Volume 34,Issue 5,2018 Table of Contents

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  • 1  Modulation of Insulin Resistant in HepG2 Cells by Water Extracts and Ethanol Extracts from Bitter Melon
    ZHU Ying LUO Yuan-ping BAI Juan ZHANG Yi XIAO Xiang DONG Ying
    2018, 34(5):1-7. DOI: 10.13982/j.mfst.1673-9078.2018.05.001
    [Abstract](855) [HTML](183) [PDF 579.11 K](981)
    Abstract:
    In order to investigate the similarities and differences in the regulation of insulin resistance between water extracts (BMWE) and ethanol extracts (BMEE) from bitter melon on insulin resistant, the insulin resistance (IR) cell model was established in HepG2 cells induced by palmitic acid. Glucose consumption, glycogen, triglyceride (TG), ATP content and the mRNA expression levels of relative gene were determined. The results showed that BMWE and BMEE could significantly increase the glucose consumption and intracellular glycogen content of IR cells, and BMEE could significantly decrease TG content in cells (112.08% vs. 132.97%) and increase ATP content in cells (80.62% vs. 48.44%); BMWE and BMEE could increase insulin receptor substrate 1 (IRS1), phosphatidylinositol 3-kinase (PI3K), adenosine 5‘-monophosphate -activated protein kinase (AMPK) and carnitine palmitoyltransferase 1 (CPT1) mRNA expression, and could decrease acetyl-CoA carboxylase 2 (ACC2) mRNA expression; BMWE could also increase protein kinase B (AKT) mRNA expression. BMWE might improve insulin resistance by activating IRS1-PI3K-AKT signaling pathway in IR cells; However, BMEE could regulate glucose and lipid metabolism of IR cells through AMPK-ACC2-CPT1 signaling pathway, and their action pathways were different.
    2  Effects of Different Kinds of High Dietary Oil on the Blood Lipid, Liver Fat and Uric Acid in Mice
    ZHOU Hui-juan LIU Shui-ping YI Xiang-lian XIAO Hai-si ZENG Yu YAN Si-si WANG Ji WEN Li-xin
    2018, 34(5):8-13. DOI: 10.13982/j.mfst.1673-9078.2018.05.002
    [Abstract](721) [HTML](186) [PDF 450.27 K](803)
    Abstract:
    In order to investigate the effect of lard oil, vegetable oil and their blend oil on the blood lipid, liver fat and blood uric acid, in addition to assess the potential health risks for a particular population, the mice were used as a model to simulate the dietary habits of residents. Fifty of 8 weeks old male C57BL/6J mice were randomly divided into 5 groups as follows: sunflower seed oil group (SSO), soybean oil group (SO), lard oil group (LO), blend oil of lard and sunflower seed oil (SSO-L), blend oil of lard and soybean oil group (SO-L group), respectively. They were fed with 10.5% of different oils for simulating high daily average cooking oil intake (95 g/d) in the part of Chinese people (5%~10%). After 8 weeks, the blood and liver tissues were collected to measure serum and liver indexes. The results showed that compared with other groups, LO significantly increased the body fat rate and blood lipid levels (p < 0.05 and p < 0.01). SSO-L and SO-L significantly increased the liver fat compared with the corresponding SSO and SO, respectively (p < 0.05). At the same time, SUA and hepatic XOD levels in SSO-L and SO-L groups were significantly higher than those in LO group (p < 0.05). The result suggested that the lard oil could greatly increase the risk of obesity and fatty liver disease at a dietary oil intake of 95 g/d. The blend oil of lard and sunflower seed oil or soybean oil could also increase the risk of gout and fatty liver disease by raising the level of uric acid. In addition, the long-term intake of these two kinds of blend oil at this level also had obvious damage to the liver function. At this level of intake, soybean oil was a better choice.
    3  Effects of Composite Probiotics on the Gastrointestinal and Immune Function of Spleen Deficiency Syndrome Rats
    XIONG Hai-yan JIN Xin YANG Han-lin GAO Qin GE Ya-zhong PENG Ying LI Xiao-bo
    2018, 34(5):14-23. DOI: 10.13982/j.mfst.1673-9078.2018.05.003
    [Abstract](593) [HTML](232) [PDF 554.67 K](932)
    Abstract:
    ELISA kit was used to investigate the regulatory effects of different doses of composite probiotics and Sinijunzi Decoction on the levels of serum gastrointestinal hormones and immune factors in spleen deficiency syndrome rats induced by Folium Sennae. The results showed that both composite probiotics and the Sijunzi Decoction could significantly reduce the serum levels of vasoactive intestinal peptide (VIP) and malondialdehyde (MDA) (p < 0.05), while increase the interleukin-2 (IL-2) level in spleen deficiency syndrome rats (p < 0.05). The composite probiotics could also significantly reduce the levels of serum cholecystokinin (CCK), substance P (SP) and interleukin-4 (IL-4) in spleen deficiency rats (p < 0.05), while the Sijunzi Decoction had no significant effect. In addition, the Sijunzi Decoction could significantly decrease the content of serum gastrin (GAS) and motilin (MTL) in spleen deficiency rats (p < 0.01). The results showed that composite probiotics could regulate the levels of gastrointestinal hormone, as well as correcting immune dysfunction of spleen deficiency rats. Compared with the traditional prescription (Sijizitang decoction) for the treatment of spleen deficiency syndrome, the probiotics and Sijunzi decoction had different indicators of gastrointestinal hormones and immune factors, suggesting that the mechanisms of composite probiotics and the Sijunzi Decoction treating on spleen deficiency syndrome may be different.
    4  Isolation, Purification and Identification of Anti-tumor Bioactive Peptides from Chinemys reevesii
    SHI Yang ZHANG Yong-jin LAI Nian-yue LIN Lin JIANG Shao-tong LU Jian-feng
    2018, 34(5):24-31. DOI: 10.13982/j.mfst.1673-9078.2018.05.004
    [Abstract](577) [HTML](328) [PDF 674.22 K](799)
    Abstract:
    The Chinemys reevesii was selected as the raw material, and the inhibitory effect of the polypeptide of papain enzymatic hydrolysate on the proliferation of human breast cancer cell MCF-7 was identified as the activity detection index in this study to evaluate the cytotoxicity effects of extracted peptides by using MTT assay. The enzymatic hydrolysate was retained by ultrafiltration membrane with a molecular weight of 10 Ku first, and then, the active components were purified by sephadex G-75, sephadex G-50, and sephadex LH-60. The results of RP-HPLC spectrum indicated that a high-purity anticancer component, here named TP-1 was isolated and purified with an IC50 value of approximately 2.7 mg/mL, showing a significant dose-dependent and time-dependent anticancer effect, and little toxicity to normal cells. In addition, the physicochemical properties of TP-1 were characterized by ultraviolet, infrared and circular dichroism, and the molecular weight of the main component of the polypeptide was identified by mass spectrometry. The results manifested the existence of secondary structure of β-sheet, β-turn and random coil in TP-1, and the molecular weight of the principal component in TP-1 was about 1410.7 u. The research laid a solid foundation for further studies on anti-tumor mechanism of bioactive peptides from C. reevesii.
    5  Effects of Swelling Agent Treatment on the Polyphenol Content and Antioxidant Activity of Kiwifruit
    SHAO Pei ZHANG Zhao WANG Lin PENG Bang-zhu FENG Wu
    2018, 34(5):32-40. DOI: 10.13982/j.mfst.1673-9078.2018.05.005
    [Abstract](625) [HTML](264) [PDF 594.04 K](864)
    Abstract:
    The kiwifruit was used as the research object to determine the total phenols, total reducing ability, hydroxyl free radical scavenging rate, superoxide free radical scavenging rate and 2,2‘-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging rate of the kiwifruit in the control group and different swelling agent treatment groups (CPPU and TDZ). The effect of different swelling agent treatments (CPPU and TDZ) on the total phenols and antioxidant activity of Kiwifruit were determined forand screening out for their possible impact. The result showed that total polyphenols content and antioxidant activity of Kiwifruit could be reduced by TDZ treatment. In brief, the TDZ treatment had a significant effect on the total polyphenols content, total reducing capacity, hydroxyl radical scavenging rate and superoxide radical scavenging rate, had little effect on the ABTS+?scavenging rate. The result showed that the content of polyphenols was significantly reduced at the TDZ residual concentration of 0.04 mg/kg. The residual of TDZ more than 0.02 mg/kg could significantly reduce the total reducing power and hydroxyl radical scavenging capacity. The residual of TDZ more than 0.04 mg/kg could significantly reduce the ABTS+? scavenging capacity and superoxide radical scavenging capacity. And TDZ had a greater influence on the total reducing power and hydroxyl radical scavenging capacity, and had little effect on the ABTS+?scavenging capacity and superoxide radical scavenging capacity.
    6  The Nutritional Value and Basic physicochemical Properties of Bamboo Bean Albumin
    YAO Hai-xia QI Bin HUANG You-ru WANG Li-mei
    2018, 34(5):41-46. DOI: 10.13982/j.mfst.1673-9078.2018.05.006
    [Abstract](1448) [HTML](597) [PDF 591.12 K](889)
    Abstract:
    The bamboo bean albumin was prepared by Osborne procedure in this study, and its amino acid composition, subunit molecular weight, thermal properties and the secondary structure were preliminarily studied using automatic amino acid analyzer, reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FT-IR), respectively. The results showed that bamboo bean albumin had abundant and comprehensive essential amino acids, belonging to a kind of high quality plant protein. Bamboo bean albumin contained nine subunits confirmed by SDS-PAGE, and the main subunits were distributed in 49.6 ku and 27.6 ku. Thermal analysis showed that the bamboo bean albumin had the highest denaturation temperature (Td) of 100.6℃ at pH = 7.0. And it had the highest degeneration enthalpy (ΔH) of 3.40 J/g at pH = 5.0. The fourier transform infrared spectroscopy showed its secondary structure was as follows: the proportion of beta angle was the highest (33.59%), followed by beta folding (31.38%), alpha helix (17.97%) and random coil (17.07%). Studies showed that bamboo bean albumin had rich nutritional value, wide molecular weight distribution, strong thermal stability, and highly ordered and stable structure, which provided a theoretical basis for subsequent research on the functional properties and application of bamboo bean albumin.
    7  Effects of Different Preservatives on the Quality of Mulberry during Storage
    ZHANG Li-hui QIAO Yu CHEN Xue-ling LV Hong-xia LIU-Lu DING An-zi SHI Liu WANG Chao LIAO Li
    2018, 34(5):47-55. DOI: 10.13982/j.mfst.1673-9078.2018.05.007
    [Abstract](637) [HTML](186) [PDF 629.09 K](887)
    Abstract:
    In order to improve the storage quality of mulberry, the garlic extract, chitosan coating, linalool, carvacrol, eugenol and 1-MCP (1-methylcyclopropene) were used as slow-release preservatives on the mulberry processing to investigate the change of quality during storage. The experimental results showed that with the extension of storage time, the nutritional components and sensory quality of mulberry gradually decreased. After the treatment of six kinds of preservative, the soluble solids, titratable acid, reducing sugar, Vc and other nutrients were significantly higher than the control group (p<0.05), and it could effectively reduce the rotting rate and the weight loss rate of mulberry, inhibit the increase of malondialdehyde (MDA), delay the decrease of polyphenol oxidase (POD) and superoxide dismutase (SOD) activity. Among them, the rotting rate, weight loss rate, soluble solids, titratable acid, Vc content and MDA, POD and SOD activity as well as other quality indicators of mulberry treated with linalool during the storage (9 D) were better than the other preservative, which could inhibit the corruption of mulberry to the greatest extent.
    8  Effects of N2O Fumigation on Postharvest Quality of Munage Grapes
    XU Jing ZHANG Lei WEI Jia ZHANG Zheng WU Bin LI Xue-ping
    2018, 34(5):56-61. DOI: 10.13982/j.mfst.1673-9078.2018.05.008
    [Abstract](655) [HTML](278) [PDF 546.13 K](729)
    Abstract:
    Munage grapes were of good quality, but the postharvest grapes were prone to a series of problems such as weight loss, softening, grain dropping and fruit stem browning. In order to investigate the effects of nitrous oxide (N2O) fumigation on postharvest storage quality of Munage grapes,, Xinjiang (Vitis vinifera L.) cv Munage grapes were fumigated in different concentration of N2O (20, 50 and 100 μL/L) every 7 days, thereafter stored in the cold room (0 ± 0.5℃, 90~95% RH) for 70 d. The changes of decay rate, shattering rate, weight loss rate, hardness, titratable acid, soluble solids, conductivity, ascorbate peroxidase (APX) and peroxidase (POD)were measured during storage. The results showed that 50 μL/L of N2O fumigation could maintain the content of soluble solids and titratable acid and effectively inhibit the increase of decay rate, shattering rate and relative conductivity. In addition, N2O also decreased the activity of POD and APX, which significantly remained the hardness of grape. It demonstrated that N2O fumigation could delay senescence of the harvested fruit and could better maintain the postharvest quality of the Munage grapes.
    9  Comparsion of Nutrient Components and Antioxidant Activities of Fruit Body and Mycelium from Ramaria botrytoides
    SHENG Zhi-cun WU Shuang WANG An-ping WANG Mi-xue ZHU Shan-yuan
    2018, 34(5):62-67. DOI: 10.13982/j.mfst.1673-9078.2018.05.009
    [Abstract](711) [HTML](218) [PDF 433.69 K](680)
    Abstract:
    The content of nutrient components of fruit body and mycelium from Ramaria botrytoides were investigated in this study by national standards and common methods, and the content of active substances (polysaccharides and polyphenols) and their antioxidant activities were also evaluated. The results showed that the carbohydrate content of fruit body and mycelium was 38.74±1.27% and 63.55±3.17%, the fat content was 2.52±0.14% and 3.21±0.19%, the protein content were 11.02±1.21% and 22.30±1.18%, and the ash content was 5.77±0.14% and 5.98±0.11%, respectively. Except Mg, the content of mineral elements in fruit body was generally higher than that in mycelium, and the content of essential amino acids in mycelium (7.08±0.15)g/100 g) was higher than that in fruit body((2.55±0.24) g/100g). In addition, the content of polysaccharides in mycelium ((35.51±1.78) mg/g) was higher than that in fruit body ((23.22±1.60) mg/g) while the content of polyphenols in fruit body ((6.85±0.41) mg/g) was higher than that in mycelium ((3.66±0.29) mg/g). The antioxidant activities of polysaccharides and polyphenols from fruit body and mycelium were in the following order: polyphenols from fruit body> polyphenols from mycelium> polysaccharides from mycelium> polysaccharides from fruit body. The results indicated that the polysaccharides from fruit body were expected to be replaced by the polysaccharides from mycelium in medicine and food, and the polyphenols from mycelium would still need further development and utilization.
    10  Effects of Heat and Calcium Treatments on the Storage Effects of Ziziphus jujubevc. Zhongqiusucui
    TANG Yan WANG Sen YAN Zhong-peng SHAO Feng-xia ZHANG Ping
    2018, 34(5):68-75. DOI: 10.13982/j.mfst.1673-9078.2018.05.010
    [Abstract](673) [HTML](200) [PDF 643.00 K](844)
    Abstract:
    In order to explore the preservation method of Ziziphus jujubevc. Zhongqiusucui, and prolong the preservation time of Ziziphus jujubevc. Zhongqiusucui under refrigerated conditions, different temperatures of hot water (45℃, 50℃, 55℃ and 60℃) and different CaCl2 concentration (3%, 4% and 5%) solutions were used to soak the fresh ziziphus jujubevc. Zhongqiusucui for 20 min, and the hardness, soluble total sugar, reducing sugar and MDA content of jujube fruit were measured every 21 days. The jujube soaked in hot water at 40℃, 50℃ and 55℃ for 20 min, the fruit hardness and Vc content were significantly higher than those of the control during storage, and could significantly affect the content of two kinds of sugar in jujube fruit and could also inhibit the increase of MDA content in jujube fruit; The three kinds of CaCl2 soaking treatments had a significant effect on the Vc content of jujube and could slow down the decrease of hardness of jujube during storage. Jujube fruits treated with 3% CaCl2 had the lowest MDA content during storage. During storage, the fruit hardness of jujube fruit was significantly positively correlated with Vc content, reducing sugar content and MDA content. Ziziphus jujubevc. Zhongqiusucui hot water pretreatment optimum temperature was 55℃, and CaCl2 soaking the appropriate concentration was 3%. The fresh fruits of these two treatments had better preservation effect.
    11  Genome Sequencing of Vibrio parahaemolyticus Strain 229 and Annotation of Its Pathogenic Factors
    LIN Yi-ying PAN Li WU Qing-ping WANG Bin
    2018, 34(5):76-80. DOI: 10.13982/j.mfst.1673-9078.2018.05.011
    [Abstract](518) [HTML](253) [PDF 483.62 K](708)
    Abstract:
    In this study, vibrio parahaemolyticusisolate 229 isolated from frozen sea fish was carried out by genome sequencing, and gene annotation was performed by gene functional analysis to elucidate its pathogenic factors, which could provide clues and genome-scale data for investigating its pathogenic mechanism. We have accomplished the genome sequencing of V. parahaemolyticus 229 and assembled its genome using the obtained paired-end sequencing reads generated on the Illumina Hiseq 2000 Genome Analyzer. The assembled genome was 4.97 Mb in size with GC content of 43.90%. 4,940 protein coding sequences (CDSs) were predicted by gene prediction, of which 1,304 CDSs were annotated with GO function. WEGO illustration revealed that a series of CDSs might play important roles in theinvasion of the host of V. parahaemolyticus and subsequent metabolic processes. And an array of pathogenic virulence factor genes were annotated including hemolysin and Type III secretion system, which were gathered in different contigs and might act as independent pathogenic factors. The assembled genome and functional annotation of V. parahaemolyticus 229 could provide valuable information for further investigating the genetic basis of its pathogenicity.
    12  Study on the Mitochondrial Protection of Stichopus japonicus Polysaccharides by Scavenging Reactive Oxygen Species
    ZHANG Hong-ling WEI Hao-hua LI Xing-tai
    2018, 34(5):81-86. DOI: 10.13982/j.mfst.1673-9078.2018.05.012
    [Abstract](501) [HTML](233) [PDF 429.99 K](723)
    Abstract:
    Stichopus japonicus polysaccharides (SJP) were extracted by enzymatic hydrolysis (pepsin and trypsin), polysaccharide content was determined by phenol/sulfate method and the possible mechanism of scavenging reactive oxygen species (ROS) for SJP to protect mitochondria were investigated in this study. The hepatic mitochondrial lipid peroxidation was induced by Fe2+-Vit C system, malondialdehyde (MDA) was used as an index to determine the effect of SJP on lipid peroxidation; effects of SJP on the reducing power and Fe2+ chelating were measured; the scavenging activity of SJP on the hydroxyl radical (·OH) which was produced by H2O2-Fe2+ system was measured; the method of titration and the method of nitrogen blue tetrazolium (NBT) were used to measure the scavenging activity of SJP on the hydrogen peroxide (H2O2) and superoxide anion (O2·−), respectively. The results showed that SJP could inhibit the production of MDA; SJP had a certain reducing power and weaker Fe2+ chelating activity. In addition, SJP could scavenge ?OH, H2O2 and O2·− within a certain concentration range. SJP could protect mitochondria through anti-oxidation and scavenging reactive oxygen species (ROS), which had the effect of protecting the body. This was the possible mechanism of SJP to protect mitochondria.
    13  Characteristics Analysis of Esterifying Enzyme of Different Flavor Daqu
    XING Shuang WEI Zhi-yang GUO Xue-wu WANG Ya-ping CHEN Bing-xu LI Qiu-zhi XIAO Dong-guang
    2018, 34(5):87-92. DOI: 10.13982/j.mfst.1673-9078.2018.05.013
    [Abstract](631) [HTML](250) [PDF 513.12 K](902)
    Abstract:
    The different characteristics of esterifying enzyme catalytic synthesis of ethyl acetate, ethyl lactate, ethyl hexanoate and ethyl butyrate in light-flavor Daqu, strong- flavor Daquand maotai-flavor Daqu were studied in this paper under the different acid concentration (or pH). The results showed that the esterifying enzymes activities of three kinds of Daqu increased at first and then decreased with the increase of acid concentration in catalyzing and synthesizing ethyl acetate, ethyl caproate, the enzyme activity decreased with the increase of lactic acid concentration in catalyzing and synthesizing ethyl lactate. However, the variation tendency of enzyme activity was different in three kinds of Daqu in catalyzing and synthesizing ethyl butyrate. As the butyric acid increased, the enzyme activity of light-flavor Daqu and strong- flavor Daqu increased at first and then decreased, while the enzyme activity of maotai-flavor Daqu increased gradually. For light-flavor Daqu, strong- flavor Daqu and maotai-flavor Daqu, the optimum pH in catalyzing and synthesizing ethyl acetate all were 4.0; the optimum pH in catalyzing and synthesizing ethyl lactate were 7.0, 7.0, 8.0, respectively; the optimum pH in catalyzing and synthesizing ethyl caproate were 5.0, 4.0, 4.5, respectively; the optimum pH in catalyzing and synthesizing ethyl butyrate were 4.5, 4.0, 3.0, respectively. In conclusion, the characteristics of esterifying enzymes of three kinds of Daqu were different, and the synthesis of eash ester had its proper acid concentration and pH range.
    14  Transcriptome Data assembly and Gene Function Annotation of Buds and Leaves of Camellia sinensis Cultivar Jing’anbaicha
    LI Ming-xi WANG Min GAN Yu-di LIU Yang HUANG Ying-jie WAN Chun-peng
    2018, 34(5):93-100. DOI: 10.13982/j.mfst.1673-9078.2018.05.014
    [Abstract](685) [HTML](341) [PDF 821.66 K](801)
    Abstract:
    Plant metabolites such as tea polyphenols, theanine, with extensive health benefits, are extremely rich in tea tree. Flavonoids are the main component of tea polyphenols, while glutamine is the precursor substance of the synthesis of theanine. This study attempted to elucidate the related genes of the metabolisms of tea polyphenols and theanine of Jing’an white tea. Fresh buds and leaves of Camellia sinensis cultivar Jing’anbaicha were selected as samples, the transcriptome was constructed using Illumina HiSeqTM 4000 sequencing technique and the data were analyzed using the bioinformatics methods subsequently. 100568 unigene sequences were obtained with length of 95121064 bp. Gene function annotations analysis showed that 32530 annotations were acquired from Nr database, 30087 annotations were acquired from KOG database, 29010 annotations were acquired from GO database, 24553 annotations were acquired from Swiss-Prot database, 18576 annotations were acquired from Pfam database, respectively. The key differences unigene sequences related to the metabolic pathway of flavonoids and glutathione in Jing’an white tea buds and leaves were explored through the GO analysis and the KEGG metabolic pathway analysis. This study could provide references for further study of the biosynthesis regulation of tea polyphenols and theanine in Jing’an white tea.
    15  Synthesis of Cinnamic Alcohol Ester Catalyzed by Candida Antarctica Lipase B-Displaying Pichia Pastoris Whole-cells in Solvent-free System
    XU Xiao-min HUANG Kui HAN Shuang-yan
    2018, 34(5):101-107. DOI: 10.13982/j.mfst.1673-9078.2018.05.015
    [Abstract](613) [HTML](244) [PDF 556.58 K](762)
    Abstract:
    Cinnamic alcohol ester were synthesized with cinnamic alcohol in solvent-free system using Candida antarctica lipase B-displaying Pichia pastoris whole-cells as catalyst and fatty acids as acyl donors. The selectivity of Pp-CALB for acyl donors was investigated, and the reaction temperatures, agitation speeds, enzyme dosage, molar ratio of substrates, initial water activity of Pp-CALB and reaction system were optimized to establish enzymatic synthesis process of cinnamyl alcohol ester in solvent-free system . The optimal reaction conditions were as follows: reaction temperature was 50 ℃, molar ratio of acid to alcohol was 2:1, agitation speed was 120 r/min, initial water activity of Pp-CALB was 0.53, and enzyme loading was 0.05 g. The reaction conversion reached 81.34% under the optimal conditions sysnthsized for 3 h, which could still reach more than 70.00% after 10 cycles of continuous reaction with Pp-CALB, indicating the good operational stability.
    16  Change and Control of Palm Oil Index in the Frying Process of Dace
    CHEN Sui XU Ting CUI Peng-ju
    2018, 34(5):108-112. DOI: 10.13982/j.mfst.1673-9078.2018.05.016
    [Abstract](587) [HTML](414) [PDF 476.90 K](722)
    Abstract:
    The change of palm oil index during the frying process of dace was evaluated by sensory and physicochemical analysis in this study, and the "Dalsorb adsorbent + plate filtration" method was used for palm oil treatment after frying. Results show that with the increase of frying time, the color of palm oil was gradually deepened, the liquidity and transparency were gradually degraded, and a large amount of fish dregs appeared. The acid value (from 0.06 mg KOH/g to 2.34 mg KOH/g), carbonyl value (from 3.64 meq/kg to 17.70 meq/kg) and polar component (3.07% to 15.1%) of palm oil increased with the increase of frying time, and there was no obvious change in the peroxide value. The change of acid value and polar component was closer to the upper limit of the national standard and could be used as evaluation index. In addition, the online monitoring should be mainly based on acid value index due to the reason for long detection time of the polar component. The "Dalsorb adsorbent + plate filtration" method could significantly reduce the acid value (from 2.36 mg KOH/g to 1.50 mg KOH/g), and the changes of carbonyl value and polar components were not obvious.
    17  Study on Solution Properties of a Novel Surfactant of Citric Acid Monoester and Its Application in Oleogel
    HUANG Di JIANG Ting WANG Wen-juan YU Ding-hua
    2018, 34(5):113-122. DOI: 10.13982/j.mfst.1673-9078.2018.05.017
    [Abstract](659) [HTML](339) [PDF 709.90 K](862)
    Abstract:
    Oleogel is not only widely used in functional foods, but also has important application prospects in the fields of pharmaceutical preparations and cosmetics. Two citric acid monoesters were synthesized by direct esterification, and their properties of gel were studied in this paper. The solution aggregation behavior and micellar thermodynamics of these two citric acid monoesters were analyzed by surface tension meter, conductivity meter and dynamic light scattering instrument, and the results showed that the critical micelle concentrations of lauryl citric acid monoester and isodecyl citric acid monoester at 25 oC were 3.30 mmol/L and 6.40 mmol/L, respectively. In addition, the effects of ionic strength on the formation of micelles were also studied, and the results showed that inorganic salts not only affected the aggregation number of micelles, but also reduced the micelle size of isodecyl citric acid monoester and lauryl citric acid monoester by about 10 nm and 200 nm. The studies of oleogel properties indicated that both of the two citric acid monoesters could form the gel with vegetable oil. The minimum concentration was 7% and the temperatures of the sol-gel transition were all between 45~53 oC. Also, the results of biocompatibility studies showed that the two citric acid monoesters had no significant effect on the growth of microorganisms at a concentration of 200 mg/L, indicating that the citric acid monoesters had good biocompatibility.
    18  Preparation of Hydrophobic Porous Starch and Its Oil Absorption Properties
    HUANG Qiang LIN Xiao-ying CAO Ya-fei ZHANG Bin
    2018, 34(5):123-129. DOI: 10.13982/j.mfst.1673-9078.2018.05.018
    [Abstract](795) [HTML](233) [PDF 667.58 K](1483)
    Abstract:
    Hydrophobic porous starch was successfully prepared in this paper by the combination of enzymatic hydrolysis pretreatment, octenyl succinic anhydride (OSA) modification and Al3+ cross-linking. The effects of enzyme addition amount on the structure, physicochemical properties, and the oil absorption capacity of hydrophobic porous starch were studied. Results showed that the synergistic treatment of α-amylase and amyloglucosidase made holes on the surface structure of corn starch granules, and the porous starch was formed. Under the same OSA addition, the degree of substitution of the hydrophobic porous starch decreased with the increase of enzyme dosage. The results of laser confocal microscope showed that the octenyl succinic acid (OS) groups were distributed throughout the particles after esterification, and the OS groups tended to distribute inside the hydrophobic porous starch granules with the increase of hydrolysis rate. In addition, the oil absorption rate of hydrophobic porous starch increased with the increase of hydrolysis rate, and the maximum oil absorption rate could be 52.30%. The adsorption rates of corn oil, engine oil and diesel oil were 80.41%, 52.30% and 41.93%, respectively. In the oil-water system, the water absorption rate was only about 6%, indicating good oil-water selectivity and oil retention ability were realized.
    19  Optimization of Decolorization Treatment for Yeast Fermentation Wastewater by High-Density Inoculation of Coccomyxa subellipsoidea C-169
    YU Zong-yi YAN Wen-jun WEI Dong
    2018, 34(5):130-135. DOI: 10.13982/j.mfst.1673-9078.2018.05.019
    [Abstract](651) [HTML](214) [PDF 508.20 K](708)
    Abstract:
    This paper investigated the optimal parameters for high-density inoculation of Coccomyxa subellipsoidea C-169 under different nutritional conditions in yeast fermentation wastewater. The effects of inoculation density and wastewater concentration on the growth of C-169 and the treatment of yeast wastewater were systematically compared. Results showed that C-169 could use glucose and sucrose for heterotrophic and mixotrophic cultivation. Under cultivation conditions, the growth rate of C-169 was the fastest and the optimal glucose concentration was 20 g/L. The effects of culture conditions (inoculation density and initial wastewater concentration) on the growth of C-169 and the treatment of yeast wastewater were studied by single-factor experiments , and the optimal culture conditions were as follows: the initial inoculum density was not less than 1 g/L, and the dilution rate of decolorization wastewater was 2 times. Under this condition, the biomass yield of C-169 was 0.23 g/(L·d), and the removal rate of COD (chemical ocygen demand), total nitrogen and total phosphorus in decolorization wastewater were 49.54%, 70.39%, 98.09%, respectively. Consequently, this study illustrated that C-169 had great potential for the purification of yeast wastewater under algal-bacterial coexistence conditions.
    20  Separation and Purification of the Antioxidant Compounds from Gutian Red Yeast Rice
    ZHANG Hong-lin LI Gui-ling SU Guo-cheng LIU Jing-wen LI Jian
    2018, 34(5):136-142. DOI: 10.13982/j.mfst.1673-9078.2018.05.020
    [Abstract](726) [HTML](217) [PDF 563.04 K](885)
    Abstract:
    The antibacterial and antioxidant activities of red yeast rice from different areas were investigated in this paper, and the results showed that the antibacterial activity of Gutian red yeast rice was slightly stronger than that of the red yeast rice from other regions. The active compounds of Gutian red yeast rice were extracted with methanol by gel column chromatography, reversed phase and positive phase silica gel column chromatography, and then were analyzed by nuclear magnetic resonance spectrum and mass spectrometry. Results indicated that the bacteriostatic effects were different for different organic solvent extracts, and the overall order of bacteriostatic effects for extracts (under the same concentration) was as follows: bacillus subtilis >E. coli > aspergillus Niger>tower bin aspergillus >brewers yeast. In antioxidant experiment, the antioxidant activity of Gutian red yeast rice was stronger than others. In addition, the antioxidant activities of ethyl acetate extract, 50% water-50% methanol extract and 0% water-100% methanol extract of Gutian red yeast rice were also stronger. Finally, two compounds with certain antioxidant and antitumor a ctivities were identified as alpha linolenic acid and linoleic acid and were successfully separated and purified from red yeast rice.
    21  Effects of Enzyme-Extrusion Composite Technology on the Preparation and Properties of High Amylose Starch-based Materials
    LIU Peng ZHOU Fu-jin LIU Xiao-tong CHEN Ying-chao
    2018, 34(5):143-147. DOI: 10.13982/j.mfst.1673-9078.2018.05.021
    [Abstract](559) [HTML](294) [PDF 525.08 K](826)
    Abstract:
    The materials prepared by high amylose starch have good properties and applications. But the melt viscosity of high amylose starch is poor and extrusion processing energy consumption is high. In this paper, the tolerance of enzyme in extrusion environment and the effects of the addition and the extrusion time on the mechanical energy and the mechanical properties of materials were investigated used the enzyme-extrusion composite technology. The results showed that the thermostable α-amylase could maintain enzyme activity in the extrusion environment under high temperature, high pressure, and high shearing force. Besides, they could improve the phase transition of high amylose granules, promote the extrusion processing, and then reduce the extrusion time and decrease the mechanical energy. Specifically, the specific mechanical energy of G50 high amylose starch could decrease by 21 %, and the tensile strength and elongation of materials were also reduced by 33 % and 83%, respectively when the addition of enzyme was only 0.25 % of starch (dry weight).. . On the other hand, the thermostable α-amylase had no significant effect on the extrusion of G80 high amylose starch. These results illustrated that the synergistic effects of enzyme-extrusion composite technology could conserve the extrusion processing energy of high amylose starch and reduce extrusion time. Moreover, enzymatic hydrolysis could increase the active site and reaction efficiency of starch, which was beneficial to the starch reaction extrusion.
    22  Optimization of Supercritical CO2 Extraction of Essential Oil from Sarcodon Aspratus by Response Surface Methodology and Analysis of Its Volatile Compounds
    MIAO Xiao-yu GU Da-hai WANG Gui-ying XU Zhi-qiang WANG Xue-feng CHENG Zhi-bin FAN Jiang-ping PU Yue-hong LIAO Guo-zhou GE Chang-rong
    2018, 34(5):148-157. DOI: 10.13982/j.mfst.1673-9078.2018.05.022
    [Abstract](719) [HTML](214) [PDF 682.52 K](929)
    Abstract:
    Using Sarcodon aspratus as the raw material, supercritical carbon dioxide (SC-CO2) extraction method was employed to extract the essential oil in Sarcodon aspratus. Based on the single factor experiment, the CO2 flow rate was set at 25 kg/h, the particle sizes-mash was 40 meshes and material mass was 800 g. The mathematical model was established by the response surface methodology (RSM) to determine the optimal process conditions. The extraction pressure, temperature and time were used as the Box-Behnken design variables. The response rate of the extract of Sarcodon aspratus oil was the response value. The results showed that the extraction yield of Sarcodon aspratus oil was 4.18 ± 0.46% when the extraction pressure was 33 MPa, extraction temperature was 55℃ and extraction time was 145 min, which was close to the theoretical value (4.23%). Moreover, gas chromatography coupled to mass spectrometry (GC-MS) analysis was carried out to analyze the volatile components of the essential oil of Sarcodon aspratus. The qualitative analysis was confirmed by manual analysis and the National Institute of Standards and Technology (NIST) library. A total of 77 kinds of volatile compounds and the peak were detected. The area normalized method was used to calculate the relative percentage of each compound. The compound content accounted for 68.868% of the total area, of which the main components were acids (28.09%), aldehydes (18.77%), oxygen heterocyclic ring (5.13%), hydrocarbons (4.90%), phenols (4.37%), alcohol (4.02%), ketones (3.61%), etc. 2-methyl-hexanoic acid (19.46 ± 0.81%) and benzaldehyde (6.86 ± 0.17%) were comparatively rich in the essential oil of Sarcodon aspratus.
    23  Identification, Safety Evaluation and Fermentation Techonlogy of High Efficient Free Gossypol-Degrading Strains
    QI Xiu-ye XIE Quan-xi YU Jia-min ZHAO Qian ZHANG Zhi-yan XU Hai-yan
    2018, 34(5):158-166. DOI: 10.13982/j.mfst.1673-9078.2018.05.023
    [Abstract](845) [HTML](198) [PDF 577.25 K](838)
    Abstract:
    The cottonseed meal fermented by Bacillus was used in this study to investigate the effects on the degradation rate of free gossypol in cottonseed meal, as well as the effects on the nutrient components before and after fermentation, such as viable count bacteria, neutral proteases activity and acid-soluble protein content.. In addition, the strains with better fermentation effects were used for identification, and safety analysis and fermentation techonlogy were also performed. The results showed that the Bacillus subtilis, which could efficiently degrade the free gossypol and improve the nutritional quality of cottonseed meal, was BLCC1-0039, and the free gossypol was determined by high performance liquid chromatography. The BLCC1-0039 was preliminarily identified as the Bacillus subtilis by the morphology, and by the biochemical characteristics combined with 16S rDNA sequence. Thein vivo safety evaluation of B.BLCC1-0039 showed that no morphological and activity abnormalities appeared for the mice used, and no organ lesions were observed, which preliminarily suggested the safety of B.BLCC1-0039. Also, the fermentation induced by B.BLCC1-0039 could effectively reduce the content of free gossypol in cottonseed meal and improve the neutral proteases activity and acid-soluble protein content, the acid soluble protein was 26.96%, the activity of neutral protease was 3897 U/g and the degradation rate of free gossypol was 97.81% after fermentation for 48 h.
    24  Effects of Enzymolysis Conditions on the Betacyanin Content and Juice Yield of Pitaya
    LUO Jin LIU Fang-mei ZHAO Lei WANG Kai HU Zhuo-yan
    2018, 34(5):167-173. DOI: 10.13982/j.mfst.1673-9078.2018.05.024
    [Abstract](1006) [HTML](260) [PDF 639.06 K](851)
    Abstract:
    In order to improve the retention rate of betacyanin and the juice yield of red pitaya juice prepared by enzymatic hydrolysis, the effects of enzyme concentration, enzymolysis time, enzymolysis temperature and substrate pH on the stability of betacyanin, juice yield and transmittance of pitaya juice were investigated. Based on the results of single-factor experiment, the Box-Behnken design and response surface analysis were used to optimize the enzymatic preparation conditions of red pitaya. The retention rate of red pitaya juice was used as the important index, and the transmittance of red pitaya were also used as response values. The function optimized the multi-objective approach and optimized the technological conditions for the preparation of red pitaya juice by enzymatic method. The results showed that when the enzyme concentration was 285 U/g, the enzymolysis temperature was 46 °C, the pH of the substrate was 3.7, and the enzymolysis time was 2 h, the retention rate of betacyanin in red pitaya juice could reach 80.8%, the juice yield could reach to 64.4% and the juice transmittance was 89.5%. The obtained enzymolysis process parameters could meet the higher retention rate of betacyanin of red pitaya juice , and also had higher juice yield and light transmittance. The experimental verification showed that the experimental value was consistent with the prediction.
    25  Optimization of Extraction Process of Polyphenols from Kumquat by Response Surface Methodology
    YANG Cong-ying LUO Ya-li GUO Shi-yin XIAO Hang RAO Li-qun TANG Zhong-hai
    2018, 34(5):174-181. DOI: 10.13982/j.mfst.1673-9078.2018.05.025
    [Abstract](563) [HTML](219) [PDF 513.98 K](824)
    Abstract:
    The optimum extraction process of polyphenols from Kumquat was investigated. Based on singe factor experiments (extract time, extract concentration, ratio of liquid to material, etc.), the extraction conditions of free polyphenols and bound polyphenols in kumquat were optimized by response surface methodology using polyphenol content as response value. The results showed that the established regression models of the free polyphenols and bound polyphenols of kumquat were significant and it could be used to predict the yield of free polyphenols and bound polyphenols. The optimum extraction conditions of free polyphenols were as follows: the acetone concentration of 77%, the liquid to material ratio of 33 mL/g; the extraction time of 48 min. The average free polyphenol content under this condition was 11.03 mg/g DW. The optimum extraction conditions of bound polyphenols were as follows: the NaOH concentration of 6.5 mol/L; the liquid to material ratio of 10 mL/g; the extraction time was 18 h. Under these optimized conditions, the yield of bound polyphenols reached 1.79 mg/g DW. The content of free polyphenols and bound polyphenols under optimal conditions were well matched with the model predicted yield, indicating that the optimized extraction process of free and bound polyphenols from kumquat was reasonable.
    26  Effect of Different Modifier and Fermentation Time on the Quality Characteristics of Potato Powder Noodle
    WANG Li LI Shu-rong JU Rong-hui WANG Hui LIU Xiao-fei JIA Hong-liang PAN Yan WANG Chang-gang
    2018, 34(5):182-188. DOI: 10.13982/j.mfst.1673-9078.2018.05.026
    [Abstract](888) [HTML](284) [PDF 586.25 K](794)
    Abstract:
    Different modifiers and appropriate fermentation time were used to improve the quality of potato powder noodles. The effects of gluten, sodium alginate, table salt and fermentation time on the organoleptic quality, texture characteristics and cooking characteristics of noodles were investigated. Experiment results showed that modifiers and appropriate fermentation time could significantly improve the quality of noodles. Suitable adding amount of gluten, sodium chloride and sodium alginate as well as proper fermentation time could increase the sensory quality, hardness and elasticity of noodles, and decrease the cooking lose rate of noodles. The sensory quality was affected by the four methods in the order of fermentation time > sodium alginate > gluten > table salt, the hardness followed the order of sodium alginate > fermentation time > table salt > gluten, the cooking lose rate followed the order of fermentation time > table salt > gluten > sodium alginate. When the fermentation time was 15 to 60 min, the sensory quality, hardness, adhesiveness and cooking lose rate of the noodles were significantly improved. When the gluten powder was added in an amount of 1% to 3%, the sensory quality, hardness, cohesiveness, elasticity and cooking lose rate was improved. As a result, the sensory quality, texture properties, and cooking quality of potato powder noodle was improved by suitable fermentation time and modifier.
    27  Optimization of Composite Modifier Process for Fruit and Vegetable Juice of Beef by Response Surface Methodology
    HUANG Cai-yan ZHANG Song-shan LEI Yuan-hua DONG Chao XIE Peng WANG Huan HAN Ling YU Qun-li TANG Hong-tao SUN Bao-zhong
    2018, 34(5):189-197. DOI: 10.13982/j.mfst.1673-9078.2018.05.027
    [Abstract](562) [HTML](209) [PDF 822.18 K](766)
    Abstract:
    Fruit and vegetable juice were used to improve the tenderness and prolong the shelf life of beef. Six twenty-month old Jin Jiang yellow cattles were selected, and their longissimus were taken as experimental materials after slaughter. the single factor experiment was carried out with the added tomato juice at 4%, 8%, 12%, 16% and 20%, respectively, ginger juice at 2%, 4%, 6%, 8% and 10%, respectively, kiwi fruit juice at 3%, 6%, 9%, 12% and 15%, respectively, papain juice at 5%, 10 %, 15%, 20% and 25%, respectively. Based on the single factor experiment, the pH, TVB-N (tomato and ginger processing group), tenderness (kiwifruit and papaya processing group) and sensory scores (storage at 3 d) were used as indicators to get the optimal conditions by response surface methodology. According to the Box-Behnken response surface optimization test, the optimum ratio of the composite vegetable and fruit modifying agent was 11.10% tomato, 6.53% ginger, 6.70% kiwifruit and 10.15% papaya juice, and the sensory score of beef was 95.10. The addition of tomato, ginger, kiwi and papaya significantly affected the sensory score of beef. Fruit and vegetable juice composite modifier optimized by response surface methodology was effective. It could be used as a kind of natural food additive to improve beef quality and prolong the shelf life.
    28  Preparation of Raloxifene Antibody and Preliminary Establishment of Enzyme-Linked Immunosorbent Assay
    TONG Ya-qi ZHANG Yu WU Jin-e CHANG Chao
    2018, 34(5):198-203. DOI: 10.13982/j.mfst.1673-9078.2018.05.028
    [Abstract](488) [HTML](192) [PDF 470.84 K](748)
    Abstract:
    The preparation of raloxifene antibody and the establishment of enzyme-linked immuno sorbent assay (ELISA) were mainly studied in this paper. Succinic anhydride was used for the raloxifene derivative and the raloxifene haptens were formed. The immunogen and inclusion antigen were synthesized by coupling the raloxifene hapten with bovine serum albumin (BSA) and ovalbumin (OVA) using the carbodiimide method, and then determined by UV spectroscopy. Results showed that raloxifene was successfully coupled with the carrier protein. Raloxifene- bovine serum albumin (Ra-BSA) was used to immune New Zealand white rabbits, and the antibodies showed a titer of 1.28×105 and a IC50 of 15.4 μg/L. There was no cross reaction with other anti-estrogens, indicating that the antibody specificity was good. The raloxifene ELISA method was initially established by optimizing the reaction concentration of antigen antibody, and the optimal conditions were as follows: antigen concentration, 300 μg/L, antibody concentration, 1:1.0×105. The standard curve was good (R2=0.9853) in the range of 0.4~102.4 g/L with a lowest detection limit, 0.4 μg/L. This research provided a technical reference for further development of the rapid test kit for raloxifene.
    29  Development on Quinolone Immunochromatographic Test Strips Labelled with Blue Latex Microspheres
    LIU Bing SUN Xiao GAO Jin YANG Yan-ling WU Qiu-yue SHENG Wei ZHANG Yan WANG Shuo
    2018, 34(5):204-208. DOI: 10.13982/j.mfst.1673-9078.2018.05.029
    [Abstract](804) [HTML](376) [PDF 468.43 K](844)
    Abstract:
    Quinolones were widely used in livestock breeding industry as the broad-spectrum antimicrobial drugs. However, veterinary drugs would remain in animal-derived foods if the use of quinolones was not standardized, causing the potential risks to consumers’ safety.. Therefore, it was inevitable to establish a rapid and simple detection method for quinolones. In this study, blue latex microspheres were used as a marker material to mark norfloxacin monoclonal, and the established method of blue latex microsphere-labeled quinolone immunochromatographic test strips was optimized to provide theoretical support for rapid detection of veterinary drug residues in foods. The detection limit of this method was 1 μg/L under optimized the conditions, and samples of pork, shrimp and chicken that might have veterinary drug residues were selected for the recovery test, the detection limits of the samples were all 10 μg/kg. The established method could detect 6 quinolone residues, including ciprofloxacin, enrofloxacin, fleroxacin, marbofloxacin, enoxacin and norfloxacin, and the test trips have good stability with an effective period of at least three months.
    30  Study on the Petrifilm Aerobic Count Plates with Non-woven Fabric as Carrier
    LIU Shuang LIU Tong YUAN Shuai SI Nan REN Da-yong BI Yun-feng CHEN Ping
    2018, 34(5):209-214. DOI: 10.13982/j.mfst.1673-9078.2018.05.030
    [Abstract](824) [HTML](208) [PDF 471.49 K](898)
    Abstract:
    The performance of non-woven fabric in Petrifilm Aerobic Count Plates was evaluated by investigating the types of non-woven fabric, processing technology, theratio of cold water soluble gel and medium and texture characteristics. When the ratio of gel to medium was 3:7, the hardness, fracturability, adhesiveness, cohesiveness, springiness and gumminess were similar with those of 1% agar medium, and the 60 g/m2 of spunlace non-woven fabric was selected as the carrier . The petrifilm plate method based on prepared cold water soluble gel could achieve the same limit of detection (2 CFU/mL) and sensitivity (100%) in colony counting of five testing strains compared with national standard aerobic bacteria plate counting method. The petrifilm plate method based on cold water soluble gel had high accuracy and linearly dependent coefficient (R2=0.996). These two methods have no significant difference (p>0.05). The spunlaced non-woven fabric can be used as a good carrier of petrifilm aerobic count plate.
    31  Preparation of Certified Reference Materials of Honokiol from M. officinalis
    GENG Yan-ling LIN Yun-liang CUI Li ZHU Heng FU Rui-ming WANG Dai-jie
    2018, 34(5):215-221. DOI: 10.13982/j.mfst.1673-9078.2018.05.031
    [Abstract](405) [HTML](191) [PDF 515.32 K](861)
    Abstract:
    The certified reference material (CRM) of honokiol was develpoed according to the technical requirements of CRM General and Statistical Principle for Certification (GB/T 15000.3-2008). Honokiol was separated and prepared by high-speed counter-current chromatography with crude extracts of Magnolia officinalis Rehd. et Wils. as material, and their structures were confirmed by UV, IR, MS, 1H and 13C NMR. Simultaneously, the purity and moisture content of Honokiol was analyzed by thin layer chromatography, LC-MS, and thermo-gravimetric to establish HPLC analysis technology. Honokiol was divided into bottles for homogeneity test, stability test, and cooperative certification by 8 laboratories. The results indicated that the homogeneity of honokiol samples were excellent, with good stability within 48 months at 0-4oC. The certified value of the reference material of honokiol was 99.72% with the expanded uncertainty of 0.22% in confidence coefficient of 95%. The reference material of honokiol was successfully developed, which reached the technical requirement of GB/T 15000.3-2008 and could be traceable. The CRM can be used in the content determination and testing method validation of honokiol related products.
    32  Establishment and Preliminary Application of Droplet Digital RT-PCR Assay for Detection of GⅡ Norovirus
    GUAN Jin-xiu WENG Wen-chuan XU Xi-lin LING Li XIAN Yu-yin YI Rong LI Zhi-yong
    2018, 34(5):222-228. DOI: 10.13982/j.mfst.1673-9078.2018.05.032
    [Abstract](499) [HTML](201) [PDF 594.90 K](787)
    Abstract:
    The droplet digital RT-PCR assay was applied in the detection of GⅡnorovirus to establish a rapid and accurate method in this study, which was compared with real-time fluorescent RT-PCR. The annealing temperature of droplet digital RT-PCR was optimized and determined to be 56℃. Compared with real-time fluorescent RT-PCR, the sensitivity of droplet digital RT-PCR was determined to be 5.40 copies/μL which was higher than that of real-time fluorescent RT-PCR, and the repeatability of real-time fluorescent RT-PCR and droplet digital RT-PCR were good determined by the comparison test. The droplet digital RT-PCR was applied to detect the artificially contaminated Romaine Lettuce with the sensitivity wof 54.00 copies/μL. Droplet digital RT-PCR assay established for detection of GⅡnorovirus had a high sensitivity and repeatability, and had an outstanding performance in the detection of the artificially contaminated Romaine Lettuce, which would own a good application prospects.
    33  Analysis of Bacterial Community Structure in Medium Temperature Daqu and High Temperature Daqu of Luzhou-flavor Liqu by High-throughput Sequencing
    LIU Yan-bo ZHAO Zhi-jun CHEN Huang-zhao SUN Xi-yu PAN Chun-mei
    2018, 34(5):229-235. DOI: 10.13982/j.mfst.1673-9078.2018.05.033
    [Abstract](745) [HTML](226) [PDF 478.48 K](1086)
    Abstract:
    The medium temperature Daqu and high temperature Daqu of Luzhou-flavor Liqu were analyzed by High-throughput sequencing through Illumin Miseq 2×300 bp sequencing platform, which revealed that 7 phyla and 19 genera were obtained from medium temperature Daqu and 15 phyla and 26 genera were obtained from high temperature Daqu at the threshold of abundance > 0.01%. The first group detected from the medium temperature Daqu was Pediococcus, Pantoea and Melghirimyces. The strains detected in the high temperature Daqu were Streptophyta, Brevibacterium, Thermus, Saccharopolyspora, Citrobacter, Streptococcus, Brevundimonas, and Allobacillus. In addition, the study also found that Bacillus and Thermoactinomyces in the high temperature Daqu were significantly increased compared to the bacteria in medium temperature Daqu , while Kroppenstedtia and Lactobacillus were significantly decreased, probably due to the unique production Daqu technology of Zhanggong. In this study, we established a high-throughput sequencing technique to analyze the bacterial community structure of Luzhou-flavor liquor, which provided theoretical basis for establishing microorganism information database of Luzhou-flavor liquor, optimizing Daqu fermentation technology and improving quality.
    34  Speciation Distribution of Arsenic in Lotus Analyzed by Liquid Chromatography coupled with Inductively Coupled Plasma Mass Spectrometry
    ZHANG Jing-yu MOU Tao WANG Ning JIAO Ji-feng ZHAO Jin-xiang PAN Yi
    2018, 34(5):236-241. DOI: 10.13982/j.mfst.1673-9078.2018.05.034
    [Abstract](929) [HTML](269) [PDF 464.42 K](803)
    Abstract:
    The speciation distribution of arsenic in lotus was investigated by determining the content of total arsenic and five arsenic species including arsenobetaine (AsB), As(Ⅲ), As(Ⅴ), monomethylarsine (MMA) and dimethyarsine (DMA) in different parts of lotus at different growth stages with different arsenic concentrations environment in this study. The arsenic species were extracted by ultrasound with 1% HNO3 solution at 70℃ for 40 minutes, which were analyzed by Liquid Chromatography coupled with Inductively Coupled Plasma Mass Spectrometry with 25 mmol/L NH4H2PO4 (pH 8.0) as the mobile phase for isocratic elution. The results showed that arsenic species were extracted completely, and baseline separation was achieved within 8 minutes. The inorganic arsenic species ratio of lotus grew in high arsenic environment was higher than that grew in low rsenic environment. The accumulation ability of lotus was better in the period of growth than that in period of root. The ratio of total arsenic and inorganic arsenic in underground parts was higher than that of the above-ground part except lotus root. The ratio of inorganic arsenic decreased in the period of root, where organic arsenic was present in AsB, MMA and DMA . The inorganic arsenic species ratios in lotus root and semen nelumbinis were lower than that in any other parts in the ratio range of 29.03%~45.21%, which would help the food security control.
    35  Effect of Pile-up Processing Duration on the White Tea Aroma Analyzed by Chemometrics Approaches
    CHEN Wei ZENG Bin MIAO Ai-qing WANG Wen-wen QI Dan-dan PANG Shi MA Cheng-ying
    2018, 34(5):242-250. DOI: 10.13982/j.mfst.1673-9078.2018.05.035
    [Abstract](711) [HTML](187) [PDF 718.26 K](852)
    Abstract:
    Pile-up is a tea manufacture process,which is beneficial to the transformation of tea aroma.. In this study, the effect of pile-up processing duration on the white tea aroma was investigated, and the relationship between sensory aroma and the changes of volatile organic compounds (VOCs) along different durations was analyzed. The sensory evaluation results indicated that pile-up treatment could improve sweetness of white tea, but decreased freshness. A total of 55 VOCs were characterized through headspace-solid phase micro-extraction (HS-SPME) coupled with gas chromatography-triple quadrupole mass spectrometry (GC/MS/MS). The VOCs profiles showed that pile-up had little effect on the composition changes, but the content changed significantly. Chemometric approaches were applied to select and analyze the 37 differential VOCs patternsin white tea. The results showed that all samples of different pile-up treatments were distinguished based on the principle component analysis and hierarchical cluster analysis, of which the difference between samples was obvious before and after pile-up processing. The content of 2-phenylethanol, benzaldehyde, phenylacetaldehyde increased after pile-up treatment, as well as the content of β-cyclocitral, (E)-2-octenal and α-ionone widely increased in post-pile-up samples, which might be the cause of stronger sweetness flavor. However, the content of 1-hexanol, (E,E)-2,4-hexadienal and octanal in post-pile-up samples decreased widely, which might be related to the reduction of freshness. The 32h pile-up was considered as the optimum duration for processing white tea. The introduction of chemometric approaches in VOCs analysis facilitated in revealing the variations and exploring the biochemical patterns among samples.
    36  Components Analysis of the Antidepressant 20(S)-Protopanoxadiol Type Ginsenosides
    YANG Hong-yan GONG Wei-fan LI Jun ZHANG Hua-lin
    2018, 34(5):251-256. DOI: 10.13982/j.mfst.1673-9078.2018.05.036
    [Abstract](848) [HTML](236) [PDF 445.80 K](824)
    Abstract:
    The 20(S)-protopanoxadiol type (PPD) ginsenosides of the antidepressant total saponins extracted from the leaves of Panax Notoginseng (TSLPN) were investigated in this study, and the ginsenoside composition of TSLPN were analyzed by reference substances and literature. The content of 5 representative PPD ginsenosides including ginsenoside Rb1, Rc, Rb2,Rb3 and notoginsenoside Fc was determined simultaneously by the high performance liquid chromatography (HPLC) with the chromatographic condition as follows: mobile phrase, methanol-0.2% phosphoric acid solution (70:30), detection wavelength, 203 nm, colunm temperature, 30 oC. Results showed that 15 components including Rb1, Rc, Fc, Rb2, and Rb3 were identified, of which 13 components were PPD ginsenosides. Rb1, Rc, Fc, Rb2, and Rb3 were well seperated by HPLC, and the resolutions were above 1.5. In addition, the average recovery rates were 98.92±2.67% (RSD=2.73%), 99.51±1.33% (RSD=1.34%), 100.09±1.45% (RSD=1.45%), 100.53±2.24 (RSD=2.22%), 100.12±1.74% (RSD=1.74%), respectively. Consequently, TSLPN was mainly composed of the PPD ginsenosides, and the total content of Rb1, Rc, Fc, Rb2, and Rb3 was as high as 38.67±0.18%.
    37  Purine Content Distribution in Foods and Purine Determination by HPLC: a Review
    LI Ting-ting REN Li-kun WANG Dang-feng LI Jian-rong
    2018, 34(5):257-266. DOI: 10.13982/j.mfst.1673-9078.2018.05.037
    [Abstract](956) [HTML](872) [PDF 539.45 K](2512)
    Abstract:
    Purine is an alkaloid and it plays extremely important physiological functions in humans such as energy supplement, metabolic regulation and coenzyme composition. But it can be converted to uric acid finally via oxidative metabolism. The hyperuricemia can be induced and leads to gout, when the level of uric acid in the body is higher than a certain threshold. Diet is the important source of purine for human and the content of purine in foods can significantly influence the body's uric acid level. Therefore, it is urgent to determine the content of purine in foods. In this paper, the purine contents in different foods were reviewed. And different pretreatment and detection methods were discussed in order to optimize and improve the detection efficiency of the purine detection method. So that we can guide consumers to control the purine intake and reduce the incidence of gout via the balanced diet.
    38  Research Advance on Chemical Constituents and Biological Activities of Anoectochilus Roxburghii
    XIAO Xiao-hua LIN Cai-xia WU Xu-li CHEN Jia-min WANG Yu-xuan WENG Bing-xun LIU Li-zhong HU Xiao-peng HE Zhen-dan
    2018, 34(5):267-275. DOI: 10.13982/j.mfst.1673-9078.2018.05.038
    [Abstract](728) [HTML](203) [PDF 634.48 K](2167)
    Abstract:
    Jin Xian Lian (Anoectochilus roxburghii (will.) lind-waldock.), which belongs to the genera Anoectochilus (Orchidaceae), is a perennial herbaceous plant. Itis also known as Jin Si Xian, Jin Er Huan, Wu Ren Shen, Jin Xian Hu Tou Jiao, Jin Xian Ru Gu Xiao and Jin Qian Cao. Jin Xian Lian is widely distributed in Fujian, Zhejiang, Guangxi and other regions. Particularly, highly ornamental value was endowed with Jin Xian Lian because of the small plant type, the golden yellow leaves and the reticular arrangement of veins. Jin Xian Lian has been widely used as a "medicine and food homology" plant in folk for a long time, and it could be used for treating diabetes, haemoptysis, acute hepatitis, bronchitis and cancer due to the characteristics of mild and sweet flavor. Jin Xian Lian is safe and has no toxic effects, which attract more and more researchers’ attention. The results of chemical analysis showed that the chemical constituents of Jin Xian Lian are really abundant, including flavones, volatile oils, polysaccharides, alkaloids and steroids. In addition, modern pharmacological studies suggest that Jin Xian Lian has the fuctions of hypoglycemic, cardiovascular protection, anti-infection and antitumor. This article systematically reviews the material foundation and biological activities of Jin Xian Lian, providing a reference for the development of natural health products.
    39  Research Progress on the Effect of Ultrasound on the Microbial Inactivation and Qualities of Fruit and Vegetable Juice
    LIU Wei SONG Yi ZHANG Jie LIN Qiong WU Jie WANG Feng-zhong WANG Zhi-dong
    2018, 34(5):276-289. DOI: 10.13982/j.mfst.1673-9078.2018.05.039
    [Abstract](787) [HTML](236) [PDF 740.11 K](1021)
    Abstract:
    Ultrasound (US) is a sound wave propagated in the medium based on the mechanical vibrations. The frequency of US is higher than 20 kHz, which exceeds the range of human hearing. US is especially suitable for the processing of fruit and vegetable juice as a non-thermal technology. On the one hand, the ultrasound could destroy microbial cell wall by cavitation and inhibit the growth of microorganisms in fruit and vegetable juice. On the other hand, compared with traditional heat sterilization technology, US could reduce water and energy consumption, maximize the retention of nutritional quality and organoleptic properties of fruit and vegetable juice, and increase the homogeneity of the products. At present, the effects of US alone can’t achieve the suf?cient lethal effect on the foodborne pathogens or spoilage microorganisms, while US combined with other preservation techniques, such as mild heat treatment, high pressure, bacteriostat, and so on., can effectively improve the microbial inactivation and enzyme inactivation. This paper introduced the action mechanism and the equipment of ultrasound. The paper also summarized the research status of US used alone or in combination with other preservation techniques in fruit and vegetable juice processing for microbial inactivation, pesticide degradation, nutritional quality, colour, aroma, stability, and turbidity improvement, and the analysis of the development trend of the US technology.

    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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