region were performed for bacteria
and yeast in the beverage, respectively. The main DNA bands in the DGGE profiles of the PCR products obtained were
subjected to sequence analysis. The results showed that the microbial flora of Bozaa was composed of Lactobacterium
plantarum, Lactobacillus brevis, Bacillus cereus, Acetobacer pasteurianus, and Saccharomyces cerevisiae, which was a successful
primary elucidation of the microbial diversity of Bozaa.

Effects of Enzymatic Hydrolysis and Subsequent Plastein Reaction on Antioxidant Properties of Soybean Protein Isolate
SONG Jia-tian,ZHAO Xin-huai
2012, 33(1):  115-119.  doi:10.7506/spkx1002-6630-201201023
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Alcalase 2.4L FG was used to hydrolyze soybean protein isolate (SPI) to prepare soybean protein hydrolysates with the highest antioxidant activity, which showed a degree of hydrolysis of 14.0% and an ABTS+ radical scavenging rate of 43.6%.  The prepared hydrolysates were modified with Alcalase 2.4L FG by plastein reaction and the optimal enzyme dosage, substrate concentration and temperature to maximize the reduction of free amino groups were determined by response surface methodology to be 1037 U/g protein, 30 g/100 mL, and 20 ℃, respectively. The maximum degree of reaction and antioxidant activity were obtained after reaction for 6 h under these conditions. Moreover, the antioxidant activity of the SPI hydrolysates and their modification products obtained after reaction for 1, 3 h and 6 h was better than that of SPI. The DPPH and superoxide anion radical scavenging activity and reducing power of the hydrolysates and modification products showed no significant difference, while a significant difference was observed in their hydroxyl radical scavenging activity.

Screening and Identification of a High-Yield Neutral Phytase-Producing Strain and Characterization of Neutral Phytase
WANG Tao,LI Wen,YUAN Pei-pei
2012, 33(1):  120-124.  doi:10.7506/spkx1002-6630-201201024
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A high-yield neutral phytase-producing strain with an enzymatic activity of 12.52 U/mL was isolated from soil and initially identified as Agrobacterium radiobacter based on its morphological, physiological and biochemical characteristics as and 16S rDNA sequence. The optimum reaction temperature and pH of neutral phytase produced by the strain were 45 ℃ and 7.0, respectively. The relative activity of the enzyme was 80% after heating at 65  ℃ for 60 min, revealing that it was thermostable to some extent. The enzyme was stable at pH values in the range of 5.5-8.0. Its activity could be activated by Ba2+ but inhibited by Fe2+ , Mg2+, Zn2+  and Cu2+ .

Extraction and Purification of Cellulase from Spent Mushroom Compost
DU Ning,XU Tian-tian,LI Xian-fu,XIA Zhi-hua,CHEN Jun
2012, 33(1):  125-130.  doi:10.7506/spkx1002-6630-201201025
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Spent mushroom compost (SMC) was used to prepare industrial grade cellulase by solvent extraction, membrane
filtration and salting out and high-purity cellulase by further aqueous two-phase extraction. The results showed that crude
cellulase solution with an enzymatic activity of 102.64 U/mL was obtained after 3 h of extraction at 25 ℃ with an extraction solvent
composed of 0.2 mol/L acetic-acetate sodium buffer at pH 5.0 and 0.2% Triton X-100. Subsequent salting out at 60% (NH4)2SO4
saturation could recover 65.54% of the total cellulase activity, and industrial grade cellulase with an enzymatic activity of
2865.47 U/mL was obtained. After further aqueous two-phase extraction with a system made up of 22% polyethylene glycol
6000 (PEG6000) and 20% (NH4)2SO4 under the conditions of 7 mmol/L NaCl, pH 5.5 and normal temperature, the cellulase activity
and specific activity were 10208.46 U/mL and 106.62 U/mg, respectively and a total activity yield of 51.22% was achieve,
revealing a 12.85-fold increase when compared with that of crude enzyme solution. As a result, high-purity cellulase was
obtained.

 

Isolation of a Strain of Non-starter Lactic Acid Bacteria Accelerating Cheese Ripening and Its Effect on Cheddar Cheese Slurry Proteolysis
ZHOU Rui,LI Xiao-dong,PAN Ch
2012, 33(1):  131-135.  doi:10.7506/spkx1002-6630-201201026
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A strain of non-starter lactic acid bacteria capable of accelerating cheese ripening were screened and isolated and its
effect on cheddar cheese slurry proteolysis during ripening was also explored. Rogosa agar medium was used for primary strain
isolation from Chinese northeastern traditional fermented food Suancai,, and the isolates obtained were screened further by
multivariate statistical analysis. Strain identification was conducted by 16S rDNA gene sequencing and Blast searches against the
public database. The results showed that a non-starter lactic acid bacterium was successfully isolated and named as S-1. The
strain was identified as Lactobacillus plantarum subsp. plantarum ST-III. Moreover, the strain displayed high aminopeptidase
activity and autolytic capacity although it had low acid-producing capacity. Furthermore, the strain revealed high proteolytic
capacity during cheese slurry ripening.

Purification and Cytotoxicity of C-Phycocyanin(C-PC) from Spirulina platensis and Its Tryptic Peptides
WANG Xue-qing,DENG Wei,YANG Jin-fang,MAO Yu-cong,SHI Zhong-ming
2012, 33(1):  136-140.  doi:10.7506/spkx1002-6630-201201027
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This paper deals with the separation, purification and cytotoxicity of C-phycocyanin (C-PC) from Spirulina platensis and its tryptic peptides. Repeated freezing and thawing coupled with ultrasonic treatment was used for disrupting the cell wall of Spirulina platensis. The purity (A620nm/A280nm) of C-PC was 2.19 after fractional precipitation by 28-55 g/100 mL (NH4)2SO4 and could reach 3.89 after further purification by sequential chromatography on hydroxylapatite (HA) column and Sephacryl S-200 HR gel column. The purified C-PC was hydrolyzed by trypsin at 40 ℃ for 60 min. Four peptides were obtained from the hydrolysate of C-PC by DEAE-Sepharose Fast Flow column chromatography. The cytotoxicity of C-PC and its hydrolysate as well as the 4 peptides on HeLa and 293T cells was evaluated by MTT assay. The results showed that the inhibition rates of peptide fractions I and IV, C-PC hydrolysate and C-PC on the growth of HeLa cells were 37.71%, 47.04%, 34.02% and 26.03%, respectively. Therefore, peptide fractions I and IV revealed obvious suppressive effect on the proliferation of cancer cells, while neither of them had cytotoxicity on 293T cells. Moreover, peptide fraction IV had the strongest tumor suppression activity, indicating a great potential to be developed as health-care products.

Isolation and Identification of Excellent Oenococcus oeni from Xinjiang Wines 
LI Cui-xia,LI Hua,JIN Gang,DU Li-ye,WANG Hua
2012, 33(1):  141-146.  doi:10.7506/spkx1002-6630-201201028
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In order to screen Oenococcus oeni with good performance for malolactic fermentation (MLF), 3 strains of O. oeni were isolated and purified from Xinjiang wines, and identified preliminarily as O. oeni based on morphological, physiological and biochemical analyses. Their resistance to individual stress conditions such as pH, ethanol or SO2 was determined. In addition, the growth of 9 screened strains under the combinatorial external stress of ethanol, pH and SO2 was also evaluated. The results indicated that 3 strains had better adaptation capability to adverse conditions. The species-specific PCR and homology analysis of 16S rRNA sequence also supported our results. Moreover, a phylogenetic tree was established based on the 16S rRNA sequence of O. oeni. The results of 16S rRNA sequencing showed that this strain was 99% homologous to O. oeni, so indicated that 9 screened strains with better performace was O. oeni species.
Process Optimization for Enzymatic Preparation of Polypeptides from Egg Yolk Protein
QIN Jia-yan,YU Na,YUE Xi-qing
2012, 33(1):  147-151.  doi:10.7506/spkx1002-6630-201201029
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In this study, enzymatic hydrolysis was used to prepare polypeptides from egg yolk protein. Two-step hydrolysis with alkaline protease and flavourzyme was found optimal for preparing polypeptides from egg yolk protein as demonstrated by a comparison of the effectiveness of flavourzyme, neutral protease, alcalase and protamex in hydrolyzing egg yolk protein. The response surface methodology was employed to investigate the effects of total enzyme dosage, alcalase-to-flavourzyme ratio, duration ratio between two hydrolysis steps and pH on degree of hydrolysis (DH) and polypeptide content. The optimal hydrolysis process was hydrolysis for 2 h with 0.8 g/100 mL alcalase at 55 °C, pH 7.2 and a substrate concentration of 10 g/100 mL and for another 2 h with 0.4 g/100 mL flavourzyme, resulting in a DH of (13.31± 0.5)% and a polypeptide content of (1.85 ± 0.5) mg/mL.
Optimization of Microencapsulation Process for Lactobacillus plantarum NCU116
XIONG Tao,FENG Chao,XIE Ming-yong
2012, 33(1):  152-156.  doi:10.7506/spkx1002-6630-201201030
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Beta-lactoglobulin, the main whey protein in bovine milk, has been shown to remain intact in the presence of pepsin and low pH. Skim milk was used as a coating material to improve microencapsulation of Lactobacillus plantarum NCU116 in calcium alginate beads. On the basis of single-factor experiments, the optimization of microencapsulation conditions was carried out using response surface analysis to maximize viable cell count in microcapsules after treatment with artificial gastric fluid. The results showed that the optimal encapsulation conditions were sodium alginate 2.68 g/100 mL, calcium chloride 0.20 mol/L, and skim milk 4.17 g/100 mL. Under these conditions, the particle size of microcapsules, encapsulation rate and viable cell count in microcapsules after treatment with artificial gastric fluid for 3 h were 1.12 mm, 73.49% and 8.79 × 109 CFU/g (close to the theoretical value, 8.85 × 109 CFU/g), respectively. Thus the microencapsulation conditions presented in this study could effectively protect Lactobacillus plantarum from adverse gastric conditions.
Optimization of Fermentation Conditions for Black Currant Fruit Vinegar by Response Surface Methodology
2012, 33(1):  157-161. 
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Response surface methodology was used to optimize fermentation conditions for black currant fruit vinegar. Based on the results of single factor experiments, Box-Behnken experiment design was used to analyze and optimize initial alcohol concentration, pH, ratio of medium volume to shake flask volume and rotational speed. The optimal fermentation conditions were determined as follows: initial alcohol concentration 5.7%, initial pH 4.5, ratio of medium volume to shake flask volume 97:500, and rotational speed 126 r/min. Further validation experiments showed that the conversion rate of acetic acid was 96.78% under the optimal conditions. The black currant fruit vinegar obtained showed red rose color, strong fruity aroma and pleasant soft sour taste.
Isolation of Lactic Acid Bacteria with Broad-Spectrum Antimicrobial Activity and Analysis of Antimicrobial Substances
MIng ZHANG
2012, 33(1):  162-165. 
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A strain with strong inhibitory activity against Gram-positive bacteria, Gram-negative bacteria and mold, named as LPEM818, was isolated from Millet by the overlay plate method. The strain was identified as Lactobacillus pentosus by physiological and biochemical characterization and 16S rRNA sequence homology analysis. In the cell-free fermentation supernatant, some antimircrobial substances including lactic acid, acetic acid, succinic acid, citric acid, palmitic acid, oleic acid, stearic acid and linoleic acid were found by GC-MS and HPLC analyses.
Screening and Preliminary Identification of a Lactic Acid Bacterium Strain with the Capacity of Nitrite Degradation from Sanjiang Pickled Potherb Mustard
2012, 33(1):  166-169. 
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A strain of lactic acid bacteria with strong ability to degrade nitrite was screened from pickled potherb mustard made in Sanjiang town, Jiangxi province. The strongest ability of the strain to degrade nitrite averagely reached 32.66 μg/mL during 68 h of fermentation. The results of 16s rRNA sequencing showed that this strain was 98% homologous to Lactobacillus fermentum PL9005. Polygenetic analysis indicated that this strain belonged to Lactobacillus fermentum.
Dynamic Variation of Main Products and Microflora during the Fermentation of Luzhou-flavor Liquor
YU You-Gui You-GuiYU
2012, 33(1):  170-173. 
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Main fermentation products in fermented grains were determined by GC and conventional analysis methods at different depth and time points in order to explore the fermentation process of Luzhou-flavor liquor. The results showed that ethanol, total acids, total esters and aroma components in fermented grains changed regularly in the whole process of fermentation. The main fermentation products in the lower fermented grains were higher than the counterparts in the upper fermented grains.The relative variation ranges in the numbers of different species of microbes decreased in the following order: yeast > bacteria >fungi. The numbers of mold, yeast and bacteria in the upper fermented grains were slightly higher than those in the lower fermented grains. This study preliminarily reveals the fermentation mechanism of Luzhou-flavor liquor.
Breeding of Strain Producing Protease with High Deamidation and the Optimization of Fermentation Conditions
2012, 33(1):  174-179. 
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The original strain Bacillus licheniformis 2709 was mutagenized by means of nitrogen ion implantation at the optimal implantation dose of 1.5 × 1015 ions/cm2. As a result, a mutant strain  with a deamidation capacity of 48.99% (increased by 85.57% compared with the original strain) but a relatively weak ability to cleave peptide bonds named as SDL-9 was obtained. The orthogonal array design method was used for the optimization of fermentation conditions for production of alkaline protease with high deamidation capacity by SDL-9. The optimal fermentation conditions were 2 g/100 mL corn meal as the carbon source, 3 g/100 mL soybean protein as the nitrogen source, 0.04 g/100 mL Fe3+ with distinct promoting effect on enzyme production, 0.9 g/100 mL glutamine that could notably induce enzyme production, initial pH 7.0, and temperature 35 ℃. Under these conditions, the deamidation capacity and hydrolysis degree of peptide bonds were 57.1% and 13.2%, respectively.
Preparation of ACE Inhibitory Peptides by Bromelain Hydrolysis of Loach (Misgurnus anguillicaudatus) Protein
2012, 33(1):  180-185. 
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The present deals with the enzymatic preparation of angiotensin-converting enzyme (ACE) inhibitory active peptides from loach (Misgurnus anguillicaudatus) protein. An L9(34) orthogonal array design methods based on single factor experiments was used to optimize the hydrolysis conditions for achieving maximum ACE inhibitory activity of loach protein hydrolysates. HPLC was used to determine ACE inhibitory activity of loach protein hydrolysates. Bromelain was found to be more suitable to prepare ACE inhibitory active peptides than trypsin, pepsin, flavourzyme and protamex. The optimal hydrolysis conditions were temperature of 55 ℃, solid-to-liquid ratio of 1:3, pH of 6.5, bromelain dose of 1000 U/g protein and hydrolysis duration of 90 min. The IC50 of the loach protein hydrolysate obtained under these conditions was 0.0184 mg/mL and the relative molecular weight distribution of ACE inhibitory peptides in it was mainly concentrated around 924.
Screening, Identification and Physiological Characteristics of Antagonistic Bacteria against  Trichoderma in Mushroom
2012, 33(1):  186-190. 
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Trichoderma can widely contaminate mushroom and result in the decay of mushroom. In order to screen antifungal bacteria for the application in mushroom cultivation industry, 283 strains were isolated from 16 kinds of cultivation media. Of them, 16 exhibited obvious antifungal activity against Trichoderma, and 6 with the strongest antagonistic activity were screened out and the inhibitory effects of their fermentation supernatants were tested by the cup method. As a result, the best strain named as B155 was screened out with an inhibition zone radius of (19.02 ± 1.65) mm. According to morphological, physiological and biochemical characteristics as well as partial 16S rDNA sequence analysis, strain B155 was identified as B. licheniformis and designated as ABM 155. The optimal growth temperature, pH and inoculum amount for the strain were 37 ℃, 7.0 and 1%, respectively.
Synthesis, Recombinant Expression and Functional Analysis of Filamentousphage Gene V Protein
Da-Chuan ZHANG
2012, 33(1):  191-194. 
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Objective: To explore the gene synthesis, recombinant expression and functions of filamentousphage gene V protein (GVP). Methods: According to the gene sequence of GVP, eight oligonucleotide fragments with the selected E. coli-preferred codon were designed, and the GVP gene sequence was synthesized by overlap extension PCR. Then the synthesized sequence was inserted into pET-28a-c(+) plasmid. The recombinant plasmids obtained were transformed into E. coli to screen positive isolates of GVP. GVP expression in the positive strains was induced with IPTG. The recombinant proteins were purified by Ni+-NTA affinity chromatography. Results: GVP gene was successfully synthesized and highly expressed in E. coli BL21 (DE3) under the induction of IPTG, and the equilibrium dissociation constant was 7.27 × 10-5 mol/L between GVP and ssDNA. Conclusion: The recombinant GVP has high affinity with ssDNA and therefore can be used for the ssDNA detection of some pathogenic microorganisms in food.
Optimization of Process Parameters for Enzymatic Preparation of Antihypertensive Peptides from Porcine Hemoglobin
2012, 33(1):  195-199. 
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In order to prepare antihypertensive peptide with high activity, trypsin was selected to hydrolyze porcine hemoglobin. The one-factor-at-a-time and orthogonal array design methods were used to optimize hydrolysis conditions such as substrate concentration, temperature, pH, enzyme dosage and time based on the ACE inhibitory rate of hydrolyzed porcine hemoglobin. The results showed that the optimal hydrolysis conditions were hydrolysis for 8 h at 45 ℃, pH 8.0, an enzyme dosage of 2000 U/g and a substrate concentration of 10 g/100 mL. Under these hydrolysis conditions, the ACE inhibitory rate of porcine hemoglobin hydrolysate was 68.74%.
Synthesis and Identification of Artificial Antigen for Glibenclamide
2012, 33(1):  200-203. 
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Objective: To synthesize artificial antigen for glibenclamide. Methods: Hapten was synthesized by diazo reaction with p-aminobenzoic acid, and conjugated separately with BSA (bovine serum albumin) and OVA (ovalbumin) by carbodiimide method. Immunogen and coating antigen were obtained and designated as Gli-BSA and Gli-OVA, respectively. The synthesized artificial antigens were identified by mass spectrometry and UV spectroscopy. The immunogen was used to immunize Balb/c mice and the generated anti-serum was analyzed by indirect ELISA. Results: Gli-BSA and Gli-OVA were successfully synthesized with a coupling ratio of 4:1 and 17.7:1, respectively. The anti-serum titers after the first, second and third immunization of Balb/c mice were all above 32000 and the IC50 was 10 μg/mL. Conclusion: Artificial antigens for glibenclamide has been successfully synthesized and anti-glibenclamide antibodies have been acquired. This study can provide a basis for further studies on immunological detection of glibenclamide.
Purification and Enzymatic Characterization of Limit Dextrinase from Malted Barley
2012, 33(1):  204-208. 
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This study was carried out to separate and purify limit dextrinase from malted barley by (NH4)2SO4 salting out, DEAE Sepharose FF column chromatography and Sephadex G-100 column chromatography. A purification fold of 31.23 and a recovery of 8.81% were achieved. The SDS-PAGE pattern of the purified limit dextrinase revealed a single band of protein (97 kD). The effects of temperature and pH on limit dextrinase in both the crude extract and purified sample were studied. The results indicated that maximum activity of the purified limit dextrinase was observed under the conditions of 45 ℃ and pH 5.5 and showed an obvious difference as compared with the crude enzyme extract. Moreover, Mg2+, Ca2+ and Mn2+ increased the activity of the enzyme at low concentrations, whereas Zn2+ and Fe2+ inhibited the activity at high concentrations. K+ did not exhibit any effects on the activity of the enzyme.
Effect of Inducers on Xylanase Activity and Biosynthesis of Ferulic Oligosaccharides in Aureobasidium pullulans
Xiao Hong-Yu
2012, 33(1):  209-214. 
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Feruloyl oligosaccharides (FOs) could be produced as a result of the hydrolysis of wheat bran fiber by xylanase synthesized during fermentation by a mutant strain of Aureobasidium pullulans without the secretion of melanin bred using wheat bran. The effects of inducers such as carbon source, nitrogen source, metal ion and surfactant on the activity of xylanase and the formation of FOs were investigated. The medium composition for FOs production by the strain was optimized using the orthogonal array design method. The highest Fos production and xylanase activity, 627 nmol/L and 52.66 IU/mL, respectively, were achieved by using a medium comprised of 50 g/L wheat bran, 15 g/L glucose, 1 g/L peptone and 1 g/L corn syrup.
Application of Lactobacilli in Cured Fish
2012, 33(1):  215-218. 
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In the present study, L. casei, L. farciminis and L. delbrueckii were inoculated together at a ratio of 1:1:1 to produce cured grass carp. The effects of total inoculum amount, salt amount, curing temperature and curing time on the quality of cured fish were studied. The optimal levels of the parameters were optimized using one-factor-at-a-time and orthogonal array design methods to be 106 CFU/g, 5%, 10 ℃ and 4 d, respectively. Products with close texture, low salinity and the flavor of conventional cured fish were obtained under these conditions. The TVB-N and peroxide value were 18.72 mg/100 g and 0.18 g/kg, which decreased by 34.9% and 51.6%, respectively, when compared with naturally fermented cured fish.
Optimization of Fermentation Conditions for High Cell Density Cultivation and High Hyperthermophilic α-Amylase Expression in Recombinant E. coli
2012, 33(1):  219-225. 
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In order to achieve high-cell-density cultivation and high expression of recombinant E. coli BL21 producing hyperthermophilic α-amylase, the medium composition and shake flask fermentation conditions were optimized using orthogonal array design. The optimal cultivation conditions for the production of α-amylase were achieved by using a pH 6.5 medium composed of 0.5 g/L glucose and 15 g/L yeast extract and an inoculum size of 3%, and adding 0.8 mmol/L IPTG for 6 h induction after 4 h of fermentation. Under these conditions, the biomass of recombinant E. coli BL21 was increased by 1.29-fold, the α-amylase activity by 1.55-fold (reaching 8.754 U/mL) and the protein expression level by 1.24-fold compared to the pre-optimization results.
Breeding and Screening of a High-Yield Tannase-Producing Strain
2012, 33(1):  226-229. 
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Tannase plays an important role in the food and fine chemical industries. The breeding and screening of a strain with high tannase activity are desired. A tannase-producing strain, DNM1-39, was isolated from resources rich in tannin. The activity of tannase in solid state medium after fermentation by the strain was 1.58 U/g. The strain was identified as Aspergillus through morphologic observation. A mutant strain named as UD-6 was obtained from DNM1-39 mutagenization with ultraviolet irradiation alone, DES treatment alone and both of them. The tannase activity produced by UD-6 was 2.80 U/g. The tannase-producing ability of UD-6 remained the same after continuous passages and displayed excellent genetic stability.
Milk-Derived Casein Glycomacropeptide Inhibits Ulcerative Colitis in Mice through Apoptosis Resistance
2012, 33(1):  230-234. 
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In order to explore the effect of casein glycomacropeptide (CGMP) on the apoptosis of colonic mucosal cells in mice with oxazolone-induced ulcerative colitis, the mice were treated respectively with CGMP at the doses of 5, 50 mg/(kg·d) and 500 mg/(kg·d) and sulfasalazine at the dose of 40 mg/(kg·d) by gavage for 4 consecutive days to establish high-, medium- and low-dose CGMP groups and positive control group. The same dose of ultra-pure water was once daily given to the normal control and model control groups.  HE staining and TdT2-mediated dUTP nick end labeling (TUNEL) assay were used to evaluate morphological and histological damage as well as epithelial cell apoptosis in the colon of the mice with oxazolone-induced ulcerative colitis. The results indicated that CGMP at each doses revealed obvious improvement on oxazolone-induced ulcerative colitis, and the improving effect at the dose of 50 mg/(kg·d) did not significantly differ from that of sulfasalazine. In conclusion, CGMP, a bioactive substance, has promising potential as a nutritional therapy for ulcerative colitis through apoptosis.
Hepatoprotective, Weight-Reducing and Hypolipidemic Effects of Hovenia dulcis Thunb. Fruit Vinegar
2012, 33(1):  235-238. 
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In order to explore the anti-alcoholic, hepatoprotective, weight-reducing and hypolipidemic effects of Hovenia dulcis Thunb. fruit vinegar, 20 mice were divided randomly into 2 groups: model and treatment groups, which were given 0.15 mL of 52% aqueous alcohol solution 30 min after daily intragastric administration of normal saline and the fruit vinegar at the dose of 0.1 mL, respectively. After 30 days of administration, the mice were killed and their livers were collected and prepared into 10% homogenate for the determination of the contents of GSH and MDA and ADH activity and pathological observation. In addition, another 50 mice were divided randomly into 5 groups of 10 mice each: normal control group, obesity model control group, weight-reducing group treated with Hovenia dulcis Thunb. fruit vinegar, and hyperlipemia model control group and blood lipid-reducing group treated with Hovenia dulcis Thunb. fruit vinegar. The body weight, fat coefficient and serum total cholesterol (TC), triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) of the mice were determined after 30 days of administration. Hovenia dulcis Thunb. fruit vinegar could increase GSH content, improve ADH activity and decrease MDA content in the liver of mice. Meanwhile, Hovenia dulcis Thunb. fruit vinegar could markedly reduce the denaturation of mouse blood lipid, and attenuate the hepatomegaly caused by chronic alcoholism. Moreover, Hovenia dulcis Thunb. fruit vinegar could inhibit the increase of body weight and fat content to realize the weight-reducing function. Furthermore, the fruit vinegar could also prevent arteriosclerosis through reducing blood lipid.
Effects of Grape Seed and Grape Skin Extracts on the Migration of Mouse Mammary Carcinoma Cells
2012, 33(1):  239-243. 
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Objective: To explore the effects of grape seed and grape skin extracts on the migration, viability and proliferation of breast cancer cells. Methods: The viability of mouse mammary carcinoma 4T1 cells was determined by MTT assay and the migration ability by transwell chemotaxis assay. Results: Both grape seed and grape skin extracts significantly reduced the migration of the 4T1 cells in a dose-dependent manner, and exhibited an obvious inhibitory effect on cell migration at a concentration as low as 5μg/mL. The extracts also obviously inhibited the viability and proliferation of the 4T1 cells with IC50 (half maximal inhibitory concentration) of 65.427μg/mL and 72.408μg/mL, respectively.
Hypolipidemic and Liver-Benefiting Effect of Sweet Potato Resistant Starch in Hyperlipidemic Rats
2012, 33(1):  244-247. 
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Objective: To examine whether sweet potato resistant starch (SPRS) lowers blood lipid levels and benefits the liver of hyperlipidemic rats. Methods: Forty SD rats (half male and half female) were randomly divided into 4 groups including normal control group, hyperlipidemia model group, SPRS low-dose group and SPRS high-dose group. Rats fed a normal diet were served as the normal control group and rats fed a high-fat diet as the hyperlipidemia model group. The rats in SPRS groups were administered with SPRS by gavage at the daily doses of respectively 10 g/(kg·d) and 20 g/(kg·d) and also fed a high-fat diet. After 45 days of administration, serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and morphological changes in the liver of all the rats were examined. Results: SPRS could significantly reduce the contents of TC, TG and LDL-C, and increase the content of HDL-C in rat serum. Meanwhile, the liver degeneration and damage of the SPRS groups were markedly attenuated compared with the hyperlipidemia model group. Conclusion: SPRS has an excellent regulatory effect on blood lipid level and enhances the recovery of liver damage in rats with hyperlipidemia.
Effect of Abelmoschus manihot Flavonoids on Blood Lipid Levels of Hyperlipidemic Rats
2012, 33(1):  248-251. 
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Objective: To explore the effect of Abelmoschus manihot flavonoids on blood lipids of hyperlipidemic rats. Methods: Totally 100 SD rats were divided randomly into 6 groups: normal control group, high-fat control group, lovastatin positive control group at the dose of 10 mg/(kg·d), and flavonoid groups at low, middle and high doses (3, 30 mg/(kg·d) and 90 mg/(kg·d)). Except normal the control group, all groups were fed high-fat diet to establish a hyperlipidemia model. Normal control group and high-fat control group were given distilled water at the dose of 10 ml/(kg·d) once a day for 6 consecutive weeks. Serum TC, TG, HDL-C, LDL-C, and ox-LDL were determined after the last administration. Results: Compared with the control group, serum TC, TG, LDL-C and ox-LDL revealed a significantly reduction in all the model groups. However, no significant difference in HDL-C level was observed among these groups. Conclusion: The flavonoids can delay the formation and development of arteriosclerosis.
Protective Effect and Mechanism of Apostichopus japonicus on Kidney of Diabetic Rats
2012, 33(1):  252-256. 
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Objective: To explore the protective effect of Apostichopus japonicus on the kidney of streptozotocin (STZ)-induced diabetic rats and its possible mechanisms. Methods: A diabetic rat model was developed by a single intraperitoneal injection of STZ at the dose of 60 mg/kg and kidney damage was induced by long-term high levels of blood glucose. The diabetic rats were administered with Apostichopus japonicus at the daily dose of 800 mg/kg for 8 consecutive weeks. The changes in fasting blood glucose, urine glucose, renal index, and the excretion amounts of urine protein, mAlb and NAG were determined. The mRNA expression of peroxisome proliferation activated receptor-γ (PPARγ), transforming growth factor beta 1 (TGF-β1) and connective tissue growth factor (CTGF) in kidney were assessed by RT-PCR. Results: Apostichopus japonicus showed remarkable a suppressive effect on fasting blood glucose, uric glucose, kidney index and the excretion amounts of protein, mAlb and NAG in diabetic rats. The expression level of PPARγ mRNA was markedly increased, while the mRNA expression levels of TGF-β1 and CTGF were effectively suppressed by Apostichopus japonicus. Conclusion: Apostichopus japonicus can remarkably reduce blood glucose through improving the expression of PPARγ and restraining the expression of TGF-β1 and CTGF, which results in a protective effect on kidney damage.
Hypolipidemic Effect of Crude Polysaccharides from Perna viridis
2012, 33(1):  257-261. 
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Objective: To investigate the hypolipidemic effect of crude polysaccharides from Perna viridis (PCP) in hyperlipidemic mice and its mechanisms. Methods: Totally 72 Kunming male mice were arbitrarily divided into normal control group, hyperlipidemia model group, positive control group, PCP low-dose group, PCP medium-dose group, and PCP high-dose group. The normal control group was fed normal diet and other five groups were fed high-dat diet. The normal control group and model control group were administered with the same volume of normal saline and the positive control group with simvastatin tablet at the dosages of 5 mg/kg. The low, medium and high dose groups were administered with crude polysaccharides from Perna viridis at the dosages of 50, 100 mg/kg and 200 mg/kg, respectively. All the administrations were carried out once a day for 30 days.  The contents of serum total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C) and NO, the contents of liver TC and TG, and the activities of serum lecithin cholesterol acyltransferase (LCAT) as well as lipoprotein lipase (LPL) and hepatic lipase (HL) in the serum and liver were determined after the last administration. Results: Crude polysaccharides from Perna viridis could decrease the contents of serum TC, TG and LDL-C and AI, increase the contents of serum HDL-C and NO, reduce the contents of liver TC and TG, and enhance the activities of serum LCAT and the activities of HPL and HL in the serum and liver. Conclusion: Crude polysaccharide from Perna viridis can significantly decrease blood lipid and the mechanism may be related to the improved activities of LCAT and LPL and increased levels of HDL-C and NO.
Research Progress in Bovine Casein Glycomacropeptide for the Improvement of Inflammatory Bowel Disease
2012, 33(1):  262-266. 
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Casein glycomacropeptide (CGMP) is mainly a class of peptides bearing carbohydrate chains derived from the hydrolysis of κ-casein by tenet. Because CGMP has many physiological functions and unique nutritional properties, it can be widely used in the fields of functional food and medicine. CGMP has been reported to have anti-inflammatory activity such as improvement and immunotherapy on inflammatory bowel disease (IBD). In this paper, the sources, structural characteristics and current research status of CGMP are outlined. Recent research advances in the regulatory, improving and therapeutic effects of CGMP on IBD are reviewed. Moreover, the future development prospects of CGMP are also proposed.
Research Progress in Safety of Fish Anesthetics
2012, 33(1):  267-270. 
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Fish anesthetics can efficiently reduce the casualty rate of fish during long-distance transportation. Therefore, fish anesthetics have been widely used in fishery production in some countries. However, the residues of such anesthetics and the safety of fish have gained public concerns. In the present paper, the toxicology and the factors affecting accumulation and elimination of anesthetic residues are reviewed. Several prospects and suggestions are also provided for the future application and administration of fish anesthetics in China.
Research Advances in Healthy Functions of Bitter Gourd
Jin Xing-Chen
2012, 33(1):  271-275. 
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As a medicinal and edible plant, bitter gourd is rich in polysaccharides, saponins, peptides, flavonoids and other active ingredients, which execute auxiliary hypoglycemic, blood lipid-lowering, antioxidant, immune-enhancing and other healthcare functions. In this paper, recent domestic and international advances in studying active ingredients of bitter gourd and its healthcare functions are reviewed.
Research Progress in Tea Saponin from Oil Residue of Camellia semiserrata
2012, 33(1):  276-279. 
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 The oil residues of Camellia semiserrata contain functional components such as tea saponin, flavonoids, polyphenols and polysaccharides with various biological activities. Current studies on tea saponin are focused on its isolation and identification. However, its structural identification remains a hot and difficult topic. Tea saponin is a nonionic surfactant and has many functions such as bacteriostasis, insecticidal action antioxidation, anti-inflammation and hemolytic effect. In this paper, the chemical structure, physical and chemical characteristics, surfactant property and biological activity of tea saponin are reviewed. 
Assessment of Health Benefits, Quality and Safety of Traditional Fermented Foods: A Review
2012, 33(1):  280-284. 
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Fermentation, an old and economical method to produce and preserve foods, is widely used all over the world. Fermented foods make an important contribution to human health. With the development of fermentation technology, the safety of fermented foods has gain extensive attention. This article provides a review of the classification of fermented foods and the assessment of their health benefits, quality and safety. Modern microbiological risk assessment (MRA) is one of the extensively used techniques for target statement, hazard identification, exposure assessment, hazard characterization and risk characterization and allows to evaluate the food safety of fermented foods in a more reliable and consistent way.
Research Progress on Peanut Proteins and Their Functional Properties
2012, 33(1):  285-289. 
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The classification, amino acid composition and subunit composition of peanut proteins and extraction methods for major peanut proteins (arachin, conarachinⅡ and conarachin I), including cryoprecipitation and ammonium sulfate precipitation, are overviewed here. The functional properties of peanut proteins, including protein solubility, emulsifying capacity, foaming capacity, gelatin properties, and so on, are reviewed. Finally, problems encountered in studying peanut proteins are summarized and further research directions are proposed. 
Ferritin: A New Mineral Carrier for Supplement
Zhen WANG
2012, 33(1):  290-293. 
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The cavity of apoferritin can be used to transport various minerals. Since this protein can be absorbed by intestinal epithelial cells via entocytosis pathways, it becomes a new promising type of mineral nanocarrier. The process of deferrization for ferritin and mineral loading has been studied by transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (X-Ray), mass spectroscopy (MS), nuclear magnetic resonance (NMR), dynamic light scattering (DLS) and ultraviolet spectroscopy (UV), respectively. Recents applications of apoferritin carriers in the field of nutrition are summarized in this paper.
Lactobacillus Surface Layer Proteins and Research Techniques for Their Adhesion: A Review
2012, 33(1):  294-297. 
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Lactobacillus, an important kind of physiological bacteria in the human body, plays an important role in maintaining human intestinal ecosystem environment and intestinal health. However, the most important premise for lactobacillus to execute its physiological functions is the adhesion on the surface of intestinal cells. More and more studies have showed that S-layer protein has the ability to adhere to intestinal cells. For example, Lactobacillus reuteri can adhere to mucoprotein and HT-9 cells. Various methods such as SDS-PAGE, chromatographic purification, and microscopic observation have been successfully applied to study the adhesion of Lactobacillus to intestinal cells. The applications of surface plasma resonance and immunological techniques to study S-layer protein adhesion have gained extensive attention as a result of the development of new techniques. In this paper, recent research advances in Lactobacillus S-layer proteins and their adhesion are reviewed.
Application of Ultra High-pressure Technology in Aquatic Product Processing
Zhi-He HU
2012, 33(1):  298-304. 
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Ultra high-pressure technology can be used for food sterilization, enzyme inactivation, natural flavor maintenance and texture improvement, which is one of the most popular technologies for food processing all over the world. In this paper, the basic working principle of ultra high-pressure technology and its application in the sterilization, improvement of storage properties and quality and extraction of color substances for aquatic products are introduced and discussed.