Volume 30,Issue 3,2014 Table of Contents

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  • 1  Mechanism of Porcine Collagen Type Ⅱ and Collagen Peptide on Anti-arthritis
    LIU An-jun SONG Xiao-di ZHENG Jie WANG Zi-jian DU Jia-jia GUO Jing WANG Yue-meng HAN Yue
    2014, 30(3):1-6.
    [Abstract](1505) [HTML](0) [PDF 601.66 K](662)
    Abstract:
    Collagen was extracted from pig cartilage by salting out, and collagen peptide was hydrolyzed by alkaline protease. Collagen purity and the physicochemical properties of collagen and peptide were analyzed. The effect of anti-arthritic was studied by constructing CIA model. 82.86% of collagen was obtained, with molecular weight of more than 300 KD.The maximum absorption peak of UV was at 230 nm, and no obvious absorption peak was observed at 280 nm. Therefore the extracted collagen possessed the characteristics of natural collagen type Ⅱ, while the molecular weight of collagen peptide was less than 20 KD and no collagen type Ⅱ was observed. Collagen type Ⅱ could reduce index score and joint deformation rate, and significantly reduce IL-17, MMP-3 and TNF-α levels. In addition, Collagen type Ⅱ could significantly increase the T cell stimulation index (P<0.05), but had no effect on B cell stimulation index (p>0.05). Tissue sections showed that Collagen type Ⅱ could reduce destruction of joint and inhibit cartilage degradation. However, no such funcions were found with collagen peptide .
    2  Structure and Properties of Soy Protein/Wheat Gluten Power Composites
    ZOU Wen-zhong WEN Qi-biao YANG Xiao-quan WEN Jing-xian PAN Zhi-min ZHANG Xiao-fang ZOU Ai-yi
    2014, 30(3):7-12.
    [Abstract](1156) [HTML](0) [PDF 436.55 K](576)
    Abstract:
    Soy protein (SP)/wheat gluten power (WGP) composites were prepared via thermo-press-mixing technology, and dynamic mechanical properties, thermal stability, mechanical properties, water absorption, structure and morphology of the composites were investigated. The results showed that hydrogen bonds were formed between soy protein and wheat gluten in SP/WGP composites. Scanning electron microscopy and dynamic mechanical thermal analysis revealed that SP/WGP composites exhibited homogeneous structure, and no new peak appeared, indicating good compatibility and plasticization occurred between soy protein and wheat gluten. When the content of wheat gluten was 3.5%, thermal stability of SP/WGP composites was improved. The tensile strength, elongation at break, and fracture energy of the composites increased by 0.33 MPa, 31.21% and 0.37 kJ/m2, respectively, when compared with non-composite material. Water absorption of SP/WGP composites decreased, which suggested that water resistance of the composites was improved.
    3  Screening and Diversity Analysis of Antimicrobial Activity Bacteria Associated with Sargassum integerrimum from Naozhou Island
    LIU Ying LUO Qi-qi LIN Xiu-yuan LAI Guo-nong HUANG Yuan LIU Huan-ming XU Chun-hou
    2014, 30(3):13-17.
    [Abstract](1298) [HTML](0) [PDF 466.93 K](711)
    Abstract:
    Antimicrobial activity bacteria associated with Sargassum integerrimum were isolated by using plate pouring method. Their antimicrobial activities were determined by Oxford cup method in which Escherichia coli, Staphylococcus aurous and Candida albicans were used as representative indicators for gram-negative bacteria, gram-negative bacteria and fungi, respectively. The antimicrobial activity strains were then identified according to morphological characteristics, biochemical properties and the phyogenetical analysis of 16S rRNA sequence. The diversity of antimicrobial activity isolates was also analyzed. Results indicated that 36 symbiotic bacteria were isolated, 11 of which had antimicrobial activity The subsequent analysis showed that all of the isolates belonged to five genera (Bacillus, Staphylococcu, Kocuria, Microbacterium, Brachybacterium) of five families (Bacillaceae, Staphylococcaceae, Micrococcaceae, Microbacteriaceae, Dermabacteraceae) in two phylogenetic groups (Firmicutes, Actinobacteria) and among them Firmicutes was their dominant phylum(7 strains, 63.6 %). In addition, four strains with potential new species (X24, X31, X21 and X34) were found. It is suggested that Sargassum integerrimum from Naozhou Island is abundant in the bacteria with antimicrobial activity and more potential new species could be collected.
    4  Characteristic Study of Phosphodiester in Corn Starch
    LI Guang-lei LI Yi-zhuo MA Han-jun SUN Jun-liang
    2014, 30(3):18-22.
    [Abstract](1176) [HTML](0) [PDF 477.98 K](658)
    Abstract:
    The granule structure, thermal property and viscosity property of corn starch phosphodiester were investigated by Fourier transform infrared (FT-IR), differential scanning calorimeter (DSC), and rapid viscosity analyzer (RAV). The in vitro digestibility of corn starch phosphodiester was also studied by simulating human intestinal system with the comparison of corn starch. Meanwhile, Glycemic index (GI) was conjectured according to the percentage of starch hydrolysis. After cross-linked with sodium trimetaphosphate, new absorption peaks were appeared at 1028 cm-1, indicating phosphate groups were incorporated into the molecular structure. In addition, the gelatinization temperature and gelatinization enthalpy of corn starch phosphodiester were increased. With the increase of phosphorus content, the viscosity of starch paste was decreased, but stability was enhanced. The contents of resistant starch of corn starch phosphodiester increased significantly, whereas the digestibility significantly decreased. The predicated GI of corn starch phosphodiester was 66.31, which belonged to middle GI foods, and could be appropriate for the diabetes food.
    5  Effect of Different Frequency Ultrasonic Treatments on the Structures of Silver Carp Myofibrillar Protein
    HU Ai-jun LU Xiu-li ZHENG Jie TIAN Fang-yuan SUN Ben-jin WANG Yun LIAO Shao-hua
    2014, 30(3):23-27.
    [Abstract](1372) [HTML](0) [PDF 491.82 K](628)
    Abstract:
    Silver carp was treated by using single frequency ultrasound, dual-frequency ultrasound and tri-frequency ultrasound respectively, and the surface hydrophobicity and surface sulfydryl amount of silver carp myofibrillar protein were studied. The results indicated that surface hydrophobicity and surface sulfydryl amount increased firstly and then decreased as ultrasonic time extended. The surface hydrophobicity and surface sulfydryl amount increased to the maximum when the protein was treated with single frequency ultrasound and tri-frequency ultrasound respectively for 15 min and 10 min. The surface hydrophobicity of the protein treated with 80 kHz ultrasonic for 15 min and tri-frequency ultrasound increased by 56.88% and 65.34% individually compared to protein without ultrasound treatment, Meanwhile, surface sulfydryl amount increased by 11.19% and 13.32%, respectively. The effect of dual-frequency ultrasound on the surface hydrophobicity and surface sulfydryl amount was higher than the effect of single ultrasound but lower than that of the tri-frequency.
    6  Community Structure and Phylogenetic Diversity Analysis of Archaeal in the Mud Pit
    HUANG Zhi-guo ZHAO Bin WEI Chun-hui DENG Jie LIU Yan-mei HUANG Jun YOU Hui TANG Yu-mei
    2014, 30(3):28-32.
    [Abstract](1429) [HTML](0) [PDF 526.61 K](607)
    Abstract:
    The clusters and succession rules of archaeal in the mud pit was studied by PCR-DGGE and sequencing of 16S rDNA. The total DNAs were extracted from the mud pit with cellar age of 30, 100 and 200 years, respectively. The results showed that 14 to 17 clear bands were displayed in each grain sample from DGGE grams, among which band 4, 7 and 11 were detected and showed relatively high dominant degree above 4% in all samples. The diversity indexes of all samples were between 1.91 and 2.29, with the increase of cellar age showed an increasing trend. The similarity indexes of samples were between 0.43 and 0.61. Meanwhile, the similarity index between 30 years and 100 years was reached to 0.61. Therefore, they were clustered into one group, compared with 200 years which was divided into two groups. The PCR-DGGE dominant bands tapping results showed that the archaeal belonged to Methanogenic archaeon,Methanoculleus sp, Methanosarcinales archaeon and Rumen archaeon.
    7  Effects of CMC and MCC on Resisting Retrogradation Regularity and Mechanism of Wheat Starch by FT-IR
    SHI Zhen-xing XIONG Jian YE Jun
    2014, 30(3):33-37.
    [Abstract](1523) [HTML](0) [PDF 478.20 K](649)
    Abstract:
    Effects of carboxymethylcellulose (CMC) and microcrystalline cellulose (MCC) on the retrogradation of wheat starch (WS) were investigated by DSC and fourier transform infrared spectroscopy (FT-IR). The result showed that the band of FT-IR at 3423 cm-1 shifted to low wavenumber, indicating that the intermolecular hydrogen bond was enhanced. The band shifted from 1647 cm-1 to 1641 cm-1 for WS/CMC and the band at 1647 cm-1 were not changed for WS/MCC. However, the characteristic peak of MCC at 1433 cm-1 disappeared. These results suggested that CMC or MCC was not simply mixed with WS, and the mixture systems resisted retrogradation by the intermolecular interaction. IR retrogradation degree (IRAD1047 = H1047/H1020, IRAD995 =H 995/H1020) of the peak intensity ratios were used to quantitative characterize the retrogradation degree changes, which was showed that 4.0% CMC resisted WS retrogradation better than 6.0%, and 6.0% MCC better than 4.0%. CMC was superior to MCC on retrogradation inhibition. Anti-retrogradation mechanism of WS/CMC and WS/MCC mixture pastes after cold storing for 14 d was also discussed. IR retrogradation degree (IRAD1047 and IRAD995) determined by FT-IR was consistent with the DSC results (DSCAD=?Hr/?H). FT-IR method has been found to be sensitive to chemical bond environments, which can get more and detailed information related to structures or properties quickly and easily.
    8  Multiplex PCR Assays for Escherichia coli Phylogenetic Assignments and Virulence Gene Ownership
    NI Yi-hong CHEN Yan-ting WEI Shuang James Chin WU Xi-yang
    2014, 30(3):38-42.
    [Abstract](1404) [HTML](0) [PDF 556.69 K](619)
    Abstract:
    The relationship between different phylogroups and virulence genes of E.coli from various origins were identified. Forty-seven virulence genes (VGs) markers found in six pathotypes of E. coli known to cause intestinal and extra-intestinal disease in humans or animals were investigated. Multiplex PCR assays were used to screen 42 strains including clinical and commensal isolates for these virulence genes and assign the strains to phylogenetic group. Results showed that IPEC isolates possessed typical IPEC genes and some ExPEC genes. The non-pathogenic strains also possessed ExPEC genes. None of the ExPEC or non-pathogenic isolates harbored VGs typical for IPEC. The phylogenetic grouping of 42 isolates showed that most of the ExPEC strains belong to group B2 or D. Most of the intestinal clinical isolates were confined to groups D (19.2%), B1 (50.0%) and A (30.8%), Three non-pathogenic strains, DH5α,BL-21 and XL-10, belonged to group A. This study indicated that the presence of virulence genes were closely related to phylogenetic groupings.
    9  Comparison of Changes in the Storage Quality among Different Late-maturing Blueberry Varieties
    WANG Rui CHEN Shun-you XIE Guo-fang MA Li-zhi WEN Guang-zhong LIU Xiao-yan LIU Zhi-gang DU Chao
    2014, 30(3):43-48.
    [Abstract](1426) [HTML](0) [PDF 552.36 K](691)
    Abstract:
    In the present study, the respiration rate, ethylene production rate, rot rate, weight loss rate, color difference, soluble solid, total acid, total alcohol, total phenols and anthocyanin content of five different late-maturing blueberry varieties (Gardenblue, Baldwin, Powderblue, Tifblue and Brightwell) from Majiang (Guizhou) were determined, which were stored under 1±0.3 ℃ for 75 days. And then the changes of storage quality were compared and analyzed. The result showed that the soluble solids, total phenols and anthocyanin content of five kinds of blueberry declined in the earlier days then rose with prolonging storage time. No obvious fluctuation was observed in total acid. The rot rate, weight loss rate and colour difference showed a rising trend. Among them, Tifblue showed the highest rot rate because of high respiration rate, water content, and soluble solid decline tendency; anthocyanin content of Gardenblue kept the highest level; the rot rate of Powderblue was the lowest. The sequence of storability was as follows: Powderblue>Brightwell> Baldwin> Gardenblue> Tifblue.
    10  Effect of Dwell Time on Partial Nutrients and Antioxidant Capacity of Black Garlic
    ZHONG Cheng XU Guo-juan WU Xiao-ying GUO Yan-ping JIA Shi-ru
    2014, 30(3):49-52.
    [Abstract](1803) [HTML](0) [PDF 349.55 K](730)
    Abstract:
    Black garlic was prepared by ultra-pressure pretreatment in combination with fermentation. It was indicated that there was significant difference in nutrient contents between white garlic and black garlic when pretreated by ultra high pressure at different dwell time. Dwell time decreased the total sugar contents of both white and black garlic, and the total sugar content of black garlic was inferior to white garlic. However, the total polyphenol content and flavonoid content in black garlic were significantly higher than those of white garlic. Total polyphenol content of black garlic reached the highest of 13.20 mg/g when treated for 15 min, while the highest flavonoid content (5.23 mg/g) was observed in unpretreated black garlic. Moreover, the antioxidant capacity of black garlic was obviously improved. The maximum values of reducing power and scavenging activity against OH? were obtained by ultra-high pressure treated for 5 and 20 min, respectively. Unpretreated black garlic showed the highest scavenging effect on DPPH.
    11  Effects of Simplified Defined Medium on Nitrite Degradation by Lactobacillus plantarum
    CHEN Zhong LIN Hao LIN Wei-feng
    2014, 30(3):53-57.
    [Abstract](1403) [HTML](0) [PDF 512.75 K](690)
    Abstract:
    Lactobacillus plantarum L134-1-P (LP) was investigated in the simplified defined mediums to understand its nutritional requirements and trying to find out nitrite degradation mechanism,. It was found that nitrite was barely degraded by LP in blank control. Growth and nitrite reduction activity were restrained in mediums with 3% carbon source (glucose, sucrose and corn starch), the final degradation rate was only 6.70% after 72 h. When adding 3% glucose and 2% nitrogen source, the pH of yeast extract medium, enzymatic and non-enzymatic hydrolysis isolated soy protein mediums were 3.84, 3.89 and 4.64 respectively, with nitrite degradation rate of 96.44%, 96.27% and 36.44 respectively, after 72 h. And the final pH and nitrite degradation rate of ammonium nitrate medium were only 5.27 and 8.34%. On that basis, pH of lactic acid solution was adjusted to 4 and 3, the degradation rates of nitrite were 31.33% and 81.30%, respectively. In short, the degradation course relied on enzymolysis and acid splitting when enough nutrition was offered. And acid splitting and enzymolysis could be reinforced when LP was afforded to ferment solution under pH of 4.
    12  Overexpression of Key Enzymes in Arginine Biosynthetic Pathway and their Effects on L-arginine Production
    HUANG Yuan-yuan ZHENG Sui-ping
    2014, 30(3):58-63.
    [Abstract](1568) [HTML](0) [PDF 506.54 K](870)
    Abstract:
    Carbamoyl phosphate synthase, Acetyl ornithine amino transferase and ornithine acetyl transferase encoded by CarAB, ArgD and ArgJ were the key enzymes in L-arginine biosynthetic pathway. In Corynebacterium glutamicum ATCC14067, with the plasmids pEC- XK99E-p and PEC-T18mob2, the genes of CarAB, ArgD and ArgJ in the arginine biosynthetic pathway were expressed individually, ArgD and ArgJ were overexpressed in series and the CarAB, ArgD and ArgJ were co-expressed. The ability of producing L-arginine of the recombination strains, 14067-pEC-CarAB, 14067-T18-ArgD, 14067-T18-ArgJ, 14067-T18-ArgDJ and 14067-pEC-CarAB-T18-ArgDJ, increased 1.61, 1.14, 1.19, 1.28 and 2.19 times, respectively, in shake flask which compared with the starting strain ATCC14067. The real-time quantitative PCR showed that the relative expression of genes CarA, CarB, ArgD and ArgJ in strain 14067-pEC-CarAB-T18-ArgDJ were 2.50, 5.60, 3.59 and 4.70 times, respectively, than ATCC14067. Therefore, overexpression of CarAB, ArgD and ArgJ genes can effectively improve the production of L-arginine.
    13  Synergistic ABTS Radical Scavenging Activity of Resveratrol with Auricularia auricular Polysaccharides
    BAI Hai-na WANG Zhen-yu LIU Rui-hai ZHAO Hai-tian ZHANG Hua
    2014, 30(3):64-68.
    [Abstract](1861) [HTML](0) [PDF 422.09 K](668)
    Abstract:
    ABTS+ radical scavenging experiments and Chou-Talalay combination index (CI) method was used to evaluate the scavenging effects, combination index (CI) and dose reduction index (DRI) of resveratrol (RES) and Auricularia auricular polysaccharides (AAP) individually as well as combination of them. The results showed that IC50 values of RES and AAP were 3.56 mg/L and 61.46mg/L, respectively, while IC50 value of the combination (mass ratio 1:1) was only 2.50 mg/L, indicating the combination had significant ABTS+ radical scavenging effect. CI analysis displayed that the clearance rate of 5~97% interaction index was less than 1. With the removal rate increased, CI was also reduced. DRI analysis demonstrated that the clearance rate of 5~97% DRI was greater than 1. With the removal rate increased, DRI also increased. Therefore, it was confirmed that RES and AAP had significant synergistic antioxidant effect when the mass ratio was 1:1.
    14  Investigation of Antibiotic Resistance and Biofilm-forming Ability in Staphylococcus aureus
    GUI Zhong-yu LI Lin LI Bing XU Zhen-bo
    2014, 30(3):69-75.
    [Abstract](1572) [HTML](0) [PDF 579.78 K](657)
    Abstract:
    Staphylococcus aureus (S. aureus) has been long recognized as a common food-borne pathogen in food safety. To study their individuality, drug resistance and biofilm-forming capacity, a total of 127 Staphylococci strains were subject to the investigation. Preliminary identification of Staphylococcus aureus was conducted with a rapid confirmatory latex agglutination test kit and API staph test strips. S.aureus was further confirmed with the detection of specific 16S rRNA and femA genes by PCR. The molecular method was also used for amplification of mecA and orfX elements to identify meticillin-resistence S. aureus (MRSA). The biofilm-forming capacity of 127 clinical isolates of S. aureus was tested using a polystyrene 96-well plate format and crystal violet staining. In this experiment, 127 staphylococci were isolated, in which 107 strains were MRSA, 12 strains belonged to meticillin-sensitive S. aureus (MSSA) and 6 strains contributed to methicillin-resistant coagulase-negative staphylococci (MRCNS). All staphylococci isolates formed biofilms, and 75 strains (59.1%) belonged to the weak adhesive group. The molecular method was more accurate and rapid for the identification of strains. The majority of the strains formed weak adhesive biofilms and there was no significant relationship between the genotype of drug resistance and biofilm formation ability.
    15  Effects of Hsian-tsao Extracts on Textural Property, Sensory Quality and Antioxidant Activity of Chinese-style Meatball
    LI Jun-guang LI Zeng JIANG Ai-min YIN Bei-bei LIU Xiao-yan
    2014, 30(3):76-80.
    [Abstract](1602) [HTML](0) [PDF 553.56 K](646)
    Abstract:
    The effects of hsian-tsao extracts (HE) addition on textural property, color and sensory quality of the meatball were investigated. The changes of Thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVB-N) in the meatball added with HE at different levels was determined at 4 ℃ for seven days. The results indicated that addition of HE significantly delayed lipid oxidation and protein oxidation when compared with control. With the increase of HE levels, the hardness, chewiness and springiness of meatballs initially increased and then decreased and a* value kept increasing, while L* and b* were gradually decreased. The textural property and sensory quality were the highest in the treatment of adding 10% HE, and it also showed a good antioxidant property. The results revealed that the hsian-tsao extracts could be used as a natural antioxidant, flavour enhancer and modifier in production of meatballs.
    16  Variation of Mitochondrial Ultrastructure and Antioxidative Enzymatic activity in Wheat Cell under Micro-environmental Conditions
    ZHANG Li-li WANG Ruo-lan LIU Li MU Yao
    2014, 30(3):81-86.
    [Abstract](1056) [HTML](0) [PDF 494.39 K](707)
    Abstract:
    The mitochondrial ultrastructure of wheat cell were investigated by transmission electron microscope under different simulated micro-environmental conditions. Simultaneously, mitochondrial O2-?, COX activity, seed vitality and the activity of antioxidative enzymes (SOD, CAT and POD) were measured, which were used to discuss the relationship between them and wheat aging at the micro perspective. The research showed that with the extension of storage time and increasing of temperature and humidity, mitochondria number was decreased, and the damage and deterioration of its ultrastructure became serious. The ultrastructure changed mainly as follows: outer membranes deformed, with broken and solution occurred; the number of internal ridges decreased, and the structure of its bilayer membranes gradually blurred; the inner mitochondria degraded and vacuolization occurred in inner cavity. At the same time, generation rate of O2-? kept increasing, COX activity and seed vitality kept decreasing. The three indexes had the most obvious variation under the conditions of 35 ℃ and 85% humidity. The activity of antioxidative enzymes in wheat cell all increased first and then decreased under high temperature and humidity (75% and 85%). The decreases of SOD, CAT and POD were more obvious under the conditions (35 ℃, 85%) than those under other conditions, being of 36%, 63% and 57% respectively.
    17  Effect of High Atmospheric Oxygen Packaging on the Postharvest Quality of Mulberry Fruits
    CHEN Yu-long WANG Sheng-you XU Yu-juan WU Ji-jun XIAO Geng-sheng YU Mao-lan
    2014, 30(3):87-92.
    [Abstract](1099) [HTML](0) [PDF 515.02 K](628)
    Abstract:
    Under the condition of packaging by high oxygen modified atmosphere (100%) combined with high barrier film, the quality variation of fresh mulberry fruit was investigated. Taking air packaging as control, the CO2/O2 concentration of package, the visual and nutritional quality parameters were determined to find out the variation trends of these parameters during storage at 4 ℃. The results showed that the treatment of high oxygen modified atmosphere packaging inhibited the anaerobic respiration in mulberry fruits. The firmness, soluble protein and sugar, vitamin C and sensory quality in fresh mulberry fruits packaged by high oxygen modified atmosphere were better than the control during the last days of storage although these parameters were more inferior than control at the first four days. In addition, the treatment showed little influence on chlorophyll, color, and anthocyanin of the samples. Thus, the quality of fresh mulberry fruit was effectively maintained by high oxygen modified atmosphere packaging.
    18  Effects of Overexpressed EHT1 on Ester Production of Saccharomyces cerevisiae
    LI Feng CHEN Ye-fu GUO Jian GUO Xue-wu XIAO Dong-guang
    2014, 30(3):93-98.
    [Abstract](1522) [HTML](0) [PDF 565.98 K](698)
    Abstract:
    To increase the production of ethyl caproate by Chinese liquor yeast (S. cerevisiae AY15), shorten the fermentation period, and reduce the grainconsumption, a recombinant strain AY-PEK was constructed by overexpressing EHT1 (encoding ethanol hexanoyl transferase) to investigate the effect of EHT1-overexpression on the performance of ester-producing. The EHT1 gene was amplified from genomic DNA of AY15, the PGK1 promoter and resistance gene KanMX were orderly inserted into vector Yep352 to construct the expression plasmid Yep-PEK. Then EHT1-overexpression mutants AY-PEK were selected by YEPD agar plates containing 1400 μg/mL G418 after the plasmid Yep-PEK was transformed into AY15. The results showed that after liquid fermentation by corn, the differences in fermentation performances (growth rate, fermentation rate and the yield of alcohol) between AY-PEK and AY15were negligible. However, the production of ethyl caproate produced by AY-PEK was markedly increased to 2.21-fold as high as that of parental strain AY15. Ethyl octanoate and ethyl decanoate were improved by 31.4% and 49.1%, respectively. The same amount of caproic acid was added to fermentation medium to imitate the actual fermentation, the production of ethyl caproate produced by AY-PEK was increased to nearly 2-fold higher than that of AY15, and the amount of total esters were also increased by 32.2%. Overexpression of EHT1 gene can significantly enhance the production of ethyl esters, especially ethyl caproate.
    19  Isolation of Allergens in Nuts and Analysis on Western Blotting
    ZHANG Ai-lin WANG Chang-lu HU Yun-feng ZHOU Zhi-jiang
    2014, 30(3):99-102.
    [Abstract](1488) [HTML](0) [PDF 407.43 K](637)
    Abstract:
    Acetone and ethyl ether solvent were used to degrease of different kinds of nuts, then the allergen were isolated from the defatted nuts. The concentration and molecular weight of allergenic proteins were tested by the BCA protein kit and SDS-PAGE. Western –blotting was adopted for the identification of nut allergens. Results showed that the extracted concentration of the protein of white sesame, black sesame seed, walnut, cashew and pistachios were 14 mg/mL, 4 mg/mL, 8 mg/mL, 28 mg/ mL and 21 mg/ mL, respectively. In addition, the molecular weight of each allergenic protein from the obove-mentioned five nuts were 15 ku, 34 ku, 19 and 37 ku, 13 ku, 13 and 21 ku, respectively. The Western - blotting method showed allergenic reaction to patients with positive mixed serum. Nut allergy had homology, and the main allergens of sesame, cashew nuts, walnut and pistachios were at 22, 20, 54 and 23 ku.
    20  Inhibitory Effects of Chlorogenic Acid and Isochlorogenic Acid from Purple Sweet Potato Leaves on α-glucosidase
    LIU Xue-hui LI Mi-Lu TAN Bin CHEN Hui-heng LU Ying
    2014, 30(3):103-107.
    [Abstract](1250) [HTML](0) [PDF 587.04 K](795)
    Abstract:
    Chlorogenic acid (1), 4,5-O-caffeoylquinic acid (2), 3,5-O-caffeoylquinic acid (3) and 3,4-O-caffeoylquinic acid (4) were isolated and prepared from purple sweet potato leaves by high speed counter-current chromatography (HSCCC). Then the inhibitory effect of these compounds and crude extract of sweet potato leaves on α-glucosidase were examined by using PNPG as substrate. The results indicated that four compounds and crude extract of sweet potato leaves exhibited certain inhibitory effects on α-glucosidase, with IC50 value of 7.556 μg/mL, 1.419 μg/mL, 0.209 μg/mL, 9.339 μg/mL and 5.371 μg/mL, respectively, which were far less than the positive control acarbose (IC50 355.4 μg/mL). In addition, the kinetic analysis showed the inhibitory effects of the four compounds on α-glucosidase were competitive, and the Ki were 27.18 μg/mL, 2.06 μg/mL, 8.42 μg/mL and 19.58 μg/mL, respectively. Therefore, sweet potato leaf extract has significant α-glucosidase inhibition, and could provide a theoretical basis for sweet potato leaves as a resource of hypoglycemic drug development or health care.
    21  Construction, Screening and Protein Structure Simulation of Single Chain Antiboday Fragment Library against Ofloxacin
    HE Kuo ZHANG Xiu-yuan DU Xin-jun WANG Jun-ping YANG Qing
    2014, 30(3):108-113.
    [Abstract](1373) [HTML](0) [PDF 750.65 K](705)
    Abstract:
    Single chain antibody fragment (scFv) libraries were constructed for Ofloxacin by the phage display technology. Specific anti-Ofloxacin scFv was screened and its three-dimensional structure was simulated. Total RNA was abstracted from hybridoma cell of the Ofloxacin and used to amplify VH and VL gene by RT-PCR by degenerate primers. VH and VL were joined by overlap extension PCR to form the single chain variable fragment (scFv) gene, then scfv was inserted into Phage T7 after incision enzyme EcoRⅠand Hind Ⅲ double digestion and was transformed by host bacteria BLT5403. Phage single chain antibody libraries consisting of 3×105 pfu/ml were successfully constructed. After four times of enriched procedure in the order of adsorption-elution-amplificatio, four Ofloxacin positive phage scFv clones were screened by direct competitve ELISA. The structure of specific scFv and physicochemical property were also simulated. This research lays a solid foundation for the further expression of anti-Ofloxacin scFv.
    22  Screening of Cholesterol-reducing Lactic acid bacteria from Human Origin
    CHEN Da-wei GUO Fei-xiang GU Rui-xia ZOU Dong-hao ZHAO Hai-qing
    2014, 30(3):114-120.
    [Abstract](1469) [HTML](0) [PDF 504.92 K](671)
    Abstract:
    Lactic acid bacteria (LAB) with probiotic were isolated and screened from intestinal tract of longevity crowd, and the ability of cholesterol-reducing in vitro were investigated. The results showed that nine of eighty strains had high survival rates in simulated gastric juice for 3 hours, being of 26.60%, 24.30%, 22.50%, 16.72%, 46.61%, 16.10%, 19.80%, 19.60% and 17.80%, respectively. The survival rates of o2 were the highest, which were 21.31%, 13.35%, 12.43% respectively in 0.3%, 0.5% and 1.0% bile salt. Nine strains were sensitive to ampicillin, penicillin G, chloramphenicol, and sensitive or moderately sensitive to tetracycline, rifampicin and ciprofloxacin. They had bacteriostatic activity against Salmonella, Staphylococcus aureus and Escherichia coli. The bacteriostatic activities of V9 and o2 to Salmonella, Staphylococcus aureu were higher. The inhibition diameters were 12.00 mm and 11.40 mm respectively, and all the nine strains had high bacteriostatic activity to Escherichia coli, with the inhibition diameters of more than 7.0 mm. The cholesterol-reducing rates of f10, o2, T1 and V9 were 45.85%, 40.76%, 41.70%, 42.87%, respectively, higher than other strains, which were identified as Enterococcus faecium, Weissella Cibaria, Lactobacillus casei and Lactobacillus fermentum by physiological and biochemical test as well as 16srDNA sequence alignment. These strains could be good candidate probiotics strains for auxiliary hypolipidemic.
    23  Effect of Konjac Glucomannan/ Guar Gum on the Quality of Pork Jerky
    ZHAO Mou-ming YANG Yuan-yuan SUN Wei-zheng CONG Yi-jie
    2014, 30(3):121-125.
    [Abstract](1752) [HTML](0) [PDF 465.77 K](1141)
    Abstract:
    To investigate the influence of konjac gum and guar gum combination on the quality of pork jerky, the sensory characteristic, colour, texture, water activity, water content and pH of the jerky were evaluated. Results showed that five different treatments got higher sensory scores and the group contained 0.24% konjac glucomannan/0.16% guar gum scored the highest. The colour and texture of the jerky were improved at different levels with addition of hydrocolloids and the group of 0.24% konjac glucomannan/0.16% guar gum achieved the best. The addition of hydrocolloids reduced the water activity and increased the water content of the jerky (p<0.05) remarkably. The group contained 0.24% konjac glucomannan/0.16% guar gum had the lowest water activity and the group with 0.4% konjac glucomannan had the highest water content. The hydrocolloids increased the pH of the jerky to some extent. The pH increased as the proportion of konjac glucomannan in hydrocolloids amplified. In conclusion, the addition of hydrocolloids can improve the sensory quality, structure characteristics and storage stability of the jerky. The combination of 0.24 % konjac gum and 0.16 % guar gum was beneficial for comprehensive quality of the jerky.
    24  Preparation and Molecular Characteristics of Arabinoxylans from Different Wheat Milling Fractions
    WANG Xiao-xi ZHENG Xue-ling MA Sen CHENG Yong-qiang
    2014, 30(3):126-129.
    [Abstract](1326) [HTML](0) [PDF 350.98 K](669)
    Abstract:
    Arabinoxylans prepared from wheat bran, shorts and flour were characterized by monosaccharide composition, weight ratio of arabinose and xylose, molecular weight and molecular weight distribution. The yields of arabinoxylans from bran (WBAX), shorts (WSAX) and flour (WFAX) were 8.99%, 7.28% and 1.12%, respectively. Arabinose and xylose were the main monosaccharide. WBAX had the lowest Ara/Xyl ratio compared with WSAX and WFAX, indicating it had less linear chain. HPSEC analysis showed that WFAX possessed the highest molecular weight, while WBAX had the lowest molecular weight. Dynamic light scattering (DLS) studies found that the particle size of the three arabinoxylans in water was larger than in alkaline solution, suggesting the degree of aggregation of arabinoxylans varied in different solvents. Based on the recovery of WBAX, WSAX and WFAX from different solvents by DLS analysis, 1.0 M NaOH solution exhibited good solvent property for wheat arabinoxylans. In contrast, water appeared to be a poor solvent. All results showed that wheat bran and shorts could be used as effective resources for arabinoxylans.
    25  Changes of Volatile Compounds during the Processing of Spiced Beef
    SUN Cheng-feng YU Qian-qian SONG Chang-kun GUO Guang-ping WEI Shuai
    2014, 30(3):130-136.
    [Abstract](1375) [HTML](0) [PDF 521.15 K](644)
    Abstract:
    In order to identify the flavor components and investigate the changes of the volatile compounds during the processing of spiced beef, the conditions of headspace-solid phase microextraction (HS-SPME) and desorption time were optimized by orthogonal experiment. The volatile compounds were extracted by HS-SPME and identified by gas chromatography mass spectrometry (GC-MS). The results showed that the optimal condition was 60 ℃ for 60 min, and then desorption of 5 min. A total of 90 kinds of volatile compounds were identified during the processing of spiced beef, including alcohols (22), aldehydes (11), esters (16), hydrocarbons (14), ketones (8), nitrogen or sulfur containing and heterocyclic compounds (13) andother compounds (6). The number of volatile components were 45, 48, 53, 52, 61 and 58, respectively within the six processing stages. The relative content of volatile compounds changed constantly during the processing, and the composition of each group of volatile compounds was also different in the samples from the six processing stages. The results provided a theoretical reference to optimize the processing technique and improve the quality of spiced beef.
    26  Preparation and Properties of High Activity Tannase with Aspergillus niger T3-5-1
    ZHANG Shuai CHEN Sui HUANG Jing-sheng LIN Jian-hui NONG Jia-yi ZHU Hua-wei CAO Yong
    2014, 30(3):137-143.
    [Abstract](1338) [HTML](0) [PDF 605.29 K](647)
    Abstract:
    Tannase was produced by Aspergillus niger T3-5-1, then the crude enzyme was preliminary purified by ammonium sulfate precipitation and dialysis respectively. The results showed that, specific activity of the crude enzyme dealed with dialysis sack of 12 kDa MWCO was higher than that of ammonium sulfate precipitation. Further purification was performed by Sephadex G-100 dextran gel chromatography, and then high purity tannase was obtained. Compared the tannase with Tannase A and Tannase B by GPC chromatogram, it was found that their molecular weight were generally consistent. However, specific activity of the tannase(5304.78 U/mg) was far higher than those of Tannase A (1788.15 U/mg) and Tannase B (935.07 U/mg). The optimum pH and reaction temperature of the tannase were 5.0 and 45 ℃, respectively,, with favorable pH and thermal stability. When the substrate, the Vmax and Km were were propyl gallate (PG), 81.96 μmol/(L?min) and 0.85 mmol/L, respectively. At last, the catalytic synthesis ability of the tannase was investigated, which suggested that the enzyme could catalyze the reaction between gallic acid and propyl alcohol to synthesize PG in the reverse micelle of AOT- isooctane.
    27  Screening and Antifungal Mechanism of Chinese Herb Extracts against Green Mold of Citrus
    ZHOU Meng-jiao WAN Chun-peng CHEN Jin-yin
    2014, 30(3):144-149.
    [Abstract](1332) [HTML](0) [PDF 511.55 K](719)
    Abstract:
    The antifungal activity of some Chinese herb extracts on citrus green mold (Penicillium Digitatum) were screened by Cylinder-plate method, the potential antifungal mechanism of the optimum extracts were investigated by determining the changes of electrical conductivity of culture media. The results showed that the ethanol extracts of Cinnamomi Ramulus, Cinnamomi Cortex and Mosla Chinensis had better inhibition effect on the green mold, the inhibition zones were all over 20 mm. Moreover, Cinnamomi Ramulus displayed remarkable inhibition effect, which was even better than Bellkute. The inhibition zone, minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) were 31.56 ± 0.66 mm, 6.25 mg/mL and 12.5 mg/mL, respectively. In addition, the research also showed that Cinnamomi Ramulus extracts effectively inhibited spore germination and mycelial growth and development. When the concentration of Cinnamomi Ramulus extracts was 50 mg/mL, the conidia germination inhibition rate were up to 99.007%; the permeability of cell plasma membrane and cellular components exosmose were increased; the total soluble protein and sugar contents of mycelium were 1187.18 μg/g and 0.307%, respectively; and the morphology of mycelium were malformed and fractured. Thus, Cinnamomi Ramulus ethanol extracts have good antifungal activity through disturbing the structure of cellular membrane and mycelium metabolism.
    28  The Infulence of High Hydrostatic Pressure on Physicochemical Properties of Tapioca Starch
    REN Rui-lin LIU Pei-ling BAO Ya-li LI Yan-jie
    2014, 30(3):150-156.
    [Abstract](1201) [HTML](0) [PDF 676.23 K](654)
    Abstract:
    The study investigated the effect of different high pressure treatments on the crystal particle morphology and physicochemical properties of tapioca starch with different moisture contents by high hydrostatic (HHP) treatment. The granule shape of the starch changed obviously after HHP treatment. Tapioca starch formed gelatin and lost its birefringence after HHP treatment under 600 MPa, while no significant effect on tapioca starch was observed below the critical pressure, such as 300 MPa or 450 MPa. Light transmittance of tapioca starch decreased after HHP treatment, and 50% of tapioca starch showed the fastest decrease rate in the first 24 hours, which dropped from 6.90 T to 3.02 T. When the temperature raised from 50 ℃ to 90 ℃, solubility and turgidity were respectively reduced from 0.029 g/g and 0.041 m/K to 0.005 g/g and 0.0035 m/K, which showed the property of restricted swelling. Bleeding rate of HHP modified tapioca starch increased from 0.037 to 0.183, while the freeze-thaw stability and viscoelastic was decreased. In addition, the agglomeration tendency increased. HHP treated tapioca starch was more easily to aging. Experiments showed that high hydrostatic denatured tapioca starch has a potential to become a new high value-added food stabilizer, and can improve characteristics of dairy products, meat and fish products and baby food.
    29  Effect of Different Precooling Methods on the Storage Quality of Litchi
    LV Sheng-ping LV En-li LV Hua-zhong YANG Song-xia GUO Jia-ming
    2014, 30(3):157-162.
    [Abstract](1487) [HTML](0) [PDF 475.78 K](717)
    Abstract:
    In order to obtain the effects of different precooling methods on the storage quality of Litchi, continuous 25 days fresh keeping experiment for “Huaizhi” precooled by ice precooling (L1), room precooling (L2), forced-air precooling (L3) and forced-air precooling with high humidity (L4) was carried out. The analysis and comparison of different precooling methods on the quality of Litchi were conducted. The results showed that the mass loss rate of Litchi pretreated by the four methods increased with time till not more than 1.5%. From the fifth day to the twenty fifth day, the good fruit rates of L1 and L2 decreased from 99.33% and 53.29% to 15.70% and 5.29%, respectively, but L3 and L4 almost had no good fruits after 10 days. The browning indexes of L1, L2, L3 and L4 increased from 1.32, 2.42, 3.37 and 3.02 to 2.97, 3.94, 4.18 and 3.97 respectively. The color difference of L1 was significantly larger than those used other three methods before 10 days. There was no significant difference for L3 and L4 in sensory evaluation, but obvious lower sensory qualities of the L3 and L4 than L1 was found. The soluble solids (TSS) content for the four methods were within 16.63 and 17.93, with tendency of increasing first, then decreasing but increasing again. The titratable acid (TA) content declined with the storage time.Hence, L1 is more suitable for precooking Litchi based and this research can facilitate the selection of precooling method for Litchi.
    30  The Quality of Squid Treated by Ultrafiltration and Ozone
    YU Hai-xia REN Xi-ying YANG Zhi-jian ZHENG Gang HU Ya-qin YANG Shui-bing HU Qing-lan YE Xing-qian
    2014, 30(3):163-168.
    [Abstract](1212) [HTML](0) [PDF 584.23 K](587)
    Abstract:
    To make full use of seawater resources and relieve the usage pressure of fresh water, seawater purified by ultrafiltration combined with ozone was applied in the processing of squid (Ommastrephes bartramii)during thawing and cleaning. Effects of the purified seawater and tap water on the quality of squid were investigated by total viable counts, whiteness, water-holding capacity, pH values, volatile base nitrogen (TVB-N) values and thiobarbituric acid (TBA) values. The results indicated that the purified seawater by ultrafiltration had great potential in squid processing. The minimal inhibitory concentration (MIC) of ozone water was 0.10 mg/L. With the increase of ozone concentrations, the total viable counts gradually reduced and the pH values and water-holding capacity of samples slightly changed. However, the whiteness and TBA values increased, and TVB-N values tended to increase first followed by decreasing. At the same ozone concentration, the TVB-N values and TBA values of samples thawed by purified seawater were lower than those thawed by tap water, while the whiteness was almost the same as those controls but the water-holding capacity was higher. Compared with tap water with ozone, 0.30 mg/L ozone in purified seawater could obviously improve the quality of squid and extend its shelf- life at 4 ℃ storage.
    31  Effect of Modified Atmosphere Package Conditions on Preservation of Green Walnut Fruit and Kernel Traits
    WANG Jin MA Yan-ping CHEN Jin-hai MA Hui-ling FENG Wen-yu WANG Dian-ru
    2014, 30(3):169-176.
    [Abstract](1356) [HTML](0) [PDF 709.44 K](716)
    Abstract:
    To explore the proper mode of modified atmosphere package for fresh walnut preservation, green walnut fruit of cv. Liaoning2 and Xifu2 were harvested and stored in active modified atmosphere package with PE50 (aPE50) and pPE50 with pretreatment of 80~85% CO2 pulse (CO2 + pPE50), passive modified atmosphere package with PE50 (pPE50) was as control. Then they were stored with two-step way at 0~1 ℃, with RH of 70~80%.The results showed that aPE50 package presented most effective function of atmosphere modification on both varieties, after 18d-storage when they reached stable relatively, the volume fraction of O2 and CO2 were 4.6~5.4% and 9.6~11.0%, respectively . Storage decay rates of the fruit from aPE50 were the lowest, being 12.2% in Liaoning 2 and 15.7% in Xifu 2 after 80 d .Sensory quality decline of kernel was slower in aPE50 and faster in CO2+pPE50 compared with control. Content of total phenols, flavonoids, tannin, ascorbic acid(VC), reduced glutathione (GSH) in green husk from both aPE50 and CO2 + pPE50 were greater statistically than those from control (p<0.01). During the continuous storage of peeled fresh walnut, kernel from aPE50 gained the least increase in acid value and peroxide value, showed increase of total phenols and flavonoid in later stage; persistent lower MDA content and lipoxygenase (LOX) activity than control and CO2+pPE50. Therefore, aPE50 was a better mode of modified atmosphere package for fresh walnut preservation than others.
    32  Physical and Chemical Properties Analysis of Different Licorice Residue Slices
    WANG Qing-qing TIAN Ying-zi MA Qian-li LUO Yu-nian SHAO Gan-hui RAO Guo-hua GUO Wen-jun
    2014, 30(3):177-181.
    [Abstract](1278) [HTML](0) [PDF 510.01 K](650)
    Abstract:
    The water, ash, pH, total sugar, total nitrogen, total flavonoids, glycyrrhizic acid, liquiritin and other physicochemical indexes of three kinds of liquorice residues from the same area (named A, B and C) were analyzed. The liquorice residue slices were made with papermaking method, by the sensory evaluation and the physical properties testing of the slices, combined with thermogravimetric analysis, the best raw material for producing licorice residue slice was screened out. The results showed that, there were obvious difference in the contents of total sugar, total nitrogen, total flavonoids, glycyrrhizic acid and liquiritin among the three different liquorice residues, among which the contents of total sugar and total flavonoids were the most significant. The maximum content of total sugar was 28.97% (B) and the minimum was 20.47% (A), while 16.98% (A) and 7.28% (C) of total flavonoids content were the maximum and the minimum, respectively. The liquorice residue slice made from licorice residue B had better sensory adsorption and physical indexes, as well as stably burning, good comfort index, good smoke temperament and aroma. Thus, B was more suitable for the research applications of papermaking liquorice residue slices.
    33  Analysis of Nutritional Components of Wheat Germ from Different Producing Areas
    ZHAO Fu-li ZHONG Kui TONG Li-tao LIU Li-ya ZHOU Xian-rong ZHOU Su-mei
    2014, 30(3):182-188.
    [Abstract](1704) [HTML](0) [PDF 487.41 K](1612)
    Abstract:
    In order to study the quality of wheat germ, different wheat germ samples were collected from different areas, the nutritional composition, pesticide and metal residues as well as the microbial contamination condition were analyzed. Among 12 wheat germ samples, the average content of protein was 29.64±1.71%, most of which was glutamic acid (4.32%). The first limiting amino acid-lysine was 1.85%, and the average fatty acid content was 9.80±1.02%. The unsaturated fatty acids accounted for more than 80%, in which linoleic acid accounted for 60.91 ±0.63%. The variation coefficient of fat and lysine was about 10% among different samples, while there was no significant difference in protein and linoleic acid content (P>0.05). The average content of total sugar was 32.75±4.82%, in which the total starch was 14.65±2.57%, making up about 44.73% of total sugar. The average content of ash was 5.12±0.41%. Heave metals residues as Hg and As, as well as pesticide residues were not detected, while Pb and Cd contents were found to be lower than the limit range. The total number of colonies average value was 3.9×103 CFU/g. Escherichia coli were less than 3.0 MPN/g, and the mold had an average of 4.8×102 CFU/g. Analyzing the quality of wheat germ can provide an important reference value for further processing and comprehensive utilization.
    34  Detection of Saccharomyces cerevisiae and Listeria monoeytogenes by Flow Cytometry
    HUANG Sheng-quan FU Meng TANG Qing-tao HUANG Yun HU Shuang-fang YU Yi-gang XIAO Xing-long
    2014, 30(3):195-200.
    [Abstract](1528) [HTML](0) [PDF 576.64 K](709)
    Abstract:
    The viable and heat-treated microorganisms such as Listeria monocytogenes and Saccharomyces cerevisiae were investigated in this study. They were stained by fluorescent staining reagents SYTO-9 and Propidium Iodide (PI) and then the red and green fluorescence signals were detected using flow cytometry to get the concentration of cells in samples. The results showed that flow cytometry was able to detect bacteria and yeast after the nucleic acid fluorescent staining. This method simplified the procedure for L. monocytogenes and S. cerevisiae detection, shortened the time of detection procedures, and also distinguished viable with heat-treated micrograms and viable bacteria with yeast in the same system. This method was capable of detecting as few as 1.2×104 cells/mL L. monocytogenes and 6 × 103 cells/mL S. cerevisiae. This improvement might shorten the time consuming of culture enrichment or simplify the process.
    35  Fingerprint of the Litchi Honey by Raman Spectroscopic
    QI Long-kai LIN Li CHEN Di-ling TAN Dong-shan
    2014, 30(3):201-205.
    [Abstract](1898) [HTML](0) [PDF 541.81 K](652)
    Abstract:
    Laser Raman spectrum technology under 785 nm was used to establish the litchi honey fingerprints. The Roman spectra of litchi honey showed that several characteristic strong peaks were found at 424, 521, 629, 706, 820, 867, 918, 1079, 1122, 1266 and 1460 cm-1. And a few obvious Raman peaks appeared at 452, 596, 776, 918, 981 and 1337 cm-1. The Raman peaks showed spectral features of amide, amino acids, proteins, carbohydrates, etc. It was basically confirmed that litchi honey contained protein, amino acid and carbohydrate, which was basic consistent with the known litchi honey biochemical components. Meanwhile, Matlab fingerprint analysis software was used for similarity analysis, it was demonstrated that the similarity of different batches of litchi honey was no less than 0.97 indicating the litchi honey fingerprint had characteristic. There were significant changes before and after processing litchi honey in peak shapes and peak intensities through analysis of first and second order derivatives. Thus, the main ingredients in litchi honey can be directly identified by Roman spectra and the established fingerprint Raman spectroscopy can provide certain theoretical basis for the identification and quality control of lichi honey.
    36  Determination of Heavy Metal Elements in Edible Olive Oil by ICP-MS
    ZHANG Ping XIE Hua-lin ZHU Qian-hua NIE Xi-du
    2014, 30(3):206-209.
    [Abstract](1604) [HTML](0) [PDF 366.39 K](616)
    Abstract:
    This paper established a simple method for the determination of Cr, Ni, As, Cd, Hg and Pb in olive oil by using inductively coupled plasma mass spectrometry (ICP-MS). The olive oil was diluted with n-propanol/xylene (70:30, V/V), then the above six heavy metal elements in the sample were analyzed directly by ICP-MS. Organic sample could keep stable in n-propanol/xylene solution for a long time in order to satisfy the multi-element determination requirement. A small amount of oxygen added into the argon gas line to prevent the deposition of carbon on the sampling cone, which might lead to the clogging of the orifice and a reduction in sensitivity. The use of octopole reaction system (ORS) eliminated the interference of polyatomic ions dramatically. The matrix effects and the instrument drift commendably calibrated with Rh as internal standard element. Under the optimal conditions, the detection limits for six heavy metal elements were in the range of 17.58~53.81 ng/L. In addition, the recoveries of standard addition were from 94.00% to 107.00% and the RSD were 1.33~2.80%.
    37  Freshness and Volatile Compounds of Muraenesox cinereus Fillet with Ice-temperature Vacuum Drying
    CHEN Qing-yun WAN Jin-qing QI Zi-yuan SHI Wen-zheng WANG Zhi-he
    2014, 30(3):210-215.
    [Abstract](1636) [HTML](0) [PDF 525.51 K](610)
    Abstract:
    The changes on freshness and volatile compounds of Muraenesox cinereus fillet with ice-temperature vacuum drying were detected by high performance liquid chromatograph and gas chromatograph-mass spectrometer, meanwhile, vacuum freeze drying and hot air drying were used as comparison. The results showed that there was no significant change in K value of ice-temperature vacuum drying sample compared with the fresh sample. Volatile compounds content was reduced and acid value, namely fat oxidation degree was increased. K values of ice-temperature vacuum drying sample and vacuum freeze drying sample were 2.28% and 2.04%, respectively, with less significant difference. While the highest K value of hot air drying sample was up to 26.64%, Meanwhile IMP content in ice-temperature vacuum drying sample was obvious higher than the other two drying samples. Carbonyl compounds and alcohols played main roles in the flavor of Muraenesox cinereus muscle. After ice-temperature vacuum drying, 11 kinds of carbonyl compounds (38.18%) were detected, which was less than that in fresh sample. Moreover, acid value of fresh, ice-temperature vacuum drying、vacuum freeze drying and hot air drying sample were 1.22, 1.74, 3.60, 4.33 in turn.
    38  Simultaneous Determination of Five Bioactive Compounds in Polygonum cuspidatum by HPLC
    ZHANG Qing-feng FU Ying-juan CHEN Ji-guang SHANGGUAN Xin-chen
    2014, 30(3):216-219.
    [Abstract](1334) [HTML](0) [PDF 410.79 K](805)
    Abstract:
    Five bioactive compounds namely polydatin, resveratrol, emodin-8-O-β-D-glucoside, emodin and physcion in Polygonum cuspidatum were determined by HPLC. An Agilent Zorbax SB C18 column (250 mm×4.6 mm i.d., 5 μm) was used. The mobile phase consisted of acetonitrile (A) and water (B) with linear gradient program of 15.0~50.0% (A) in 0~40 min and 50.0~90.0% (A) in 40~60 min. The column temperature, detection wavelength and flow rate were set at 40 ℃, 290 nm and 1.0 mL/min respectively. The calibration curve of each analyte was constructed under six concentrations. The correlation coefficients were all more than 0.999, and the RSD of tR ranged from 0.14% to 1.67%, while RSD of the peak area was from 0.96% to 2.96%. The spike recovery of the five analytes was 96.8~104.7%. The extraction condition was optimized, and ultrasonic extraction with 60% ethanol for 30 min was chosen. The method was successfully applied for analysis of ten Polygonum cuspidatum samples. The results showed that polydatin and emodin-8-O-β-D-glucoside were the two most dominant constituents in Polygonum cuspidatum with contents ranges of 9.80~20.42 mg/g and 5.56~24.45 mg/g, respectively. The method has good repeatability and high precision, and can be used for simultaneous analysis of the five constitutes in Polygonum cuspidatum.
    39  Effect of Ultra-high Pressure Treatment on Aroma Compounds in Cucumber Water Analyzed by Principal Component
    MA Hui WANG Ya-chao MA Yong-kun ZHANG Hai-ning DENG Na-na WANG Xing
    2014, 30(3):220-226.
    [Abstract](1488) [HTML](0) [PDF 517.71 K](632)
    Abstract:
    In this study, the aroma components in cucumber water before and after ultra high pressure (UHP) treatments were investigated by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) combined with principal component analysis. The results showed that 33 aroma components in cucumber water were detected and the majorities were alcohols and aldehydes. Seven of them were characteristic, and the content of (E,Z)-2,6-nonadienal was the highest, accounting for 27.23% of the total aroma components. The results of the principal component analysis showed that the rate of the first and second principal components was 65.67% and 27.71%, respectively. The cumulative rate of the first and second principal components was 93.38%, which was stand for the change of aroma components in cucumber water. The cucumber water treated by different ultra high pressures was divided into three groups, due to the effect of the different pressures to the second principal component. The untreated cucumber water was separated from the three groups because of the different pressure treatments to the first and second principal components. Thus, principal component analysis was feasible to study the aroma components in cucumber water treated by ultra high pressure.
    40  Determination of Three Chloropropanols in Chafing Dish Additives by GC-MS/MS and Isotope Dilution Technique
    ZHAN She-xia GUO Xin-dong LU You-yan WANG An-na ZANG Li-na XIAN Yan-ping
    2014, 30(3):227-232.
    [Abstract](1480) [HTML](0) [PDF 465.24 K](608)
    Abstract:
    A new method was developed to determine three kinds of chloropropanols in chafing dish additives by gas chromatography with tandem mass spectrometry (GC-MS/MS) using isotope dilution technique. After spiked with isotope internal standards, the samples were eluted by chromatographic column, extracted with hexane and ether (1:1, V/V), and then purified by solid phase column (SPE). Trifluoroacetic anhydride (TFAA) was used as derivating agent. The targeted compounds were determined by GC-MS/MS and quantified by internal standard method. Under the optimized condition, the method could be accurately to simultaneously determine three kinds of chloropropanols in chafing dish additives products with two kinds of internal standards (1,3-dichloro-2-propanol-d5 and 3-chloropropane-1, 2-diol-d5) for calibration . Within the linear range of 50 to 1000 μg /L, the correlation coefficients were up to 0.999. The recoveries rates were between 82.5% and 104.0% with RSD less than 5% (n=6). This method is sensitive, accuracy, and the derivative agent is inexpensive, which is suitable for determining three kinds of chloropropanols in chafing dish additives.
    41  Changes of Aroma Compounds of Jujube Vinegar at Different Fermentation Stages
    CAO Miao LU Zhou-min HUA Zhi-xiu CAO Qing-guo HONG Wen-long
    2014, 30(3):233-238.
    [Abstract](1384) [HTML](0) [PDF 498.20 K](723)
    Abstract:
    Solid phase micro-extraction coupled with gas chromatography mass spectrometry (SPME/GC-MS) technique was applied in isolation and identification of aroma compounds of the products in different liquid fermentation stages including the initial jujube juice, the jujube wine mash and the jujube vinegar. The results showed that 56, 56 and 54 kinds of aroma components were identified in the three stages, accounting for 94.57%, 97.37% and 98.86% of the total aroma, respectively. The main aroma components were hydrocarbons, acids, esters, alcohols, aldehydes, ketones, and a small amount of other compounds. The number of aroma components in three products showed little difference, but the component ratio and relative content were significantly different. In the alcohol fermentation process, hydrocarbons content increased significantly, the acids content increased slightly, and the ester and alcohol contents decreased. In the acetic fermentation process, the alcohols and aldehydes contents decreased while the contents of acids and esters increased significantly. These acids and esters were the main components of aroma compounds, and a small amount of hydrocarbons, alcohols, aldehydes, ketones were also an indispensable part of the aroma. These aroma compounds endowed jujube vinegar the unique flavor and quality.
    42  Determination of β-Carotene in Spirulina by ASE-UPLC
    XIAN Rui-qing LI Qi-yan DIAO Fei-yan WANG Xiao-bing HU De-fu
    2014, 30(3):239-243.
    [Abstract](1397) [HTML](0) [PDF 510.79 K](596)
    Abstract:
    A novel method has been developed for the rapid extraction and determination of β-Carotene in Spirulina by accelerated solvent extraction (ASE) coupled with ultra performance liquid chromatography (UPLC). The ASE parameters (extraction solvent, temperature, static time and cycles) were optimized by Single factor experiment and Orthogonal experiment design in order to maximize the extraction efficiency. The result showed that the optimum condition for extraction was as followed: petroleum ether (30~60 ℃) as solvent, extraction temperature of 120 ℃, extraction time of 5 min and static loop of three times. The ASE extract was then diluted and determined by UPLC on the Agilent Eclipse Pluse C18 column (1.8 μm, 2.1 mm×50 mm) at 25 ℃, using 85% CH3OH-15% CH3CN as mobile phase and a Diode array detector at 450 nm. The results showed that the linear ranges of β-Carotene was 1~50 μg/mL with correlation coefficient higher than 0.999. The recoveries ranged from 98.65% to 103.18% with RSDs of 0.68~1.74% and the limit of detection was 0.10 μg/kg. The method was simple, rapid and accurate, with high sensitivity and reproducibility, which was suitable for the determination of β-Carotene in Spirulina.
    43  Residues and Risk Assessment of 13 Triazine Herbicides in Apostichopus japonicus
    REN Chuan-bo TIAN Xiu-hui SUN Yan DENG Xu-xiu LIU Hui-hui XUE Jing-lin XU Ying-jiang GONG Xiang-hong WANG Mao-jian
    2014, 30(3):244-249.
    [Abstract](1356) [HTML](0) [PDF 480.70 K](635)
    Abstract:
    A method for the determination of triazine herbicide residues in Apostichopus japonicus by ultra performance liquid chromatography tandem mass spectrometry was established. In order to investigate the situation of 13 triazine herbicide residues, food safety indexes and risk coefficient were used to evaluate the potential risk of triazine herbicide. The triazine herbicides of atrazine, prometryn and ametryn were detected in 57 samples. The highest detection rate was prometryn (77.2%), followed by atrazine (15.8%) and ametryn (8.77%). The maximum concentration of atrazine, prometryn and ametryn was 0.84 μg/kg, 54.4 μg/kg and 0.69 μg/kg, respectively. The detection ratio in August were significantly higher than those in September, October and November, which suggested that during the collected month, triazine herbicide had few influence on Apostichopus japonicus. According to the assessment of food safety indexes of 57 Apostichopus japonicus samples collected from six cities, the safety indexes of 13 analytes were less than 1, indicating Apostichopus japonicus were in safe and good condition. The risk coefficients of atrazine, prometryn and ametryn were 0.2, 0.38 and 0.2, all less than 1.5, which proved that the three analytes were at low risk group. Therefore, Apostichopus japonicus from six cities was at low risk on triazine herbicides and safe to eat.
    44  Simultaneous Determination of Nine Kinds Halogen-containing Plasticizers in Rice and Flour Products by GC–MS
    PI Xiao-di LI Ye-qing ZENG Shi-qiao CHENG Lian YIN Zhao-ping XU Yu-cheng
    2014, 30(3):250-254.
    [Abstract](1162) [HTML](0) [PDF 539.11 K](644)
    Abstract:
    Nine kinds of halogen-containing plasticizers including chlorendic anhydride (CA), 1,1,2,3,3,3-hexafluoro-1-Propene (HFP), difluoro-chloromethane (R-22), 5-Chloro-2-Methyl- 4-Isothiazolin -3-One (CMI), chlorinated paraffin 42 (CP-42), chlorinated paraffin 52 (CP-52), 1-(3-Chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride (Quaternium-15), 2 - (2 - hydroxy - 3 - tert-butyl -5 - methyl-phenyl) -5- (UV-326), and pentachlorophenol methyl stearate (MPCS) were extracted by ultrasonic with ethyl acetate as solvent.. Rice and flour products were made from spiked samples as halogen-containing plasticizer. The effects of solid-liquid ratio, ultrasonic power and ultrasonic extraction time on halogen-containing plasticizers extraction yield were investigated. The optimum condition of extraction was obtained by response surface methodology test. The optimal process conditions were solid-liquid ratio of 1:13 (m/V), extraction time of 20 min and ultrasonic power of 120 W. Under these conditions, the standard deviations of retention time and peak area were no more than 0.007 and 0.061 respectively. Detection limit of the nine kinds of halogen-containing plasticizers varied between 0.01 μg/L~15 mg/L, the average recovery were between 87.54~97.65%, and the relative standard deviations were 4.63~7.81%.Therefore, the method was suitable for the extraction of the nine plasticizers mentioned above in rice and flour products.
    45  Determination of Sodium in Food by Two Pretreatment Methods
    MEI Can-hui
    2014, 30(3):255-257.
    [Abstract](961) [HTML](0) [PDF 297.95 K](658)
    Abstract:
    Aiming at the problem of complicated operation and low efficiency of the normal pretreatment method (wet digestion) in sodium determination, comparative study was carried out with two pretreatment methods (dry ashing and microwave digestion). The feasibility of the methods was evaluated by the recovery of standard addition, and the effects of monochromator adjustment concentration, the concentration range of standard curve and the dilution multiple of sample on the determination of sodium by atomic emission method were investigated. The monochromator adjustment concentration of 1 mg/L was better than that of 2 mg/L. The quadratic curve fit well in the concentration range of 0~2 mg/L. The proper dilution multiple of the sample solution was close to the monochromator adjustment concentration. In three different sodium-contenting foods, including sauce, sausage and milk drink, the determination result of microwave digestion was higher than dry ashing. For milk drink, the recovery of microwave digestion was 96.88%, while dry ashing was 87.18%. There was no significant difference between the estimated results of two methods. Thus, dry ashing and microwave digestion could be the pretreatment methods for sodium determination in food, as supplement to the national standard method.
    46  The Content Variation of Phytochemicals in Different Parts of Chinese Jujube from Different Cultivars
    LIU Cong HAI Ni ZHANG Ying
    2014, 30(3):258-261.
    [Abstract](1420) [HTML](0) [PDF 460.20 K](1139)
    Abstract:
    Phytochemicals, such as polysaccharide, flavonoid, total phenol, triterpene and cyclic adenosine monophosphate (cAMP), were studied in different parts (pulps, peels and seeds) of three Chinese jujube cultivars: Shandongdazao, Hetianyuzao and Ruoqianghuizao. The results showed that the inedible parts (peels and seeds) contained 20~30% total weight of Chinese jujube. The peel of all cultivars had the highest total flavonoids (0.29~0.43%) and total phenol (0.77~1.20%). Peels and pulps also contained the highest triterpene in jujube cultivars (0.36~0.40 mg/g), significantly higher than that in seeds. The pulp had the highest polysaccharide of 4.72~6.13%. cAMP was mainly distributed in pulps and peels, ranging from 7.22 to 33.56 mg/g, and it had significant difference between different varieties. In addition, cAMP content in the peels and pulps of Hetianyuzao (0.27-0.34 mg/g) was much higher than those in the other two cultivars. Therefore, phytochemicals in the inedible parts of Chinese jujube are proved to have applicable values and potential on deep processing.
    47  The Functions of Gut Clostridum spp. in Over-ingesting Energy of Body
    PENG Xi-chun HUANG Jia-cheng
    2014, 30(3):262-265.
    [Abstract](1268) [HTML](0) [PDF 294.76 K](798)
    Abstract:
    Obesity is colsely relative to the over-ingestion of gut microbiota on energy. It has been discovered that obesity is connected with bacteria of gut Firmicutes and Bacteroidetes recently. Reports present that Clostridum spp. is mainly responsible for the overenergy ingestion of body. Additionally, glycan-hydrolyzing enzymes from gut microbiota can break dietary fibres and produce short chain fatty acids that provide extra energy for body; more absorbance of bacterial lipopolysaccharide enhances the over-ingestion of energy; and energy can easily deposit as fat when the expression of fasting -induced adipose factor (FIAF) is inhibited. The above factors have all been reported to relate to obesity. But it remains unclear about what roles Clostridum spp. play during the process, including the main scource of the glycan-hydrolyzing enzymes, the contribution of short chain fatty acids (SCFA) during overenergy ingestion, the impact of Clostridum spp. on the production and absorption of bacterial lipopolysaccharide, and the factors influencing the expression of FIAF. This paper provided possible mechanism of Clostridum spp. involving in the process, which might be a reference for further study.

    Editor in chief:李琳

    Inauguration:现代食品科技

    International standard number:ISSN 1673-9078

    Unified domestic issue:CN 44-1620/TS

    Domestic postal code:46-349

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