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Table of Content

15 September 2012, Volume 33 Issue 17
Bioaccumulation and Speciation Analysis of Selenium in Garlic (Allium sativum L.)
2012, 33(17):  1-5. 
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The bioaccumulation and chemical species of selenium in garlic (Allium sativum L.) were investigated. Total selenium content in garlic bulb and stem were determined. The selenium speciation of garlic was analyzed by water extraction, acid extraction or enzymatic extraction followed by HPLC-ICP/MS. The results showed that total selenium content in garlic was significantly increased from 0.047μg/g to 0.200—0.834μg/g (P<0.05), and total selenium content in stem with 0.043μg/g was significantly increased to 0.291— 0.962μg/g (P<0.05) by foliar application of Se fertilizer. Compared with water and acid extraction, enzymatic extraction was selected for the extraction of Se species as the preferable method. Subsequently, the major selenospecies in regular garlic and Se-enriched garlic were identified as MeSeCys, SeCys2 and SeⅣ. Compared with regular garlic, the major transformed organic selenospecies in Se-enriched garlic by foliar application was MeSeCys, which represented  nearly 81.2% of total selenium in garlic extract. Moreover, MeSeCys from Se-enriched garlic was identified by ESI-MS. However, an unknown selenospecies in acid extract needs to be clarified in future study.
Chitosan Degradation by Pulsed Electric Field in Acetic Acid Homogeneous Phase
2012, 33(17):  6-9. 
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The effects of electric field strength, reaction time, chitosan concentration and solution conductivity on the degradation rate of chitosan were studied by pulsed electric field (PEF) treatment. The results showed that the molecular weight of chitosan revealed a decrease trend with increasing electric field strength, and a significant degradation was observed at high electric field strength. The degradation rate increased up to 54.2% after PEF treatment at 33.3 kV/cm; the degradation rate revealed a reduction with prolonged reaction time by 18.5% and 8.5% over the first 20 min and the last 70 min, respectively. Increasing solution concentration or conductivity was unfavorable for the degradation of chitosan. Infrared spectral analysis indicated that the structure of chitosan was not changed during degradation. The X-ray diffraction patterns of original chitosan and degraded chitosan exhibited a similar structure with characteristic peaks at 2θ of 10.4° and 20.2°, suggesting that degraded chitosan maintains its crystal structure.
Effect of Emulsifiers on Water State and Glass Transition Temperature of Frozen Dough
2012, 33(17):  10-14. 
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Emulsifiers can affect the textural structure and glass transition temperature (Tg) of dough by changing its water state. In this study, the effect of five emulsifiers on water state in dough was by using LF-NMR. Meanwhile, DSC and SEM were used to analyze their effect on the Tg and microstructure after low-temperature storage of dough, respectively. The results showed that emulsifiers could decrease the proportion of free water in dough. The addition of 0.15% DATEM resulted in a 5.78% decrease in free water. In addition, emulsifiers also caused changes in the Tg of dough. Moreover, the Tg of dough with the addition of 0.50% glyceryli monostearici was -17.3 ℃, and revealed an increase of 14 ℃ compared with blank dough. However, the addition of SP60 or lecithin did not cause a significant increase in the Tg of dough. Furthermore, emulsifiers improved the textural structure of frozen dough to different extent. Glass-state storage of frozen dough was achieved by adding 0.50% glyceryli monostearici or 0.15% DATEM and the textural structure of frozen dough was well protected.
Preparation and Structural Characterization of Inclusion Complexes of Amylose with Different Flavor Molecules
2012, 33(17):  15-20. 
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Five inclusion complexes of amylose with C6 through C9 aliphatic alcohols or naphthol were prepared by hot melt method in this study. Amylose was entirely gelatinized at 100 ℃, put into an airtight container along with flavor molecules, held at 80℃ for 6 h, cooled down naturally, centrifugated, and lyophilized to obtain inclusion complexes with a yield of 45%—50%. The inclusion complexes were confirmed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and nuclear magnetic resonance (NMR). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) showed that the inclusion reaction of amylose with n-heptanol yielded the most stable complex. This result was also obtained by using other characterization technologies. Therefore, stable inclusion complexes of amylose with flavor molecules can be prepared by hot melt method. Furthermore, inclusion complexes of amylose with longer-chain fatty alcohols showed a decreased embedding rate.
Effects of Seven Amino Acids on the Elimination of Acrylamide
2012, 33(17):  21-24. 
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Seven amino acids including glutamic acid, glutamine, aspartic acid, asparagine, lysine, glycine and cysteine were used to explore their effects on the elimination of acrylamide generated in heat-initiated reaction model systems. After 30 min of reaction with cysteine at 160 ℃ at a molar ratio of 1.5:1 (cysteine: acrylamide), 99.4% of acrylamide was eliminated. Acrylamide showed an elimination rate of 66.7% and 70.4%, respectively after 30 min of reaction with lysine or glycine at a molar ratio of 5:1. ESI-MS analysis showed the formation of adducts of acrylamide with cysteine, lysine or glycine. Moreover, cysteine could eliminate acrylamide through different pathways.
Effect of Xylanase from S. rameus L2001 on the Properties of Steamed Breads
2012, 33(17):  25-29. 
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In the present study, the effect of xylanase from S. rameus L2001 on the specific volume, extension rate, hardness, moisture content and color of steamed bread was investigated. The results showed that the optimal amount of xylanase in steamed breads was 0.9 mg/kg. The prepared samples had the largest volume and the smallest hardness, and showed a 9.14% increase in specific volume, a 16.39% increase in extension rate, and a 19.0% decrease in hardness compared with the control samples. During the first 10 h of storage, the hardness, cohesiveness, adherence, and chewiness of steamed breads changed slowly, but the hardness obviously increased and the values of cohesiveness, adherence, and chewiness tended to decrease with increasing storage time. The addition of xylanase from S. rameus L2001 at 0.9 mg/kg resulted in decreases in the hardness, cohesiveness, adherence, and chewiness of steamed breads. As a consequence, the ageing of steamed breads was inhibited most obviously.
Ordered Assemblies of Water-Soluble Chitosan as Carriers for Vitamin C
Zhen LI zhong-Ni WANG Wu ZHOU Feng LIU
2012, 33(17):  30-34. 
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Two ordered assemblies of water-soluble chitosan were formed in aqueous solution at various chitosan concentrations and temperatures. Steady and dynamic rheological properties of both assemblies were investigated at different temperatures. Meanwhile, the effect of both assemblies as separate carriers for vitamin C on sustained release and stability of vitamin C was determined. The steady rheological curves indicated that both assemblies had strong pseudoplastic property. The dynamic rheological curves revealed that the assembly I could be fitted with Maxwell model under the condition of low frequency and performed as an elastomer under the condition of high frequency. In the tested frequency range, the loss modulus(G'') of the assembly Ⅱ was always lower than its storage modulus(G'). Therefore, both assemblies allows sustained release and stability maintenance of vitamin C.
Chemical Composition and Antimicrobial Mechanism of Essential Oil from Dendranthema indicum var. aromaticum
2012, 33(17):  35-39. 
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The chemical composition of essential oil isolated from the whole plant of Dendranthema indicum var. aromaticum was investigated by gas chromatography-mass spectrometry (GC-MS), and its antimicrobial activity was evaluated against 4 bacterial strains by filter paper agar diffusion and constant dilution methods. Meanwhile, the antimicrobial mechanism was explored by transmission electron microscopy (TEM) and sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that 149 components were detected in the essential oil and 63 compounds were identified. The major compounds included terpenes (13.99%), alcohols (25.82%), and aldehydes and ketones (3.69%). The essential oil had obvious inhibitory effect on all four tested species of bacteria with an inhibitory ring diameter of 8.15—10.90 mm. Its inhibitory activity against Gram-positive bacteria was much higher than against Gram-negative bacteria. TEM and SDS-PAGE analyses revealed that the antimicrobial mechanism may be achieved by damaging bacterial cell walls, causing deformed bacterial cells and reduced protein content until the cells are broken into pieces.
Qualitative Analysis of Oligomeric Procyanidins from Litchi chinensis Pericarp
2012, 33(17):  40-43. 
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Litchi (Litchi chinensis Sonn.) is a subtropical fruit of high commercial value; however, its pericarp results in a reduced market value. In the present study, oligomeric procyanidins from Litchi chinensis pericarp (LPOPC) were prepared and qualitatively analyzed. LPOPC were extracted with ethanol aqueous solution, purified by AB-8 macroporous resin chromatography, and fractionated by Toyopearl HW-40S resin chromatography to obtain LPOPC. LPOPC was found to comprise three fractions with different degrees of polymerization (DP). The results of FT-IR, HPLC and LC-MS analyses revealed that the major components of LPOPC were (-)-epicatechin, procyanidin A2, procyanidin A3. Highly pure monomer, dimmers and trimers were obtained through selective collection of fractions.
Comparison of Analytical Methods for Evaluating the Stability of Soybean Protein Isolate Emulsions
2012, 33(17):  44-47. 
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Oil-in-water emulsions were prepared by combinations of various concentrations (0.5%, 1%, 2% and 3%) of soybean protein isolate (SPI) with 3% soybean oil. We analyzed the differences of these emulsions in stability under various centrifugal forces and viscosity under various shearing rates. Meanwhile, we evaluated the storage stability of these emulsions by measuring the turbidity, and the changes in particle size and Zeta potential and performing visible and microscopic observations. The above experiments consistently showed that the emulsion with 3% SPI had the best stability. Moreover increasing SPI concentration resulted in higher viscosity and better stability. Despite of having changes during storage, average particle size and Zeta potential were not suitable to be used for evaluating the stability of emulsions. This study further confirms that the centrifugation method allows rapid and accurate prediction of the stability of emulsions and therefore can be used in product development and testing.
Investigation of Salmonella Contamination in Broiler Slaughter and Processing Chain and ERIC-PCR Analysis of Its Sources
2012, 33(17):  48-53. 
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Objective: In the present study, the contamination of Salmonella in the slaughter and processing chain of broilers was investigated and the sources were traced with the aim of determining the critical control points of Salmonella contamination and reducing the risk of foodborn Salmonella infection. Methods: The carcass surface, cloaca and crop contents of broilers, processing environments, and the surface of processing equipment and apparatus were sampled from two broiler slaughter and processing plants (FX and GZ). The routine procedure and PCR were performed for the isolation and identification of Salmonella, then enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) were used for subtyping the isolates and the NTSYS-pc 2.10 software was applied for clustering analysis. Results: The total positive rate of Salmonella in 1171 samples from both plants was 1.37% (16 positive samples). The positive rate of FX samples was lower (0.18%), and showed a significant difference from that of GZ samples (2.39%, P < 0.01). None of the FX samples were found positive for genotype I Salmonella except broiler carcass surface samples. Genotype I Salmonella was detected in samples of carcass surface, cloaca and crop contents, and the surfaces of plucking fingers and eviscerators,s gloves collected from the GZ plant, and genotype III Salmonella was detected in samples from the surfaces of carcass and eviscerators,s gloves, but genotype V and II Salmonella were detected only on the surfaces of transport vehicles and plucking fingers, respectively. Conclusion: Pre-slaughter, defeathering and evisceration are the key stages of Salmonella contamination. Strengthening entry quarantine and the daily hygiene management of equipment and apparatus is helpful for reducing the risk of Salmonella contamination.
Antibacterial Effects of Major Compounds in Essential Oil from Bamboo Leaves
2012, 33(17):  54-57. 
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This paper reports the antibacterial effect of three major monomeric compounds (tricosane, cedrol and hexadecanoic acid) in the essential oil from bamboo leaves. Using agar diffusion method, the antibacterial action of these monomers and their mixtures were studied against different microorganisms: Gram-positive bacteria (Bacillus subtilis), Gram-negative bacteria (Escherichia coli, Pseudomonas fluorescens, Flavobacterium columnare) and yeast. The results showed that cedrol had the strongest antibacterial effect, followed by hexadecanoic acid. The antibacterial effect of combinations of the three monomers was stronger than that seen when they were separately tested. The antibacterial effect of tricosane when used in combination with cedrol was much better than that observed when it was used alone, but slightly lower than that of cedrol alone. Similarly, the antibacterial effect of tricosane was increased by combination with hexadecanoic acid, but was weaker than that of hexadecanoic acid. The antibacterial effect of a mixture of cedrol and hexadecanoic acid was higher than that observed when hexadecanoic acid was tested alone, but slightly lower than that of sole hexadecanoic acid treatment. The antioxidant effect of a mixture of the three monomers was higher than that seen when tricosane and hexadecanoic acid were tested alone, and also higher than that of combinations of two of them.
Physical and Chemical Properties of Starch from Major Summer Millet Cultivars in China
2012, 33(17):  58-63. 
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In order to offer theoretical references for the application of millet starch and the screening of cultivars with good processing suitability, 9 major summer millet cultivars in China were selected to systematically study the granule morphology and size, chemical composition, iodine blue value, light transmittance, freeze-thaw stability, pasting properties, solubility and swelling power, retrogradation properties and other physicochemical properties of starches from these cultivars. The results showed that starch granules from each millet cultivar were single granules with a particle size in the range of 0.48—2.25μm and 3.50—29.32 μm. Starch granules were mostly polygonal though sometimes oval in shape, and displayed clear polarization cross. The different millet cultivars showed an obvious difference in the morphology of starch. The amylose content, iodine blue value, light transmittance, and syneresis rate of the tested millet cultivars were in the range of 2.91%—15.80%, 0.601—0.809, 4.4%—22.3% and 0.77%—62.23%, respectively, with significant differences among these millet cultivars. Moreover, significant differences in starch pasting properties, solubility and swelling power and retrogradation properties were also observed. Therefore, different millet cultivars are specifically suitable for different processing purposes.
Kinetic Model of Chlorophyll Degradation in Cabbage during Drying Process
2012, 33(17):  64-67. 
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A kinetic model was proposed for evaluating the degradation of chlorophyll in cabbage during drying process. After blanching, cabbage was dried at 50, 60, 70, 80 ℃ and 90 ℃, respectively. The content of chlorophyll was the major factor affecting the color of cabbage during drying process. The chlorophyll degradation was fitted to a first-order reaction model with an activation energy of 15391.11 J/mol. The kinetic model of chlorophyll degradation in cabbage was validated with a relative error of 5.58% in comparison with the actual values, indicating high reliability and reasonability, which was reliability and reasonable.
Fruit Quality Analysis of Different Apple Varieties
2012, 33(17):  68-72. 
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Forty-four apple varieties were evaluated for differences in fruit quality indicators including individual fruit weight, flesh weight, edible rate, volume, density, longitudinal diameter, transverse diameter, shape index, core size, L*, a* and b*. Meanwhile, these quality indicators were analyzed by correlation analysis and principal component analysis (PCA). The results showed that the 12 quality indicators revealed a significant difference among 44 different apple varieties. A significantly positive or negative correlation was observed among some of the quality indicators. Three major components with a characteristic value larger than 1 during PCA were extracted and the cumulative variance contribution rate was 82.618%. The first principal component represented fruit size; the second principal component represented skin color and the third principal component represented fruit density, shape index and core size.
Rheological Properties of Hydroxypropyl Cassava Starch Paste
Shan-shan HU
2012, 33(17):  73-77. 
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A C-LTD80 rheometer was used to determine rheological properties of hydroxypropyl cassava starch paste under various conditions of concentration, temperature, heating time and pH. The results showed that hydroxypropyl cassava starch paste was a pseudoplastic non-Newtonian fluid and could be fitted by Herschel-Bulkley model. Increasing hydroxypropyl cassava starch concentration resulted in enhanced non-Newtonian characteristics and increased viscosity coefficient k, while the higher the temperature, the lower the non-Newtonian fluidity, and the smaller the viscosity coefficient. The non-Newtonian fluidity initially increased and then reached a plateau, but viscosity coefficient k tended to increase first and then decrease as the heating time was prolonged. Over the range of pH 2.5-11.5, the non-Newtonian fluidity and the viscosity coefficient k also showed an initial increase followed by a decrease.
Effect of Annealing on Physico-chemical Characteristics of Different Maize Starches
2012, 33(17):  78-81. 
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Maize starches with different amylose/amylopectin ratios (normal maize starch and waxy maize starch) were annealed at 40, 50 ℃and 60 ℃, respectively to study the effect of annealing on physicochemical properties of maize starches. The granular shape of normal maize starch and waxy maize starch was slightly deformed after the annealing treatment. With increasing annealing temperature, the swelling capacity and solubility of both starches revealed a decreasing trend. The viscosity of annealed starches was lower than their native counterparts. Meanwhile, annealing treatment caused an increase in the gelatinization temperature and little change in the gelatinization enthalpy of maize starch.
Properties of Octenyl Succinic Anhydride Modified Starch and Its Application in Chicken Sausages
2012, 33(17):  82-86. 
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Octenyl succinic anhydride (OSA) modified starches with different viscosities were prepared from early indica rice starch in aqueous slurry systems. The pasting property and freeze-thaw stability of the products were analyzed and their application in chicken sausages was evaluated. The results showed that acid hydrolysis of starch followed by OSA modification produced OSA modified starch, which had better freeze-thaw stability than its native counterpart. The texture of sausages with added OSA modified indica rice starch was improved in hardness, springiness and chewiness when compared to sausages with added modified tapioca starch (P < 0.05). SEM observations revealed that sausages with the addition of tapioca modified starch had large pores in its structure and fluffy texture, while sausages with the addition of OSA modified indica rice starch was compact in texture. In summary, OSA modified starch can improve texture characteristics of meat products and consequently holds potential for applications in meat products.
Effect of Extraction Solvents on the Stability of Red Pigment from Red Beet Stems
2012, 33(17):  87-89. 
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Objective: To explore the thermal and light stability of red pigment extracted with different solvents from red beet stems (Beta vulgaris L. var. rubra). Methods: Red pigment from red beet stems was extracted with two different solvents, 80% ethanol solution and distilled water. The resulting extracts were scanned in the wavelength range of 230-700 nm and evaluated for their stability under various temperature and light conditions. Besides, both extracts were analyzed by HPLC. Results: The UV-visible absorption spectra of the aqueous and ethanol extracts displayed two distinct absorption peaks at 270 nm and 538 nm, respectively. The aqueous extract exhibited better thermal and light stability and higher purity than the ethanol extract.
Effect of Microwave Treatment on Relative Activity of Lipase in Pine Pollen
2012, 33(17):  90-93. 
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Effect of microwave treatment on the inactivation of lipase and the retention rate of vitamin C in pine pollen was explored by one-factor-at-a-time and orthogonal array design methods. The results showed that lipase was effectively inactivated by microwave radiation. The optimal conditions for inactivating lipase in pine pollen were initial water content of 14%, microwave power of 324.3 W, and microwave treatment time of 2 min. Under these conditions, the inactivation rate of lipase in pine pollen was 92.4%, and the retention rate of vitamin C was 97.7%.
Separation, Purification and Anti-Aging Activity of Phycocyanin from Porphyra yezoensis
2012, 33(17):  94-97. 
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Objective: To isolate and purify phycocyanin from Porphyra yezoensis and explore the anti-aging activity of phycocyanin. Methods: Phycocyanin from Porphyra yezoensis was purified by salting-out and Sephadex G200 chromatography. The stability of phycocyanin under various pH and temperature conditions was also investigated. D-Galactose induced mouse models of subacute ageing were established and used to study the anti-ageing function of phycocyanin from Porphyra yezoensis. Results: Phycocyanin with the highest purity (1.73) was obtained by salting out with 40% (NH4)2SO4 at room temperature. The hycocyanin extract was stable at 30 ℃ and pH 7.0. Its oral administration resulted in a significant increased in SOD activity, thymus index and spleen index in aging mouse models (P<0.05, P<0.01), and a significant reduction in serum MDA level (P<0.05, P<0.01). Conclusion: Phycocyanin from Porphyra yezoensis has excellent anti-aging activity.
Antimicrobial Activity of Chinese Yellow Wine against Escherichia coli in Simulated Stomach Acid
2012, 33(17):  98-100. 
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This study focused on the antimicrobial activity of Chinese yellow wine and its major components (alcohol and organic acids) against Escherichia coli in simulated stomach acid. The results showed that Chinese yellow wine had remarkable antimicrobial activity. The survival rate of Escherichia coli was reduced to 1% and 0.002% after 120 min treatment with 30 mL and 130 mL of yellow wine, respectively compared with the blank control (100% survival rate). The antimicrobial activity of organic acids in Chinese yellow wine (such as malic, acetic, oxalic and lactic acids) observed when tested separately was stronger than that of alcohol. Moreover, organic acids in Chinese yellow wine showed a synergistic effect with alcohol.
in vitro Antioxidant Activity of Proanthocyanidins in Syzygium cumini Fruits
ZHANG Jing
2012, 33(17):  101-105. 
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The antioxidant activity in vitro of proanthocyanidins purified from S. cumini fruits by semi-preparative HPLC was assessed in the present study. The results showed that the IC50 values of proanthocyanidins from S. cumini fruits obtained in DPPH, superoxide anion and hydroxyl radical assays were 4.448, 5.718 μg/mLand 60.490 μg/mL, respectively. An IC50 of 117.091 μg/mL was obtained in anti-linoleic acid peroxidation assay. The total antioxidant capacity and reducing power were significantly higher than those of vitamin C, and the metal-chelating activity was better than that of EDTA. These findings suggest that proanthocyanidins from S. cumini fruits have strong free radical scavenging and antioxidant activities in vitro.
Influence of Injection of Water and Calcium Chloride Solution on the Color and Color Stability of Pork
2012, 33(17):  106-111. 
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Purpose: To investigate the effects of injection of water and calcium chloride (CaCl2) solution on the color and color stability of chilled pork longissimus dorsi muscle during storage. Methods: At 1.5 h postmortem, pork longissimus dorsi muscle was injected 200 mmol/L CaCl2 solution or pure water at a dose of 5%, tray-packaged, and stored at 4 ℃. Total pigment content, a* value, relative metmyoglobin (MetMb) percentage, and MetMb reductase activity were measured during storage. Results: CaCl2 injection reduced a* value, total pigment content, MetMb reductase activity and LDH-B activity, increased relative MetMb percentage and MDA content during storage. Water injection reduced total pigment content and MetMb reductase activity and increased relative MetMb percentage during storage. Conclusions: Both CaCl2 and water injections result in a reduction in total pigment content and an increase in relative MetMb percentage and accordingly accelerate the discoloration of pork longissimus dorsi muscle, which is unfavorable to the maintenance of fresh meat color during chilled storage.
Dynamics and Thermodynamics of Adsorption of Cholesterol on Superfine Powder of Astragalus membranaceus Radix
Xu Huai-De
2012, 33(17):  112-117. 
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In this study, the effects of superfine powdered Astragalus membranaceus radix-to-cholesterol solution ratio, adsorption time, particle size of superfine powdered Astragalus membranaceus radix, initial cholesterol concentration and temperature on the adsorption of cholesterol on superfine powdered Astragalus membranaceus radix. Meanwhile, the adsorption process was dynamically and thermodynamically analyzed. Good results were obtained after 60 min adsorption of 1.50 mg/mL cholesterol solution by superfine powdered Astragalus membranaceus radix at ratio of 1:30 (m/V) and 25 ℃. Under these conditions, the maximum adsorption quantity was 15.60 mg/g. Therefore, the adsorption process is a spontaneous process in which physical adsorption is dominant and easily occurs. Furthermore, surface absorption was dominant at low cholesterol concentrations, but both surface adsorption and intraparticle diffusion were dominant at high cholesterol concentrations.
Structural Analysis of Major Anthocyanins in Black Sunflower Seed Shell
2012, 33(17):  118-121. 
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The structures of major anthocyanins purified from black sunflower seed shell were analyzed by HPLC and HPLC-tandem quadrupole mass spectrometry (HPLC-MS/MS). Two major monomers were observed in purified anthocyanins. Both monomers were further separated by paper chromatography (PC). They were identified as cyanidin-3-O-monoglucoside and peonidin-3-O-monoglucoside, respectively according to the results of infrared spectroscopy (IR), ultraviolet spectroscopy (UV) and Francis studies and HPLC-MS/MS analysis.
Quality Analysis of Chinese Quince (Chaenomeles sinensis Koehne) Based on Data Mining Technology
2012, 33(17):  122-124. 
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Chinese quince fruits collected from 10 growing areas in Baihe County, Shaanxi Province were analyzed by HPLC to establish fingerprint profiles. The information obtained was analyzed by digital processing. The similarity of these samples was analyzed and the different growing areas were assigned by cluster analysis to three categories. Meanwhile, a general fingerprint profile model was proposed in which 11 common peaks were found. Therefore, combined HPLC fingerprinting and cluster analysis can provide a new analytical method for quality evaluation of Chinese quince.
Physical Properties of Oxidized Caffeic Acid Cross-Linked Whey Protein Films
2012, 33(17):  125-128. 
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Oxidized caffeic acid (OCA) was used to cross-link whey proteins for making cast films. The prepared films were analyzed for mechanical properties, water binding capacity, and protein solubility in Mc,Ilvaine buffer (pH 3 to 7) and the molecular weight of leached fractions. The results showed that the tensile strength, Young’s modulus and water binding capacity of films was markedly increased but its extensibility was not affected by the OCA incorporation. The degree of swelling significantly increased with increasing OCA concentrations. The protein solubility (leachability) of OCA-treated films slightly decreased at pH 3-5 but noticeably increased at pH 6 and 7 compared to untreated (control) films. Electrophoresis indicated that disulfide-linked proteins were the dominant components in leached fractions in pH 6 buffer solution.
Isolation, Identification and Biological Characterization of a Strain of Alicyclobacillus from Orchard Soil in Shaanxi
2012, 33(17):  129-135. 
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The aim of this study was to isolate Alicyclobacillus from orchard soil collected from apple farms in Shaanxi province, China and to study the distribution of Alicyclobacillus. A strain of Alicyclobacillus was isolated by using a YSG medium acidified with sulphuric acid. The morphology, cultural characteristics and physiological characteristics of the isolate were tested and the carbohydrate fermentation and enzyme profile were investigated by API ZYM and APY 50CHB System. The fatty acid composition was analyzed by GC. In addition, a phylogenetic tree was constructed by 16S rDNA sequence analysis. The strain of Alicyclobacillus was basically consistent with the reference stain Alicyclobacillus acidoterrestris DSM 3922T in morphology, and showed high similarity in enzyme profile, but great differences in carbohydrate fermentation performance. 16S rDNA sequence analysis indicated that both strains belonged to different species of the same genus. Moreover, the isolated strain shared a homology of 99% with the reference strain. In conclusion, the internationally recognized method for Alicyclobacillus isolation in combination with API System, fatty acid composition analysis and 16S rDNA sequence analysis permits rapid isolation and identification of Alicyclobacillus. As expected, Alicyclobacillus is distributed in orchard soil, which may pose a threat to the quality of fruit juice.
Prediction of Cathepsin B and L Activities in Cured Silver Carp during Drying Using Response Surface Methodology
2012, 33(17):  136-140. 
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The activities of cathepsin B and L in cured silver carp (Hypophthalmichthys molitrix) were determined during curing and heat pump drying. Three process parameters (temperature, pH and salt concentration) were identified as main variables that influence the activities of cathepsin B and L. According to the properties of both enzymes and the results of physiochemical analysis of cured silver carp during drying, different levels of the main variables were selected to study their effects on the activities of cathepsin B and L by response surface methodology. A separate predicative regression model for the activities of both cathepsin enzymes was proposed and applied. The results indicated that the proposed regression models could be used to predict the activities of cathepsin B and L. The activities of both enzymes in cured silver carp showed a downward trend during processing and 43.18% and 26.08% of their original activities were retained at the end of the drying stage, respectively. The actual activity of cathepsin B before curing, after curing, and after drying for 2, 5 d and 7 d was 36.7%, 39.9%, 46.5%, 46.5% and 53.5% of its potential activity, respectively; the actual activity of cathepsin L at these time points was 6.6%, 5.6%, 10.4%, 10% and 12.6% of its potential activity, respectively as demonstrated by model predictions. 
Effect of Citric Acid on Relative Activity and Kinetic and Browning Parameters of Polyphenol Oxidase
2012, 33(17):  141-144. 
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The effect of different concentrations of citric acid treatment on the relative activity, kinetic parameters (Km and Vmax) and browning parameters (Hue, Chroma and BI) of polyphenol oxidase (PPO) from mushroom. The results showed that the relative activity of PPO decreased gradually with increasing citric acid concentration and was only 1% of its original activity at 70 mmol/L. In the presence of citric acid, the reaction rate of PPO showed a gradual increase with increasing concentration of catechol, the substrate and reached its maximum level at a substrate concentration of 15 mmol/L. However, the Km remained basically unchanged despite an increase in citric acid concentration, while the Vmax gradually decreased. Lineweaver-Burk plots demonstrated that the Vmax values of PPO in the presence of citric acid at concentrations of 0, 20 mmol/L and 40 mmol/L were 578.4, 437.8 U/min and 111.6 U/min, respectively, suggesting that citric acid is a non-competitive inhibitor for the reaction between PPO and catechol. Increasing citric acid concentration resulted in small changes in L* and a* and a sharp decrease in b*. The b* values from browning catalyzed by PPO in the presence of 40 mmol/L and 70 mmol/L citric acid were reduced to 57.5% to 13.7% of its origin value observed when citric acid was absent. In addition, Hue, Chroma and BI (browning index) presented a dramatic decline as well. These consistent changes implied that relative activity and Vmax had direct correlations with b*, Hue, Chroma and BI.
Cloning and Molecular Characterization of f3′h Gene in Dendranthema morifolium
2012, 33(17):  145-149. 
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Dendranthema morifolium ‘chuju’, a traditional Chinese medicine resource unique to Chuzhou, Anhui, was used to clone flavonoid 3′-hydroxylase (f3′h) gene with a registration number of HQ256697 in NCBI by homology-based cloning strategy in this study. The results showed that a separate 381 bp DNA fragment was amplified by polymerase chain reaction (PCR) from three‘chuju’ samples collected from different places. Sequence analysis showed that the amplified DNA fragments were closely homologous to the 3rd exon of f3′h gene in Chrysanthemum morifolium (GU249553) at a homology rate of 98.69% for nucleotide sequences. Five SNPs in the homology area were observed, and only 3 of them resulted in amino acid sequence variations. The homology rates of nucleotide and amino acid sequences between Dendranthema morifolium‘chuju’and Sorghum bicolor, Brassica napus, Ipomoea nil Magenta, Malus domestica or Ipomoea purpurea were 60%~98% and 68%~97%, respectively. The classification of f3′h gene in different plants was significantly related to their genetic relationship. The f3′h gene of Dendranthema was more advanced than that ofother plants in system evolution.
Secondary Structure of Bifunctional Chitosanase-Cellulase from Trichoderma viride as Determined by FT-IR Spectrometry
2012, 33(17):  150-153. 
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The secondary structure of two bifunctional chitosanase-cellulase enzymes (CCBEⅠ and CCBEⅡ) from Trichoderma viride was explored by FT-IR spectroscopy. Amide Ⅰ and Ⅲ FT-IR bands allowed prediction of the secondary structure of CCBE. The errors of determination for α-helix and β-sheet contents in CCBEs were less than 2% and 4%, respectively. The quantitative analysis of CCBEⅠ revealed that the amino acid sequence was consistent with the results of circular dichroism analysis and Garnier-Robson prediction. The β-sheet content was approximately 70% in CCBEⅠ, while the β-sheet and α-helix contents of CCBEⅡ were approximately 53.6% and 14.6%, respectively. The measurement errors of α-helix and β-sheet of CCBEs were less than 2% and 4%, respectively.
Effects of Some Food Additives on Biofilm Formation of Food-Borne Staphylococcus aureus
2012, 33(17):  154-157. 
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To investigate the effect of food additives on biofilm formation (BF), Staphylococcus aureus (S.aureus) from spoiled food were isolated and identified. BF of this strain was tested in 96-well microplates in the presence of food additives. The results showed that BF of the strains was inhibited by low concentrations of preservatives (potassium sorbate and sodium benzoate). No biofilm was formed when the concentration of anticorrosive reached 0.4 g/L or higher. The BF inhibiting capacity of potassium sorbate was much greater than that of sodium benzoate. Generally, glycol mannate sulfate had greater BF inhibiting action than diacylglycerol at concentrations of 2—4g/L. Glycol mannate sulfate and diacylglycerol had maximum BF inhibiting capacity at concentrations of 3 g/L and 4 g/L, respectively. For sucrose ester emulsifier, SE7 and SE13 inhibited BF at concentrations of 0.3—4 g/L, while SE11 inhibited BF at all concentrations tested. Nonionic surfactants such as Span-60 and Tween-80 showed different effects on BF of S.aureus, which might be related to their amphipathic property. In summary, all these tested food additives had inhibitory effect on biofilm formation of food-borne S. aureus. This study will provide references for the prevention and control of bacteria biofilm formation.
Isolation, Purification and Characterization of Cellulases from Streptomyces Strains in the Gut of the Termite Odontotermes formosanus
Huo GuangHua
2012, 33(17):  158-164. 
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An exoglucanase (C1), two endoglucanases (Cx) and a β-glucosidase (βG) were isolated from the fermentation broth of two Actinomycete strains in the gut of the termite Odontotermes formosanus. These enzymes were purified sequentially by ammonium sulfate precipitation, and Sephadex G100 and DEAE-Sephadex A50 column chromatographies. Both Actinomycete strains were identified as belonging to Streptomyces spp. based on their morphological, growth, physiological and biochemical characteristics. The molecular masses of C1, two Cx enzymes and βG were determined by SDS-PAGE to be 76.9, 22.3, 66.2 kD and 31.9 kD, respectively. The optimal pH was 5.6 for C1 and 5.0 for Cx and βG, respectively; the optimal reaction temperature was 50 ℃ for Cx and C1, and 40 ℃ for βG, respectively. Moreover, these enzymes retained more than 50% activity even at a temperature as high as 70 ℃. These enzymes could be activated by Fe2+ and Ca2+, but inhibited by Mn2+, Cu2+, Zn2+ and Co2+. These results indicate that these cellulases originated from Streptomyce strains in O. formosanus gut are acidic, heat-tolerant enzymes and that their prosthetic groups may be Fe2+ and Ca2+. Therefore, these enzymes has potential in industrial applications for the decomposition of insoluble cellulose.
Expression and Activity Analysis of Bile Salt Hydrolases from Lactobacillus plantarum ST-Ⅲ
2012, 33(17):  165-168. 
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In vertebrates, bile salt hydrolysis plays an essential role in fat metabolism. Bile salts are synthesized in the liver. In the small intestine, glycine or taurine are de-conjugated from bile salts by the enzyme bile salt hydrolase (BSH, EC 3.5.1.24) from intestinal microbes, which reduces the serum cholesterol level. In this study, four predicted bile salt hydrolase (bsh) genes from Lactobacillus plantarum ST-III were cloned into pET-28b(+) vector and expressed in Escherichia coli. The hydrolysis activity of these enzymes was 29.00, 20.49, 24.90 U/mL and 21.13 U/mL, respectively.
Fermentation of Wheat Bran to Prepare Dietary Fiber
2012, 33(17):  169-173. 
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High quality wheat bran dietary fiber (DF) has been reportedly by microbial fermentation to decompose, convert and utilize celluloses, proteins and starches in wheat bran. The effects of fermentation with individual and mixed strains of R. oryzae, T. reesei and A. niger on the contents of soluble and insoluble dietary fiber (SDF and IDF) was examined. An orthogonal array design was employed to optimize process parameters for mixed strain fermentation. The results indicated that mixed strain fermentation was better than single strain fermentation. The SDF content was increased from 11.74% to 86.94% by fermentation with a 10% inoculum (T. reesei:A. niger = 1:1) at a material-to-liquid ratio of 1:10 and 32 ℃. The obtained product showed a water-holding capacity of 9.34 g/g and a swelling property of 12.46 mL/g and met the requirements of high quality dietary fiber.
Optimization of Determination Conditions for Phospholipase Activity
2012, 33(17):  174-178. 
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To establish a method to determine the activity of phospholipase Lecitase?Ultra using oil-free phospholipids as the substrate, three reaction parameters including time, temperature and pH were optimized by response surface methodology based on one-factor-at-a-time experiments. A quadratic regression model for phospholipase activity was proposed. The results showed all these parameters had an extremely significant effect on phospholipase activity. The optimal conditions for determining phospholipase activity required substrate concentration of 4 g/100 mL, final pH 9.0, enzyme dilution factor of 100, reaction pH 5.1, reaction temperature of 53 ℃ and reaction time of 8 min.
Optimization of Fermentation Conditions for the Production of Glycerol from Saccharomyces cerevisiae
2012, 33(17):  179-183. 
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In order to improve the production of glycerol from Saccharomyces cerevisiae D254, the effect of fermentation conditions such as initial glucose or fructose content, pH, temperature and SO2 amount on the yield of glycerol were explored by one-factor-at-a-time and Plackett-Burman array design methods. The optimal fermentation conditions for the production of glycerol  were 216 g/L initial glucose, 144 g/L fructose, fermentation pH 3.0, fermentation temperature 32 ℃ and 40 mg/L SO2. Under these conditions, the highest yield of glycerol was achieved, 655.64 μmol/L.
RAPD Typing of Enterohemorrhagic E. coli Mutants
2012, 33(17):  184-187. 
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Four enterohemorrhagic Escherichia coli (EHEC) strains were analyzed by random amplified polymorphic DNA (RAPD) method, and the reliability of genotyping of pathogenic E. coli by RAPD was discussed in terms of the major toxic genes, eae and hly and Shiga toxin titer. Two of the test strains carried stx genes but did not express Shiga toxins. Of them, one mutant strain, O157 EC169, had a similar RAPD profile with the other two O157 strains which could express Shiga toxins, while the other mutant, O157 EC130 revealed significant cluster difference from other strains. Several primers with strong repeatability and polymorphism that are available for fast identification of E. coli pathogenic bacteria and the food poisoning traceability were selected from 20 random primers.
Combined Mutation Screening of High Yield Strain for Pullulan Production
2012, 33(17):  188-192. 
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Aureobasidium pullulans AP8, an original strain conserved in our laboratory, was treated with both EMS (ethyl methyl sulfonate) and UV (ultraviolet) to screen a high yield strain for pullulan production. The best mutation results were obtained through EMS treatment for 40—60 min at a final concentration of 0.4 mol/L followed by UV irradiation for 1.5—2.5 min at a distance of 30 cm. A genetically stable mutant named as UV60 was obtained which is high in pullulan production (22.1 g/L) and low in pigment content. The mutant strain was markedly superior to the starting strain AP8 in terms of colony color, size and texture as well as fermentation performance. Using one-factor-at-a-time and orthogonal array design methods, the optimal shake fermentation medium for this mutant to produce pullulan was composed of 50.0 g/L sugar, 1.5 g/L yeast extract, 1.5 g/L NaCl, 0.3 g/L MgSO4, 2.0 g/L K2HPO4 and 0.7 g/L (NH4)2SO4, resulting in a pullulan yield of 27.24 g/L and a conversion rate of 54.48% for polysaccharides.
Effect of Juglone on the Cell Membrane of Escherichia coli
2012, 33(17):  193-197. 
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Juglone (5-hydroxyl-1,4-naphthalene hydroquinone), a natural antibacterial compound, has reportedly showed  antibacterial effect on many microbial species. However, its antibacterial mechanism has never been reported. In this study, the effect of juglone on the cell membrane of Escherichia coli during culture in the presence of juglone at various concentrations was evaluated in terms of relative conductivity, protein content, K+ and Na+ efflux, and also examined under transmission electron microscopy (TEM). The results showed that juglone increased membrane permeability and therefore resulted in an outflow of charged ions and protein. Compared with the control samples, K+ and Na+ concentrations revealed a significant change. TEM observation exhibited that E. coli cells were destroyed by juglone, causing thin cell membrane, blurred cell boundary and outflowed cytoplasm. In addition, increasing juglone concentration could result in more obvious damage to the cell membrane in E. coli. In conclusion, the inhibitory activity of juglone is directly related to its damage to the cell membrane of E. coli.
Isolation, Purification and Characterization of Lysozyme from Duck Egg White
2012, 33(17):  198-202. 
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Lysozyme was purified from duck egg white by ammonium sulfate precipitation, CM-Sepharose chromatography and Superdex-200 gel filtration chromatography. The specific activity, yield and purification fold of lysozyme were 33687.26 U/mg, 28.00% and 109.44, respectively. The molecular weight of lysozyme was estimated as approximately 14.82 kD. The optimal pH and temperature against Micrococcus lysodlekticus were 7.0 and 50 ℃, respectively. The enzyme was stable at temperatures below 50 ℃ and pH 5.0—9.0. The apparent Km determined by Lineweaver-Burk method under the optimum conditions was 0.0864 mg/mL. The activity of lysozyme was inhibited by Mg2+, Mn2+, or Fe2+, and enhanced by Zn2+, Cu2+ or Co2+.
Optimization of Liquid Medium for Pleurotus abalonus
2012, 33(17):  203-206. 
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In this study, the appropriate carbon and nitrogen sources were selected from six carbon sources and seven nitrogen sources, respectively for optimizing liquid culture medium for the growth of mycelia of Pleurotus abalones and the production of exopolysaccharide. The optimal fermentation medium formula was evaluated by orthogonal array design method in terms of mycelium biomass and exopolysaccharide yield. The results showed that the optimal liquid medium (100 mL) for the growth of mycelia consisted of 2 g of brown sugar, 0.3 g of yeast extract and 0.1 g of MgSO4. The optimal liquid medium (100 mL) for the production of exopolysaccharide was composed of 2 g of fructose, 0.3 g of beef extract and 0.1 g of KH2PO4.
Activity and Browning Inhibition of Polyphenol Oxidase from Purple Sweet Potato
2012, 33(17):  207-211. 
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Purple sweet potato is prone to browning during processing. pH, temperature, ascorbic acid and citric acid concentrations were investigated to control browning during the extraction of anthocyanins and starch from purple sweet potato. The results indicated that the optimal pH and temperature for the activity of polyphenol oxidase (PPO) of purple sweet potato were 5.5—7.5 and 30 ℃, respectively. The optimal inhibitory condition for browning was blanching at 80 ℃ for 10 min with 0.9‰ ascorbic acid and 1.2 g/L citric acid.
Effect of Intense Pulsed Light Irradiation on Membrane Damage and Intracellular Enzyme Activities in Aspergillus niger
2012, 33(17):  212-215. 
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This study was designed to investigate changes in the membrane permeability and intracellular enzyme activities of Aspergillus niger before and after intense pulsed light irradiation. The results indicated that protein spillage and MDA leakage in Aspergillus niger suspension after intense pulsed light irradiation revealed an obvious increase when compared with the control group. Meanwhile, uneven and wrinkle cell membranes and walls were observed by transmission electron microscopy. Moreover, the activities of dehydrogenase and other major intracellular antioxidant enzymes also revealed a decreasing trend. Therefore, the destruction of the barrier structure of mold could result in changes in the osmotic pressure and cell membrane permeability, thus leading to changes to intracellular substances, and even cell death.
Immobilization of Lysozyme onto AB-8 Macroporous Resin and Its Enzymatic Characterization
2012, 33(17):  216-220. 
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AB-8 macroporous resin was used as a carrier to immobilize lysozyme by glutaraldehyde cross-linking. The preparation conditions, enzymatic characteristics, microstructure and antimicrobial efficacy of immobilized lysozyme were explored. Immobilized lysozyme prepared by 4 h immobilization at 25 ℃, an enzyme-to-carrier ratio of 1:200 and a glutaraldehyde concentration of 0.3 g/100 mL presented the highest relative activity. The immobilized lysozyme showed significant improvements over free lysozyme in heat and acid tolerance. Trough a comparative analysis of their Michaelis Menten Equations, we found that immobilization resulted in a decrease in the affinity of lysozyme with chitosan, the substrate. After fifth repeated use, the immobilized lysozyme retained 57.6% of its original activity. The immobilized enzyme had good antimicrobial effect on pure milk.
Optimization of Fermentation Medium for Pullulan Production by Response Surface Methodology
2012, 33(17):  221-224. 
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The aim of this study is to optimize the fermentation medium for enhancing pullulan production by Aureobasidium pullulans. Important medium components affecting pullulan production were identified by one-factor-at-a-time analysis and further optimized by response surface analysis based on a Box-Behnken design. Sucrose (carbon source) and yeast extract (nitrogen source) concentration and metal ion type had significant effects on pullulan production (P < 0.05). There was a significant interaction effect between sucrose and yeast extract concentration, but no significant interaction effects were observed between metal ion type and sucrose or yeast extract concentration. The optimized fermentation medium was composed of 56.63 g/L sucrose, 3.74 g/L yeast extract and Mg2+, resulting in a pullulan yield of 60.358 g/L.
Optimization of Fermentation Conditions for Enzymes Production by Rhizopus ERh3421
2012, 33(17):  225-228. 
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The effects of initial medium pH, culture time and temperature, and corn flour concentration in the medium on the production of saccharification enzyme, liquefaction enzyme and protease by Rhizopus ERh3421 were explored in the present study. To enhance the production of saccharification and liquefaction enzymes, initial medium pH, culture temperature and corn flour concentration in the medium were optimized using an L9 (33) orthogonal array design. The results obtained were analyzed by one-way analysis of variance. The optimal culture conditions for enhanced enzymes production were initial medium pH 5.2, 30 ℃ and 5 g/100 mL of corn flour concentration in the medium. Under these conditions, the activities of saccharification and liquefaction enzymes in fermentation broth were 9.43 × 103 U/g and 6.83 × 103 U/g, respectively.
Optimization of Fermentation Conditions for Polypetide Production from Sika Deer Placenta
Si-Wen Qin
2012, 33(17):  229-233. 
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Sika deer placenta was fermented with Bacillus subtilis to produce polypeptides. The fermentation conditions were optimized by one-factor-at-a-time method and response surface methodology based on polypeptide yield and degree of hydrolysis. The optimal fermentation conditions were determined as 2% of inoculum size, initial medium pH 7.5, 31 ℃ of fermentation temperature, 53 h of fermentation time, and 130 r/min of shake flask speed. Under these conditions, the actual polypeptide yield was 55.43%.
Effects of Different Types of Light and Nitrogen Source on the Growth and Pigment Production of Serratia marcescens y2
2012, 33(17):  234-240. 
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The effects of different types of light (sunlight, darkness, red, yellow, blue and green) and nitrogen source (ammonium chloride, glycine, potassium nitrate, urea, lactalbumin hydrolysate and yeast extract) on the growth and pigment production of Serratia marcescens y2 were studied by solid-state culture and spectrometry. The results showed that darkness was favorable for microbial growth and pigment production. Green light resulted in the lowest biomass of Serratia marcescens y2 among all monochromatic lights tested along with large amounts of pigment leaks out of the cells and a high degree of leaking pigment. Conversely, red light caused the smallest change in the biomass of Serratia marcescens y2 and consequently, the least amount of pigment leaks and a low degree of leaking pigment were found. These findings demonstrate that the strain produces red pigment and therefore absorbs green light in the largest quantity, leading to the occurrence of photooxidative damage and consequent pigment leakage. All organic nitrogen sources tested had a growth-promoting effect on Serratia marcescens y2. All the organic nitrogen sources expect yeast resulted in an increase in pigment production by the strain and of them, glycine was the best source. Moreover, more pigments were produced by this strain in the presence of glycine compared to inorganic nitrogen sources. There results suggest that glycine can promote pigment production and the accumulation of pigments with different structures by altering their synthetic pathways.
Anti-Alcohol Function of Corn Peptides Produced by Continuous Enzymatic Membrane Reaction
2012, 33(17):  241-245. 
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The purpose of this study was to comparatively assess the anti-alcohol function of corn peptides (CPs) produced by continuous or intermittent enzymatic membrane reaction (EMR) in animals. Righting reflex and anti-alcohol tests were carried out with mouse models and Haiwangjinzun (HWJZ), a commercial anti-alcohol drug in China, was used as a positive control to observe ebriety rate and ebriety time. Besides, serum alcohol level and hepatic alcohol dehydrogenase (ADH) activity were measured. The results showed that CPs produced by continuous EMR could highly significantly shorten the ebriety time of mice, decrease the level of alcohol in the serum, and activate the activity of ADH in the liver (P <0.01). Taken together, our results demonstrate that CPs has an excellent anti-alcohol function. Furthermore, the anti-alcohol function of CPs produced by continuous EMR is superior to that of those produced by intermittent EMR. CPs administration shortly after alcohol consumption is more effective. The anti-alcohol function of CPs produced by continuous EMR at a dose of 300 mg/kg is comparable to that of HWJZ at 450 mg/kg. Thus, CPs produced from continuous EMR can be considered as an excellent anti-alcohol drug.
Thrombolytic Function of Fermentation Broth of Flammulina velutipes
2012, 33(17):  246-248. 
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Objective: To explore the thrombolytic function of fermentation broth of Flammulina velutipes (FV). Methods: The fibrinolytic and clot liquefaction activity of the fermentation broth in vitro was measured, and its effect on bleeding time and coagulation time in Kunming mice were evaluated. Meanwhile, its effect on blood lipids was also evaluated in hyperlipidemic animal models. Results: The fermentation broth had fibrinolytic activity, and could prolong coagulation time and bleeding time, and reduce serum levels of total triglycerides and total cholesterols in hyperlipidemic animals. Conclusion: FV fermentation broth has thrombolytic function due to its anticoagulant, hypolipidemic and fibrinolytic functions.
Effect of Polysaccharides from Branchiostoma belcheri on Lymphocyte Proliferation and Antioxidant Activity in S180-Bearing Mice
2012, 33(17):  249-252. 
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Objective: To explore the monosaccharide composition of polysaccharides extracted from Branchiostoma belcheri (PBBs), and the effect of PBBs on lymphocyte proliferation and antioxidant activity in S180-bearing mice. Methods: Polysaccharides were isolated from Branchistoma belcheri by enzymatic hydrolysis and alcohol precipitation. The monosaccharides obtained by alcoholysis with HCl-CH3OH from PBBs were determined by gas chromatography with internal standard method. S180-bearing mouse models were established and the model mice were randomly divided into six groups including model group, normal group, PBBs groups (25, 50, 100 mg/(kg·d)) and cyclophosphamide group. The tumor inhibition rate of S180-bearing mice was determined. The effect of PBBs on spleen lymphocyte proliferation was evaluated by MTT assay. The contents of SOD, MDA and GSH-Px in mouse plasma were determined using test kits. Results: The purity of PBBs was determined to be 89.3%. The neutral monosaccharides included rhamnose, xylose, fucose, mannose, glucose and galactose. PBBs administration at daily dosages of 25, 50, 100 mg/kg for 2 consecutive weeks could inhibit the growth of S180 sarcoma with inhibitory rates of 39.1%, 47.5% and 53.4%, respectively. Meanwhile, PBBs revealed an obvious reduction in MDA content and a significant increase in plasma SOD and GSH-Px activities. Conclusion: Branchiostoma belcheri is rich in PBBs that function to inhibit the growth of S180 sarcoma through enhancing spleen lymphocyte proliferation and antioxidant activity in S180-bearing mice.
Effect of Bacillus subtilis JS01 Ingestion on Intestinal Flora and Lipofuscin in Obese Mice
2012, 33(17):  253-257. 
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This study was undertaken to observe whether or not Bacillus subtilis JS01 ingestion has a positive therapeutic effect on high-fat diet caused intestinal flora disorder, obesity, lipid peroxidation and fat deposition in mice. Male mice were used to create experimental obesity model groups (C through F) and different doses of Bacillus subtilis JS01 were fed to low-, middle- and high-dose intervention groups (D, E and F), respectively. The results showed that Bacillus subtilis JS01 supplementation resulted in a significant reduction in the body weight of intervention group F and in the weight gain of intervention groups E and F. High-fat diet model group C showed an increase in intestinal Bifidobacteria level, a decrease in intestinal Lactobacillus level, remarkable hepatic steatosis, and a rise in hepatic lipofuscin. Oral administration of Bacillus subtilis JS01 could decrease intestinal Bifidobacteria and Lactobacillus levels, relieve hepatic steatosis and reduce hepatic lipofuscin. In conclusion, Bacillus subtilis JS01 can improve high-fat diet caused obesity, intestinal flora disorder, lipid peroxidation and fat deposition in mice.
Comparison of Nutrient Composition in Muscles of Wild and Farmed Yellowcheek Carp
2012, 33(17):  258-262. 
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A comparative analysis on the nutrient composition of muscles of wild and farmed yellowcheek carp was carried out in the present study. The results showed that wild and farmed yellowcheek carp muscles did not significantly differ in water content (P = 0.07779 > 0.05). Wild yellowcheek carp was significantly higher in the contents of crude protein and ash than farmed yellowcheek carp (P= 0.00115, 0.00415 < 0.05), while crude fat content in farmed yellowcheek carp was significantly higher than in wild yellowcheek carp (P= 0.000215 < 0.05). The essential amino acid index of farmed yellowcheek carp muscle was 94.16 compared with 66.03 for mild yellowcheek carp muscle. Both values meet the FAO/WHO requirements. The total percentage of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in wild and farmed yellowcheek carp muscles represented 4.25% and 4.8% of total fatty acids, respectively. Taken collectively, the results obtained suggest that farmed yellowcheek carp is superior to wild yellowcheek carp in terms of both amino acid composition and total content of EPA and DHA, while wild yellowcheek carp is superior in terms of protein content and n-3/n-6 PUFA ratio.
Comprehensive Evaluation of Nutrition and Health Functions and Safety of Soybean by Benefit-Damage Index
2012, 33(17):  263-268. 
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Objective: In the present study, a novel BDI-GS evaluation system for the functions and safety of foods was established through accumulated general scores (GS) as well as benefit-damage index (BDI) from an animal model by feeding low-nutrient corn. Methods: Mice at the normal growth stage were used as test subjects to evaluate the comprehensive nutrition and health-promoting functions as well as safety of foods. Control mice were fed simply on common maize, and trial mice were fed on maize supplemented with soybean. Body weight, 9 viscera weights and indices, BDI, GS and serum biochemical parameters in mice were determined to analyze the rationality, scientificity and feasibility of BDI-GS evaluation system in nutrition and health-promoting functions as well as safety of foods. Results: Changes in body weight, viscera weight and BDI in mice could reflect the nutritional benefits of soybean. BDI and BDI accumulation index indicated health-promoting functions, especially thymus index BDI revealed an increase in a dose-independent manner and a significant difference (P < 0.01). Conclusion: An intuitive, overall, easy, economical comprehensive evaluation system for the functions and safety of various foods and drinks has been established. 
Effects of Cultured Cordyceps militaris-Ganoderma lucidum Spore Complex on Immune Function in Mice
2012, 33(17):  269-273. 
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Objective: To study the modulatory effect of cultured Cordyceps militaris-Ganoderma lucidum spore complex on the immune function of mice. Methods: In this study, mice were orally administered with the complex at low, medium and high doses for 30 days. After the last administration, mouse body weight, immune organ indices, delayed-type hypersensitivity (DTH), T lymphocyte proliferation induced by ConA, serum hemolysin formation, carbon clearance capability and the chicken red blood cell phagocytosis ability of mouse macrophages were assayed. Results: Compared with the control group, the high-dose treatment group significantly improved the body weight and thymus index of mice, the low- and medium- dose treatment groups showed a significant increase in delayed-type hypersensitivity, and the high-dose treatment group significantly enhanced the ability of ConA induced lymphocyte proliferation. These findings suggest that cultured Cordyceps militaris-Ganoderma lucidum spore complex can enhance specific immune responses in mice. Moreover, both the low and medium doses could also significantly enhance mouse carbon clearance capability and the chicken red blood cell phagocytosis ability of mouse macrophages, suggesting that the complex can enhance non-specific immune responses in mice. Conclusions: Cultured Cordyceps militaris-Ganoderma lucidum spore complex can enhance specific immune response and non-specific immune responses in mice, thus enhancing the immune system function of mice.
Evaluation of Nutritional Composition and Quality of Farmed Silurus meridionalis Chen Muscle
2012, 33(17):  274-278. 
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In this study, routine biochemical assays were used to evaluate the nutritional composition and quality of farmed Silurus meridionalis Chen muscle from a farm in Shuangliu region, Sichuan. The contents of crude protein, crude fat, crude ash and water in fresh fish muscles were (18.06 ± 0.49)%, (2.47 ± 1.08)%, (1.17 ± 0.06)% and (78.49 ± 0.45)%, respectively. Eighteen amino acids were found in the muscle of farmed Silurus meridionalis Chen, including all 8 essential amino acids (EAA), all 2 half-essential amino acids (histidine and arginine), 8 nonessential amino acids (NEAA, namely glutamic acid, aspartic acid, glycin, alanine, serine, cystine, tyrosine and proline). In dry samples, the total content of amino acids (TAA) was (83.59 ± 2.30)%, and the contents of EAA, was (34.43 ± 1.45)%, respectively. Four delicious amino acids (DAA) accounted for (31.52 ± 1.20)% in dry sample. The ratio of DAA to TAA was 37.71%. The essential amino acids index (EAAI) was 74.82. The ratio of EAA to TAA was 41.19%, and the ratio of TAA to NEAA was 70.04%. These data suggest that the EAA profile of the muscle of farmed Silurus meridionalis Chen can meet completely the FAO/WHO Standard. In terms of amino acids score (AAS) and chemical score (CS), the first and second limiting amino acids were identified as valine and (methionine + cystine), respectively. Eight saturated fatty acids (SFA), 8 mono-unsaturated fatty acids (MUFA) and 10 polyunsaturated fatty acids (PUFA) were found in the muscle of Silurus meridionalis Chen. The relative contents of PUFA, EPA and DHA in total fatty acids were (41.05 ± 0.77)%, (4.00 ± 0.21)% and (7.80 ± 1.42)%, respectively, which were much higher than those of Ictalurus punctatus and P.vachelli muscles. The index of atherogenicity (IA) and index of thrombogenicity (IT) of fatty acids were 0.42 and 0.35, respectively. Farmed Silurus meridionalis Chen muscle was rich in minerals, such as K, Zn and Fe and had a reasonable Zn/Fe ratio. Our study demonstrates that farmed Silurus meridionalis Chen muscle tastes delicious, and is rich in amino acids with an even balance and also abundant in PUFAs, EPA and DHA, thus having great nutritional and edible value and being worthy of further processing and utilization.
Research Progress in Conformational Epitope Mapping Approaches for Food Allergens
Hong-bing CHEN
2012, 33(17):  279-283. 
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Conformational epitope is an important type of epitope and plays a critical role in allergy. Epitope mapping is the core of allergen research. Today, there are three main conformational epitope mapping approaches, including conformational epitope prediction based on the amino acid composition and characteristics of linear epitopes, epitope mapping by phage display technique and bioinformatics, and conformational epitope mapping by spectroscopic analysis and parameters related to coupling with antibodies. The first two approaches are commonly used in conformational epitope mapping. As a more accurate approach, spectroscopy has not been used in this field until recently. These approaches allow for a better knowledge and understanding of conformational epitopes in allergen research and also provide theoretical evidence for the mechanisms of action of conformational epitopes in allergy.
Progress in Spectroscopic Research on Structural Changes of Food Allergens
2012, 33(17):  284-289. 
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Spectroscopy has been widely used in the investigation of structural change of food allergens. The commonly used spectroscopic techniques include circular dichroism (CD), fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and UV absorption spectroscopy. CD is often used to define the change in secondary and tertiary structures of allergens, but is restricted to clear low-concentration solutions only. FTIR can override influence of allergen molecular weight, light scattering and fluorescent light. FTIR amide I band is the most valuable for the analysis of secondary structure of allergens. Raman spectroscopy with photon probe is suitable for non-destructive detection of rare and precious microgram-scale samples. Fluorescence spectroscopy is often used to define hydrophobic and microenvironmental changes of allergens in the course of denaturation, and UV absorption spectroscopy needs to be coordinated closely with other spectroscopic methods for structural identification. In addition, CD, fluorescence spectroscopy and FTIR are available for characterizing the type and relative content of secondary structure of food allergens, and their specific applications are still worthy of further exploration.
Bibliometric Analysis of Plant Polyphenol Research and Hot Topics in China
2012, 33(17):  290-296. 
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Based on the CNKI database, bibliometric methodology was applied to analyze relevant records related to plant polyphenols from 2001 through 2010, including journals, affiliations, authors, discipline distribution and research topics. The research focuses were also reviewed and analyzed, with the aim of providing a reference for future studies and utilization of plant polyphenols.
Research Progress on Inhibitors of Advanced Glycation Endproducts
2012, 33(17):  297-302. 
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Advanced glycation endproducts (AGEs), which are produced by glycation reaction related to the Mallard reaction, are involved in accelerated aging and diabetic complication. A huge body of literature has reported AGE research and developing AGE inhibitors has been a hot topic of intensive studies recently. In this review, we provide an outline of the formation of AGEs, their pathological damage, and the mechanisms underlying the anti-glycation and anti-glycation properties of foodstuffs. Prospects for future direction are also discussed.
Research Progress in Bioactive Ingredients and Pharmacological Functions of Silkworm Pupa
2012, 33(17):  303-307. 
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Silkworm pupa is a medicinal and edible insect resource abundant in many bioactive constituents such as unsaturated fatty acids, rare amino acids, active peptides, chitins, etc. It has such functions as protecting liver, improving immunity, anti-tumor, decreasing blood sugar, blood fat and blood pressure, promoting wound healing and so on. This article summarizes extraction methods and pharmaceutical functions of bioactive compounds from silkworm pupa. Future trends in its research and development are also proposed.
Research Progress of Fungal Chitosanase
2012, 33(17):  308-311. 
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Chitosanase is a glycoside hydrolase for specific degradation of chitosan. In this article, the recent research progress in the classification and characterization of chitosanases, and the current strategies for improving chitosanse activity are summarized. To the best of our knowledge and after an extensive literature review, we present that the degradation products by chitosanase from fungi are chitoligosaccharide and glucosamine with a high molecular weight and a low specific activity. Potential strategies for improving chitosanse activity are also discussed in this paper.
Research Advances in Catechin Modification
2012, 33(17):  312-317. 
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Catechins are major bioactive substances in tea. However, the low solubility, poor stability and reduced bioavailability in vivo restrict their application. In this review, the current major methods for catechin modification and the physico-chemical properties and bioactivity of modified catechins are summarized. Meanwhile, future trends in the development of catechin modification are also proposed.
Research Advance in Synthesis and Pharmacological Effects of Catechin Derivatives
2012, 33(17):  318-326. 
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As main polyphenolic components in tea, catechins have various pharmacological functions and are widely used in various fields such as the food, medicine, and daily chemical industries. However, weak liposolubility and stability as well as low bioavailability limit their application in practice. As a result, structural modification of catechins comes into being. This review focuses on the synthesis mainly by enzymatic or chemical modification and biological activities of catechin derivatives. Moreover, their application prospects are forecasted.
Reflection on Approval and Evaluation of Healthy Foods Containing Bee Products
2012, 33(17):  327-330. 
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Bee products are widely used in healthy foods, such as propolis, honey and royal jelly. In this article, the approval situation and common problems especially in the aspects of approved quantity, formulation, process and quality control of healthy foods containing bee products are reviewed. The problems related to the evaluation of healthy foods are also specifically analyzed. Moreover, some suggestions for the application of healthy foods containing bee products are proposed too, with the aim of providing theoretical supports for future research and development of healthy foods.
Influence of Agricultural Non-Point Source Pollution on the Quality and Safety of Agricultural Products
2012, 33(17):  331-335. 
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Major factors for agricultural non-point source pollution such as fertilizer pollution, pesticide pollution, poultry and animal fecal pollution have negative effects on the quality and safety of agricultural products. Therefore, agricultural non-point source pollution can not be ignored. Developing green and sustainable agriculture is important for the prevention and management of these problems.
Research Progress in Chemical Components, Medicinal Effects and Comprehensive Utilization of Loquat Seeds
2012, 33(17):  336-340. 
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As a by-product of loquat flesh processing, loquat seeds are almost treated as a waste instead of a useful material. However, loquat seeds are rich in nutritional and bioactive components such as starches, proteins, fatty acids, amygdalins and flavonoids. Pharmaceutical studies have showed that loquat seeds possess immunoregulatory, antioxidant, anti-inflammatory and hypoglycemic activities. Many tons of loquat seeds are produced during processing every year so that it is important to develop valuable products from them. In order to explore a strategy for utilizing loquat seeds, we review the nutritional and medicinal value, current utilization status and development prospect of loquat seeds in this paper.