Volume 29,Issue 12,2013 Table of Contents

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  • 1  Effects of Gynura procumbens on the Blood Glucose and Lipid of Mice
    ZHENG Guo-dong ZHONG Shu-sheng ZHANG Qing-feng LI Dong-ming
    2013, 29(12):2800-2804.
    [Abstract](1558) [HTML](0) [PDF 522.07 K](818)
    Abstract:
    Hyperglycemia and hyperlipidemia have become strong threat on human health. This study investigated hypoglycemia and hypolipidemia effects of Gynura procumbens on mice, and to elucidate its mechanism by molecular biology methods. Forty Kunming mice were randomly divided into 4 groups: control, 2%, 4% and 8% Gynura procumbens fed for 12 weeks. Body and organs were weighed, and serum biochemical index and lipids levels in the liver and the feces were measured. The changes of mRNA and protein expression levels were analyzed by qRT-PCR and western blotting, respectively. Gynura procumbens had no significantly influence on body and organs weight in mice. Concentrations of triglycerides (TG) in blood, total cholesterols, low density lipoprotein (LDL) cholesterols, glucose in serum, and the hepatic TG level were remarkably decreased by feeding 4% GPM compared with control, while feces TG level obviously increased. The enzyme activity, mRNA and protein expression levels of HMG-CoA reductase (HMGCR) were significantly reduced by feeding 8% GPM, while mRNA and protein expression of Glut4 were up-regulated considerably by Gynura procumbens. The results suggested that Gynura procumbens had hypoglycemic and hypolipidemic efforts through regulating protein and mRNA expression of HMGCR and Glut4, and inhibiting TG absorption in intestinal tract.
    2  Characterization of Maillard Reaction Products Derived From Antioxidant Peptides of Ctenopharyngodonidellus
    ZHAO Mou-ming LIU Yang SUN Wei-zheng SU Guo-wan
    2013, 29(12):2805-2809.
    [Abstract](1149) [HTML](0) [PDF 649.34 K](643)
    Abstract:
    Thermal degradation products (TDPs) and Maillard reaction products (MRPs) were prepared by heating Ctenopharyngodonidellus peptide with or without addition of xylose. Antioxidant activity, molecular weight distribution and amino acid composition of MRPs and TDPs with different reaction time were evaluated. The results showed that when heating Ctenopharyngodonidellus peptide without adding xylose, the total amino acids content of TDPs had no significant change, while the free amino acid and peptides below 3000 Da increased. The degree of Maillard reaction enhanced by increasing the reaction time, while the total/free amino acids contents decreased. Moreover, arginine and lysine showed remarkable reduction; peptides which above 3000 Da from MRPs increased while below 3000 Da decreased. In addition, the antioxidant activity of peptides increased significantly after Maillard reaction.
    3  Influencing Factors of Conductivity and Dielectric Loss Factor in Apple Juice
    WANG Yun-yang LI Zhan-long YANG Shao-long DONG Yu
    2013, 29(12):2810-2815.
    [Abstract](1407) [HTML](0) [PDF 615.91 K](902)
    Abstract:
    The relationship between electrical conductivity and factors such as soluble solids content, temperature, viscosity and NaCl concentration was studied. Dielectric loss factors interrelated to ionic conductivity of apple juice under different frequencies was calculated according to the equation of electrical conductivity and dielectric loss factors. The results showed that electrical conductivity appeared paracurve trend which increased first and then decreased with the increase of soluble solids content of the apple juice; it was increased linearly with temperature and remarkably increased with adding little of NaCl; viscosity had little effect on electrical conductivity. Using statistical package social sciences (SPSS) data analysis software, non-linear regression equation of temperature-concentration dependent electrical conductivity for apple juice was obtained, which was σ=-28.69C2+17.292C+0.02T+0.135 with R2 of 0.974, showing quite high fitting degree. The results provide basic data for the application of ohmic and radio frequency heating in industrial manufacturing of apple juice.
    4  Influence of Phosphorylation Treatment on Enzymatic Hydrolysis Characteristics of Casein
    WANG Jin-shui LIN Dan-hua SU Yin-jie GAO Yun-fang
    2013, 29(12):2816-2820.
    [Abstract](1116) [HTML](0) [PDF 514.44 K](701)
    Abstract:
    Casein was phosphorylated using sodium tripolyphosphate (STP) under the following optimal conditions: 5% STP, 30 ℃ and pH 9. The degree of phosphorylation reached to the largest (18.18 mg phosphorus/g casein) after treatment for 3 h under above conditions. And then the different levels of phosphorylated casein were hydrolyzed with trypsin. The degree of hydrolysis, the changes of soluble nitrogen, aminonitrogen and peptide nitrogen contents during enzymatic hydrolysis process were studied. The molecular weight distribution (MWD) of hydrolysate was detected by high performance size exclusion chromatography (HPSEC). The results showed that the degree of hydrolysis and amino nitrogen content significantly (P<0.01) increased after phosphorylated, and obvious (P<0.05) differences were found between different levels of phosphorylation. In the hydrolysates of casein phosphorylated for 3 h, the soluble nitrogen and peptide nitrogen contents were significantly (P<0.01) improved. Compared with the control, the retention time of phosphorylated was shorter, and a new peak appeared at 12 min. The content of peptides with molecular weight between 2×104 u and 3.5×104 u increased obviously compared with the control.
    5  Analysis of Structure and Free Radical Scavenging Activities of Ribes nigrum Polysaccharides
    XU Ya-qin SONG Xiu-mei REN Zhong-jie SHAO Tie-hua ZHANG Xin
    2013, 29(12):2821-2825.
    [Abstract](1014) [HTML](0) [PDF 536.99 K](668)
    Abstract:
    Six kinds of crude polysaccharides were precipitated with 80%, 70%, 60%, 50%, 40% and 30% ethyl alcohol respectively from Ribes nigrum fruit. Then the DPPH?, OH?and O2-?scavenging activities were investigated after purified by macroporous resin D4006. The results showed that six kinds of polysaccharides had certain scavenging activities and the polysaccharides precipitated with 80% ethanol (BCP-1) had stronger free radical elimination capacity. Homogeneous component (BCP-1-Ⅱ) was prepared after further purification from BCP-1 by Sephadex G-100. The compositions of the main fraction BCP-1-Ⅱ were identified and quantified by GC and HPLC. Results indicated that BCP-1-Ⅱhad an average molecular weight of 51880 u and contained arabinose, mannose, glucose and galactose with the molar ratio of 9.08:1.00:15.77:0.41. Characteristic absorption of polysaccharide was shown in IR spectrum and the monomer of backbone of BCP-1-Ⅱ might be α-pyranose.
    6  Isolation and Antimicrobial Susceptibilities of Listeria monocytogenes in Pork
    SHI Lei WANG Wen-yan YAN He
    2013, 29(12):2826-2829.
    [Abstract](1338) [HTML](0) [PDF 491.69 K](818)
    Abstract:
    To investigate the pork contamination by Listeria monocytogenes, its susceptibility to antimicrobial agents and serotypes, all strains were isolated by the GB 4789.30-2010 method; L. monocytogenes serotypes were identified by PCR; and antibiotic resistant profile of the isolates was examined using disc diffusion assay. A total of 273 pork samples were examined, out of which 52 samples (19.02%) were positive for L. monocytogenes and 78 strains were detected. And 33 (42.31%), 24 (30.71%), 16 (20.51%), 2 (2.56%), 3 (3.85%) of the isolates were identified as serotypes 1/2a (or 3a), 1/2b (or 3b or 7), 1/2c (or 3c), 4a (or4c)and 4b (or 4d or 4e), respectively. With disc diffusion assay, all strains were susceptible to the antibiotics, including ampicillin, ampicillin-sulbactam, imipenem, ciprofloxacin, levofloxacin, and vancomycin. However, the percentages of tetracycline resistances were higher. 11.54% isolates were resistant to penicillin, gentamicin, erythromycin. The conjugative transposon Tn916 is the important determinants of the resistance in spreading of the L. monocytogenes.
    7  Antibacterial Effect of Plant Essential Oils Against Pseudomonas aeruginosa
    WU Ke-gang ZHAO San-e CHAI Xiang-hua ZHAO Xin-xin
    2013, 29(12):2830-2833.
    [Abstract](1279) [HTML](0) [PDF 518.84 K](732)
    Abstract:
    The gas phase fumigation was used to study the vapor antibacterial activity of ten plant essential oils, namely pine needle oil, citronella oil, Ylang oil, Kang Niangke oil, Litsea cubeba oil, curcuma zedoary oil, sage oil, agarwood oil, mugwort oil, rosemary oil, against Pseudomonas aeruginosa. Antibacterial effects were compared by measuring the minimum inhibitory concentration (MIC). Results showed that Litsea cubeba oil and citronella oil presented the best inhibitory effects against Pseudomonas aeruginosa, the MIC of which were 250 μL/L, followed by sage oil and ylang oil with MIC of 500 μL/L. The MIC of mugwort oil, curcuma zedoary oil and rosemary oil were 1000 μL/L. Pine needle oil, Kang Niangke oil and agarwood oil showed no obvious antibacterial activities. When the compound ratio of Litsea cubeba oil and citronella oil was 2:3 or 3:2, they appeared significant synergistic effects. When the space volume concentration was 100 μL/L, the compound completely inhibited the growth of Pseudomonas aeruginosa. Different solvents had different antimicrobial activities on the compound essential oils, among which ice acetic acid had the best effect, followed by ethanol.
    8  Probiotic Functions and Structural Changes of Mung Bean Resistant Starch Before and After Digestion
    XIE Tao ZHANG Ru
    2013, 29(12):2834-2838.
    [Abstract](1540) [HTML](0) [PDF 521.03 K](801)
    Abstract:
    Resistant starches from mung bean before and after in vitro digestion were prepared and purified, and their probiotic functions and structural changes were studied. The results demonstrated that these resistant starches before and after digestion had more than 100 times proliferative effect on Bifidobacterium and Lactobacillus, as high as more than 106 times inhibitory impact on Escherichia coli and Clostridium perfringens, 10 times inhibitory effect on Enterococcus faecalis, and no obvious influence on Bacillus fusiformis. The total fermentation liquid acidities increased by more than 30% which demonstrated that these resistant starches before and after digestion could be used by intestinal probiotics. Compared with resistant starch, digested resistant starches had larger specific surface areas, and enlarged after in vitro anaerobic fermentation. The average degree of polymerization of resistant starch was half of the native starch, and both resistant and digested resistant starches sequentially reduced more than 30% after fermentation. Crystal form of resistant starches before and after in vitro digestion was type B. After fermentation, they all transformed to type A, and the degree of microcrystal, submicrocrystal and total crystallinity obviously decreased.
    9  Comparison of Cell Tolerance Capacity of Two Microalgae Species to High Concentration Wastewater from Yeast Fermentation
    WEI Dong CHEN Jiao-min BAYIN Ke-xi-ke
    2013, 29(12):2839-2843.
    [Abstract](1139) [HTML](0) [PDF 511.84 K](713)
    Abstract:
    In the present work, the heterotrophic growth of Chlorella pyrenoidosa and Scenedesmus dimorphus NIES-119 were analyzed to investigate the tolerant concentrations of sucrose and the cell tolerance capacity to high concentration wastewater from yeast fermentation. The results showed that Chlorella pyrenoidosa and Scenedesmus dimorphus NIES-119 had high specific growth rates (0.90 d-1 and 0.63 d-1, respectively) in medium containing high concentration of sucrose up to 70 g/L, and the maximal biomass concentrations reached to 3.37 g/L and 2.84 g/L, respectively. After adding molasses in the wastewater medium, the chemical oxygen demand (COD) of 104~ 105 mg/L was observed with high concentration of total nitrogen and phosphorus. The maximal specific growth rates and highest biomass concentrations were 0.43 d-1 and 1.95 g/L, respectively, for Chlorella pyrenoidosa, and were 0.42 d-1 and 1.70 g/L, respectively, for Scenedesmus dimorphus NIES-119, which were significantly higher than the maximum in the molasses-free wastewater medium. Furthermore, the highest removal rates of COD, total nitrogen and total phosphorus were 34.56%, 20.63% and 20.00%, respectively, by Chlorella pyrenoidosa and 21.46%, 16.11% and 31.25%, respectively, by Scenedesmus dimorphus NIES-119. These resultsdemonstrated the two kinds of microalgae had feasibility and great potential for wastewater cleaning.
    10  Effect of Ultrasonic Treatment on Rheological Properties of Cold-set Soybean 11S Protein-dextran Blending Gel
    ZHU Jian-hua YANG Xiao-quan QI Jun-ru LAI Fu-rao SHAN Bin ZOU Xiu-rong
    2013, 29(12):2844-2849.
    [Abstract](1225) [HTML](0) [PDF 732.14 K](650)
    Abstract:
    The effects of ultrasonic time and power on the steady shear viscosity of soybean 11S protein-dextran blend solution and dynamic rheological properties of the cold blend gels were investigated with analysis of steady shear and low amplitude dynamicoscillatory. The results showed that both the blend and the control with ultrasonic treatment were pseudoplastic fluids, and the apparent viscosity of the blend was decreased with the increase of ultrasonic time or ultrasonic power. Compared to the control, the viscosity of the blend decreased by 46.6% after ultrasonic treatment with 237.5 W for 6 min. When the ultrasonic treatment time or power was in range of 0~9 min or 0~142.5 W, the blend solution could be formed non-covalent three dimensional network by cold treatment. G' and G" displayed an increased trend with increasing ultrasonic time or power. However as the time or power further increased to 12 min or 237.5 W respectively, G' of blending gel reduced from the peak of 609.9 Pa and 954.7 Pa to367.3 Pa and 507.8 Pa, respectively, while the initial gelation time was delayed. After ultrasonic treatment, the linear viscoelastic region of the blend gel was not significantly influenced.
    11  Growth and Malolactic Fermentation Characteristics of Lactobacillus plantarum in Plum Juice
    XIONG Jian HE Cui-chan LIN Wei-feng YE Jun CHEN Zhong
    2013, 29(12):2850-2854.
    [Abstract](1324) [HTML](0) [PDF 500.58 K](728)
    Abstract:
    Plum juice was used as material and Lactobacillus Plantarum LP-L134-1-P was used as inoculation strain for malolactic fermentation (MLF) to reduce acids in juice. The effects of the inoculation amount, pH, fermentation temperature, sugar content, and sodium citrates buffer system on deacidification and the growth of Lactobacillus Plantarum LP-L134-1-P in plum juice were studied. The results showed that the total acids increased at the first stage and then decreased during the fermentation. The MLF proceeded normally at pH 3.50 with the inoculation amount of 108 CFU/g. And the bigger inoculation amount was, the more acids were reduced through MLF. When the inoculation amount was increased to 109 CFU/g and pH was 3.50, the MLF could be performed only if the fermentation temperature was more than 25 ℃. It would be easy to perform MLF when the inoculation amount was 109 CFU/g and pH was no less than 3.10. The acidity of plum juice went up with addition of 1.00% glucose, indicating that glucose was prior to convert into lactic acid, thus inhibiting the MLF. In sodium citrates buffer system, the acidity was not reduced, proving that Lactobacillus Plantarum LP-L134-1-P could not use citric acid as carbon resource to run MLF.
    12  Characteristic Analysis of the Composition and Thermal Decomposition of Palm Wax
    LI Gui-hua YANG Ying NIE Liu-jun WANG Xiang-yu
    2013, 29(12):2855-2859.
    [Abstract](1273) [HTML](0) [PDF 612.76 K](1039)
    Abstract:
    The basic physicochemical properties, functional group compositions and thermal decomposition characteristics of palm wax were analyzed. GC-MS was used to detect the structural composition of palm wax. The results showed that only 22C of wax and 24C of alcohols in palm wax were detected, and further research was needed to make out structures of the particular constituents. FT-IR analysis showed that the main functional groups of palm wax were C-O, C=O, -OH, -CH3 and -CH2. The melting temperature and the final decomposition temperature of palm wax were 25~80 ℃ and 80~375 ℃, respectively, which was determined by the differential scanning calorimetry (DSC). Using TG/DSC analyzer test, the thermal stability was analyzed. It was found that the wax had good thermal stability under 150 ℃. During 150~300 ℃ the wax decomposed rapidly with 68.75% components being decomposed. During 300~425 ℃, the remaining 31.25% parts were decomposed completely. DTA diagram showed that the decomposition rate of palm wax reached the maximum at 258.57 ℃, followed with that at 332.92 ℃ and completely decomposed after 450℃.
    13  Effect of Diethyl Phthalate on the Structure and Thermal Stability of Starch Ester Film
    LI Xiao-xi LIU Kun HUANG Chen ZHU Jie CHEN Ling LI Lin
    2013, 29(12):2860-2864.
    [Abstract](1425) [HTML](0) [PDF 485.97 K](725)
    Abstract:
    The starch ester film was prepared by solvent-casting method using Diethyl phthalate (DEP) as plasticizer. The changes in structure of the starch ester film and the intermolecular interaction between the molecule of DEP and starch ester were investigated by scanning electron microscope (SEM), attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), and small-wide angel X-ray scattering (SAXS/WAXS). The results indicated that with the increase of DEP amount in the film, the inter- and intra-molecule interaction among the molecules of the starch ester was weakened and a greater amount of ordered microcrystalline structures was formed in the amorphous regions which resulted in the formation of more ordered aggregation microstructures. But the Rg of the microstructure remained 37~38 nm. Thus, intermolecular interaction, the order of molecular arrangement and aggregation structures of the starch ester can be controlled by adjusting the DEP content in the starch ester film, which provides fundamental data for the design of the starch-based materials with restrained plasticizer migration.
    14  Rapid Induction of Glucoamylase by Rhizopus oryzae on Corncob
    CUI Li ZHU Hai-jun LI Da-jing GAO Xiao-nv YU Yin LIU Chun-quan
    2013, 29(12):2865-2869.
    [Abstract](1472) [HTML](0) [PDF 558.97 K](722)
    Abstract:
    The glucoamylase produced by strain CL-6 was two-fold hastened when the organism was grown on media containing corncob. Strain CL-6 isolated from sweet starter was identified by morphological observation and ITS sequence analysis and indicated as Rhizopus oryzae. The enzymatic activity was measured by glucose oxidase-peroxide enzyme (GOD-POD). The sugar components in corncob were determined by thin-layer chromatography (TLC) and HPLC-RID. The sugars in the water-soluble components of the corncob were as follows: sucrose(520.33 mg/2.5 g wet resin), glucose (242.67 mg/2.5 g wet resin), fructose(228.67 mg/2.5 g wet resin) and maltose(30.33 mg/2.5 g wet resin). The effect of separately adding corncob, soluble fractions of corncob, sugar components and soluble fractions with molecular weight higher than 8~14.4 KD on the activity of glucoamylase were analyzed It was showed that glucoamylase formation was not enhanced when the organisms grew on media containing the four sugars, and the components with molecular weight exceeding 8~14.4 KD in the water-soluble parts of corncob was the important factor in stimulating glucoamylase prodution by Rhizopus oryzae CL-6.
    15  Antioxidant Activity Constituents of Lonicera japonica Leaves
    ZHENG Bi-sheng LI Hui-na
    2013, 29(12):2870-2876.
    [Abstract](1427) [HTML](0) [PDF 546.59 K](752)
    Abstract:
    A wavelength conversion method was established to determine chlorogenic acid, luteolin and luteoloside in Lonicera japonica leaves. The content of chlorogenic acid in aqueous phase was 2.05%, while the content of luteolin and luteoloside in EA phase were 1.12% and 0.57%, respectively. The antioxidative activity of effective components in Lonicera japonica leaves was evaluated by DPPH?, FRAP and ORAC with Vc as reference substance. The results showed that crude extraction, crude fraction, chlorogenic acid, luteolin and luteoloside in Lonicera japonica leaves all had great antioxidative activity. The strongest antioxidant capacity substance was luteolin, its IC50 value, reducing capacity and ORAC value were 0.01764 mg/mL, 1751.8±13.9 mmol/L and 23817.44 μmol Trolox/g, respectively. The crude fraction eluted by 30% ethanol also showed high antioxidative acitivity, its IC50 value, reduction capability and ORAC value were 0.02548 mg/mL, 933.8±11.6 mmol/L, and 10557.97 μmol Trolox/g, respectively. The antioxidative activity of each constituent increased with the increase of concentration and purity of the antioxidant. Therefore, there is broad development and utilization prospect of the antioxidant activity constituents of Lonicera Japonica leaves as a new type efficient non-toxic antioxidant.
    16  Antidepressant Effects of the Enzymatic Products from the Total Saponins in Panax notoginseng Leaves
    ZHANG Hua-lin LI Meng-tao PENG Hao ZHOU Zhong-liu YANG Hong-yan XIANG Hui
    2013, 29(12):2877-2882.
    [Abstract](1399) [HTML](0) [PDF 516.25 K](738)
    Abstract:
    To evaluate the antidepressant effects of the enzymatic products EP-3 from the total saponins in leaves of Panax notoginseng, a series of animal models and tests, such as the forced swim test (FST), the tail suspension test (TST), learned helplessness procedure, reserpine-induced syndrome, head-twitch test, running and aggressive behaviors were used. EP-3 could shorten the immobility time of FST mice for 43.39% to 52.00% that showed an obvious antidepressant-like effect. EP-3 could significantly reduce the times of escape failures in the model of learned helplessness procedure, which was reduced by 16.56% to 29.96% and 29.63% to 62.82% on day 2 and 4, respectively. EP-3 could significantly reverse the reduction in rectal temperature and the degree of palpebral ptosis, and moderately remit the condition of akinesia induced by reserpine. Moreover, EP-3 could significantly increase the times of head twitches induced by 5-HTP, decrease the times of aggression induced by clonidine and improve the running behavior induced by L-Dopa. However, EP-3 had no effect on the immobility time of TST mice (P>0.05). In conclusion, EP-3 exerts excellent antidepressant-like effects that maybe have a close relationship with the monoamine neurotransmitters 5-HT, NE, DA or their receptors.
    17  Effects of Soup on the Main Compositions, Texture and Odour of Grey Sufu During Ripening Process
    CHEN Tao CHEN Yan-hua CHEN Fu-sheng
    2013, 29(12):2883-2888.
    [Abstract](1313) [HTML](0) [PDF 614.15 K](822)
    Abstract:
    The effects of soup obtained from commercial grey sufu on the main compositions, texture and odour were researched. The results showed that compared to the control of sufu (no addition of soup), the contents of protein and crude fat were lower in the sample sufu (adding of soup), but the free amino acid content was higher in sample sufu during ripening process. After ripening for 49 d, the free amino acid content in sample sufu reached to 11.70% (dry weight), which was 60% higher than that achieved in control. The hardness and resilience were lower in sample sufu body, but the cohesiveness was higher. After ripening for 49 d, the values of hardness, cohesiveness and resilience were 213.75 g, 0.37 and 0.35 in sample sufu body and 258.28 g, 0.29 and 0.43 in the control, respectively. The textural parameters (hardness, cohesiveness and resilience) showed a significant correlation with protein content in the two kinds of sufu. It produced volatile sulfide and indole after adding the soup. But when the soup centrifuged by high speed or filtered by microfiltration membrane, it could not produce these substances.
    18  Effect of Different Wavelength Ultraviolet Radiation on Photoreactivation in Vibrio parahaemolyticus
    SU Ze-hong HE Shu-ya LI Li-juan LIAN Gao-jian AKIRA Takahashi
    2013, 29(12):2889-2893.
    [Abstract](1084) [HTML](0) [PDF 510.09 K](693)
    Abstract:
    The low pressure mercury lamp is used as a common tool for disinfection, with wavelength 254 nm as light source. Previous results suggested that when connected with light-emitting diodes (LED), UVA could kill bacterial effectively. In this research, we found that the disinfection effect of UVA/LED was much stronger than that of UVC; meanwhile, the regeneration of Vibrio parahaemolyticus after radiated by UVA/LED was more slowly than that only exposed by UVC. The results showed that photoreactivation did not happen in Vibrio parahaemolyticus after radiation by UVA/LED, and gene expression of photoreactivation related enzymes was not induced either. However, after UVC radiation, the photoreactivation happened and the gene expression level of photolyase increased. Thus results indicated that UVA/LED might inhibit photoreactivation in vibrio paraheamolyticus. Nevertheless, UVA/LED equipment needs much higher energy than UVC disinfection device, which should be improved.
    19  Antibacterial Mechanism of Garlic Extract Against Specific Spoilage Organisms
    XIAO Xiang WANG Yao JIANG Song ZHOU Hui ZHI Zhu-wei DONG Ying
    2013, 29(12):2894-2900.
    [Abstract](1257) [HTML](0) [PDF 662.57 K](654)
    Abstract:
    The antibacterial mechanism of garlic extract-tea polyphones complex against 3 strains of specific spoilage organisms (SSOs) -Enterococcus faecium, Yersinia intermedia and Lactobacillus sake in meat was studied. The results showed that the complex destroyed SSOs cell ultra-structure at a concentration of 0.84 mg/mLand the conductivities of three strains were more than 14 ms/cm which significantly increased than controls after treating 10h. PI dyeing rates of the three strains raised obviously, being of 36.34% (control 0.42%), 99.64% (control 3.72%) and 92.95% (control 28.67%) , respectively, after 2 h complex treatment. The contents of stearic acid in the cytomembrane and intracellular malic acid were also changed much. For the intracellular protein synthesis, only Enterococcus faecium was changed. This research showed that, the garlic extract-tea polyphones complex could destroy the cell membrane and DNA structure of the strains of SSOs, thus changed the normal metabolisms of the intra- and extra-cellular, and eventually leaded to the spoilage bacteria inhibition or death. The inhibition mechanism of garlic extract-tea polyphones complex still needs further study.
    20  Physical and Chemical Properties of the Different Millet Starches in Shanxi
    YANG Bin ZHANG Xi-wen ZHANG Guo-quan LI Ping ZHANG Wen-xing ZHANG Ai-ying JIANG Long-bo DU Wen-juan
    2013, 29(12):2901-2908.
    [Abstract](1098) [HTML](0) [PDF 632.99 K](813)
    Abstract:
    To further understand the physical and chemical properties of the millet starches in Shanxi province, eight typical species of millet were chosen and the particle morphology, size, amylose content, iodine blue value, light transmittance, freeze-thaw stability, gelatinization characteristics, solubility, swelling power, retrogradation curve and other physicochemical characterizations were evaluated. Results showed that the millet starch granules were all single particle with regular shape, and most of the millet starch particles were polygonal while few were ovoid. All the particles had clear polarizing cross, and the morphological differences of starch grain particles were evident between varieties. Moreover, on the basis of particle size, the eight millet cultivars were clearly classified as two categories which ranged from 0.42 to 2.25 μm and 3.42 to 29.26 μm, respectively. The amylose content, iodine blue value, light transmittance, water segregation rate, and gelatinization temperature were in the range of 2.22~17.96%, 0.586~0.872, 2.4~29.2%, 3.67~49.85% and 67.6~78.8 ℃, respectively, indicating that the differences between different varieties were significant. All of these results suggested that the different millet varieties should be chosen according to the different processing purposes.
    21  Quality Changes of Litchi Juice after Fermentation and the Stability during Low-temperature Storage
    ZHENG Xin YU Yuan-shan WU Ji-jun XU Yu-juan XIAO Geng-sheng CHENG Yin-qi
    2013, 29(12):2909-2914.
    [Abstract](1032) [HTML](0) [PDF 636.06 K](807)
    Abstract:
    In this study, litchi juice was fermented at 30 ℃ by probiotics of Lactobacillus casei, Lactobacillus bulgaricus and Leuconstoc mesenteroides, and the changes of microbial count and quality of fermented litchi juice during storage at 4 ℃ were also investigated. Results showed that the three lactic acid bacteria grew rapidly in litchi juice, and received the highest number (above 9.0 log) after fermented 12 h. The three lactic acid bacteria showed obvious difference in utilizing sugar and organic acid of litchi juice, where Lactobacillus casei and Lactobacillus bulgaricus produced as much as 37.5 g/L exopolysaccharides. Moreover, after 12 h fermentation, the polyphenol and Vc contents appeared no significant change (p>0.05). But L* values were significantly decrease (p<0.05), and the color became more pale in all fermented litchi juice. During storage of 28 d at 4 ℃, no further fermentation was found in all fermented litchi juice, but the number of Leuconostoc mesenteroides dropped to less than 7 log, whereas Lactobacillus casei and Lactobacillus bulgaricus only decreased 0.5 log.
    22  Effects of Different Hot-air Drying Parameters on Drying Characteristics and Quality of Scallops
    WANG Ya-jiao GUO Jie YAO Si-yuan WANG Jie
    2013, 29(12):2915-2920.
    [Abstract](1330) [HTML](0) [PDF 565.67 K](829)
    Abstract:
    In order to observe the thin layer hot-air drying character of scallops, the influences of the different air flow velocities and different relative humidities on the drying process of thin layer hot-air drying of the scallops under constant temperature condition were studied. The results showed that the whole drying procedure of scallops was slowly. Increasing the air flow velocity or decreasing the relative humidity resulted in a significant decrease of drying time and water activity (Aw). Different air flow velocities and different relative humidities had obvious influence on the textural properties, shrinkage ratio and rehydration rate, but had no significant effect on the scallops color. The optimal parameters were air flow velocity 0.8~1.2 m/s and relative humidity 8%.
    23  Application of Heavy Rare Earth Element Fingerprints in Discrimination of Pu 'er Old Plant Tea and Tableland Tea
    LIN Xin LI Qi-wan HE Li-zhong LAN Shan-shan LIN Tao LIU Hong-cheng
    2013, 29(12):2921-2925.
    [Abstract](1542) [HTML](0) [PDF 518.43 K](835)
    Abstract:
    Pu 'er teas are divided into old plant tea and tableland tea according to their origins. Old plant tea has a unique aroma and quality distinctive from tableland tea. The preliminary investigation was carried out to examine the feasibility of rare earth elements in identifying old plant tea and tableland tea. The samples of the two kinds of teas were selected from Xishuangbanna state of Yunan province, and the contents of 15 rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, Er, Tm, Yb, Lu and Sc) from these Pu 'er teas were determined by inductively coupled plasma mass spectrometry (ICP-MS). The analysis of variance (ANOVA), principal component analysis (PCA) and discriminant analysis (DA) showed that the discrimination models were established by four key variables (La, Ce, Eu and Sc), in which 100% classification validation for both teas and 88.9% cross validation for plant tea and 94.4% for tableland tea. It is feasible to classification of old plant tea and tableland tea by using pattern recognition technique combining with heavy rare-earth element fingerprints .
    24  Properties of the Hydrophilic Copolymer Supporter Containing Oxirane for Immobilized Glucose Oxidase
    LI Pi-wu LI Rui-rui LIU Dian-lei HAO Qiong YANG Qing WANG Sheng
    2013, 29(12):2926-2930.
    [Abstract](1119) [HTML](0) [PDF 616.55 K](718)
    Abstract:
    Oxirane groups can react with the amino groups of enzyme under mild conditions so that could be immobilized on the surface of copolymer supporter. The macroporous Ferrofluid-GMA-MBAA (FGM) polymer were synthesized by inverse suspension polymerization with glycidyl methacrylate (GMA) as the reactive monomer and N,N′-methylene-bis-acrylamide (MBAA) as the cross-linking agent. Polyvinylpyrrolidone (PVP) was used as the stabilizer monomer and azodiisobutyronitrile (AIBN) was used as the initiator monomer. Fe3O4 was added as magnetofluid to the dispersion medium, ethanol solution. The effects of the amount of magnetofluid and crosslinking agent on the structure properties and the apparent activity of immobilized enzyme were investigated. The recovery rate of apparent relative activity of 90.45% (about 546.23±2.33 U/g) was obtained when the glucose oxidase (GOD) enzyme was immobilized on FGM polymer [w (GMA) = 20%, w (ferrofluid) = 0.4%, w (MBAA) = 40%] at 55 ℃ and pH 8.0. The enzyme activity was nearly 60% of its initial even after being used for 15 times. After a 30-day storage at 4 ℃, the immobilized enzyme showed little changes in its activity.
    25  Extraction of Volatile Oil from Tangerine Peel by Low-temperature Continuous Phase Transition and Analysis of Its Properties
    ZHOU Guo-hai MIAO Jian-yin LIU Fei GUAN Xiao-sheng ZHANG Yong LI Yun YANG Yi-ting CAO Yong
    2013, 29(12):2931-2936.
    [Abstract](1704) [HTML](0) [PDF 528.18 K](1403)
    Abstract:
    Tangerine peel is a traditional Chinese medicinal material. The volatile oil of tangerine peel has a variety of pharmacological effects, such as dispelling phlegm and relieving asthma. The volatile oil was extracted by continuous phase transition n-butane in low- temperature environment, and the effects of granularity, extraction time, extraction temperature, extraction pressure and separation temperature were discussed. The orthogonal experiment (L9(34)) was adopted to optimize extraction conditions, the extracted yield was 3.31% with granularity of 40 mesh, extraction time of 60 min, extraction temperature of 30 ℃, extraction pressure of 0.6 MPa, and separation temperature of 70 ℃. The physical and chemical properties and fatty acid compositions of oil were analyzed. The extracted tangerine peel oil was semisolid paste with a yellow to reddish brown color, containing 10.6% of methoxy flavone, iodine value 122.4 g I/100 g, acid value 73.8 mg KOH/g and peroxide value 0.1 g/100 g. The major components of volatile oil from tangerine peel were linoleic acid (30.01%), 9-Octadecenoic acid (25.43%), linolenic acid (16.32%), and stearic acid (4.56%) by GC-MS.
    26  Preparation of Electrospun Antimicrobial Nanofiber Film and the Effect of Electrospinning Condition on Its Morphology
    WU Hong WEN Peng CUI Xiu-xiu ZHU Ding-he LOU Wen-yong ZONG Min-hua
    2013, 29(12):2937-2941.
    [Abstract](1238) [HTML](0) [PDF 665.02 K](733)
    Abstract:
    Biodegradable polymer of polyvinyl alcohol (PVA) and cinnamon essential oil with a good antimicrobial effect were successfully electrospinned into antimicrobial nanofiber film in this study. The solution composition and electrospinning parameters had significant effect on the distribution of fiber diameter,leading to the variation of antimicrobial property of nano-material. Therefore, we first investigated the effect of PVA and β-cyclodextrin (β-CD) concentrations on the fiber diameter distribution. SEM was applied to observe the morphology of the nanofibers, and the optimal mass concentration of PVA and β-CD was found to be 6% and 2%, respectively. SPSS methodology was used to analyze the effect of the flow rate and distance on the diameter distribution under constant voltage condition The results showed that the distance had more remarkable influence on the nanofiber diameter than that of flow rate. The optimal electrospinning conditions were: voltage 15 kV, flow rate 0.4 mL/h and distance 14 cm. Under the above-mentioned optimal conditions, the diameters of the resulting nanofibers were equally distributed, and the nanofiber film had a good morphology, which could enhance the persistence of its antimicrobial ability.
    27  Hot-air and Heat Pump Drying of Lactobacillus Fermented Half-dry Tilapia Fillets
    WU Jian-zhong ZHANG Cheng OU Shi-yi ZHOU Hua JIN Jun
    2013, 29(12):2942-2946.
    [Abstract](1132) [HTML](0) [PDF 424.80 K](689)
    Abstract:
    The fermented half-dry tilapia fillets were dried by hot-air and heat pump in order to find an optimum drying method. The effects of the two drying methods on drying rate, sensory properties, color, microstructure and microbial contents of products were investigated. The results showed that the hot-air drying had a higher efficiency which required just half time of drying by heat pump. But the tilapia fillets dried by heat pump advanced sensory score, color index and uniform texture. The total bacteria count and lactobacillus count of the tilapia fillets dried by heat pump were 1.46×108 cfu/g and 1.38×108cfu/g, respectively, while 2.44×108 cfu/g and 2.9×107 cfu/g when the tilapia fillets were dried by hot-air. The heat pump drying was preferable to preserve lactobacillus, reduce bacterial pollution, which was more suitable for drying lactobacillus fermented half-dry tilapia fillets. The results can provide references for drying process of lactobacillus fermented foods.
    28  Preparation, Identification and Purification of Apigenin
    LIU Ben-guo YANG Ji-guo QIU Xiao-bin ZHANG Rui-ting NING Zheng-xiang
    2013, 29(12):2947-2952.
    [Abstract](1417) [HTML](0) [PDF 555.77 K](1120)
    Abstract:
    Apigenin possesses many bioactivities such as antitumor and antihypertension, which can be widely used in functional food and medicine. Apigenin was used to be prepared from Matricaria recutita and Apium graveolens. Their low contents of apigenin led the low yield and high cost of apigenin, which limited the extensive application of apigenin. Adinandra nitida is a special plant in China, whose leaves is rich in flavonoids with apigenin as aglycone. The preparation of apigenin from Adinandra nitida leaves was studied. The water extract of Adinandra nitida leaves was heated and hydrolyzed with sulfuric acid. The main component of the obtained precipitate was identified as apigenin by UV, IR, ESI-MS and NMR. And the content of apigenin in the precipitate was determined as 64.80 % by HPLC. The solubility of apigenin in the ethanol with different temperatures and concentrations was measured, and the constant temperature-concentration gradient technology was developed to purify apigenin. The purity of apigenin reached 92.44 %。
    29  Experimental Study and Comprehensive Evaluation on Meat Grinding
    TONG Bao-hong SUN Jun XU Zheng-hua CHEN Zhi-yong JI Bin SONG Bin
    2013, 29(12):2953-2957.
    [Abstract](1125) [HTML](0) [PDF 650.63 K](795)
    Abstract:
    An experiment system was developed in order to evaluate the grinding process and the properties of ground meat. Functions including the evaluation of the properties of ground meat and machine’s efficiency were also introduced in the system. The grinding capability, resisting torque of screw shaft, power loss and temperature rising of meat were carried out. Biochemical parameters such as freshness and water-holding capacity were adopted as the quality evaluation of meat. The testing results showed that the grinding capability of meat grinder increased with the rising of rotating speed of screw shaft, and the tested meat grinder was good to match with grinding operating and conveying speed. It also had stable heat dissipation under all test conditions. The research identified that both the quality of ground meat and physiochemical properties of meat were influenced by the matching of blade and disk.
    30  Concentration of Engraulis japonicus Soup by Ceramic Membrane
    ZHANG Jian-you LIN Long WANG Bin DING Yu-ting
    2013, 29(12):2958-2963.
    [Abstract](1268) [HTML](0) [PDF 570.37 K](697)
    Abstract:
    Microfiltration is a promising technology for concentrating Engraulis japonicus soup by ceramic membrane. Effects of membrane pore size, pressure, temperature, initial concentration and addition modes on permeate flux were examined during microfiltration. There was no difference of the protein concentration efficiency between 0.14 μm and 0.45 μm ceramic membrane, and the integral concentration efficiency was much higher when using 0.14 μm ceramic memebrane; the permeate flux increased with temperature and pressure increased; and decreasing soup concentration could increase the permeate flux but reduced the protein concentration efficiency either. At 45 ℃,the permeate flux was higher, and the growth rate of total bacterial count and total volatile base nitrogen (TVB-N) value was minimum compared to 25 ℃ and 35 ℃, while the growth rate of thiobarbituric acid reactive substances (TBARS) value had little effect with temperature. Consequently, the optimal concentrate process was obtained under the conditions of 0.14 μm ceramic membrane, 0.3 MPa, 45 ℃ and intermittent feeding. The most effective cleaning method was 40 min at 45 ℃ with solution containing 1% (m/V) NaOH and 0.05% (m/V) SDS. The flux recovery ratio of the most effective method was 98.99%, which was 22.85% higher than that of solution only with 1% NaOH.
    31  Purification of Flavones from Gingko biloba Leaves by Macroporous Resin
    WU Hai-xia WU Cai-e LI Ting-ting FAN Gong-jian YING Rui-feng
    2013, 29(12):2964-2969.
    [Abstract](1417) [HTML](0) [PDF 530.64 K](709)
    Abstract:
    The flavones was extracted with 70% ethanol from degreased powder of Ginkgo biloba leaves (GBLs), and technical conditions of macroporous resins for the purification of flavones from GBLs were studied. The performances of adsorption-desorption of three resins AB-8, D101 and HPD-100 were investigated by using adsorption and desorption rate as indexes. And the AB-8 was considered to be the optimum resin to purify the flavones of GBLs due to its highest adsorption-desorption properties. Combination of static and dynamic experiments of resin adsorption-desorption, the preferable technical conditions of flavones of GBLs by AB-8 resin were obtained. The results were as follows: dilution of extracted solution 1.5 times (concentration of diluted sample 0.094 mg/mL), pH 4.85, loading velocity 1.5 BV/h, sample volume 200 mL, pH 4.95 eluant for desorption and 80% alcohol, desorption velocity 2~2.5 BV/h and eluant volume 50 mL. The flavones content of GBLs gained under these conditions was 26.16%, and 3.2 times more than that of the original sample. The technical condition is scientific and reasonable that can be used to separate and purify flavones of GBLs and improve the content of flavones in GBLs extracts.
    32  Inactivation of Bacillus subtilis by Pulsed Magnetic Field Combined with Temperature, Ultrasonic, and Nisin
    QIAN Jing-ya MA Hai-le LI Shu-jun LIU Bin ZHANG Chao
    2013, 29(12):2970-2974.
    [Abstract](999) [HTML](0) [PDF 395.84 K](745)
    Abstract:
    The effect of pulsed magnetic field (PMF) with the intensity of 3T and 30 pulses combined with temperature (50~100 ℃), ultrasonic (200 W, 5~30 min), and nisin (100~350 IU/mL) on the inactivation of Bacillus. subtilis (B.subtilis) was investigated. The results showed that after pretreated by PMF, the survival rate decreased with the increase of the temperature, ultrasonic power and the nisin concentration, and the lowest survival rate (3.17%) was achieved when B. subtilis were treated by PMF followed by the temperature at 100 ℃. The survival rate decreased with the the increase of treatment time by ultrasonic and the lowest survival rate of 8.18% was obtained when B. subtilis were treateded by PMF followed by ultrasonic at the power of 200 W with working time of 5 s and the interval of 10 s for 30 min. Increase in concentration of nisin led to the reduce of survival rate of B. subtilis. The combined treatments of PMF followed by nisin at 350 IU/mL exhibited a lowest survival rate of 19.21%. The inactivation effect was better when B. subtilis were treated by PMF followed by temperature, ultrasonic, and nisin than treated by temperature, ultrasonic, and nisin followed by PMF, which was in agreement with the phenomenon observed by the SEM. The morphology of B. subtilis changed and the cells shrunk after the combined treatments. The release of cytoplasmic contents of B. subtilis occurred after the treatments of PMF followed by nisin.
    33  Characteristics of Acetylated Starch Prepared with Ultra High Pressure
    MENG Shuang YANG Qi-yun YAN Zu-gen
    2013, 29(12):2975-2979.
    [Abstract](943) [HTML](0) [PDF 413.09 K](777)
    Abstract:
    Acetylated starch as one of the most important modified starches is widely applied in food and non-food processing fields. The impact of ultra high pressure (UHP) on the physicochemical properties of the modified acetylated starch was investigated. Corn starch was substituted with acetic anhydride at pressure range of 300 to 400 MPa for 10 to 20 min. Conventionally prepared acetylated starch (30 ℃, 0.1 MP, 60 min) was conducted as control. Characteristics of acetylated corn starches in terms of degree of substitution, thermal properties, solubility, swelling power, retrogradation, paste clarity and so on were assessed, and the structure of acetylated starch was charactered by FT-IR. Compared with the conventional method, the UHP processing was favorable for shortening reaction time and increasing the degree of substitution. The degree of substitution reached to the maximum value of 0.0461 at 400 MPa for 20 min, and acetylated starches by using UHP had lower retrogradation.
    34  Effect of Infrared Drying on the Quality of Instant Shrimp and Establishment of Quality Evaluation Model
    LI Xin-yue SUN Jian-feng CUI Xiao-peng
    2013, 29(12):2980-2985.
    [Abstract](1418) [HTML](0) [PDF 645.45 K](739)
    Abstract:
    In order to study the effect of infrared drying on the quality of instant shrimp and investigate the relationship between the physicochemical indexes and sensory quality of instant shrimp, moisture content, water activity, color parameters, texture parameters and sensory evaluation scores of instant shrimp treated by different infrared drying time were measured and analyzed. Also correlation analysis between sensory evaluation scores and texture parameters was carried out. The results showed that infrared drying had a significant influence on the moisture content, water activity, color and texture parameters of the instant shrimp. Hardness, resilience, cohesion and a* value of color parameter could be objectively used to evaluate the product quality instead of sensory evaluation through a regression model. The regression model between sensory evaluation scores and texture parameters was Y (sensory evaluation scores) = 0.260X1 (Hardness) + 2.800X2 (Resilience) + 5.425X3 (Cohesion) + 0.218X4 (a*) - 10.744, R2=0.972.
    35  Comparison of Nutritional Values of Acaudina molpadioides, Holothuria nobilis, and Actinopyga miliaris
    DONG Xiao-di PAN Ru-jia WANG Chang-hai
    2013, 29(12):2986-2990.
    [Abstract](1835) [HTML](0) [PDF 500.78 K](674)
    Abstract:
    The compositions of body wall, amino acid, fatty acid, polysaccharide as well as mineral and trace element contents of Acaudina molpadioides, Holothuria nobilis, and Actinopyga miliaris were analyzed and compared to assess their nutritional qualities. The three sea cucumbers shared similar characteristics with high protein and low lipid. Delicious amino acids (DAA), including glutamic acid, aspartic acid, glycine, threonine, and alanine, with the following contents: 61.6% for A.molpadioides, 58.1% for H. nobilis, and 59.7% for A.miliaris. A low lysine and arginine ratio ranging from 0.39 to 0.46 was observed in all species. A. molpadioides contained less saturated fatty acids (21.4%) and more unsaturated fatty acids (67.1%) than other two species, and arachidonic acid (C20:4) constituted most of the polyunsaturated fatty acids (PUFA). The three samples showed relatively high Fe (16.3 to 24.1 mg/kg) and Zn (11.7 to 19.0 mg/kg) contents but low As (0.58 to 0.66 mg/kg) and Cd (0.49 to 1.21 mg/kg) contents. The comparison revealed that the body walls of A. molpadioides contained higher nutritional values than H. nobilis and A. miliaris.
    36  Composition Analysis and Nutritional Evaluation of Pyrus sinkiangensis cv. Piteguo
    WANG Yong-gang REN Hai-wei WANG Xiao-li YANG Ming-jun LI Zhi-zhong
    2013, 29(12):2991-2996.
    [Abstract](1637) [HTML](0) [PDF 548.01 K](888)
    Abstract:
    The nutritional components of Pyrus sinkiangensis cv. Piteguo were analyzed and evaluated. Results showed that the contents of water, total ash, crude fat, protein, total sugar, total acid, crude fiber and total soluble solid were 88.2%, 3.3%, 0.82%, 0.38%, 6.47%, 1.05%, 3.05% and 13.8%, respectively. Vitamin C, B1, B2, B6 and carotene were 2.2 mg, 0.001 mg, 0.139 mg, 6.8 mg and 0.042 mg per 100g, respectively. Contents of 18 amino acids, EAA/TAA ratio, and EAA/NEAA ratio were 0.2658%, 37.02% and 58.78%, respectively. All kinds of human essential amino acids were in the appropriate proportion, and the first limiting amino acid was Lys. The score of ratio coefficient of amino acids (SRC) was 62.0. The mineral element contents of K, Ca, P, Mg, Na, Fe, Zn, Cu and Mn were 768.32 mg, 101.64 mg, 98.78 mg, 85.14 mg, 40.62 mg, 36.92 mg, 1.38 mg/kg, 0.84 mg and 0.37 mg in 1 kg, respectively. Twenty-five kinds of volatile components were isolated, including n-hexaldehyde, ethyl acetate, butyl acetate, ethyl propionate, methyl butyrate and 2-ethyl crotonate with their relative contents being of 3.981%, 0.215%, 0.187%, 0.132%, 0.103% and 0.137%, respectively. It suggested that Pyrus sinkiangensis cv. Piteguo was rich in all kinds of nutritional components, which have high exploitation value.
    37  Fast Discriminating of Chicken Adulteration in Minced Mutton by Electronic Nose
    TIAN Xiao-jing WANG Jun CUI Shao-qing
    2013, 29(12):2997-3001.
    [Abstract](1186) [HTML](0) [PDF 423.22 K](645)
    Abstract:
    The adulteration of mutton has attracted increasing attention that requires reliable methods for the authentication. An electronic nose (Pen 2) was employed to analysis the adulteration of chicken in minced mutton. The effects of sample weight, headspace-generated time, headspace volume and flow rate of carrier gas on sensor responses were studied by single-factor experiment. Results of one-way analysis of variance found that the responses of electronic sensors were significantly affected by these factors. The optimum experimental parameters were 10 g sample with 30 min headspace-generated time in 250 mL beaker with a flow rate of 200 mL/min by using principle component analysis (PCA). The adulterated mutton was made by mixing mutton with chicken at different proportions. With the optimum experimental parameters, 144 samples of adulterated mutton were detected and the signals were analyzed by pattern recognition techniques to build models for classification of adulterated mutton with different proportions of chicken and prediction of the content of chicken in minced mutton. With PCA and CDA, the adulterated mutton samples were grouped according to their content of chicken with overlapping with each other, and better classification results were found with CDA. Principle component regression (PCR) and partial least square analysis (PLS) were employed to build the predictive model for the content of chicken adulterated into minced mutton. Both models could predict the adulteration with high determination coefficient (higher than 0.95). PCR was more effective for the prediction of chicken content. The E-nose has been proved to be a useful authentication method for meat adulteration detection for its efficiency and high accuracy.
    38  A Real-time Turbidimeter-based Loopmediated Isothermal Amplification Assay for Rapid Detection of Genetically Modified Maize MON810
    WANG Xiao-yu KUANG Xiao-shan HU Song-nan YU Yi-gang CHENG Xiao-wei FENG Jia-wang ZHANG Huang XIAO Xing-long
    2013, 29(12):3002-3005.
    [Abstract](1428) [HTML](0) [PDF 504.29 K](637)
    Abstract:
    LAMP real-time turbidity method is based on the loop-mediated isothermal amplification, detecting a white precipitate generated during the reaction by a real-time turbidimeter, in order to monitor the whole process of amplification. This technique overcomes the defects of LAMP chromomeric method which could only monitor the end of reaction, therefore becomes more scientific for primers screening and the reaction optimization. Six specific primers were designed for the junction sequences of exogenous gene CryIA(b) and endogenous gene of genetically modified maize MON810. Detection conducted by real-time turbidity method at 63 ℃, the detection sensitivity, specificity and stability were verified. The results indicated that the lowest detection limit of this method was 0.5%, and the coincidence rate compared with the LAMP chromomeric method and the real-time PCR method was 100%, The method had high specificity, stability, accuracy and convenience which was suitable for the rapid detection of genetically modified maize MON810 and has good application value.
    39  Aroma Quality Evaluation of Yunnan Black Tea by Multiple Statistics Analysis
    REN Hong-tao ZHOU Bin QIN Tai-feng XIA Kai-guo FANG Lin-jiang
    2013, 29(12):3006-3013.
    [Abstract](1327) [HTML](0) [PDF 586.68 K](920)
    Abstract:
    To compare and evaluate the aroma quality of Yunnan black tea, the aroma compounds of 30 Yunnan black tea samples were extracted by simultaneous distillation extraction (SDE), the main constituents contents were determined by GC-MS and analyzed by sensory evaluation. Taking the contents of 16 main aroma components as the indices, the quality of samples was assessed by multiple linear regression analysis, principal component analysis and cluster analysis methods. Results showed that the quality of black tea was closely related with the contents of hexanal, (E)-2-hexanal, phenylacetaldehyde, linalool oxide, linalool, geraniol and β-ionone. The correlation equation was as: Y=88.027+0.53X1-0.596X2-0.239X3+0.246X4+0.12X5-0.052X6-5.615X7, R2=0.902. The principal component analysis showed that four of main components contributed 77.156% to the aroma quality of Yunnan black tea. The cluster analysis was useful for the classification of Yunnan black tea. The multiple linear regression analysis provides a new method for evaluating aroma quality of black tea.
    40  Determination of Five Fluorescent Whitening Agents in Foam Plastic Tableware by High Performance Liquid Chromatography Tandem Mass Spectrometry
    DU Zhi-feng XIAN Yan-ping LIU Fu-jian HUANG Jin-feng WU Yu-luan GUO Xin-dong WANG Yong-hua LUO Dong-hui
    2013, 29(12):3014-3018.
    [Abstract](1833) [HTML](0) [PDF 515.91 K](769)
    Abstract:
    A simple and sensitive method has been developed for the simultaneous determination of five fluorescent whitening agents (FWA135, FWA184, FWA367, FWA368 and FWA393) in foam plastic tableware using high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The samples were extracted with trichloromethane, and the polymer in the extracts were precipitated by adding methanol. The separation of five FWAs was carried out on a Phenomenex kinetex C18 column (2.1 mm×100 mm, 2.6 μm) by gradient elution with 0.1% formic acid methanol and 0.1% formic acid as mobile phase. Electrospray ionization mass was operated in the positive mode (ESI+) using multiple reaction monitoring (MRM) for the qualitative and quantitative analysis of five FWAby retention time and ion ratio. The result indicated that the linear correlation coefficients (r>0.995) of five FWAs were obtained with the linear relationship between 0.5 to 50 μg/L. The limits of detection (ILOD, S/N=3) were ranged from 0.1 μg/L to 0.5 μg/L, and the limits of qualification of the method (MLOQ, S/N=10) were varied from 0.4 μg/kg to 2.0 μg/kg. The recoveries of five FWAs from spiked samples at the spiking levels of 2 μg/kg, 8μg/kg and 200 μg/kg were between 86.4% and 98.4% with RSD (n=6) less than 3.9% to 8.1%. The method was simple and precise for the determination of five FWAs in foam plastic tableware.
    41  Analysis of Volatile Components in Gonad of Eriocheir sinensis by Monolithic Material Sorptive Extraction Coupled with Gas Chromatography and Mass Spectrometry
    GU Sai-qi WU Hao ZHANG Jing-jing WANG Xi-chang
    2013, 29(12):3019-3025.
    [Abstract](1473) [HTML](0) [PDF 823.43 K](862)
    Abstract:
    Eriocheir sinensis farmed in Yangcheng Lake is a valuable traditional aquatic product and quite welcomed by Chinese consumers due to its outstanding flavor. In this study, a new type of material (MonoTrap) was applied as the adsorbent to extract the volatile compounds in gonad of Eriocheir sinensis. The volatile compounds were then isolated and identified by GC-MS. The optimal extraction conditions were using seven MonoTrap RCC18 at 100 ℃ for 50 minutes. 55 volatiles that could be divided into seven classes were finally detected under the forementioned conditions. Odor activity values (OAV) of all 55 volatiles were calculated according to their odor thresholds and 22 aroma-active compounds (AACs) were further selected. Among the AACs, 2,4-decadienal, trimethylamine and decanal mainly contributed to integral aroma profile of the gonad sample. Monolithic Material Sorptive Extraction (MMSE) is considered as an excellent method for food flavor analysis because of its high efficiency of volatile compounds absorption.
    42  Resonance Light Scattering Method for Determination of Mercury Content in Fish
    LI Yong-mei LI Ren-yu
    2013, 29(12):3026-3030.
    [Abstract](1213) [HTML](0) [PDF 573.19 K](651)
    Abstract:
    The fish samples were pretreated by using microwave digestion Based on the obvious enhancing effect of Hg2+ in acetic acid- sodium acetate buffer solution on resonance light scattering (RLS) produced by 1,10-phenanthroline monohydrate and brilliant yellow, RLS method for determination of trace amount of mercury in fish was established. The results showed that the optimal determination conditions were: 1.5 mL acetic acid-sodium acetate buffer solution at pH 5.7, 1.0 mL 1.0×10-4 mol/L 1,10-phenanthroline monohydrate solution and 0.8 mL 4.0×10-5 mol/L brilliant yellow, reaction temperature 25 ℃ and reaction time 5 min. Good linear relationship was obtained between the enhanced RLS intensity and Hg2+ concentration in the range of 0~50 μg/L with the maximum RLS peak at 451.6 nm. The detection limit was 0.54 μg/L. Interfering ions as Cu2+ and Fe3+ could be masked by a mixture of sodium fluoride and thiourea. The result of measured mercury content in fish was in accordance with that measured by cold vapor atomic absorption spectrometry. The relative standard deviation was 1.38~2.19% (n = 5), and the average recovery was 99.33~102.00%. This method was sensitive, accurate, simple, rapid and environmentally friendly, which was suitable for determination of mercury in fish.
    43  Purification of Flavonoids from Potentilla fulgens and Identification by HPLC-ESI-MS/MS
    CHEN Xin JIANG Zi-tao LI Rong
    2013, 29(12):3031-3037.
    [Abstract](1255) [HTML](0) [PDF 647.52 K](613)
    Abstract:
    Purification effects of seven kinds of macroporous resins through static adsorption on the flavonoids from Potentilla fulgens were studied. The factors including the flow rate, pH of the sample solution, ethanol concentration and pH of the desorbent were determined through dynamic adsorption. The results showed that macroporous resin D101 was the best to purify flavonoids from Potentilla fulgens. The optimal purifying conditions were as follows: the adsorption flow rate 2 BV/h, sample solution pH 4, desorbent pH 8, and 60% ethanol in the desorbent and the purity of flavonoids increased from 28.24% to 46.60%. The flavonoids were qualitatively identified using high performance liquid chromatography-electrospray tandem mass spectrometry (HPLC-ESI-MS/MS), according to retention time, molecular ions, and fragment ions in MS/MS. Favonoids quantitative analyzed by external and internal standard methods through multiple reactions monitoring (MRM) to monitor specific fragment ions and standard curves of three standard substances. The main components in the flavonoids and their contents were apigenin-7-O-β-D-glucuronide (6.66 μg/mg), hyperoside (2.39 μg/mg), astragalin (2.30 μg/mg), scutellarin (1.95 μg/mg), luteoloside (0.44 μg/mg), potengriffioside A (0.39 μg/mg), and isovitexin (0.01 μg/mg).
    44  Analysis of Volatile Compounds in the Processing of Instant Smoked Tilapia
    SHENG Jin-feng JIANG Yuan-xin LIU Xiao-ling
    2013, 29(12):3038-3045.
    [Abstract](1185) [HTML](0) [PDF 553.95 K](735)
    Abstract:
    In order to understand the change of volatile compounds during processing of instant smoked tilapia, the volatile compounds in fresh fish, smoked fish, smoked and salted fish, smoked and salted fish adding spice oil were identified by SDE-GC-MS. The results showed that 17, 35, 45 and 53 kinds of volatile compounds were detected in fresh fish, smoked fish, smoked and salted fish, and smoked and salted fish adding spice oil, respectively. Many phenolic substances were produced in the smoking process of the tilapia fillets, which mainly were guaiaco l,4-methyl-guaiacol, 4-hexyl-guaiacol, phenol; otherwise, aldehyde, ketone and acids rendering special smoking flavor. Salted processing had little effect to the product; adding spices oil endowed ester, phenolic and unsaturated olefins compounds, which had an obvious effect on flavor of products.
    45  Hydrogen Peroxide Biosensor Based on Graphene Modified Horseradish Peroxidase Electrode
    SUN Ying-en ZHANG Xiu-hua TAN Yun-bing WANG Lan-teng LIN Xu-zhang PIAO Jin-hua
    2013, 29(12):3046-3052.
    [Abstract](1531) [HTML](0) [PDF 722.00 K](789)
    Abstract:
    Graphite oxide was prepared by Hummers method. Graphene oxide was obtained from ultrasonic oscillation of graphite oxide and then reduced by using hydrazine hydrate to get graphene (GR). The results showed that the prepared graphene oxide enlarged interlamellar spaces compared to graphite which was from 0.33 nm to about 0.86 nm. The structure of graphene oxide contained many oxygen groups which resulted in the increase of interlamellar space and hydrophilism. After reducion, some oxygen groups disappeared. Hydrogen peroxide biosensor based on graphene modified horseradish peroxidase electrode was prepared by using graphene as enzyme carrier, chitosan (CS) as binder, thionine (Th) as electrical mediator and glass carbon (GC) as electrode matrix. Graphene and Th had the synergistic effect on HRP-GR-Th- CS/GC electrode. The cyclic voltammetric experiment results demonstrated that the current response of the biosensor was linear to hydrogen peroxide content ranging from 5.0×10-5 to 1.1×10-3 mol/L, with detection limit of 1.50×10-6 mol/L and apparent Michaelis-Menten constant ( ) of 6.55×10-5 mol/L. The biosensor has good detection performance especially for hydrogen peroxide thus can be used for detecting hydrogen peroxide content.
    46  Determination of Peroxide Value of Edible Oils Based on Electric Conductivity Change during Iodine Reaction
    YANG Yan-die CHEN Xiu-mei YU Xiu-zhu WANG Ya-ge
    2013, 29(12):3053-3058.
    [Abstract](1088) [HTML](0) [PDF 494.19 K](757)
    Abstract:
    Based on the principle of the decreased ion concentration in aqueous phase resulted from the iodine reaction, the electric conductivity (EC) instrument was used to detect the difference of EC from the reaction solutions thereby PV changes of common edible oils were obtained. The effects of testing temperature, standing time, oscillating time, stability of saturated solution of potassium iodide and types of the oil samples on determination of EC were studied. The PV calibration was established and then validated by iodometry method of Chinese national standards. The results indicated that the experimental conditions had no significant effects on the determination of EC at room temperature (25 ℃), and the calibration of PV was y=15.05x-0.0327, R2 = 0.9961. The validation suggested that the linear correlativity of the determination of PV between two methods was very well, where R2 was 0.9981, and the relative deviation of blind test was less than 10%. The results indicated that the method was effective to determine PV of edible oil.
    47  Chemical Composition of Volatile Oil by Supercritical CO2 Fluid Extraction from Macadamia ternifolia Flowers
    GUO Gang-jun WU Ying XU Rong LIU Chang-fen
    2013, 29(12):3059-3062.
    [Abstract](1169) [HTML](0) [PDF 493.76 K](693)
    Abstract:
    To analyze the chemical composition of volatile oil of macadamia ternifolia flowers and provide the scientific proof for further exploitation, the volatile oil was extracted by supercritical CO2 fluid in this paper. Their compositions and relative contents were quantitatively determined by GC-MS with peak area normalization method. Results showed that 50 chromatogram peaks from volatile oil of macadamia ternifolia flowers were isolated, and 43 volatile compounds were identified, which was accounted for 87.09% of total volatile compounds. These compounds included alkenes (2.66%), alcohols (18.44%), phenols (0.78%), aldehyde (13.91%), ketone (3.60%), esters (7.20%), acids (21.74%) and alkylene oxide (9.54%). The predominant volatile components were phenethyl alcohol (8.75%), 4-hydroxybenzaldehyde (6.88%), trans-linaloloxide (6.25%), phenylacetic acid (5.94%), α-phenylmethyl benzeneethanol (4.22%), benzyl alcohol (3.75%), cinnamic acid (2.19%), ethyl phenylacetate (1.72%), linalool (1.25%).
    48  Bioactivity, Synthesis, Extraction and Analysis of Sterol Ferulate: A Review
    LU Bai-yi YANG Jia-jia XIONG Li-na
    2013, 29(12):3063-3069.
    [Abstract](1545) [HTML](0) [PDF 607.03 K](888)
    Abstract:
    Sterol ferulate is a kind of plant sterol derivatives, including cycloartenyl ferulate, β- sitosteryl ferulate, stigmasteryl ferulate, campesteryl ferulate and dihydrogen sitosteryl ferulate etc., which is of phytocholesterol derivatives by dehydration reaction ofby ferulic acid and the hydroxyl group at C3 site of sterol. Sterol ferulate is the main existence of natural sterol mofetil, which widely exists in rice bran, corn, soybean, wheat and other grains. Some researchers have confirmed that it owns better biological activities than phytosterol and ferulic acid due to its structure of both phytosterol and ferulic acid. The review was briefly introduced its distribution, structure, physical and chemical properties, and biological activities in terms of cholesterol-lowering, anti-oxidant, anti-inflammatory, anti-tumor, and immuno-enhancement. Furthermore, the preparation methods of extracting from plants, chemical and biological synthesis were summerized, and the advantages and disadvantages about the detecting techniques by HPLC, GC and TLC were discussed. The advances and trends of sterol ferulate on preparation methods, detecting techniques, biological activities and mechanisms of action were proposed.

    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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