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15 December 2010, Volume 31 Issue 23
Basic Research
Molecular Mechanism Study of Targeting of Two Angiotensin-converting Enzyme Inhibitory Peptides
GUO Hui-qing1,MAO Hui1,ZHAO Bo1,PAN Dao-dong1,2,*
2010, 31(23):  1-5.  doi:10.7506/spkx1002-6630-201023001
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Two angiotensin-converting enzyme inhibitory peptides VPP and IPP were purified from the sour milk fermented with Lactobacillus helveticus JCM1004 and Lactobacillus casei subsp. casei ATCC393 by using four-step reverse-phase HPLC. VPP and IPP had 50% inhibition of ACE (IC50) of 8.89μmol/L and 5.17μmol/L, respectively. According to their amino acid sequence, the molecular structure of VPP and IPP were simulated, and the molecular mechanism for the function position, type and energy of the interaction between ACE inhibitory peptides and ACE were investigated by the flexible molecule docking technology. It was shown from the theoretical calculation that the three hydrogen bonds existed between the bioactive peptides poses of VPP and IPP. Hydrophobic and hydrophilic interactions also existed between residues at the ACE active site and the peptide poses. The binding between IPP and ACE was more stable than VPP with ACE. This is in good agreement with the experimental result that the IC50 value of IPP is lower than that of VPP.

Release Kinetics and Application of Spherical Multinuclear Peppermint Oil Microcapsules Prepared by Complex Coacervation
DONG Zhi-jian1,WANG Yu2,XIA Shu-qin2,JIA Cheng-sheng2,ZHANG Xiao-ming2,*,XU Shi-ying2
2010, 31(23):  6-9.  doi:10.7506/spkx1002-6630-201023002
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Spherical multinuclear peppermint oil microcapsules were prepared by complex coacervation and their release kinetics and application in biscuits were investigated. The results showed that the release of the microcapsules by coacervation followed the first order release kinetics in hot water and its releasing constant increased with the ratio of core/wall, while their release followed zero order release kinetics in oven and its releasing constant increased with the temperature. The sensory evaluation indicated that double encapsulating could strengthen the encapsulating effectiveness of microcapsules by coacervation. The effectiveness of coacervation microcapsules by double encapsulation in the biscuit was the same as cyclodextrin.

Comparative Oxidation Stability of Meat from Castrated and Entire Male Pigs
LI Feng1,2,SHEN Jia-chuan1,HUANG Ye-chuan1,2,LI Hong-jun1,*
2010, 31(23):  10-13.  doi:10.7506/spkx1002-6630-201023003
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This study was devoted to explore the difference of oxidation stability between meat from Rongchang boar (RC) and normal castrated pigs (PT) and the possible causes of this difference. Thiobarbituric acid reactive substance (TBARS) value of different products made from RC and PT were compared. Intramuscular fat content (IMF), fatty acid composition and water content were also determined. Results showed that there was no significant difference between TBARS of cured meat, frozen meat and frozen cooked meat made for RC and PT but that of RC was higher than PT. However the difference was significant for repeatedly frozen-thawed meat. Results also showed that RC and PT were different significantly in water content, IMF content and fatty acid composition. It appeared that meat of RC was oxidized more readily than PT but the difference may not just result from the difference of fatty acid composition. RC may be used to produce cured meat, frozen meat and frozen cooked meat under appropriate condition.

Structural Identification of Malvidin-3-galactoside from St. Cloud Blueberry Fruits
LI Ying-chang1,LU Chun-mao2,MENG Xian-jun2,MA Yong1,FENG Yan-bo1
2010, 31(23):  14-17.  doi:10.7506/spkx1002-6630-201023004
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The anthocyanins in St. cloud blueberry fruits were extracted with 60% ethanol (pH 3.0) at 40 ℃ and the extract was concentrated, followed by purification with AB-8 macroporous resin and vacuum drying, to obtain a dark purple powder. A monomeric compound was isolated from the powder by preparative high-performance liquid chromatography (HPLC) and identified as malvidin-3-arabinoside by ultraviolet-visible, infrared, mass and nuclear magnetic resource spectroscopy as well as thin layer chromatography. This indicates that St. cloud blueberry fruits are exploitable for further development.

Antioxidant Activity of Total Flavonoids from Different Organs of Clematis glauca Willd. in Xinjiang
Gulibahaer ABABAIKELI
2010, 31(23 ):  18-21.  doi:10.7506/spkx1002-6630-201023005
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The organic solvent extraction of different organs of Clematis glauca Willd. in Xinjiang was performed for obtaining total flavonoids, and the extract obtained was tested for its reducing power and its abilities to scavenge hydroxyl, superoxide anion and DPPH free radicals using VC as the control. The order of reducing power of different organs of Clematis glauca Willd and VC from strong to weak was VC > leaf > flower > fruit > stem. The leaves of Clematis glauca Willd. was superior to the other three organs of the plant in hydroxyl and superoxide anion free radical scavenging capacities. As for the ability to scavenge DPPH free radicals, the four organs of the plant were ranked as follows: fruit > flower > leaf > stem. In a word, the total falavonoids from Clematis glauca Willd. have some antioxidant activity and thus, deserve to be developed as functional products based on in-depth studies of their physiological functions.

Comparative Evaluation of Antioxidant Activity in vitro of Aqueous Extracts from Ilex kudingcha C.J. Tseng and Ilex latifolia Thunb Leaf Teas
ZHANG Wen-qin,XU Wen-qing,SUN Yi,YE Hong,ZENG Xiao-xiong*
2010, 31(23):  22-26.  doi:10.7506/spkx1002-6630-201023006
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The contents of polyphenols and flavonoids and the antioxidant activities in vitro of aqueous extracts from the leaf teas of Ilex latifolia Thunb and Ilex kudingcha C.J. Tseng were determined. It was found that the aqueous extract from Ilex kudingcha C.J. Tseng had both higher polyphenol content and in vitro antixodiant performance than that from Ilex latifolia Thunb. The correlation analysis among five antioxidant evaluation methods in vitro demonstrated that there was a good correlation among them (R2 >0.8478), and the correlation between DPPH and ABTS+ free radical scavenging assays was the most significant (R2 = 0.9967).

in vitro Antioxidant Evaluation of Anthocyanins from Bilberry Fruits
LU Chun-mao1,2,WANG Xin-xian2,BAO Jing2,MENG Xian-jun2,DONG Wen-xuan1,*
2010, 31(23):  27-31.  doi:10.7506/spkx1002-6630-201023007
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To take full advantage of the bilberry resources, DPPH, hydroxyl and superoxide anion free radical scavenging and reducing power assays were used to study the in vitro antioxidant activity of the fruits of cultivated bilberry varieties, including Lanfeng, Beichun, Meideng, and wild bilberry fruits. The contents of polyphenol and anthocyanins were also determined. The results showed that, the anthocyanin content of Lanfeng, Beichun, Meideng and wild bilberry were 19.77, 12.67, 24.73 mg/g and 32.44 mg/g frozen fruit, respectively, and anthocyanin had noticeable antioxidant activities. Among the four varieties of bilberry, the antioxidant activity of wild bilberry was the highest, followed by Meideng. The anthocyanins from the four varieties of bilberry had different antioxidant effects at the same concentrations. It is deduced that this is ascribed to the differences in anthocyanin composition and content.

Stability and Antibacterial Activity of Purple Cabbage Pigment
YANG Xiao-ling1,GUO Yan-dong2
2010, 31(23):  32-35.  doi:10.7506/spkx1002-6630-201023008
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The pigment in the leaves of purple cabbage was extracted from, and its stability and antibacterial activity were measured by spectrophotometry. The pigment extracted looked carmine, the original color of purple cabbage, and was stable when exposed to acidic aqueous solution at pH 2. As pH increased, its color gradually changed from carmine to blue, then to green, with the occurrence of a red-shift of maximum absorption wavelength. The preservation rates of the pigment after illumination under natural light for 2 and 6 days were more than 91% and more than 79%, respectively, and the value after 2 hours of heating at temperatures below 70 ℃ was still more than 90%, suggesting that the pigment has good tolerance to light and heating. In the presences of some metal ions including sodium, potassium, calcium, magnesium or oxygen, the pigment was stable, whereas the attendance of iron would deteriorate it. The pigment had significant concentration-dependent inhibitory effect against Staphyloccus aureus and Bacillus subtilis at a concentration of 10 mg/100 mL, but no anti-E. coli effect was observed.

Essential Oils from Four Species of Aromatic Plants Cultivated in Xinjiang: A Comparative Study of Antioxidant Effect
GAN Lu,LIU Ting,SHE Wen-bo,ZHANG Hong-cui,ZHENG Qiu-sheng,WANG Zhen-hua*
2010, 31(23):  36-39.  doi:10.7506/spkx1002-6630-201023009
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The antioxidant effects of the essential oils from four species of aromatic plants cultivated in Xinjiang, Rose rugosa Thumb., Rosmarinus officinalis L., Mentha piperita L. and Chamaemelum nobile L., were assessed and compared by measuring their DPPH, hydroxyl and superoxide anion free radical scavenging capacities and their inhibitory effect on lipid peroxidation in a triobarbituric acid (TBA) reaction system. The four essential oils were all able to scavenge DPPH, hydroxyl and superoxide anion free radicals and inhibit the peroxidation of unsaturated fatty acids in egg yolk in a positive concentration-dependent fashion. Rose oil had the most excellent antioxidant activity, followed by rosemary oil, peppermint oil and roman chamomile oil.

Anti-aging Effect of Antioxidant Peptides from Rice Bran
FAN Jin-juan1,FU Yan-song1,ZONG Li-li3, ZHANG Xin-yu2,LUO Xia1,ZHU Yan-shu1
2010, 31(23):  40-43.  doi:10.7506/spkx1002-6630-201023010
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The D-galactose (D-gal)-induced aging model mice were used to explore the effects of antioxidant peptides from rice bran on the activities of catalase (CAT), glutathione peroxidase (GSH-Px), succinate dehydrogenase (SDH) and total adenosine triphosphatase (T-ATPase) in mitochondria of heart and brain and on deletion mutation of mitochondria DNA (mtDNA) in brain by polymerase chain reaction (PCR) and photodensity scan. Results indicated that rice bran antioxidant peptides at the condition of high dosage could significantly increase the activities of CAT, GSH-Px, SDH and T-ATPase in mitochondria of heart and brain (P < 0.05); and significantly decrease the depletion of mtDNA in brain (P < 0.01) of D-gal-induced-aging mice when compared with the model group. These investigations suggest that rice bran antioxidant peptides are able to enhance antioxidant function of aging mice induced by D-gal, and have good protective effect on mtDNA.

Purification and Identification of Donkey s Milk Protein Fractions
SU Wei1,YANG Jie2,*,SHEN Xiao-li3,JIANG Xin-yue3
2010, 31(23):  44-48.  doi:10.7506/spkx1002-6630-201023011
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Objective: To provide a theoretical basis for further exploring the exploitability of donkey milk as an adjuvant for disease treatment or as a substitute for human milk. Methods: The protein fractions of donkey whey were separated and purified by DEAE-52 anion-exchange chromatography and Sephadex G-100 gel-filtration chromatography. The purified protein fractions were identified by SDS-PAGE and high-performance gel permeation chromatography. Results: Three unknown proteins having molecular masses of 32, 70.1 kD and 72.2 kD were found to be present in donkey whey in comparison with the protein composition profile of cow s milk whey. Conclusion: Along with the similar nutritional components to those in cow s milk, other bioactive components were also contained in donkey s milk, which might be some protective proteins playing an important role in protecting the organism against diseases.

Deposition Regularity of Fatty Acids in Livers of Fat Geese
LIU Zhen-chun,DUAN Xu,LI Hui,LI Xia,WU Wei
2010, 31(23):  49-51.  doi:10.7506/spkx1002-6630-201023012
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In order to explore the deposition regularity of fatty acids in liver, Landes geese were used as the experimental subjects to overfeeding. The deposition regularity of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids in fat geese during different feeding periods were determined. Results indicated that total fat of geese before overfeeding and after overfeeding for 1, 2, 3 and 4 weeks were 4.70%, 15.42%, 24.19%, 50.35% and 81.40%, respectively. A significant difference was observed among different overfeeding periods except the first 2 weeks (P< 0.05). The saturated fatty acid contents in total fat after overfeeding for 1, 2, 3 and 4 weeks were 1.96%, 2.08%, 3.82%, 8.20% and 14.78%, respectively, and there was a significant difference (P<0.05) observed among them. The corresponding unsaturated fatty acid contents in total fat were 20.17%, 33.47%, 34.29%, 45.33% and 75.63%, with a significant difference (P<0.05). This study suggests that an obvious increase of unsaturated fatty acids occurs in the late overfeeding period.

Monosaccharide Compositions and Antioxidant Activity of Water-soluble Polysaccharide Isolated from Tuber indicum
LUO Qiang,YAN Liang,WU Li-sha,ZHANG Jie,YANG Zhi-rong,SUN Qun*
2010, 31(23):  52-56.  doi:10.7506/spkx1002-6630-201023013
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A water-soluble crude polysaccharide was extracted from Truffle (Tuber indicum) by water extraction and alcohol precipitation and then purified by DEAE 52 cellulose and Sephadex G-100 chromatographic column to obtain a major fraction of polysaccharide (TIP-A). The relative molecular weight (Mr) of TIP-A was determined to be 17500 by high performance gel permeation chromatography (HPGPC). In addition, gas chromatography-mass spectrometry (GC-MS) analysis exhibited that TIP-A was a homogeneous heteropolysaccharide consisted of mannose, glucose, galactose and rhamannose with a molar ratio of 7:2:2:2. TIP-A had strong scavenging activity on hydroxyl, superoxide anion, and 1-diphenyl-2-picryldydrazyl (DPPH) free radicals and IC50 values of TIP-A for three kinds of free radicals were 1.06, 1.02 mg/mL and 1.13 mg/mL, respectively. TIP-A could also significantly attenuate PC12 cell damage caused by hydrogen peroxide at the concentration of 300 mmol/L.

Extraction and Bioactivity of Usnic Acid from Cladonia cornuta (L.) Hoffm.
Reyim MAMUT,Adilijiang ABDULLA,Abdulla ABBAS*
2010, 31(23 ):  57-60.  doi:10.7506/spkx1002-6630-201023014
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Cladonia cornuta (L.) Hoffm harvested from Xinjiang’s Tianshan No.1 glacier was used as the experimental material to extract usnic acid and determine its antioxidant activity and antibacterial activity. Results indicated that the usnic acid extracted from Cladonia cornuta (L.) had higher reducing power and antioxidant capacity. Meanwhile, usnic acid exhibited a significant inhibition on the growth of bacteria such as Proteusbacillus vulgaris, Escherichia coli, Staphylococcus aureus and Bacillus subtilis.

Antioxidant Activity of Selenium-rich Cordyceps militaris
LI Hua-wei1,ZHAO Su-yun2,TIE Mei2,*
2010, 31(23):  61-64.  doi:10.7506/spkx1002-6630-201023015
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In this study, selenium polysaccharide and selenium protein were extracted from selenium-rich Cordyceps militaris by modern separation techniques. The contents of selenium, polysaccharide and protein in Se-polysaccharide and Se-protein were determined by ICP-MS, phenol-sulfuric acid method and Coomassie brilliant blue method. In addition, the scavenging capabilities of Se-polysaccharide and Se-protein on hydroxyl free radicals were evaluated by the absorbance at 510 nm in Fenton system. Results indicated that the scavenging activities of Se-polysaccharide and Se-protein were obvious higher than those of inorganic selenium, polysaccharide and protein under the same condition. The highest scavenging rates of Se-polysaccharide and Seprotein were 38.02% and 75.00%, respectively.

Sedimental Characteristics of Fouling in Mimic Experiment for Alcohol Production from Molasses
MAO Rui-feng1,GUO Li-dong1,WANG Shuang-fei1,*,LIANG Zhong-yun2,QIN Yan-yan1
2010, 31(23):  65-71.  doi:10.7506/spkx1002-6630-201023016
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In this study, a mimic experiment for alcohol production from sugar cane molasses was used to explore the fouling factors in sedimentary process. Chemical and quality analysis methods were used to characterize chemical compositions and settlement pattern of materials in key process points. The physical and chemical properties of fouling factors were also analyzed during the change of processing. Three important parameters such as apparent fouling, apparent heat-degradable fouling and apparent heat-stable fouling were proposed to illustrate general formation process of fouling in the whole alcohol production process from sugar cane molasses.

Effect of Chemical Components in Houttuynia cordata on the Blocking of N-Nitrosation Reaction
GUO Yan-hua,QIU Hong-xin,ZHANG yuan-fang,WAN Kun,FAN Jian-hong
2010, 31(23):  72-75.  doi:10.7506/spkx1002-6630-201023017
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Objective: To explore the effect of chemical components in Houttuynia cordata on the blocking of N-nitrosation reaction. Methods: UV-visible spectrum and gas chromatography-mass spectrometry methods were used to determine the chemical components including flavonoids, vitamin C, polyphenols, polysaccharides and 2-undecenal in Houttuynia cordata for exploring their blocking capabilities to N-nitrosation reaction. Results: The contents of chemical components in Houttuynia cordata from different areas did not exhibit an obvious difference. Although the content of total sugar exhibited an increase trend, other chemical components exhibited a declined trend during the extension of drying time. The contents of vitamin C, flavonoids and total polyphenols were positively correlated with the blocking rate of N-nitrosation reaction. However, the contents of 2-undecenal and total sugar had no correlation with the blocking rate. Conclusion: Houttuynia cordata can prevent human endogenous nitro-compound synthesis. The major components for influencing N-nitrosation reaction were flavonoids, vitamin C and polyphenols.

Antioxidant Activity of Intracellular Polysaccharides (IPS) from Morchella esculenta L.
YANG Fang1,2,WANG Xin-feng1,2,*,WENG Liang1,GE Qun-mei1,CHEN Shan-shan1
2010, 31(23):  76-78.  doi:10.7506/spkx1002-6630-201023018
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The crude intracellular polysaccharides (CIPSMB and CIPSMH) extracted from the mycelia of Morchella esculenta L. from Beijing (MB) and Huaiyin (MH) areas by water extraction and alcohol precipitation were subjected to decolorization and deproteinization to obtain purified CIPSMB and CIPSMH, denoted as PIPSMB and PIPSMH, respectively. The scavenging effects of the four samples on hydroxyl and superoxide anion free radicals were tested by salicylic acid method and pyrogallol autoxidation method, respectively. It was observed that all the four samples were able to obviously scavenge both free radicals, displaying a positive concentration-dependent response in a concentration range between 1 mg/mL and 5 mg/mL. No statistical significance in the ability to scavenge superoxide anion free radicals was found between CIPSMB and PIPSMB and between CIPSMH and PIPSMH. CIPSMB and CIPSMH had no significant difference in the ability to scavenge hydroxyl free radicals. However, there was a significant difference in the ability to scavenge hydroxyl free radicals observed between CIPSMH and PIPSMH; the scavenging rate of CIPSMH at a concentration of 5 mg/mL was only 22.57%, whereas that of PIPSMH was as high as 46.27%, indicating that purification greatly enhances the hydroxyl free radical scavenging capacity of intracellular polysaccharides from the mycelia of Morchella esculenta L. from Huaiyin area.

Kinetics and Influencing Factors of Nonenzymatic Browning in Apple Juice Concentrate
GUO Shan-guang1,QIU Nong-xue2
2010, 31(23):  79-83.  doi:10.7506/spkx1002-6630-201023019
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The effects of various processing operation units on browning and the rate of nonenzymatic browning in commercial apple juice concentrates (70.5 °Brix) stored at 5, 20 or 37 ℃ were investigated. The changes of color value (T440), browning index (A420nm), amino nitrogen content and 5-hydroxymethylfurfural content were evaluated. The rates of browning at all three temperatures obeyed the first-order kinetic model. Browning reaction occurred more obviously at high temperature. There was a general decrease in amino nitrogen content and an increase in 5-hydroxymethylfurfural content with prolonged storage; this effect was most pronounced for samples stored at 37 ℃. The relation between 5-hydroxymethylfurfural content and fruit browning could be described as an exponential explanation for the reason why browning occurs in apple juice concentrate during storage is Maillard reaction, which could also be validated by the linear relation between amino nitrogen and browning. During the early processing stages, including crushing, pressing, enzymolysis, ultrafiltration and first pasteurization, no obvious Maillard reaction was found. The follow-up operation unit, adsorption, resulted in the removal of amino nitrogen and other dark colored compounds. However, Maillard reaction was undesirably promoted, leading to an obvious reduction of amino nitrogen in apple juice.

CSB Image Meater Use based Predictive Modeling Lean Meat Percentage of Commercial Pig Carcasses in China
YIN Jia,ZHOU Guang-hong*,XU Xing-lian
2010, 31(23):  84-87.  doi:10.7506/spkx1002-6630-201023020
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To accurately predict lean meat percentage of commercial pig carcasses in China and to achieve grading on line and fast accounting so as to optimize price and quality, CSB image meater was employed to analyze lean meat percentages, hot carcass weights, back-fat thicknesses and muscle thicknesses of 436 different types of commercial pig carcasses. A regression equation for predicting lean meat percentage of commercial pig carcasses was established based on the data from CSB image meater through multiple linear regression as follows: y = 61.264-0.583x1 + 0.173x2, where x1 was the thickness of the thinnest back fat, and x2 was the vertical distance between the end of gluteus medius muscle and the edge of spinal column, with a determination coefficient R2 of 0.87 and a standard residual error of 2.31%, indicating good degree of fitness. No significant difference between the actual and model-predicted values was observed. Therefore, the established equation has a high accuracy and is suitable to be applied in practice.

Preliminary Study on Glass Transition of Semi-dried Lichi
CAI Chang-he1,2,CHEN Yu-xu1,ZENG Qing-xiao1
2010, 31(23):  88-92.  doi:10.7506/spkx1002-6630-201023021
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In order to explore a moisture absorption isotherm and glass transition temperature of semi-dried litchi for long-term preservation, the glass transition temperature of semi-dried litchi was determined by using differential scanning calorimetry. Results indicated that the moisture absorption isotherm of semi-dried litchi exhibited an excellent fitting with GAB isotherm model to reveal a "J" shaped. The glass transition temperature (Tg) of semi-dried litchi was between -77.35 ℃ and 65.51 ℃. After the annealing treatment, the glass transition temperature was increased by 10 ℃ and devitrification peaks were eliminated. After freeze-drying treatment, the glass transition temperature semi-dried litchi was increased by 7 ℃.

Effect of Combinatorial Treatment between Ultra-high Hydrostatic Pressure and Moderate Temperature on Lycopene and Vitamin C in Tomato Juice
QIU Wei-fen,WANG Hai-feng,TAO Ting-ting
2010, 31(23 ):  93-95.  doi:10.7506/spkx1002-6630-201023022
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Effect of combinatorial treatment between ultra-high hydrostatic pressure and moderate temperature on the contents of lycopene and vitamin C in tomato juice was investigated. Results indicated that the treatment with temperature of 33.5 ℃, pressure of 469.2 MPa and pressure-holding time of 14.0 min could result in the increase of lycopene content when compared with the control, while the isomers of lycopene remained unchanged; in contrast, vitamin C content did not exhibit an obvious change.

Comparison on the Stability of Collagens from Skin and Bone of Carp (Cyprinus carpio) Caught in Winter and Summer
DUAN Rui1,2,*,ZHANG Jun-jie1,2,CHEN Ling1,KONNO Kunihiko3,XU Bing1
2010, 31(23):  96-100.  doi:10.7506/spkx1002-6630-201023023
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The acid-soluble collagens (ASC) were isolated from skin and bone of carp (Cyprinus carpio) caught in the winter (February in 2008) and summer (July in 2008). Thermal stability of collagens was studied by the increased pepsin digestibility upon heating and by circular dichroism (CD) spectroscopy. Collagens from skin and bone in the winter (w-skin ASC and w-bone ASC) exhibited transition curves with midpoints of 31.0 ℃and 32.8 ℃, respectively, which were 1.0 ℃ and 0.6 ℃ below their equivalents from summer season fish. The CD spectrum changes of collagens upon heating were in accordance with the results of pepsin digestion. The results indicated that collagens from skin and bone of summer carp were more stable than their equivalents of winter.

Effects of Ozone Treatment on the Organoleptic Character, Anthocyanins, Chromaticity and Tonality of Dry Red Wine
LI Hui1,WANG Jiang-xing2,WANG Jie3
2010, 31(23):  101-106.  doi:10.7506/spkx1002-6630-201023024
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Several Cabernet Sauvignon dry red wines made in 2007 were treated with ozone, the organoleptic characters and physicochemical items (anthocyanins, chromaticity, tonality) of the wines were studied and compared with different treatments for 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 min, from which we got the appropriate treating time. The results showed that through treating 18 mins with ozone, the total sensory evaluation scores rose from 8.8 to16.6; the OD520nm values of anthocyanins dropped from 0.37 to 0.12; the chromaticity values(OD420nm + OD520nm + OD620nm) rose from 1.02 to 1.36; the tonality values(OD420nm/ OD520nm) dropped from 0.76 to 0.50. In this experiment, there weren t linear relationships between the OD520nm values of anthocyanins or the tonality values and the total sensory evaluation scores; there were linear relationships between the chromaticity values and the total sensory evaluation scores, the colour of the wine evolved from the initial purple-red hues of young wines towards more ruby ones, so that the appearance of the wine showed ripe.

Factors and Control Methods for Greening of Garlic Puree
CUI Gang
2010, 31(23):  107-108.  doi:10.7506/spkx1002-6630-201023025
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The factors including garlic species, temperature, pH, oxidative and reducing reagents, and the control methods for greening of garlic puree were investigated in this paper. Results indicated that the greening of garlic puree did not exhibit a correlation with the species of garlic. However, the greening of garlic puree was highly sensitive to pH. The addition of reducing reagents to garlic puree has an inhibitory effect, while the addition of oxidative reagents such as hydrogen peroxide could promote the greening of garlic puree. Low temperature also provided a promotion role in the greening of garlic puree. In contrast, hightemperature storage of garlic puree can inhibit its greening.

Bioengineering
Characterization of Chicken Egg Yolk Antibodies against Dominant Spoilage Organisms in Paralichthys olivaceus during Cold Storage
XU Ya-fu,LIN Hong,ZHANG Qian,TIAN Liang-liang,ZHAO Shuo,SUI Jian-xin,CAO Li-min*
2010, 31(23):  109-113.  doi:10.7506/spkx1002-6630-201023026
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The dominant spoilage organisms in cultured Paralichthys olivaceus during cold storage at 4 ℃ were qualitatively and quantitatively investigated. Based on the colony morphology, biochemical and physiological characteristics, spoilage bacteria were isolated at the end of shelf life and identified using bacteria identification systems. Shewanella putrefaciens was dominated spoilage bacteria, which accounted for about 58.4% of all bacteria at the end of shelf life at 4 ℃. Pseudomonas which were common spoilage bacteria in aquatic products included Pseudomonas fluorescens, Pseudomonas taetrolens and Pseudomonas marginalis,with a corresponding proportion of 63.2%, 29.2% and 7.6%, respectively. Two types of egg yolk antibodies (IgY) against Shewanella putrefaciens, Pseudomonas fluorescens and Pseudomonas taetrolens were obtained by immunizing leghorn chicken by two methods, and their antibacterial efficiencies in liquid and solid media were evaluated. After incubation for 8 h in liquid culture, the inhibition ratio of the two IgYs at 100 mg/mL against antigen bacteria could attain between 61% and 78%, and after incubation for 24 h in solid culture, the inhibition ratio could reached between 27% and 40%. This demonstrates the potential application of egg yolk antibody as a natural antimicrobial agent for preservation and bacteria inhibition.

Effect of Different Neutralizers on L-Lactic Acid Production by Rhizopus oryzae
JIANG Shao-tong,ZHANG Qiao-lan*,WU Xue-feng,LUO Shui-zhong,PAN Li-jun
2010, 31(23):  114-117.  doi:10.7506/spkx1002-6630-201023027
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Calcium carbonate added as the neutralizer during Rhizopus oryzae fermentation for L-lactic acid production would cause membrane fouling and environmental pressure during the downstream separation. As a consequence, ammonia and sodium hydroxide were separately used as a substitute for calcium carbonate in this study, and the fermentation conditions for L-lactic acid production and the fermentation kinetics were dealt with. Added calcium carbonate during during Rhizopus oryzae fermentation resulted in an average 7.3-fold increase in L-lactic acid production. The optimal concentrations of added ammonia and sodium hydroxide were 10 mol/L and 25%, respectively. Mycelial pellets in diameter ranges between 0.2 mm and 1.2 mm and between 1.2 mm and 2.2 mm were formed after 72 h fermentation under these concentration conditions, and the residual sugar amounts were 2.58g/L and 1.37 g/L and the L-lactic acid concentrations in the fermentation broths were 74.34 g/L and 80.61 g/L, respectively.

Analysis of Spoilage Ability of Single and Mixed Spoilage Bacteria in Pseudosciaena crocea
XU Zhen-wei1,2,XU Zhong1,YANG Xian-shi1,*,GUO Quan-you1,LI Xue-ying1
2010, 31(23):  118-122.  doi:10.7506/spkx1002-6630-201023028
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Sensory quality, metabolic products of spoilage bacteria and change of spoilage bacteria were assayed on sterile Pseudosciaena crocea tissue blocks inoculated with spoilage bacteria, with YTVB-N/CFU and YTMA/CFU, the growth kinetic parameters of the spoilage bacteria and the yield factor of microbial metabolites, respectively, used as the index. Spoilage ability of two spoilage bacteria Shewanella putrefaciens and Pseudomonas spp., as well as the mixing of the two spoilage bacteria were analyzed on Pseudosciaena crocea stored aerobically at chilled condition. The results showed that shelf life was 168 h, 174 h, and 168h, respectively, for sterile tissue blocks inoculated with Shewanella putrefaciens, Pseudomonas spp. and their mixture, while it was relatively longer with Pseudomonas spp. The YTVB-N/CFU for Shewanella putrefaciens, Pseudomonas spp. and mixed bacteria was basically similar, meanwhile YTMA/CFU for Shewanella putrefaciens was higher than for Pseudomonas spp. and mixed bacteria. The spoilage ability of Shewanella putrefaciens was more significant than Pseudomonas spp. and mixed bacteria. Pseudomonas spp. had inhibitory effect on he growth of Shewanella putrefaciens to some extent, however it was not significant until it reached high counts. Shewanella putrefaciens was specific spoilage organism in Pseudosciaena crocea stored at chilled temperature aerobically.

Preparation and Application of Polyclonal Antibodies against Oviduct Glucoprotein in Rana Chensinensis Changbaishanensis
CHEN Liang1,LAN Hai-nan2,ZHENG Xin2,LIU Jing-sheng1,*
2010, 31(23):  123-127.  doi:10.7506/spkx1002-6630-201023029
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In order to prepare specific polyclonal antibodies against oviduct glucoprotein (OGP) in Rana Chensinensis Changbaishanensis, the crude fresh OGP-rich extract was purified by Sepharose fast flow anion exchange column and Sephadex G-100 gel column chromatography, and New-Zealand albino rabbits were immunized with the purified OGP for the generation of polyclonal antisera. The purification and identification of the polyclonal antisera obtained were performed using the caprylic acid-saturated ammonium sulfate method. The titer of the purified polyclonal antibodies was measured by enzyme linked immunosorbent assay to be 1:64000, which were characterized by high sensitivity, specificity and titer. Moreover, the polyclonal antibodies prepared in this study were used for the immunohistochemical localization and detection of OGP secreting cells in the oviduct of Rana Chensinensis Changbaishanensis, which was expected to lay an experimental foundation for determining OGP in the culture product of OGP secreting cells.

Optimization of Medium Composition and Fermentation Conditions for the Production of Fusarium decemcellulare Brick Inhibitor by Bacillus subtilis B26
ZHANG Li-zhen1,GENG Hai-feng2,FANG Jing-jing3,NIU Wei4,JI Chun3,ZHAO Ting-ting2,NIU Yu5
2010, 31(23):  128-131.  doi:10.7506/spkx1002-6630-201023030
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A four-factor, three-level orthogonal array design was employed to optimize four medium components for the production of Fusarium decemcellulare Brick inhibitor by Bacillus subtilis B26, and the effects of fermentation conditions on the production of Fusarium decemcellulare Brick inhibitor were explored through single factor experiments. The optimal medium composition for maximizing inhibition rate against Fusarium decemcellulare Brick was found to be composed of peptone 25 g/L, starch 45 g/L, sodium chloride 1.5 g/L, ammonium sulfate 1.0 g/L, and dipotassium hydrogen phosphate 1.5 g/L. Seed age of 24 h, inoculmum size of 5%, initial pH of 7, the volume of medium in the fermentation vessel of 20%, the amount of added Tween -80 of 0.5%, fermentation temperature of 30 ℃, rotational speed of 150 r/min and fermentation period of 60 h were found optimal. The inhibition circle diameter of the fermentation broth obtained under these conditions was 26 mm.

Effect of Adding Aquatic Products Processing Waste on the Production of Fish Sauce Prepared from Fermented Mackerel (Decapterus maruadsi)
FANG Zhong-xing,WENG Wu-yin,WANG Mei-gui,LIU Guang-ming,CAO Min-jie*
2010, 31(23):  132-137.  doi:10.7506/spkx1002-6630-201023031
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To shorten the fermentation period of fish sauce and effectively utilize aquatic products processing waste, aquatic products processing waste was added to mackerel (Decapterus maruadsi) before starting the fermentation at a hold temperature of 30 ℃ or under sunlight illumination. Meanwhile, protamex was added as a substitute for aquatic products processing waste for a comparative investigation. pH and the contents of total nitrogen, amino nitrogen and non-salt soluble solids and water activity of the fermentation products at different fermentation stages were measured. The best fish sauce was produced by fermentation with the addition of aquatic products processing waste under sunlight illumination, its total nitrogen and amino nitrogen contents after 80 days of fermentation were 2.03 g/100 mL and 1.44 g/100 mL, respectively. The free amino acid composition analysis indicated that its amino acid composition was different from that of a commercial product, but it was acceptable to consumers in smell, taste and so on.

Optimization of Lnulinase Fermentation by Aspergillus niger X-6 Using Response Surface Methodology
LUO Deng-lin,YUAN Hai-li,ZENG Xiao-yu,LIU Jian-xue
2010, 31(23):  138-141.  doi:10.7506/spkx1002-6630-201023032
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The objective of this study was to obtain the optimum conditions for Aspergillus niger X-6 fermentation to improve inulinase yield. The effects of the amounts of wheat bran, inulin, peptone and yeast extract in the fermentation medium, fermentation time and temperature, pH, and inoculum size on inulinase yield were evaluated using Plackett- Burmen design. Inulinase yield was significantly influenced by the amount of wheat bran addition, fermentation time and pH. Subsequently, the optimization of the three factors was conducted using Box-Behnken experimental design and response surface methodology, in which, a quadratic polynomial model for inulinase yield was established. The optimal fermentation conditions for inulinase prodtion were determined to be: the amount of wheat bran addition, 4.64%; fermentation time, 81.5 h; and initial mdedim pH 6.0. Under these conditions, the yield of inulinase reached 20.42 U/mL, 30.81% higher than that before optimization.

Change Regularity and Predictive Modeling of Dominant Spoilage Microorganisms in Chinese Spiced Beef during Modified Atmosphere Storage
HU Jie-yun,YAN Wei-ling*,LIN Lu,CHEN Ping
2010, 31(23):  142-145.  doi:10.7506/spkx1002-6630-201023033
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The changes of total bacterial count as well as the counts of Brochothrix thermosphacta, lactic acid bacteria and Pseudomonas in Chinese spiced beef samples unpackaged and packaged in vacuum, oxygen-free, low-oxygen or high-oxygen environments were measured during storage at 5 ℃. Meanwhile, primary prediction models for total bacterial count in unpackaged beef samples were constructed. The growth of spoilage bacteria in spiced beef during 5 ℃ storage was effectively inhibited by low-oxygen packaging (35% O2 + 55% CO2 + 10% N2). The comparison between the linear and the modified Gompertz prediction models revealed that the determination coefficient R2 of the latter exceeded 0.98 and had higher reliability.

Optimization of Culture Conditions for the Mycelial Growth of Pyrofomes demidoffii
SU Jue,HE Xin-sheng*,ZHU Wen-kun
2010, 31(23):  146-150.  doi:10.7506/spkx1002-6630-201023034
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Pyrofomes demidoffii is a newly recorded species of a newly recorded genus in China, and it is also a rare medicinal mushroom. To find a both high yield and economical medium for the mycelial growth of Pyrofomes demidoffii, several culture conditions including carbon source, nitrogen source, C/N ratio, rational speed, culture temperature, initial medium pH value, the volume of medium in the fermentation vessel and inoculum amount were investigated through single factor experiments and the effects of three medium components and pH on the mycelial growth of Pyrofomes demidoffii were analyzed by multifactor uniform design. The above investigations were performed using a liquid medium. The optimum carbon source, nitrogen source and C/N ratio for the mycelial growth of Pyrofomes demidoffii were starch, wheat bran and 20:1-25:1. The mycelial growth of Pyrofomes demidoffii was promoted by P, K and Mg. A pH range between 5 and 7, the volume of medium in the fermentation vessel of 100mL and inoculum amount of 8 mL/100mL were found optimum. The optimum composition of the liquid medium used consisted of glucose 25 g/L, bran 125 g/L and K2HPO4 0.25 g/L, pH 6.5. The mycelial growth of Pyrofomes demidoffii could be described by the logistic equation: y = 0.22/(1+1.019e - 0.013x).

Purification and Enzymatic Characterization of Thermostable β-Galactosidase from Bacillus stearothermophilus XG24
GAO Zhao-jian,HOU Jin-hui,SUN Hui-gang,DIAO Jin-jin
2010, 31(23):  151-156.  doi:10.7506/spkx1002-6630-201023035
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The fermentation supernatant of Bacillus stearothermophilus XG24 received salting out with ammonium sulfate, separation on DEAE-Sepharose Fast Flow anion exchange column and purification on Sephadex G-75 gel filtration column to obtain high-purity thermostable β-galactosidase, which was subsequently subjected to enzymatic characterization with o-nitrophenyl- β-D-galactopyranoside (ONPG) as a substrate. After the above separation and purification procedures, the purity of this enzyme showed a 54.5-fold increase, with an activity recovery of 20.4%, and the specific activity of the purified enzyme was 32.7 U/mg protein. The optimal pH and temperature for the reaction of this enzyme were 6.5 and 65 ℃, respectively. It was stable at temperatures below 70 ℃ or in a pH range between 4.0 and 8.0. Its activity was notably promoted by Mg2+, Mn2+, Fe2+ and Co2+, whereas Cu2+, Ag+ and Hg2+ were almost able to entirely inhibit its activity. The Km towards ONPG was determined to be 4.32 mmol/L. The SDS-PAGE analysis revealed that this enzyme was a single-chain protein. Based on the results of Sephadex G-75 gel filtration chromatographic measurement, it was deduced that the apparent molecular weight of this enzyme was 64 kD. Therefore, Bacillus stearothermophilus XG24-derived thermostable β-galactosidase has high application potential in the dairy industry.

Separation, Purification and Identification of Lipoxygenase from Silver Carp Muscle
WANG Wei-dong1,2,YANG Wan-gen1,2,FU Xiang-jin2,3,*
2010, 31(23):  157-159.  doi:10.7506/spkx1002-6630-201023036
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The separation and purification of lipoxygenase (LOX) from silver carp muscle were achieved by using ammonium sulfate precipitation and subsequent hydroxylapatite column chromatographic fractionation. Besides, the oxidation products of arachidonic acid under the catalysis of this enzyme were analyzed by reversed-phase HPLC (RP-HPLC) with the aim of identification, and its substrate specificity was also explored. Arachidonic acid was mainly transformed into 12-hydroxyeicosatetraenoic acid (12-HETE) under the catalysis of the LOX enzyme, suggesting that the main type of LOX in silver carp muscle is 12-LOX. Furthermore, the optimal substrate for this enzyme was linolenic acid.

Optimization of Expression Conditions for Listeria monocytogenes p60 Protein
LU Tian,CAO Zheng-mao,WU Hai-tao,WANG Xiao-hong
2010, 31(23):  160-163.  doi:10.7506/spkx1002-6630-201023037
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In this study, the optimal conditions for the expression of Listeria monocytogenes p60 protein, for which the recombinant expression vector pET-28a-p60 and the recombinant E. coli BL21(DE3) host strain were available, were investigated. The results showed that the optimal expression process determined was that the host strain was enriched to a OD600nm value between 0.7 and 0.8, and IPTG was then added to a final concentration of 1 mmol/L, followed by 6 h expression on a shake table with a shaking speed of 150 r/min at 25 ℃, and that after the expression, the content of p60 protein as a percentage of total protein content was 42.32%, and soluble protein occupied around 85.36% of the total p60 protein.

Rapid PCR Detection of Listeria monocytogenes Virulence in Food
YU Feng-yu1,LI Lin1,WANG Hong2,WANG Wen-zhen2,HE Yuan2,LIU Xiao-peng2, LING Hua2YU Feng-yu1,LI Lin1,WANG Hong2,WANG Wen-zhen2,HE Yuan2,LIU Xiao-peng2, LING Hua2
2010, 31(23):  164-168.  doi:10.7506/spkx1002-6630-201023038
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Objective: The virulence-associated genes of Listeria monocytogenes (L.m) isolates were detected by PCR amplification assay in order to provide experimental references for evaluating the virulence of L.m isolates and effectively limiting the transmission of L.m. Methods: Forty strains of L.m isolated in Chongqing from 2007 to 2009 were subjected to the PCR detection of seven virulence-associated genes (hly, plcB, inlA, inlB, inlC, inlJ, prfA) and toxicity test in mice. Results: The PCR assay revealed that 15 of the 40 L.m isolates possessed all the seven virulence-associated genes, 6 strains were hly-, 4 strains were plcB-,4 strains were prfA- , 5 strains were inlA-, inlB-, 11 strains were inlC -, 9 strains were inlJ -, and 1 strain was negative for inlA, inlB, inlC and inlJ. Four isolates were defined as virulent strains, whose virulence was equivalent to the standard strain, ATCC 1961E with a mouse LD50 between 1.2 × 108 CFU/mL and 6.0 × 108 CFU/mL. The LD50 of the screened low virulent strain 09-132 was 1.7 × 1011 CFU/mL . Conclusions: There is a potential risk of Listeria food poisoning in Chongqing City, and the internalized gene (inlA, inlB, inlC, inlJ) loss may lead to virulence declination, while the prfA and plcB genes are less relevant to the virulent isolates.

Optimization of Fermentation Conditions for L-Lactic Acid Production from Wheat Straw Hydrolysate
LI Xing-jiang1,YANG Wei-hua2,JIANG Shao-tong1,PAN Li-jun1
2010, 31(23):  169-173.  doi:10.7506/spkx1002-6630-201023039
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In the present study, wheat straw hydrolysate was fermented in a 500 mL shaking flask to prepare high-optical purity L-lactic acid for effectively elevating the utilization value of the agricultural waste. Considering metabolitic inhibition probably occurring during fermentation, the optimization of wheat straw hydrolysate concentration, amounts of added HN-Y13 type activated carbon and DM11 type macroporous resin as adsorbents to the fermentation inhibitors in wheat straw hydrolysate and shaking speed was carried out using orthogonal array design and back-propagation artificial neural network (BP-ANN). From the results of orthogonal array experiments, it was found that L-lactic acid production was remarkably influence by all the above four factors and reached up to 82.8 g/L under optimized conditions determined through range analysis. The optimal values of wheat straw hydrolysate concentration, amounts of added HN-Y13 type activated carbon and DM11 type macroporous resin and shaking speed were predicted with BP-ANN to be 126, 2.48 g/L and 1.6 g/L, and 234 r/min, respectively. The yield of L-lactic acid was 86.9 g/L under these conditions, much higher than before optimization.

Optimization of Culture Medium for Phenyllactic Acid Production by Lactobacillus paracasei W2
LIU Ge1,WANG Li-mei2,3,*
2010, 31(23):  174-177.  doi:10.7506/spkx1002-6630-201023040
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The optimal medium for phenyllactic acid (PLA) production by Lactobacillus paracasei W2 was investigated in order to improve PLA yield. Three most significant components affecting PLA production were selected out of seven components using Plackett-Burman design, namely glucose, Tween-80 and phenylpyruvic acid. Their optimal concentrations were determined by steepest ascent method and response surface methodology (RSM) to be 19.5 g/L, 4 mL/L and 3 g/L, respectively. PLA production reached 801 mg/L under these conditions, 1.4-fold higher than before optimization.

Effect of Liquid-state Fermentation with Cordyceps sinensis (Berk.) Sacc. on the Contents of Lipids and Selenium in Selenium-rich Soybean
JIANG Sheng-yan,WANG Yao-qiong,ZHAO Liang-zhong*
2010, 31(23):  178-181.  doi:10.7506/spkx1002-6630-201023041
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The activated mycelial suspension of Cordyceps sinensis (Berk.) Sacc. was inoculated into selenium-rich soybean and cultured in a shake flask, and total lipid content, acid value, iodine value, free amino acid composition, selenium content in fermentation broth at different time points during fermentation were measured. The 48 h fermentation broth showed no obvious difference in total lipid content but 2.8-, 1.2-, 5.3-, 2.9-, 6.8-fold and 5.6-fold increases in acid value, iodine value, linolenic acid, linoleic acid,oleic acid, and arachidonic acid, respectively, as compared to the control (unfermented). Similarly, no obvious change in total lipid content was observed during prolonged fermentation. Selenium content in fermentation broth was kept basically unchanged over the entire fermentation period of 96 hours.

Optimization of Fermentation of Yacon Fruit Wine by Response Surface Methodology
WU Zhu-qing1,2,CHEN Jing2,HUANG Qun1,2,HUANG Wei2,CHEN Gong-xi1
2010, 31(23):  182-187.  doi:10.7506/spkx1002-6630-201023042
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The yacon juice was utilized as raw material to brew fruit wine. Response surface methodology (RSM) was applied to optimize the fermentation conditions of Yacon fruit wine. Based on single factor experiment, sugar concentration of the fruit juice was adjusted to 22%, and the inoculating amount of yeast, fermentation time, temperature and quantity of sulfur dioxide used were chosen as influencing factors, and the alcoholicity was selected as response value and the mathematical model was established by Box-behnken central composite design. The optimal fermentation conditions were determined as follows: inoculating amount of yeast 0.45%, fermentation time 14 days, fermentation temperature 28.5 ℃ and sulfur dioxide 57 mg/L. Under this optimal condition, the alcoholicity was 11.46% (V/V).

Effect of Casein Hydrolysate on Promoting the Growth of Lactobacillus helvecticus
HU Zhi-he1,OU Cui-yan1,ZHU Li-min2,FENG Yong-qiang2,ZHANG Jian-jun2
2010, 31(23):  188-193.  doi:10.7506/spkx1002-6630-201023043
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Effect of casein hydrolysate on promoting the growth of Lactobacillus helvectucus was studied and the hydrolysis condition was optimized based on the growth promoting effect. The results showed that optimal hydrolysis conditions of casein by trypsin included temperature at 37 ℃, pH value 8.0, substrate concentration 5%, ratio of enzyme to substrate 1:600, and hydrolysis time 180 min. Casein hydrolysate prepared at this optimal condition was added into L. helvectucus culture solution, and the addition of 1 g/100mL casein hydrolysate exhibited the highest promoting effect on the growth of L. helveticus, while addition more than 4 g/100mL had the inhibiting effect.

Effect of Oligosaccharide Extracted from Edible Burdock and the Process Optimization of Burdock Pickle
HE Ju-ping,LIU Hui,SHAO Ying,LIU En-qi,LI Dan-dan
2010, 31(23):  194-197.  doi:10.7506/spkx1002-6630-201023044
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The prebiotic effect of oligosaccharides extracted from burdock (B-OLI) in Man-Rogosa-Sharp (MRS) medium on the growth of lactic acid bacteria and the optimization of burdock pickle processing was studied in this paper. B-OLI stimulated the growth of lactic acid bacteria in MRS, with 1 g/100mL B-OLI promoted the growth rate the strongest. Under the same processing, amount of lactic acid bacteria in burdock pickle was higher than that in cabbage pickle. The best processing parameters of burdock pickle includes salt 6 g/100mL, sugar 3 g/100mL, and fermentation at room temperature for 8 days.

Isolation, Identification and Biological Activity of ECSYW-28 Strain
ZHANG Xiao-ling1,YANG Qiao1,*,WU Wen-hui2
2010, 31(23):  198-203.  doi:10.7506/spkx1002-6630-201023045
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A new carotenoid-producing symbiotic bacterium was isolated from a poison-producing paralytic shellfish Gymnodium sp., and then the heterogeneous taxonomic identification of this strain was performed. The 16S rRNA sequence (GU385809) homology analysis exhibited that the strain had 95.1% similarity with Kocuria rosea DSM 20447T. The cell wall was mainly composed of fatty acids that were identified as anteiso C15:0 and iso C15:0 by Sherlock MIDI system. This strain was identified as a new strain Kocuria sp. ECSYW-28 belonging to the genus of Kocuria based on physiological and biochemical characteristics, BIOLOG identification system and molecular evolution analysis. Meanwhile, this strain was confirmed to have stronger resistance to 60Co γ-ray irradiation and H2O2 treatment. Liquid chromatography-mass spectrometry analysis showed that this strain could produce carotenoids that are composed ofβ -carotene and an unknown-structural carotenoid-compound B. Antioxidant capacity analysis was analyzed by using ESR spectroscopy to reveal stronger scavenging effect of compound B on superoxide anion free radicals, one of the major free radicals generated duringγ-ray ionizing irradiation. The phytoene synthase (crtB) and phytoene dehydrogenase (crtI) genes involved in carotenoid biosynthesis pathway in ECSYW-28 strain were subjected to PCR amplification and bioinformatic comparison to confirm the molecular basis of carotenoid biosynthesis in the strain.

Optimization of Submerged-fermentation Processing of Mycelia from Auricularia polytricha
JI Hong,LI Zhi,ZHENG Li-xue
2010, 31(23):  204-209.  doi:10.7506/spkx1002-6630-201023046
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Biomass (dry weight) of mycelia was used as index to explore the optimal culture medium and processing conditions of submerged-fermentation of mycelia from Auricularia polytricha. The optimal fermentation broth formula was investigated by Box-Behnken and response surface analysis to be 2.00 g glucose, 0.20 g yeast extract, 0.25 g KH2PO4, and 0.15 g MgSO4 in 100mL of culture medium. The optimal fermentation conditions were fermentation temperature of 26 ℃, rotation speed of 182 r/min and fermentation time of 145.7 h. Under the optimal culture medium and fermentation conditions, the dry mycelia was up to 1.93 g in 100 mL of culture medium, which was increased by 1.24 fold compared with the conditions before optimization.

Liquor-making Effect of Machine-compressed Wrapped Starter with Waste Lees
YU You-gui1,LI Juan2,XIONG Xiang3,WANG Xiao-yu3,YANG Zhi-long3,LIU An-ran3
2010, 31(23):  210-213.  doi:10.7506/spkx1002-6630-201023047
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In order to explore the liquor-making effect of machine-compressed wrapped starter with waste lees, wrapped starters containing 5%, 7%, 9% and 11% waste lees and pure wheat compressed by machine were used to compare the liquor-making efficiency. Results showed that wrapped starters with waste lees compressed by machine could improve saccharification, fermentation, and liquor productivity. Meanwhile, the wrapped starter containing 9% waste lees had the best liquor-making effect on the productivity and quality of liquor. Therefore, it is feasible to make liquor using machine-compressed wrapped starters with waste lees.

Biological Characteristics of Lytic SF-A2 Phage and Its Sterilization Effect in Milk
ZHANG Hui,WANG Ran*,BAO Hong-duo
2010, 31(23):  214-218.  doi:10.7506/spkx1002-6630-201023048
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In order to analyze biological characteristics of Shigella flexneri (S. flexneri) phage and its sterilization effect in milk, the lytic S. flexneri phage SF-A2 was isolated from sewage. Electron microscope observation showed that purified phage SF-A2 was a member of family Myoviridae. Based on its biological characteristic assay, phage SF-A2 exhibited the tolerance to temperature and pH. In addition, phage SF-A2 could effectively inactivate S. flexneri. After adding phage SF-A2 for 48 h, the concentration of S. flexneri was reduced by 103 folds compared with the host control. After 72 h incubation, the concentration of S. flexneri was declined to the limit of detection. Therefore, SF-A2 is a virulent bacteriophage and can effectively inactivate S. flexneri in ready-to-eat milk. It will be a good biological control agent for food safety and also an efficient antimicrobial source for diarrhea.

Fermentation Processing of Microbial Polysaccharide Welan Gum
ZHAO Yan1,2,CHEN Fang1,2,LI Jian-ke1,2,LIAO Bin1,2,TU Yong-gang3
2010, 31(23):  219-223.  doi:10.7506/spkx1002-6630-201023049
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Optimal preparation conditions such as strain, fermentation medium and fermentation processing parameters were explored. The growth of strain and second stage of seed were achieved by the growth curve of ATCC31555 in medium. The optimal fermentation medium for preparing Welan gum were explored by single factor and orthogonal experiments to be 40 g/L sucrose, 3 g/L yeast extract, 5 g/L K2HPO4·7H2O, 2 g/L MgSO4·7H2O, 1 mg/L FeSO4·7H2O and 0.5 g/L CaCl2. The yield of Welan gum was increased from 7.31 to 17.23 g/L by using the improved medium. The optimal fermentation conditions were the seed age of 18 hours, inoculation amount of 0.5% (V/V), medium volume of 40 mL in 250 mL flask, pH 7.0, shaking speed of 220 r/min, fermentation temperature of 30 ℃ and fermentation time of 72 h. Under the optimal fermentation conditions, the yield of Welan gum was up to 20.64 g/L.

Mutation Breeding of Monascus purpureus with High Productivity of Orange Pigments by Microwave Irradiation
XU Wei,FAN Zhi-cheng,LIU Yan-hua
2010, 31(23):  224-227.  doi:10.7506/spkx1002-6630-201023050
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Microwave irradiation with water-cooling device was used for the mutagenesis of Monascus purpureus. The optimal microwave power, irradiation duration and dosage for the mutagenesis of Monascus purpureus were explored by evaluating the lethal and mutation regularity of Monascus purpureus. Results indicated that the optimal mutation conditions were microwave power of 500 W and irradiation duration of 80 s. Under the optimal microwave irradiation conditions, a mutated strain W5S8 with the highest productivity of orange pigments was achieved and the color value of orange pigments from strain W5S8 was 16.38 U/mL, which was increased by 59.62% compared with the parent strain. Its productivity for orange pigments remained stable after subculture for 5 generations or storage.

Breeding and Application of Tolerant Chinese Rice Wine Yeast YS6.2.5
XIA Yan-qiu1,ZHU Qiang1,WANG Zhi-jun2,LU Qi1
2010, 31(23):  228-232.  doi:10.7506/spkx1002-6630-201023051
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Tolerance of rice wine yeast is essential for brewing rice wine. In order to breed tolerant rice wine yeast, original yeast strain YS (Saccharomyces cerevisiae) was subjected to ethanol-heat-shock, UV-induced mutagenesis of cells and proptoplasts coupled with high temperature domestication to screen and obtain a mutant yeast YS6.2.5 with normal growth at 30 ℃ for rice wine fermentation. The mutant YS6.2.5 had the characteristics of small size, round shape, good aroma-producing favor and low acid-producing property. The alcohol-producing capability, alcohol tolerance, sugar tolerance of YS6.2.5 were 9.0%, 19% and 30 °Bx at 30 ℃, and 6.5%, 20% and 28 °Bx at 38 ℃, respectively. Fermentation tests showed that the YS6.2.5 had strong physiological tolerance, high fermentation power, stable hereditary, and better industrial application prospect.

Amino Acid Addition Technology during Mycelium Fermentation of Cordyceps militaris
BEN Song-bin1,LI Hui-jiao2,HUANG Zi-qi1,SANG Yu-li2,MENG Cheng-cheng1,HOU Xiao1,
2010, 31(23):  233-237.  doi:10.7506/spkx1002-6630-201023052
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Histidine, arginine and lysine are alkaline amino acids that have an important effect on the growth of Cordyceps militaris. In this study, the effects of amino acid addition under various conditions on the growth of mycelium and the production of cordycepin as an anti-cancer functional ingredient during the fermentation process was investigated. Single factor experiments confirmed that the order of factors to affect the growth of mycelium during fermentation process from strong to weak was amino acid type, fermentation temperature, initial pH and amino acid amount. The optimal fermentation conditions for the growth of mycelium were explored by orthogonal experiments to be lysine as the selected amino acid, fermentation temperature of 26 ℃, initial pH of 6 and lysine amount of 0.3 g in 100 mL of medium. Similarly, single factor experiments confirmed that the order of factors to affect the production of cordycepin during fermentation process from strong to weak was amino acid type, initial pH, fermentation temperature and amino acid amount. The optimal fermentation conditions for the production of cordycepin were achieved by orthogonal experiments to be arginine as the selected amino acid, initial pH of 6, fermentation temperature of 24 ℃ and arginine amount of 0.3 g in 100 mL of medium.

Solid Fermentation of Grifola frondosa in Rice Bran Medium for Grifolan Production
LIU Wei-min,XU Li-ping,GUO Chun-mei,YANG Suo-hua,ZHANG Jian,ZHAO Jie-wen
2010, 31(23):  238-242.  doi:10.7506/spkx1002-6630-201023053
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In order to effectively exploit rice bran for preparing health food containing polysaccharides through mimic solid fermentation, rice bran was used as the culture medium matrix to explore the effects of water content, peptone, glucose and pH on solid fermentation of Grifola frondosa. The optimal culture medium and fermentation conditions were explored by single factor and orthogonal experiments on the basis of grifolan productivity. Results indicated that the optimal medium formula was composed of rice bran as solid culture medium matrix with 65% water, 0.5% peptone, 4% glucose (by mass of rice bran) and pH 5.5. The optimal fermentation conditions were 20 g rice bran matrix in a 250 mL fermentation flask, inoculation amount of 10%, fermentation temperature of 25 ℃, rotation speed of 170 r/min and fermentation time of 11 days. The yield of grifolan was 4.52% under the optimal conditions. By calculating with SPSS software, a regression model of total grifolan was achieved.

Fermentation Processing of Fiber Degradation from Oil-tea-cake Residue by Neurospora. crassa
XIAO Yu-juan,DENG Ze-yuan*,FAN Ya-wei,LI Jing,LIU Rong,HU Jiang-ning
2010, 31(23):  243-247.  doi:10.7506/spkx1002-6630-201023054
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The fermentation processing for fiber degradation from the residue of oil-tea-cake after the extraction of tea saponin was investigated. According to results of single-factor experiments, soybean residue, rice bran, water content and fermentation time were selected for the Box-Behnken design to establish a quadric regression equation for describing the degradation of fiber. The optimal fermentation conditions were achieved by response surface analysis to be soybean residue of 29.38%, rice bran of 18.54%, water content of 72% and fermentation time of 74.9 h. Under the optimal fermentation conditions, the highest degradation of fiber reached up to 48.65%, which was consistent with 48.36% of the validated value.

Effect of Primary Fermentation Temperature on Volatile Compounds and Quality of Sweet Flour Paste
MENG Yuan1,QIAO Yu2,LIU Cai-xiang1,KANG Xu1,LI Dong-sheng1,3,HU Jian-zhong1,HUANG Hong-xia1,*
2010, 31(23):  248-252.  doi:10.7506/spkx1002-6630-201023055
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Volatile compounds in sweet flour paste in the early period of fermentation at different temperatures were extracted using head space solid-phase microextraction (HS-SPME) apparatus and analyzed by GC-MS. Results showed that increased fermentation temperature could result in a gradual decrease in the contents of esters, alcohols and acids, and gradual increase in the content of aldehydes. The highest contents of ketones and phenols were observed at the fermentation temperature of 40 ℃. However, less species of volatile compounds was identified in sweet flour paste prepared by low-temperature fermentation. Based on the comprehensive analysis of pH, total acids, amino nitrogen and reducing sugars, the optimal fermentation temperature in the early stage was 40 ℃.

Effect of Selenium Enrichment on Nutritional Composition of Rhodopseudomonas palustris G3
YANG Qi-yin1,2,3,LIU Shu-chao1,JIA Bing-sheng1,WANG Jia-fang1,NANG Xiao-xiao4
2010, 31(23):  253-257.  doi:10.7506/spkx1002-6630-201023056
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In order to explore the effect of selenium enrichment on nutritional compositions of Rhodopseudomonas palustris, general nutrients, amino acids, vitamin B family, nicotinic acid, β-caroteneare, superoxide dismutase (SOD) and catalase (CAT) in selenium-enriched Rhodopseudomonas palustris (sRP) and normal Rhodopseudomonas palustris (nRP) were compared. Results indicated that the contents of protein, soluble sugar and crude fat of sRP were higher than those of nRP, which exhibited an enhancement by 9.10%, 5.13% and 42.86%, respectively. Whereas, the ash content of sRP was lower than that of nRP with a decrease by 23.73%. In addition, totally 17 amino acids were detected in sRP, while only 16 amino acids was detected in nRP. Moreover, the contents of amino acids in sRP were much higher than those in nRP, especially for methionine and lysine with an increase by 100% and 9.2%, respectively. Vitamin B2, vitamin B6, nicotinic acid and carotenoid in sRP were 6.45%, 5.77%, 7.20% and 45.08%, which were also higher than those in nRP, respectively. However, the content of vitamin B1 in sRP was lower than nRP. The activities of SOD and CAT in sRP exhibited an enhancement of 158.43% and 54.51% when compared with those in nRP. Therefore, selenium-enrichment can improve nutritional quality of Rhodopseudomonas palustris.

Expression and Activity Assay of Amylomaltase in Pichia pastoris
ZHU Guo-qiang,WANG Shui-xing*,HUANG Lan,ZHU Shi-long
2010, 31(23):  258-261.  doi:10.7506/spkx1002-6630-201023057
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The gene of MalQ was amplified from genomic DNA of E. coli BL21(DE3) and subcloned intoα secretion signal open reading frame of pPIC9K expression vector to obtain a recombinant plasmid pPIC9K-MalQ. The recombinant plasmid was verified by DNA sequence. The resultant recombinant plasmid bearing MalQ gene was digested by Sal I and transformed into Pichia pastoris strain GS115. The cells with stable expression of amylomaltase were screened in the medium containing G418. The positive clones were induced with methanol to express amylomaltase. The activity of 4-α-glucanotransferase in the crude enzyme was validated through TLC.

Construction and L-valine Accumulation of a Genetic Engineering Brevibacterium flavum Strain
XU Da-qing1,2, TAN Yan-zhen1, MIAO Ming1, WANG Xiao-yuan1,*
2010, 31(23):  262-266.  doi:10.7506/spkx1002-6630-201023058
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As a rate-limiting enzyme for L-valine biosynthesis, the ilvBN gene encoding acetyl-carboxylic acid synthase (AHAS) from Corynebacterium glutamicum ATCC13032 was amplified by PCR, followed by site-direct mutagenesis to obtain an ilvBNr gene, the anti-feedback inhibition gene of ilvBN. The ilvBNr gene inserted into E. coli-Brevibacterium flavum shuttle expression vector pDXW-10 to construct a recombinant plasmid pDXW-10-ilvBNr, which was subsequently transformed into B. flavum ATCC14067, producing a genetic engineering strain ATCC14067/pDXW-10-ilvBNr. The fermentation experiments conducted in a 3 L fermentor showed that no L-valine accumulation was detected in the fermentation broth of the original strain, while an L-valine accumulation of 5.0 g/L was observed in the fermentation broth of the constructed engineering strain.

Cloning and Eukaryotic Expression of Trehalose Synthase Gene from Thermus aquaticus FL-03
LIU Jun-mei,NIE Hai-yan,ZHENG Wei-wei,HU Yao-hui*
2010, 31(23):  267-270.  doi:10.7506/spkx1002-6630-201023059
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The full-length trehalose synthase gene (Tres) was synthesized by genetic engineering and inserted into the Pichia expression vector pPICZα. The expression vector carrying Tres gene was transformed into the competent cells of Pichia GS115 by means of electroporation, and Zeocin resistance screening was then performed to find positive strains. PCR and gene sequencing were used to identify the expression of the target gene. The expressed protein was analyzed by SDS-PAGE and Western blotting. The results suggested that the recombinant plamid pPICZα-Tres was successfully constructed and that the target gene had been integrated into the Pichia genome.

Screening and Purification of Insect Chitinase Inhibitor of Microbial Origin
ZHANG Hong-bin,LIU Ming-yan,TIAN Yu-jing,HU Xue-qin
2010, 31(23):  271-275.  doi:10.7506/spkx1002-6630-201023060
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Helicoverpa armigera chitinase was used as the target to screen strains able to inhibit chitinase by transparent ring plate screening method and DNS colorimetric screening method. A total of 29 strains including strain A0901# were selected out of 500 ones. For separation and purification, the fermentation products of strain A0901# were subjected to alcohol precipitation, protein removal by Sevag s method and gel filtration chromatographic fractionation, and a pure bioactive material was obtained. This bioactive material exhibited a single HPLC peak with a retention time of 15 min. Its inhibition rate on chitinase was evaluated by DNS colorimetric method to be 54.2%. Moreover, its formula was C9H18O10 according to the IR and mass and element analyses, and its nature also proved a multiple hydroxyl compound.

Screening and Optimization of Fermentation Medium of an Antioxidant Exopolysaccharide-producing Marine Strain
FANG Yao-wei1,LU Ming-sheng1,XU Wei-feng2,LIU Shu1,JIAO Yu-liang1,WANG Shu-jun1,*
2010, 31(23):  276-280.  doi:10.7506/spkx1002-6630-201023061
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In this study, a marine strain named OST23a with the ability to produce antioxidant exopolysaccharide (EPS) was screened out of the strains isolated from the samples of sea water or sea mud collected from the sea area near Lianyungang. The strain OST23a was identified as Bacillus subtilis according to its morphological, physiological, biochemical characteristics and 16S rRNA sequence. The EPS produced by this strain exhibited an obvious antioxidant activity. The optimal carbon and nitrogen sources as well as metal ion for the production of EPS were determined to be n-hexane, yeast extract and CaCl2 by single-factor experiments. The optimal formula of fermentation medium for the production of EPS by OST23a were explored to be 1.5% n-hexane, 0.1% yeast extract, 0.3% K2HPO4, 0.1% KH2PO4, and 0.1% CaCl2 by orthogonal array experiments. The productivity of EPS was up to 9.06 mg/L using this optimal medium.

Interdelta PCR Fingerprinting for the Identification of Saccharomyce cerevisiae from Shacheng Area
ZHAO Jing-jing1,LI Yan1,2,*,ZHANG Li-zhong3,ZHUANG Yu-ting1
2010, 31(23):  281-284.  doi:10.7506/spkx1002-6630-201023062
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Interdelta PCR fingerprinting technology was used to differentiate 54 Saccharomyce cerevisiae strains isolated from vineyard soil, brewing equipments and spontaneous fermentation process of Longan grape in Shacheng area. Results indicated that 7 genetic patterns were distinguished by Interdelta PCR fingerprinting. The genetic patterns I through VII accounted for 31.5%, 11.1%, 7.4%, 42.6%, 3.7%, 1.85% and 1.85%, respectively. The numbers of genotypes of yeasts isolated the late stage of spontaneous fermentation, the surface of brewing equipments and vineyard soil were 4, 3 and 2, respectively. Based on the cluster analysis tree, the genetic pattern I and IV had the closest genetic relationship, and the genetic pattern VII had the most far genetic relationship with others. The distribution and variation discipline of different Saccharomyce cerevisiae strains will provide a theoretical foundation for choosing excellent strains with their own favor characteristics.

Effect of Resveratrol on Glucose Metabolism in Insulin-resistant 3T3-L1 Adipocytes
CHEN Si-fan1,KE Liang-ru2,ZHENG Lin1,SHAN Zhi-ming2,ZHOU Ni-man2,FENG Xiang1,*
2010, 31(23):  285-288.  doi:10.7506/spkx1002-6630-201023063
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Objective: To explore the effect and mechanism of resveratrol on glucose metabolism in insulin-resistant 3T3-L1 adipocytes. Methods: Insulin-resistant model was established by the induction of dexamethasone in 3T3-L1 adipocytes. The glucose consumption of insulin-resistant 3T3-L1 adipocytes with and without resveratrol stimulation was determined. The mRNA expression of leptin, adiponectin and resistin was determined by real time PCR, and the expression and phosphorylation of AMPKα were determined by Western blotting. Results: After insulin stimulation with the concentration of 0.01, 0.1μmol/L and 1μmol/L, resveratrol could increase the glucose consumption by 1.3, 1.5 folds and 1.4 folds compared with the control (P < 0.05). Meanwhile, resveratrol could increase mRNA expression of adiponectin and leptin and decrease mRNA expression of resistin. Moreover, resveratrol increased the phosphorylation of AMPKα. Conclusion: Resveratrol can improve glucose metabolism in insulin-resistant 3T3-L1 adipocytes. The molecular mechanism may be the phosphorylation of AMPK α by increasing the expression of adiponectin and leptin and inhibiting the expression of resistin.

Preparation of Antioxidant Peptides from Soybean Meal by Aspergillus niger Fermentation
QIN Wei-dong,CHEN Xue-hong,MA Li-hua,LU Jie
2010, 31(23):  289-293.  doi:10.7506/spkx1002-6630-201023064
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The optimal processing conditions and antioxidant activity of soybean peptides prepared by Aspergillus niger fermentation were investigated and the molecular weights of soybean peptides were determined. The highest concentration of soybean peptides in the fermentation broth, 3.38 mg/mL, was achieved under the optimal preparation conditions, which were the inoculation amount of 2%, fermentation pH of 6.0, substrate concentration of 9 g/100 mL and fermentation time of 34 h. Fractions I and II were obtained from the fermentation supernatant of soybean meal through Sephadex G-15 gel permeation chromatographic separation. Both of them exhibited DPPH and hydroxyl free radical scavenging activities and inhibitory effect on lipid peroxidation, which were all linearly dependent on concentration, and fraction I was superior to fraction II. Moreover, it was found that the molecular weights of fractions I and II were 675.58D and 1625.54 D, respectively.

Amylase from Penicillium sp. Strain PS031: Fermentation Conditions and Optimal Reaction Temperature and pH
ZHANG Jing1,LI Wei-dong2,XIAO Qiong-na1
2010, 31(23):  294-299.  doi:10.7506/spkx1002-6630-201023065
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The strain PS03 isolated from oil and preserved in our laboratory, which was a special bioactive strain belonging to the family of Penicillium sp., was solid-state cultured in a triangular flask to produce amylase in this work. The effects of medium composition and culture conditions on the production of amylase were examined. PS03 cultured in the medium consisting of 30.04% wheat bran, 3.70% soybean meal powder, 3.70% rise hull and 55.56% distilled water gave the highest amylase production. The optimal culture conditions were determined through single factor experiments to be: initial medium pH 3; the amount of the inoculated seed (containing108 conidia/mL), 1.85%; culture temperature, 28 ℃; and culture time, 96 h. In addition, the crude enzyme solution obtained under the above conditions was sampled to determine optimal pH and temperature for the reaction of this enzyme. The amylase from PS03 showed high activity in a pH range between 2.0 and 10.0. The relationship between enzyme activity and pH was a double peak-shaped curve. The highest peak of enzyme activity was observed at pH 3, with 100% relative activity, and the peak of enzyme activity appearing at pH 9 was lower, indicating a relative activity of 84.98%. The optimal reaction temperature of this enzyme was 60 ℃, and the relative activity at 90 ℃ was 39.06%. It can be concluded through this study that the amylase produced by PS03 is a special acidic middle-temperature amylase having good tolerance to strong alkaline and acidic conditions as well as high temperature.

Restoration Capability of Bifidobacteria with Different Treatments on Imbalanced Flora in Intestine
SHANG Nan,LIU Li-sha,XU Ri-hua*,WU Rui-yun
2010, 31(23 ):  300-304.  doi:10.7506/spkx1002-6630-201023066
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In order to explore the restoration capability of Bifidobacteria on imbalanced flora in intestine, live bacteria (LB), cell-free extract (CE) and fermentation supernatant (FS) of Bifidobacteria were used to treat the vancomycin-induced mice model with imbalanced flora by gastric gavage. The effects of three different treatments of Bifidobacteria on major species of intestinal flora were evaluated. Results showed that three different treatments could significantly increase the proliferation of Bifidobacteria and Lactobacillia (P < 0.01) and decrease the amounts of Clostridium perfringens and Enterococcus (P < 0.05 and P <0.01). Bacteroide and Enterobacteriaceae were increased to the normal level. Therefore, LB, CE and FS of Bifidobacterium RH could restore and modulate the intestinal microecological balance of mice.

Fermentation Characteristics of Yeast from Lonicera edulis Fruits
SUN Guang-ren1,2,ZHANG Qi-chang1,DONG Feng-ying1,ZHAO Hong-nan1,DU Feng-guo1,*
2010, 31(23):  305-309.  doi:10.7506/spkx1002-6630-201023067
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The predominant yeast strain isolated from Lonicera edulis fruits after enrichment culture was tested for its acidresistant, alcohol-resistant, sulfurous acid-resistant and acid degrading properties. This was followed by fermentation of Lonicera edulis fruit wine with this strain after activation. It was found that this yeast strain could utilize citric acid and malic acid well and its ability to utilize tartaric acid was bad. Meanwhile, this yeast strain exhibited the resistance to sulfurous acid and alcohol. Moreover, fermentation with it resulted in a 13.2% decrease of acidity in Lonicera edulis fruit wine. Therefore, this strain will have promising application prospect in the fermentation of high-acidity fruit wine.

Inhibitory Effect of Catechins on Potato Tyrosinase
ZENG Liang1,WU Liang-liang1,GUAN Xing-li1,LUO Li-yong1,LIU Yong-sheng2
2010, 31(23):  310-313.  doi:10.7506/spkx1002-6630-201023068
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The effects of the quantity of enzyme solution, substrate concentration, temperature and pH on the activity of potato tyrosinase were determined by spectrophotometer method in order to determine the optimal reaction conditions of potato tyrosinase. Along with this, the inhibitory effect of catechins on potato tyrosinase in a Na2HPO4-NaH2PO4 buffer solution (pH 6.8) at 30 ℃ was examined by enzymatic kinetics methods. The optimal conditions for the reaction of potato tyrosinase were found to be adding 0.5 mL of the crude tyrosinase solution extracted from potato to the 2 mmol/L substrate solution for reaction at 30 ℃, pH 6.8. Catechins could inhibit potato tyrosinase, and the concentration for 50% inhibition rate was approximately 0.27 mg/mL. The Lineweaver-Burk plot showed that the inhibitory effect of catechins on potato tyrosinase was competitive, and the inhibition constant (KI) was 0.16 mg/mL.

Sensory Quality Improvement of Pickled Cabbage by Adding Natamycin before Fermentation
HAN De-quan,WANG Yi,SUN Qing-shen,WU Tong
2010, 31(23):  314-316.  doi:10.7506/spkx1002-6630-201023069
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Pickled cabbage is often contaminated by mold, yeast and other microorganisms during fermentation, which disrupts the sensory quality of picked cabbage. Safe non-toxic natamycin, an effective biological preservative, was added to different final concentrations before starting the fermentation of pickled cabbage, and the effect of added natamycin on microbial growth was dealt with. The final concentration of natamycin of 20 mg/L had no effect on the growth of lactic acid bacteria, but inhibited the growth of undesired microorganisms, thus obviously improving the sensory quality of pickled cabbage.

Regulatory Effect of Hormones on the Growth and Metabolism of Paecilomyces cicadae in Submerged Fermentation
CHEN An-hui,WANG Wei-dong,CHEN Hong-wei,HAN Fu-hai,LI Nian
2010, 31(23):  317-321.  doi:10.7506/spkx1002-6630-201023070
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The regulatory effects of separated added 6-benzylaminopurine and juvenile hormone III before the submerged fermentation of Paecilomyces cicadae on the mycelial growth, intracellular polysaccharide (IPS), cordycepin and adenosine production were explored. The rhythm of mycelial growth and metabolism were different between the control group and the test groups during the whole fermentation process. Two hormones had an promotion effect on the maximum biomass of Paecilomyces cicadae, the biomass of Paecilomyces cicadae was increased by 28.96% and the fermentation time could shorten to 12 h when 6-benzylaminopurine was added at a concentration level of 4 mg/L. In addition, 6-benzylaminopurine and juvenile hormone III could regulate the metabolic rhythm of bioactive materials in Paecilomyces cicadae. The content of IPS was notably increased when 6-benzylaminopurine was added at the low concentration (2 mg/L) (P < 0.05), and juvenile hormone III had an significant inhibitory effect at a concentration level of 4(middle) or 8 mg/L(high) after fermentation for 36 h (P < 0.05). Furthermore, both kinds of hormones also could change the metabolic rhythm of cordycepin and adenosine based on their productivity during the fermentation.

Induced Mutagenesis of Mortierella M11for Improving the Abilities to Produce Lipid and γ-Linolenic Acid
ZHANG Chao1,2,XU Zhou2,WEI Qin2,LI Zheng-guo1,*
2010, 31(23):  322-325.  doi:10.7506/spkx1002-6630-201023071
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In order to improve the productivity of lipid and γ-linolenic acid in Mortierella M11, the mutagenesis of Mortierella M11 was induced by UV irradiation, DES treatment and their combination, respectively. All the three mutant strains of Mortierella M11 obtained exhibited higher contents of lipid and γ-linolenic acid in comparison with it, and the combined induction was the most effective mutagenesis approach. The mutant strain M117 obtained through the combined induction of UV irradiation and DES treatment showed 41.3% lipid content, 9.28% GLA content and 1.52 g/L GLA yield, with incremental percentages of 11.26%, 11.81% and 24.59% as compared to the original strain, respectively. After nine generations of passage, the abilities of this stain to produce lipid and γ-linolenic acid were both kept stable.

Immobilization and Enzymatic Properties of Chitosanase from Bacillus thuringiensis ZJOU-010
CHEN Jing1,CHEN Yu2,LU Liu-qi1,CHEN Xiao-e1,FANG Xu-bo1
2010, 31(23):  326-330.  doi:10.7506/spkx1002-6630-201023072
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The chitosanase in the fermentation broth of B.thuringiensis ZJOU-010 was immobilized by adsorption onto DEAE- 22 cellulose and cross-linking with glutaraldehyde. The immobilization conditions of this enzyme were investigated. Apart from this, its enzymatic properties after the immobilization were characterized. The optimal enzyme immobilization process determined was that the immobilization was allowed to proceed for 10 h under the conditions of 3.0% glutaraldehyde concentration and 20 mg enzyme loading. The optimal pH and temperature of the immobilized enzyme obtained under these conditions were 4.83 and 50 ℃, respectively. It had better thermostability than its free counterpart, displaying half-lives of 36.3 h at 40 ℃ and 6.2 h at 50 ℃ and a kinetic parameter Km of 9.19 g/L. After being repeatedly used for 10 times, the residual activity of the immobilized enzyme as percentage of original activity was 88.32%.

Development of a Novel Perilla Flavored Bean Sauce
TIAN Hai-juan,LENG Jin-song
2010, 31(23):  331-334.  doi:10.7506/spkx1002-6630-201023073
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The development of a novel Perilla flavored bean sauce based on a rapid fermentation method is proposed. The optimal fermentation conditions were obtained through single factor and orthogonal array design experiments to be: the amount of inoculated Aspergillus oryzae 0.40%; primary fermentation temperature 50 ℃; the amount of added Perilla leaf juice 4%; and the amount of added water for koji making 150%. The Perilla flavored bean sauce manufactured under the optimal conditions showed the highest sensory quality and fermentation performance as well as shorter processing cycle, which is beneficial to its industrial production. It had the unique aroma of Perilla and a pure taste, thus being suitable to be used as a seasoning sauce for seafood.

Nutrition & Hygiene
Effects of Lactobacillus helveticus on Immune Response and Cytokines in Intestinal Mucosa of Mice
JIA Yu-chen,CHEN Qing-sen*,WANG You-xiang,YAN Ya-li
2010, 31(23):  335-339.  doi:10.7506/spkx1002-6630-201023074
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Our aim was to investigate the effects of Lactobacillus helveticus TS206 on intestinal immune response and cytokines in intestinal mucosa of healthy Balb/c mice. Mice were randomly assigned to three groups - normal control group, saline control group and L.helveticus group which were administered with the dose 108 CFU/mL. All the mice were executed after 0, 1, 2, 3, 4, 6, 8, 12, 24 h of administration and the SIgA and cytokines concentration were determined in intestine mucosa of all mice by radioimmunoassay (RIA) and enzyme linked immunosorbent assay (ELISA). The results showed that compared with control group and physiological saline group, the SIgA content in intestinal mucosa of mice with the oral administration of L. helveticus was significant different (P<0.01); IL-2 and IFN-γ content was also significant different (P<0.05). IL-4 content in the intestinal mucosa of mice from treatment was significantly higher than control (P<0.05), but not IL-6 expression level (P>0.05). IFN-γ/IL-4 ratio exerted mutual antagonistic action, suggesting that L. helveticus maintain mucosa immunization balance in healthy mice, and also keep Th1/Th2 balance. Our results indicate that probiotic bacteria L.helveticus is provided with modulation of immune response in intestinal mucosa of mice.

Effect of Transferred Human Lactoferrin Milk Powder on Serum iron and Ferritin in Rats
QI Xiao-zhe,WANG Jing,ZHOU Cui,XU Chao,CHE Hui-lian*
2010, 31(23):  340-343.  doi:10.7506/spkx1002-6630-201023075
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Objective: Feed on SD rats for 90 days with transferred human lactoferrin whole milk powder and their nutrition, physiological status, and biochemical indicators were investigated, thus to evaluate the influence of transferred human lactoferrin milk powder on rats serum iron and ferritin. Methods: The study refers to the People s Republic of China Agriculture Industry Standard Transgenic plants and products food safety testing (NY/T 1102—2006). A total of 140 SD rats were divided into 7 groups, including control group, transgenic low-dose group, transgenic middle-dose group, transgenic high-dose group, non-transgenic low-dose group, non-transgenic middle-dose group, and non-transgenic high-dose group. Male and female were equally distributed. The weight, feed efficiency, and blood biochemical indicators during 90 days of feeding were measured. Results: SD rats fed on transferred human lactoferrin whole milk powder for 90 days were healthy, and compared with non-transgenic group, transgenic group did not show significant difference. Transgenic milk powder can increase the serum iron and ferritin in rats noticeably, and no adverse effects were observed during the study. Conclusion: Transferred human lactoferrin whole milk powder can increase the serum iron and ferritin in rats.

Hypoglycemic Effects of Garlic oil and Onion oil on Alloxan Diabetic Mice
LI Li-hua,LU Hui,YANG Li-gang,WANG Shao-kang,SUN Gui-ju*,MIAO Miao,ZUO Ping-guo,
2010, 31(23):  344-348.  doi:10.7506/spkx1002-6630-201023076
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Objective:To study the hypoglycemic effects of garlic oil and onion oil on diabetic mice. Methods: The diabetic mice induced by alloxan in different groups were fed with different dose of garlic oil or onion oil for 30-day continuously. Fasting blood glucose was determined on day 0 and 30, while glucose tolerance level was determined on day 30. The blood samples of mice were collected for the analysis of glycosylated serum protein and blood urea nitrogen as well as lipid levels. Results: There were significant differences between the diabetic mice given garlic oil or onion oil at the dose of 92.6 mg/(kg bw·d) and model group mice on the levels of fasting blood glucose, glucose area under curve, the levels of blood urea nitrogen, glycosylated serum protein (P<0.05). Further more, garlic oil and onion oil at the dose of 92.6 mg/(kg bw·d) had protection on liver, kidney and pancreatic damage in diabetic mice. Conclusion: The garlic oil and onion oil had the hypoglycemic effects on diabetic mice, and they also had protective effects on liver and kidney as well as pancreatic injury caused by diabetes mellitus.

Attenuation of Oxidative Stress in Diabetes Rats by Water Buffaloes Colostrums Powder
HUANG Yi,LI Xing-fang,QIN Xiao-rong,CHEN Rui-fang,JIANG Wei-wei,LIANG Zi-cheng,WANG Shi-chang*
2010, 31(23):  349-352.  doi:10.7506/spkx1002-6630-201023077
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Effects of water buffaloes colostrums powder (WBCP) on serum anti-oxidative activity and organic indexes in insulindependent diabetes mellitus (IDDM) rats were studied. Insulin-dependent diabetes mellitus rats were induced by intraperitoneal injection of STZ with high-dose of 65 mg/kg bw. Rats were randomly assigned to normal group, diabetic model group, medicine group and WBCP group. With intragastric administration, sterilized water were provided to the normal and the diabetic model group, while metformin and WBCP groups were supplied for the medicine group and the WBCP group daily, respectively. Blood sugar level in fasting rats was determined regularly and blood samples were collected on day 31. Serum anti-oxidative activity was determined and internal organs were weighed and organic indexes were calculated. Compared with the diabetic model group, fasting blood sugar level drop at the beginning (P<0.01 and P<0.05) and serum SOD activity increased (P<0.01), however NO concentration decreased (P<0.05) in the WBCP group. Moreover, pancreas index and lung index decreased (P< 0.01 and P < 0.05). In conclusion, WBCP can maintain the fasting blood sugar level at the beginning and oxidative stress is attenuated in IDDM rats with pancreases and lungs being protected.

Protective Effect of Liquiritin against Cerebral Ischemia/Reperfusion Inflammatory Injury in Mice
SUN Ya-xuan1,2,LIU Ting3,DAI Xue-ling1,GAO Zhao-lan1,WEI Rong1,ZHENG Qiu-sheng3
2010, 31(23):  353-355.  doi:10.7506/spkx1002-6630-201023078
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Objective: To investigate the protective effect and mechanism of liquiritin against cerebral ischemia/reperfusion inflammatory injury in mice. Methods: ICR mice were randomly divided into sham group, model group, positive control group (intraperitoneally administered edaravone, 3 mg/(kg bw·d)), and liquiritin groups (intragastrically administered, 40, 20 mg/(kg bw·d) and 10 mg/(kg bw·d)). Focal cerebral ischemia/reperfusion models were set up by using intraluminal filament method. After cerebral ischemia for 2 h and subsequent reperfusion for 22 h, histopathology changes were monitored, and the activity of MPO and the expression of intercellular adhesion molecule-1(ICAM-1) in brain tissue were measured. Results: Compared with the model group, liquiritin noticeably decreased the activity of MPO and the expression of ICAM-1. Conclusion: Liquiritin has protective effects against cerebral ischemic/reperfusion inflammatory injury.

Effect of Beef Supplementation on Body Weight and Sport Performance of Mice
CAO Yuan1,YU Shang-yu2,HU Hong-bo1,*
2010, 31(23):  356-359.  doi:10.7506/spkx1002-6630-201023079
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Objective: To investigate the effect of beef supplementation on body weight and sport performance of mice. Methods: Fifty male mice were randomly divided into two groups: control group (n = 20) and beef group (n = 30), with each mouse in separate cages. During the first four weeks, the intake of mice were limited to 6.0 g/d. Exhaustion time of exercise, holding power, body weight were measured before mice were immediately slaughtered and the tissues of liver and hind leg muscle were sampled. Results: Body weight gain in beef group tended to decline compared with control while exhaustion time of swimming and holding power tended to increase (P> 0.05). For beef group, liver glycogen, muscle glycogen, and serum SOD in mice increased (P<0.05) while the serum MDA level was reduced (P<0.05) with or without extra load. Conclusion: Under the same dietary protein and energy intakes, the ration with beef included enables mice to have a stable body weight and increase holding power and exhaustion time of swimming, as well as to increase glycogen levels in liver and muscle tissue and significantly improve the animal s antioxidant capacity no matter whether there was additional load to mice.

Evaluation of Immunoregulatory Function of Formula Milk Powder Added with Lactoprotein Hydrolysates
MENG Wei-bin1, HU Zhi-he1,*, WANG Li-juan1, FENG Yong-qiang2, ZHU Li-min2
2010, 31(23):  360-365.  doi:10.7506/spkx1002-6630-201023080
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To understand the immunoregulatory function of formula milk powder added with lactoprotein hydrolysates, different doses of infant formula milk powder and middle-aged and senior formula milk powder with and without the additions of casein and milk whey protein hydrolysates were orally administered to the Balb/c mouse model with immunosuppression induced by intraperitoneal injection of cyclophosphate (Cy) for 15 successive days, respectively. Spleen index, thymus index, cellular immune response, humoral immune function and phagocytic function of mononuclear macrophage were determined on the second day after the last administration. It was found that the evaluation results of infant formula milk powder and middleaged and senior formula milk powder added with lactoprotein hydrolysates were both positive, thus proving that adding lactoprotein hydrolysates enhances the immunoregulatory function of formula milk powder.

Analysis and Evaluation of Nutritional Components in Cyclina sinensis and Meretrix meretrix
LI Xiao-ying1,DONG Zhi-guo1,2,YAN Bin-lun1,CHENG Han-liang1,MENG Xue-ping1,SHEN He-ding2,LI Jia-le2
2010, 31(23):  366-370.  doi:10.7506/spkx1002-6630-201023081
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The nutritional compositions in Cyclina sinensis and Meretrix meretrix cultured in pond of Haizhou bay in winter were determined. Results indicated that the water content (77.23g/100g mf) and carbohydrate (4.45 g/100g mf) in C. sinensis was similar to that in M. meretrix (76.39 g/100g mf and 4.14 g/100g mf). However, a significant difference in crude ash, protein and fat between two clams was observed (P < 0.05). The content of crude protein was 15.54% in M. meretrix and 11.55% in C. sinensis; contents of crude ash and crude fat in C. sinensis (4.91 g/100g mf and 1.86 g/100g mf) were significantly higher than those in M. meretrix (2.86 g/100g mf and 1.07 g/100g mf). Among six heavy metals including Cd, Cr, Cu, Ni, Pb and Zn, the Zn exhibited the highest content. The content of Zn was 12.77μg/g in C. sinensis and 252.59μg/g in M. meretrix. The contamination assessment results for both clams by single factor index method indicated six heavy metals in both clams were in the permit range of national standard for health aquatic products except for Pb in M. meretrix slightly exceeding the standard limit. There were 18 common amino acids and 10 essential amino acids for human demand. The first limited amino acid was Val and the second limited amino acid was Phe + Tyr in both clams. The content of Glu was the highest among 18 amino acids and its content was up to 116.5 mg/g in C. sinensis and 111.5 mg/g in M. meretrix. The content of delicious amino acids was close in both clams and more than 42%. These investigations suggested that both clams were suitable for diet and delicious additives. The essential amino acid index (IEAA) for C. sinensis was 50.0, which was close to that of M. meretrix (50.3). The ratio of essential amino acids to total amino acids was approximately 45%, which was higher than that of amino acid mode recommended by WHO/FAO (35.38%). Therefore, two clams were ideal as protein source for human.

in vitro Anti-tumor Effect of Germanium-riched Barley Seedling
DU Rong1,WANG Xiao-jie1,*,XU Qing1,RUAN Xin2,LIU Xin-sheng3,QU Yan-qing3,
2010, 31(23):  371-374.  doi:10.7506/spkx1002-6630-201023082
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Objective: To investigate the anti-tumor effect of Germanium-enriched barley seedling (GEBS) in vivo and in vitro. Methods: The S-180 model mice were administered with GEBS at different dosages by gavage for 12 consecutive days. The effect of GEBS on tumor weight, thymus index and spleen index of mice was explored. Meanwhile, the inhibition effect of GEBS on the proliferation of mouse sarcoma cell S-180 and myeloma cell SP-2 was also evaluated by MTT assay. Results: GEBS with high dosage could obviously suppress the growth of S-180 sarcoma in mice with an inhibition rate of 68.52% (P<0.05) and increase the thymus index and spleen index (P<0.05). Moreover, GEBS could obviously inhibit the growth of mouse sarcoma cell S-180 and myeloma cell SP-2 in vitro in a positive dosage-dependent manner. Conclusion: GEBS can obviously inhibit the growth of tumor in vivo and in vitro.

Regulatory Function of ω -6 Linoleic Acid on Mouse Immune System
LIU Xiao-juan,PANG Guang-chang*,LI Yang
2010, 31(23):  375-379.  doi:10.7506/spkx1002-6630-201023083
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Objective: To explore the effect of ω-6 linoleic acid on cytokines of mice. Methods: The mice were administered with linoleic acid by intragastric administration, intraperitoneal injection and vein injection respectively. At 3, 2 h and 2 h after administration, the concentration changes of 24 cytokines including IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-12 (p40), IFN-γ, G-CSF, MCP-1 and VEGF in mouse serum were determined. Results: An obvious increase in IL-1, Eotaxin and VEGF, and significant decline in IL-6, IL-12 (p40), G-CSF and KC were observed in mice with intragastric administration of ω-6 linoleic acid; In intraperitoneal injection group, the concentration of IL-1, IL-17, IL-4, IL-10 exhibited an obvious increase, whereas GCSF exhibited an obvious decrease; The mice in vein-injection group showed a remarkable change with inflammation, which exhibited a dramatic increase of IL-2, IL-5 and IL-6, and a significant decrease of IL-3, IL-4, IL-9, IL-10, IL-12 (p40), and IL-17. Conclusion: ω-6 linoleic acid can transfer signal through mucosal immunity of intestine and blood system to regulate immune system. In intragastric administration group, PKC/NF-κB and partial STAT pathways can be activated and JAK-STAT3 and PI3K pathways can be inhabited; in intraperitoneal injection group, NF-κB, JNK/p38/MAPK, PI3K and JAK/STAT6 can be activated and STAT3 can be inhabited; in vein-injection group, NF-κB, MAPK and JAK/STAT3 can be activated, and PI3K/ATK, ERK/MAPK and STAT1, 4, 5 can inhabited. Nowadays, due to excessive nutrition for some people, it is not scientific strategy for these people to pursue immune-enhancing food, which can keep their body in a continuous inflammation status. Therefore, our health should be result from a dietary structure that is benefit for immune balance.

Preparation and Toxicity Evaluation of Compound Lithospermum Antioxidant
ZHANG Feng-qing
2010, 31(23):  380-382.  doi:10.7506/spkx1002-6630-201023084
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A compound Lithospermum antioxidant (FZK) was prepared using Lithospermum ethanol extract (Z), licorice ethanol extract (G), Sophora japonica extraction (H) from alkali extraction and acid precipitation, citric acid (N) and vitamin E (E) by the ratio of 10:5:5:2:1 (Z:G:H:N:E). The toxicity of FZK was evaluated by acute toxicity test, micronucleus test of bone marrow cells in mice, and chromosomal aberration test of bone marrow cells. Results indicated that the maximum tolerance dose of oral administration in mice was 16000 mg/kg body weight. According to acute toxicity classification criteria, FZK is non-toxic. However, FZK didn t exhibit a role in improving micronucleus rate of polychromatic erythrocyte and the mutagenicity in mice at the dose of less than 8000 mg/kg body weight.

Effect of Momordica charantia L. Saponins on Osteoblast Proliferation and Alkaline Phosphatase Expression
YANG Zhi-gang,SHEN Zong-gen,ZHANG Yan-ping
2010, 31(23 ):  383-385.  doi:10.7506/spkx1002-6630-201023085
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The present study was aimed at investigating the effect of Momordica charantia L. saponins on the proliferation and alkaline phosphatase (ALP) expression of in vitro cultivated osteoblasts of new born neonatal SD rats. The in vitro cultivation of new born SD rat (aged within 24 h) osteoblast at gradient concentrations of Momordica charantia L. saponins in MEM medium was performed, and MTT and PNPP assays were used to measure the proliferation and ALP activity of osteoblasts, respectively. Our findings suggest that Momordica charantia L. saponins promote the proliferation and ALP activity of osteoblasts in timeand dose-dependent manners.

Nutritional Composition Analysis of Marine Cultured and Fresh-water Cultured Scylla serrata
WANG Xue-feng,GU Hong-xin,GUO Qian-lin,WU Shou-liang,HAN Yao-ping,LIU Jing-jing*
2010, 31(23 ):  386-390.  doi:10.7506/spkx1002-6630-201023086
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The nutritional composition in the muscles of marine cultured and fresh-water cultured Scylla serrata was preliminarily analyzed by routine methods. The contents of water and crude ash, protein and fat in marine cultured Scylla serrata were 70.26%, 4.59%, 15.57% and 1.09%, respectively, and those in fresh-water cultured Scylla serrata were 78.36%, 4.35%, 17.42% and 0.75%. This indicates that the muscles of Scylla serrata cultivated in different environments have a large difference in water content. A total of 17 amino acids were detected in both of them, and the percentages of essential amino acids occupying total amino acids in the muscles of marine cultured and fresh-water cultured Scylla serrata were 34.39% and 31.20%, respectively, reaching the FAO/WHO evaluation standards. The essential amino acid index (EAAI) of the muscle of marine cultured Scylla serrata was 85.20, while freshwater Scylla serrata was 68.35. The first limiting amino acids in the muscles of marine cultured and freshwater cultured Scylla serrata were both valine. The content of saturated fatty acids in marine cultured Scylla serrata was significantly higher than that in fresh-water cultured Scylla serrata (P<0.05). Their contents of EPA + DHA were 11.18% and 9.27%, having no significant difference (P>0.05). Considering collectively the above experimental results, it can be concluded that the muscle of marine cultured Scylla serrata has slightly better nutritional value but worse flavor than that of fresh-water cultured Scylla serrata.

Reviews
A Review of the Effect of Enzymatic Modification on the Allergenicity of Food Proteins
CHENG Wei1,2,3,CHEN Hong-bing1,2,*,GAO Jin-yan4,LI Xin4
2010, 31(23):  391-394.  doi:10.7506/spkx1002-6630-201023087
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Enzymatic modification of protein technology, including enzyme hydrolysis and enzymatic cross-linking technology, with modification of the protein structure thus resulting in the change of functional properties, has been widely used in food processing. However, the effect of enzymatic modification on the allergenicity of food proteins has not been explored in full detail. Enzymes like pepsin, trypsin, papain, alcalase, and chymotrysin may digest allergen epitopes in food proteins and decrease its allergenicity, while transglutaminase, peroxidase, and polyphenoloxidase may polymerize the allergen proteins, package the allergen epitopes by enzymatic cross-linking, and thus reduce its allergenincity. Therefore enzymatic modification is an effective method to reduce the allergenicity of food proteins and needs further study.

Research Progress on Microalgae Pigment
WU Ji-lin1,ZHOU Bo2,MA Ming-you1,3,PENG Mi-jun1,3,*
2010, 31(23):  395-400.  doi:10.7506/spkx1002-6630-201023088
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It has been long history for pigment used as colorant in foods, cosmetics and pharmaceutical fields. In this paper, the current situation of microalgae pigment, including physical, chemical, and biological properties as well as the production process optimization have been reviewed. The pigments discussed in this paper have been produced at large industrial scale or will be in a wide application in the future. Development and application of microalgae pigment are also predicted.

Research Progress on Purple Sweet Potato and Its Anthocyanins
PENG Qiang,GAO Yan-xiang*,YUAN Fang
2010, 31(23):  401-405.  doi:10.7506/spkx1002-6630-201023089
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Purple sweet potato (PSP) contains a variety of functional components, such as anthocyanins, chlorogenic acid and isochlorogenic acid. Therefore, PSP is endowed with multiple physiological functions including antioxidation, antimutation, hepato-protection, antihypertension, antihyperglycemia, antihyperlipidemia, memory enhancing, and antibacterial activities. Varied foods and food materials have been developed from PSP both at home and abroad. Therefore, PSP can be recommended as a superior cash crop for the production of foods of health benefits. In order to provide theoretical basis for better exploration of PSP resources, the research progress on physicochemical property, physiological functions, development and application of PSP and its anthocyanins in recent years is summarized in this paper.

Research Progress on the Epitope Mapping Technology for Food Allergens
WU Yong1,2,LI Xin1,3,CHEN Hong-bing1,2,*,GAO Jin-yan3
2010, 31(23):  406-410.  doi:10.7506/spkx1002-6630-201023090
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Epitopes is the material basis of allergens. Epitope mapping technology is the tool for studying allergen epitopes, which involves epitope mapping and epitope prediction. In recent years, there have been some newly emerging epitope mapping technologies include phage display techniques, mass spectrometry, surface plasmon resonance, protein microarray and nuclear magnetic resonance. Compared with the traditional epitope mapping technology, they have advantages of high sensitivity and accuracy as well as rapidity. Epitope prediction is a prediction of allergen epitopes achieved by means of the bioinformatics methods. This paper reviews the applications of the aforementioned epitope mapping technologies in epitope prediction and research progresses on epitope prediction.

Research Advances on Structural Characteristics and Bioactivity of Tremella fuciformis Polysaccharides
MA Su-yun1,HE Liang1,YAO Li-fen2
2010, 31(23):  411-416.  doi:10.7506/spkx1002-6630-201023091
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The chemical structures of the polysaccharides from fruit body, spore, and submerged culture of T. fuciformis are similar. T. fuciformis polysaccharides mainly consist of heteropolysaccharides with α-(1→3)-linked D-mannan as the backbone chain, exhibiting diverse activities such as immunomodulation, antitumor, antioxidation, and antiaging. The present paper reviews the structural characteristics, various activities and structure -activity correlation of T. fuciformis polysaccharides.

Research Progress in Determination Methods for Amylose Content
YANG You-xian1,2,ZHAO Yan1,2,LI Jian-ke1,2,*,HUANG Xin-qiu2
2010, 31(23):  417-422.  doi:10.7506/spkx1002-6630-201023092
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Based on the significance of amylose content to the quality of grain as well as the processing and utilization of starch, systematic and comprehensive studying of the methodology for the content determinination in amylose is necessary. This article systematically introduces standard methods, commonly used methods and newly emerging methods reported in recent years. This may provide useful references for the choice of an appropriate method for the determination of amylose content according to the actual requirements.

Research Progress in the Detection of Agricultural Products/Food by Imaging Spectrometry
ZHOU Quan1,ZHU Da-zhou2,3,WANG Cheng3,ZHENG Yao4,WANG Qiu-ping1,MA Zhi-hong2,*
2010, 31(23):  423-428.  doi:10.7506/spkx1002-6630-201023093
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As a newly emerging technology for process analysis, imaging spectrometry can acquire spatial information of samples and provide thousands of spectral data points for each pixel in an image. In this way, the spectral data of each wavelength form an image and result in the syncretism of spectra and image. By analyzing corresponding spectra and images, the components, concentration, status, spatial distribution and dynamic change of samples can be detected. In this paper, technical principles, system compositions and data processing methods of imaging spectrometry are described. The research progress in the detection of agricultural products/food by imaging spectrometry is discussed. Based on the current research achievements, imaging spectrometry reveals a wide range of application prospect in the detection of agricultural products/food.

Research Progress in Isolation and Purification of Major Allergens from Bovine Milk
CAI Xiao-hu1,2,LI Xin1,3,CHEN Hong-bing1,2,*,GAO Jin-yan3
2010, 31(23):  429-433.  doi:10.7506/spkx1002-6630-201023094
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The bovine milk contains three kinds of major allergen proteins such as casein, β-lactoglobulin and α-lactalbumin. This article has reviewed research progresses on purification methods of major milk allergens. The purification methods including precipitation, ion exchange chromatography, gel filtration chromatography, hydroxyapatite chromatography, hydrophobic interaction chromatography, high performance liquid chromatography and membrane technology have been discussed. Among them, ion exchange chromatography and gel filtration have been used widely, and precipitation method has been generally used in the rough purification step. Although hydroxyapatite chromatography and hydrophobic interaction chromatography are also common for the purification, they can not be used to isolate allergens individually and need to combine with other methods for the separation of allergens. High performance liquid chromatography and membrane technology are suitable for the follow-up purification to improve the purity of allergens.

Research Progresses on the Oxidative Stability of Phytosterol and Its Applications in Food
PANG Min,JIANG Shao-tong*
2010, 31(23):  434-438.  doi:10.7506/spkx1002-6630-201023095
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As phytosterols were found to have a cholesterol-lowering effect, more and more attention has been paid to the development of phytosterols-rich foods by adding phytosterol ingredients to food matrices in order to increase the variety of functional foods. The current situation of research on the biological effects of phytosterols, the formation mechanisms, characteristics and determination methods of their oxidation products and the development of functional phytosterols-rich foods is review in the paper. In addition, many suggestions concerning the development and research of functional phytosterols-rich foods in our country are propose considering that the habitual use way of oil for Chinese style food manufacturing is mainly high temperature frying.

Research Progress of the Use of Bacteriophage to Detect Foodborne Pathogenic Bacteria
LI Meng,WANG Jing-xue*,LIN Hong
2010, 31(23):  439-446.  doi:10.7506/spkx1002-6630-201023096
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Foodborne pathogenic bacteria have a significant impact on food safety. Traditional detection techniques are not sufficient to achieve a satisfactory detection results in short time period. Novel methods with rapidity, sensitivity and specificity are highly desired. Bacteriophages are virus-infecting bacteria, which are widespread in environment and have the characteristic of simple structure, high specificity and rapid propagation. Currently, many phage-based methods have been developed for inexpensive, fast and sensitive detection for foodborne pathogenic bacteria. In this paper, the principles and applications of phage-based methods are reviewed.

Heterocyclic Aromatic Amines in Processed Meat Products
YAO Yao,PENG Zeng-qi*,SHAO Bin,WANG Rong-rong,JIN Hong-guo
2010, 31(23):  447-453.  doi:10.7506/spkx1002-6630-201023097
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In processed meat products, there are two kinds of heterocyclic aromatic amines (HAAs) such as aminoimidazoazarens and amino-carbolin, which have mutagenic and carcinogenic effects. Especially for IQ (2-amino-3-methyl-imidazo [4,5-f] quinoline), it is commonly recognized as highly carcinogenic agent to humans by International Agency for the Research of Cancer (IARC). Long-term investigations indicate that increased processing temperature and prolonged processing time can result in a dramatic increase in the amount of HAAs. The type of raw meat also can exhibit an obvious influence on the content of HAAs. In addition, gravy and broth is one of the most important factors for the assessment of heterocyclic aromatic amine content of the daily intake. In this paper, the structures, classification, toxicity as well as extraction and detection methods of HAAs are introduced. The formation of heterocyclic aromatic amines is discussed to enhance the public attention.

Advances in Research and Applications of Critical Processes and Equipment Technologies for Low-temperature Meat Products
SUN Jiang-qing1,2,XU Bao-cai1,3,*,ZHOU Hui1,2,WANG Yun1,2,LI Jing-jun1,2
2010, 31(23):  454-460.  doi:10.7506/spkx1002-6630-201023098
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Low-temperature meat products are the main development direction of meat processing in the future in China. However their processing qualities such as cooking yield, water-holding capacity, texture characteristics and sensory characteristics are influenced differently by some mechanical treatments including tumbling, mechanical tenderization, brine injection and chopping. This paper reviews the current applications of mechanical treatments in the processing of low-temperature meat products. Low temperature and high vacuum tumble technology being widely used at home and abroad can shorten the curing time and improve product textural properties. The textural properties, water binding capacity, cooking yield of the products obtained through pressure-transform tumbling are better than those of the products obtained through low temperature and high vacuum tumbling. Besides, the bacteriostatic effect of pressure-transform tumbling is better than that of low temperature and high vacuum tumbling. Pre-tumbling treatment combined with other mechanical treatments can reduce the total massaging time, improve brine penetration and increase product yield. Mechanical tenderization can destruct muscle tissue, reduce shearing value and improve the sensory tenderness of a product. Brine injection is capable of accelerating brine penetration and increasing product yield, and the composition and concentration of brine and pump rates affect product quality. The textural characteristics of an emulsification-type product are remarkably influenced by final chopping temperature.

Research Progress of Carotenoids of Microbial Origin
ZHAO Ting,LIN Kong-liang,HUI Bo-di*
2010, 31(23):  461-467.  doi:10.7506/spkx1002-6630-201023099
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The importance of carotenoids to human health is increasingly attracting people s attention. More and more carotenoid based functional foods are coming to markets. It is a tendency to progressively replace synthetic compounds and phytochemicals by low-cost, high-purity and safe products of microbial origin to meet the ever-increasing consumer demand for carotenoids. This article reviews the distribution, sources, production techniques and market potential of carotenoids of microbial origin in an effort to provide references for more effective utilization of this resource and the research and development of production techniques for safer and premium carotenoids based products.

Research Advances on Specific Spoilage Organisms of Aquatic Products
LUO Qing-hua
2010, 31(23):  468-472.  doi:10.7506/spkx1002-6630-201023100
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The most familiar specific spoilage organisms (SSOs) of fresh-water aquatic products are Pseudomonas spp. and Shewanella putrefaciens during oxygenic cold storage. It has been reported both at home and abroad that Photobacterium phosphoreum, Lactobacillus and Enterobacteriaceae are the SSOs of aquatic products stored in a vacuum environment or in an atmosphere modified package. The SSO composition of aquatic products processed under mild conditions was complicated and generally consisted of Lactobacillus, Photobacterium phosphoreum, Enterobacteriaceae and so on. Modeling for predicting the spoilage course and residual shelf-life of an aquatic product is one of the applications of the SSO concept, and another is the targeting inhibition for the prolongation of shelf-life.