Volume 34,Issue 4,2018 Table of Contents

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  • 1  Effects of Konjac Glucomannan on the Intestinal Physiological Structure and Peristaltic Function in Mice
    HUANG Xia-ling ZHANG Wei LI Yu-sang
    2018, 34(4):1-5. DOI: 10.13982/j.mfst.1673-9078.2018.04.001
    [Abstract](674) [HTML](223) [PDF 520.03 K](920)
    Abstract:
    Effects of Konjac glucomannan (KGM) on theintestinal physiological structure and peristaltic function in mice were investigated in this study. Modeling human intestinal motility disorders, using sucralfate-modeled young mice (4 weeks old) and old mice (60 weeks old) to explore different doses (low dose:0.18 g/kg and high dose:0.90 g/kg) of KGM on intestinal motility in mice with different ages. After the administration, the defecation time, stool weight, fecal water content, carbon propulsion rates were determined. The results showed that compared with the control group, the high dosage of KGM treatment on sucralfate-treated young and aged mice could significantly prolong the first defecation time and decrease the stool weight. The results of H&E staining showed that the structure integrity of intestinal tissues were destroyed and colonic inflammatory cell aggregation increased in the aged mice treated with high dose of KGM. high dose uptakes of KGM could result in insufficient intestinal motility and the difficulty of defecation in aged people.
    2  Preventive Protective Effects of Wild Kiwifruit and Vitamin C on Alcoholic Liver and Brain Injury in Rats
    CHEN Xia ZHANG Rui HU Kai LUO Ting-ting GUO Wen-bo YANG Yan
    2018, 34(4):6-10. DOI: 10.13982/j.mfst.1673-9078.2018.04.002
    [Abstract](671) [HTML](276) [PDF 421.54 K](738)
    Abstract:
    The preventive protective effects of wild kiwifruit and pure vitamin C on alcoholic liver and brain injury in rats were investigated in this study. 40 male SD rats were randomly divided into four groups: normal group, model group, vitamin C group and wild kiwifruit group. The normal group was given the same amount of normal saline, and other groups were given 56°Red Star Erguotou by gavage to establish the alcoholic liver and brain injury model(8 mL/kg for first week, and 10 mL/kg for the second week once a day). The normal group and the model group were given the common feed. The wild kiwifruit group was fed with 30% concentration of wild kiwifruit, and the vitamin C group was given vitamin C-fortified feed (420 mg/kg). The liver function, liver lipid content and oxidative stress level were measured after two weeks, and pathological changes of liver and brain were observed by HE staining. Results showed that compared with the model group, wild kiwifruit and vitamin C could significantly reduce alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride(TG), total cholesterol (TC), lipid peroxidation (LPO), malondialdehyde (MDA) in serum, and increase superoxide dismutase(SOD) in serum and brain homogenate (p<0.01). In addition, the decrease and increase indexes were even more significant in wild kiwifruit group (p<0.05). Consequently, wild kiwifruit and vitamin C had preventive protection effects on alcoholic liver and brain injury, and the former had the better effects.
    3  Analysis of the Composition and Function of Different Part Protein in Milk
    YANG Mei WU Jun-rui PENG Xiu-ming WANG Jun-yi LIU Biao YUE Xi-qing
    2018, 34(4):11-17. DOI: 10.13982/j.mfst.1673-9078.2018.04.003
    [Abstract](683) [HTML](312) [PDF 636.73 K](1022)
    Abstract:
    In this study, SDS-PAGE was used for separating of different component protein parts in milk, and mass spectrometry was used for identifying. It found that there were 201 kinds of protein in milk fat globule membrane, 96 kinds of protein in whey, and 43 kinds of protein in exosome and in these proteins, there were 27 kinds of the same expression protein. It found that the function of milk fat globule protein in the process of biological process was higher than whey protein and milk exosome protein, especially in biological regulation through the functional analysis of GO. In the molecular function, the main molecular function of different proteins in milk is the combination, and the function of milk fat globule proteins is the strongest. Exosome proteins involved in the molecule function of transport activity are greater than the milk fat globule membrane and whey proteins. Milk exosome involving in more cellular composition is the membrane, compared with whey and milk exosome, MFGM protein involved in cellular composition are more. KEGG pathway analysis shown that milk fat globule membrane, whey, milk exosome involved in metabolic pathways are not the same, metabolic pathways involved in the three parts was the peroxisome proliferator-activated receptor signaling pathway. Studying on milk protein can not only increase the utilization rate of milk, and the milk fat globule membrane, milk protein particles could provide a theoretical basis for producing dairy products as a raw material in the future.
    4  B Cell Epitopes Analysis and Prokaryotic Expression of PGIP in Citrus
    CHEN Bo LUO Qing-hua TAN Ya-qin YAN Hui-qing
    2018, 34(4):18-22. DOI: 10.13982/j.mfst.1673-9078.2018.04.004
    [Abstract](597) [HTML](190) [PDF 586.37 K](736)
    Abstract:
    Citrus is an important horticulture. However consumption of citrus fruits could cause allergen for some people. With the method of Jameson-Wolf, Kyte-Doolittle, Emini and Karplus-Schulz, the antigenicity, hydrophilicity, protein surface accessibility and flexibility of citrus allergen protein PGIP (polygalacturonase inhibitor protein) were predicted. Meanwhile PET-28 a-PGIP vector was constructed, and then transfer to Escherichia coli. The target gene was induced and expressed. The results showed: When the secondary structure of amino acid was β-angle and irregular curl, the antigen index>0, the flexibility>0, the hydrophilicity>0, the protein surface accessibility>1 amino acid region, the sequences of the B cell epitope binding amino acid were 19~22, 37~41, 49~52, 68~69, 117~120, 163~164, 173~177, 221~226, 236~240. By estimating the amino acid region, it provides support for finding the best possible region of the B cell epitope of citrus allergen protein PGIP, and also provides a theoretical basis for the further study of citrus allergen protein PGIP.
    5  Comparative Analysis of Physicochemical Properties from Yam Flours of Six Varieties
    LI Qing-ming SHU Qing-qing XIA Lei LI Yan SU Xiao-jun WANG Feng XIONG Xing-yao WEI Ben-hui
    2018, 34(4):23-29. DOI: 10.13982/j.mfst.1673-9078.2018.04.005
    [Abstract](559) [HTML](200) [PDF 767.33 K](734)
    Abstract:
    The physicochemical characteristics of yam flours produced by hot air drying process with different yam varieties as materials were investigated to explore the new application of yam in food processing in this study.. The results indicated that the physicochemical characteristics of yam flours were significant different with different yam varieties. The contents of starch, total carbohydrate, protein, ash and fat of 6 yam flours were around 60.36~62.63%, 72.32~78.77%, 12.0~13.0%, 3.05~3.25% and 0.5%, respectively. In addition, the contents of allantoin, catechinic acid, syringic acid and flavone were 26.48-69.08 mg/g, 0.25-1.64 mg/g, 0.32~0.58 mg/g and 0.31~0.94 mg/g, respectively. The equilibrium moisture contents of yam flours were low, and moisture adsorption isotherms presented a sigmoid shape corresponding to Type Ⅱ isotherms according to BET classi?cation. The equilibrium moisture contents of yam samples Guihuai No.2, No.3 and No.6 were higher than that of others. Guihuai No.5 displayed the most favor color, with the highest whiteness value, starch-iodine-blue value, syringic acid and flavone content. Guihuai No.4 had the highest water holding capacity and catechinic acid content. Guihuai No.6 displayed the shortest dispersion time and the highest allantoin content, while Guihuai No.2 had the longest stability time and dispersion time. Guihuai No.1 displayed good freeze-thaw stability, and it was suitable for refrigerant food processing.
    6  Increase of Lipid-soluble Nutritional Components Content in Peanuts by Germination
    LI Shu-ying LIU Guo-qin
    2018, 34(4):30-38. DOI: 10.13982/j.mfst.1673-9078.2018.04.006
    [Abstract](680) [HTML](328) [PDF 686.22 K](1158)
    Abstract:
    Germination of Yueyou No. 13 peanuts at 25 °C in dark for 7 days was conducted to explore the changs of the main lipid-soluble bioactive components such as resveratrol, tocopherol, phytosterol and phenolics. The nutritional changes of oil fraction were also evaluated by determination of fat content and fatty acids composition . The result showed that germination significantly increased the total amount of resveratrol, tocopherol, phytosterol, and polyphenol in peanuts (p < 0.05), which were 4.71, 3.25, 2.27, and 2.74 times, respectively, higher than those of unmalted peanuts, respectively, enriching the nutrition of peanuts. Compared to ungerminated peanuts, resveratrol, piceid, α-tocopherol, δ-tocopherol, β-sitosterol and stigmasterol contents in germinated peanuts significantly increased up to 5.94, 2.96, 5.98, 8.64, 1.96 and 2.80 fold, respectively. Although the fat contents of peanut decreased significantly by 21.39% during the germination process, the oil content was still in line with the requirements of oil crops, and the fatty acid composition did not change much, and the peanut oil quality was maintained. At the same time, the content of aflatoxin B1 in the peanut sprouts during germination was monitored and the results were not detected (method detection limit (MDLs) 1 μg/kg), which met the safety standards and provided theoretical support for the development of peanut sprouts.
    7  Reduce the Cold Damage of Apricot Fruit and Its Active Oxygen Metabolism Treating by 24 - Epibrassinolide
    ZHANG Rui-jie ZHANG Zhu-run JIN Peng LI Ya-ling ZHU Xuan
    2018, 34(4):39-44. DOI: 10.13982/j.mfst.1673-9078.2018.04.007
    [Abstract](601) [HTML](255) [PDF 528.82 K](735)
    Abstract:
    Saimaiti apricots sampled from Xinjiang were infiltrated by 0.9 mg/L 24-epibrassinolide (EBR) under the pressure of 0.05 MPa, and the distilled water treatment was used as a control. The treated fruits were taken out, air-dried and stored in a cold room at 4℃ and relative humidity of 90%-95%. Incidence of chilling injury and chilling injury index, the activities of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD),peroxidase (POD) and superoxide anion (O2-) and the content ofhydrogen peroxide (H2O2) of apricot fruits were determined regularly. The results showed that 0.9 mg/L 24-epibrassionolide treatment could increase the activities of SOD and APX, and decreased the activities of POD and CAT in apricot fruit during cold storage. It also inhibited the content of H2O2 and the increase of generation rate of O2-, and significantly decreased the incidence of chilling injury and chilling injury index of apricot fruit. Results indicated that the 24-epibrassionolide treatment was related to the reduction of chilling injury, prevention of oxidative damage and the accumulation of free radical scavenging during apricot preservation.
    8  Physical Properties and Bioavailability of Active Components of Osmunda Japonica Thunb by using Ultrafine Grinding
    FU Qun LI Hui WANG Zhen-yu WANG Lu
    2018, 34(4):45-50. DOI: 10.13982/j.mfst.1673-9078.2018.04.008
    [Abstract](633) [HTML](235) [PDF 554.49 K](652)
    Abstract:
    Using traditional osmunda japonica thunb powder as control, Osmunda japonica Thunb was ultrafine grind by planetary ball milling and high pressure homogenization, and their average particle size, angle of repose and the powder expansion force characteristics were determined and compared. Besides, the in vitro digestion model was designed to calculate the bioavailability and release amount of total flavonoids and total polyphenols in Osmunda japonica Thunb powder., The results indicated that the bioavailability and release amounts of total flavonoids and total polyphenols were significantly improved after ultrafine grinding. Compared with traditional Osmunda japonica Thunb powder, the bioavailabilities of flavonoids in power treated with the planetary ball milling and high- pressure homogenization method were increased by 6.09% and 3.58%, respectively, and the bioavailabilities of polyphenols were increased by 6.41% and 6.72%, respectively. Besides, the release amounts of total flavonoid were increased by 16.47% and 12.24%, respectively, and release amounts of polyphenols were increased by 50.07% and 50.08%, respectively. The results suggested that ultrafine grinding technology can effectively improve the extraction of active ingredients and increase its utilization in the digestion and absorption of the human body, which can provide reference for the research and development of functional products.
    9  Optimized Expression and Vaccine Activity of Recombinant Porcine Circovirus Type 2 Capsid Protein in Pichia Pastoris
    WANG Bin LUO Shi-yu XIE Jing-yi YE Yan-rui PAN Li
    2018, 34(4):51-55. DOI: 10.13982/j.mfst.1673-9078.2018.04.009
    [Abstract](569) [HTML](255) [PDF 618.87 K](757)
    Abstract:
    Porcine circovirus type2 (PCV2) is the major pathogen of weaning multi-systemic wasting syndrome (PMWS), which has caused significant economic losses to the swine industry worldwide. Porcine circovirus type 2 capsid protein(PCV2-Cap)is the main target protein for the preparation of vaccine against weaning multi-systemic wasting syndrome (PMWS). In this study, the recombinant expression and vaccine activity of PCV2-Cap protein in Pichia pastoris were investigated to solve the problems of complex production process and high cost of PCV2 vaccine. After removing the nuclear localization sequence (NLS) from PCV2-Cap gene sequence, a preferential optimization of codon was performed to construct a recombinant expression vector and transformed into the host bacteria (X-33) of P. pastoris. The results of SDS-PAGE and Western blot showed that the Cap protein was successfully expressed in the yeast expression system with a protein size of 26 Ku, and the high density fermentation test in 5 L bioreactor suggested that the concentration of PCV2-Cap protein in fermentation supernatant was 0.53 mg/mL, accounting for 23.5% of the total cell protein. In addition, the animal immunization test demonstrated that Cap protein could stimulate the body to produce specific antibodies. Consequently, the PCV2-Cap gene was secreted and expressed P. pastoris, which might make a contribution to the development of PCV2-Cap subunit vaccines.
    10  Biochemical Component Analysis and Antioxidant Activities of Different Kinds of Aged Tea
    XIANG Li-min LIU Ya-qiong LAI Xing-fei LI Qiu-hua SUN Ling-li CHEN Wen-pin CHEN Dong SUN Shi-li
    2018, 34(4):56-62. DOI: 10.13982/j.mfst.1673-9078.2018.04.010
    [Abstract](1082) [HTML](505) [PDF 511.62 K](1495)
    Abstract:
    The biochemical composition and antioxidative activity of three varieties of aged tea, including black tea, oolong tea and dark tea, were determined in this study. The contents of water extracts, tea polyphenols, total flavonoids, total soluble sugars, free amino acids, total soluble sugar theaflavins, thearubigins and theabrownin in these tea samples were determined by colorimetry. High performance liquid chromatography was used to analyze the contents of gallic acid, caffeine and catechin monomer in these aged tea samples. The total antioxidant capacity was determined by FRAP method. The results showed that there was a significant difference in the contents of the main quality biochemical components in the different aged tea samples. There was also a significant difference in the contents of the main biochemical components in the aged tea samples of different tea varieties or regions. No EGC was detected in tea samples from three different teas. Neither GC or CG was detected in aged black tea samples. GC and EGCG contents in aged oolong tea samples were significantly higher than those in other tea samples. The content of GA in black tea samples was generally low, and the components of catechins in Yunnan pu brick tea were not detected. The total antioxidant capacity of different tea aged tea samples differed greatly. Among them, the aged Qianjiazhai Shengpu tea had the strongest antioxidant capacity, and its antioxidant capacity of tea is related to the total contents of tea polyphenols and catechins.
    11  In vitro and in vivo Antifungal Activities of Essential Oil from Inula salsoloides Flowers
    NIU Dong-ling LIU Xiang-cai LI Yan
    2018, 34(4):63-68. DOI: 10.13982/j.mfst.1673-9078.2018.04.011
    [Abstract](547) [HTML](219) [PDF 452.25 K](712)
    Abstract:
    The in vitro and in vivo antifungal effects of essential oil (EO) extracted by CO2 supercritical fluid extracted from Inula salsoloides flowers on fruits and vegetables were investigated in this study. The results showed that EO had significant activities against all tested fungi in vitro with diameter of inhibition zone greater than 20 mm. The fungus showed extremely high sensitivity to EO and the minimum inhibitory concentration (MIC) was 3.13 mg/mL. The antifungal activities of EO in vivo were investigated by soaking method and fumigation method.. EO showed obvious antifungal activity on grapes with the treatment of EO fumigation method, which significantly slowed the spoilage process of fresh grapes and kept fresh during storage with 0.5 mL EO in vivo. There were 21 EO compounds identified by gas chromatography-mass spectrometry (GC/MS) from Inula salsoloides flowers, of which the content of vanillin was the highest(30.35%) and the antifungal activity of EO was closely related to this composition., The results provide a scientific basis for the development and application of EO of Inula salsoloides flowers in the local food industry.
    12  Improvement of the Quality and Digestibility of Bread Using High Amylose Maize Starch
    WANG Kai MA Jun-yu WU Yu-bing OU Zhuo-shen XU Bao-shan ZHAO Lei HU Zhuo-yan
    2018, 34(4):69-74. DOI: 10.13982/j.mfst.1673-9078.2018.04.012
    [Abstract](799) [HTML](307) [PDF 483.19 K](706)
    Abstract:
    The effects of high amylose maize starch addition on the quality and digestion properties of bread were investigated in order to provide theoretical support for the application of resistant starch, such as high amylose maize starch, in slowly digestible foods. The results showed that the water-holding ability and surface brightness of bread were improved with the addition of high amylose maize starch, which might be beneficial to improve the consumer acceptability of the bakery products. However, the specific volume of bread was significantly decreased with the increasing addition of high amylose maize starch. In terms of the texture properties of bread, springiness, adhesiveness and resilience were not significantly impacted by the addition of high amylose maize starch, whereas the hardness was apparently increased. The hardness of bread with adding 10% and 20% of high amylose maize starch increased to 1.2 and 1.8 folds, respectively, as that of the control bread. The gumminess and chewiness of bread were not significantly impacted when the addition amount of high amylose maize starch was less than 10%, while the gumminess and chewiness were both significantly increased with further increase of the addition amount. In addition, high amylose maize starch could effectively reduce the in vitro digestion rate of bread, and the digestion rate of bread reduced by 54% with the addition high amylose maize starch of20%. These results showed that the addition of high amylose maize starch could influence the quality of bread at some extent, and reasonable addition amount of high amylose maize starch could significantly decrease the digestion rate of bread and simultaneously maintain the bread quality.
    13  Dough Character of a Compounded System Comprising Highland Barley Flour with Different Digestibility and Medium Strength Flour
    ZHONG Shao-wen ZHENG Bo LI Xiao-xi CHEN Ling
    2018, 34(4):75-80. DOI: 10.13982/j.mfst.1673-9078.2018.04.013
    [Abstract](784) [HTML](192) [PDF 500.27 K](744)
    Abstract:
    In this study, the process ability of highland barley flour with different digestibility was strengthened by compounding with medium strength flour to obtain highland barley products with better nutritional function and fabrication properties. Meanwhile, viscosity and dough characters of the compounded system comprising highland barley flours and medium strength flour were evaluated by rheometer, micro-dough LAB and texture analyzer to obtain the effects of different compound conditions on the processing properties of highland barley. The study indicated that highland barley flour with higher resistant content had a lower paste peak viscosity (113 cp), paste stability (76 cp), retrogradation (15) and gel property (75 cp), and had a higher pasting temperature (92.5 ℃), cold paste stability (15 cp) and anticoagulation sinking (55 cp). Moreover, the farinograph characteristics of highland barley flour was improved by the addition of medium strength flour and significantly affected by other components with the increase of RC content. The extensographical properties of the dough were also significantly improved by the addition of medium strength flour, thus achieving better processing properties of highland barley flour. The results provide theoretical basis for the development of new nutritional highland barley product and accelerating the development of highland barley industry.
    14  Fractionated Extrative Property Analysis of Different Parts of Fat from Hazake Sheep by Solvent Extraction
    LI Tao LU Yan CHEN Wei-lin LI Jin-yu MA Xin LIU Dan KAEr Sai-jiang WANG Zi-rong
    2018, 34(4):81-87. DOI: 10.13982/j.mfst.1673-9078.2018.04.014
    [Abstract](849) [HTML](285) [PDF 478.73 K](757)
    Abstract:
    This paper aimed to investigate the fat changes in different parts of Hazake sheep from Xingjiang by solvent extraction, and analyze the fatty acid composition by GC/MS. The results showed that the sequence of fat extraction was 37 oC (solid fat), 17 oC (solid fat), 2 oC (solid fat) and 2 oC (liquid fat). The melting point decreased (p<0.05) and the iodine value increased (p<0.05). Similar changes of fatty acid content in tail fat, perirenal fat and omentum fat were found. Compared to raw fat, the content of saturated fatty acid (SFA) in the extracted fraction decreased first and then increased. The change trend of unsaturated fatty acid (UFA) was opposite to that of SFA . The fatty acids that changed more obviously in SFA were palmitic acid (C16:0) and stearic acid (C18:0), while in UFA, the fatty acid was oleic acid (C18:1n-9c). In conclusion, whether the content of unsaturated fatty acids or the value of n-6/n-3, the edible value of liquid fat of Kazak sheep tail (using the solvent extraction,2 oC ) was better than others. It could be used as a potential substitute for commercial salad oil due to its characteristics of low melting point (16.67 ℃~17.07 oC) and high unsaturated fatty acids (58.13%~59.65%).
    15  Effects of Persimmon Tannin on the Rheological Properties of Pectins
    Torkun.Mamet ZHANG Meng-ying LI Chun-mei
    2018, 34(4):88-93. DOI: 10.13982/j.mfst.1673-9078.2018.04.015
    [Abstract](675) [HTML](186) [PDF 544.08 K](862)
    Abstract:
    The effects of different polymerization degrees of persimmon tannin (DP 26/5) on the steady and dynamic rheological properties of high-methoxyl/low-methoxyl pectin (HM/LM) were investigated under various shear rates and temperatures. TA-DHR2 rheometer was used to measure the rheological properties of persimmon tannin-pectin complex. The results of static rheological tests indicated that persimmon tannin did not change the fluid type of HM/LM pectin, which was in line with Cross model, showing a shear-thinning and the pseudoplastic non-Newtonian fluid characteristic. Furthermore, the persimmon tannin-pectin composite system showed a tendency of decreasing viscosity with the increase of temperature, which was in accordance with the Arrhenius equation. Under the same temperature conditions, 0.2 % of persimmon tannin could significantly enhance the viscosity of HM/LM pectin (p < 0.001), and the viscosity of tannin-HM pectin complex was slightly higher than that of tannin-LM pectin complex. The degree of polymerization of persimmon tannin had no obvious effect on the viscosity of pectin. In addition, the results of dynamic rheological properties showed that DP26/5 persimmon tannin could shorten the HM/LM pectin gelation time and gelation temperature. Consequently, the effects of persimmon tannin on the rheological properties of pectin provided a theoretical basis for the development of functional compound ingredients of persimmon tannin-pectin.
    16  Identification, Isolation and Purification of the bioactive Compounds from Eucalyptus Leave Extract and theirs Antioxidant Activity
    CHEN Hong-zhang LI Wei XIAO Su-yao CAO Yong CHEN Yun-jiao
    2018, 34(4):94-101. DOI: 10.13982/j.mfst.1673-9078.2018.04.016
    [Abstract](640) [HTML](179) [PDF 803.43 K](723)
    Abstract:
    To further elucidate antioxidant compounds of Eucalyptus leave extract, four compounds were isolated and purified from the fraction P95 of eucalyptus leave extract by medium-pressure silica gel column chromatography and preparative high performance liquid chromatography (HPLC). And three of the compounds were identified as hyperoside, guava glycosides and quercetin-3-o- alpha-pyranol-2"-gallate, by comparison of their 1H-NMR and 13C-NMR data. Then 1,1-diphenyl-2-picrylhydrazyl (DPPH·), 2,2‘-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS+·), and oxygen radical absorbance capacity (ORAC) assays were used for analyzing the antioxidant activity of the compounds. Among the DPPH and ORAC methods, guava glycosides showed the highest antioxidant activity, and quercetin-3-o- alpha-pyranol-2"-gallate showed the lowest antioxidant capacity. Hyperoside had the highest antioxidant activity, and guava glycosides had the lowest in ABTS+·assay. All of three compounds showed higher antioxidant activity than trolox, and they were natural antioxidants with better development prospects. This study provided a theoretical guidance for the comprehensive development of the Eucalyptus leaves.
    17  Bagging on Pigment Synthesis and Expression of PbcrtZ in ‘Chili’ Fruit
    LI Qian LI Ming-tong WANG Cai-hong WANG Yu-ling YANG Shao-lan
    2018, 34(4):102-106. DOI: 10.13982/j.mfst.1673-9078.2018.04.017
    [Abstract](585) [HTML](201) [PDF 495.62 K](753)
    Abstract:
    The best bagging time of Chili pear was 60 d after anthesis by determining the appearance quality and the weight loss rate during the storage period. The Chili pear fruit, which was bagged at 60 d after anthesis, was used as the material, and the contents of chlorophyll, flavonoids, carotenoids and the expression of the color-related difference gene. PbcrtZ were determined in fruit peels treated with plastic fabrics and non-woven bags. The results showed that the content of chlorophyll in non-woven fabric and plastic bagged developmental Chili fruits was significantly lower than that in non-bagged fruits, and the contents of flavonoid and carotenoid were significantly higher than those of non-bagged fruits on 180 d after anthesis. In addition, the expression of PbcrtZ in non-woven fabric and plastic bagged fruits were higher than that in non-bagged fruits, and the expression on 180 d after anthesis was 4.36 and 3.48 times higher than that of the control group, which was in according with the difference of flavonoid content and carotenoid content. Consequently, the color of the fruits treated with non-woven fabrics and plastic bags was green-yellow and the non-bagged fruit showed a green color, and the fruits treated with non-woven fabrics showed better appearance quality and storage property.
    18  Effect of Suitable Ozone Treatment on Postharvest Quality of Muskmelon
    BAI You-qiang ZHAO Xiao-min XU Jian WANG Zhi-hong hao DONG Zi-fan ZHOU Yan-qin XIE Ji-yun DU Lin-xiao MA Nan LI Dan LI Xue-wen
    2018, 34(4):107-113. DOI: 10.13982/j.mfst.1673-9078.2018.04.018
    [Abstract](724) [HTML](193) [PDF 571.66 K](720)
    Abstract:
    In this paper, the melon “Xizhoumi No.25” was treated with suitable ozone at the temperature of at 6~8 ℃ and RH of 80~85% for 40 min through a ozone generator in a plastic bucket of 50 L. After ozone treatment, the samples were sealed for storage. The dynamic changes of relevant quality indexes of melon treated by appropriate ozone during a 42-day storage and the antibacterial effects of suitable ozone treatment on Alternaria alternata and Fusarium were investigated. The results showed that the average sugar content and hardness of melon decreased by only 0.07% and 0.03%, respectively, after ozone treatment (concentration 4.28 mg/cm3, Intervals 24 h), indicating ozone had significant delaying effect on the decrease. Simultaneously, ozone treatment also reduced the weightlessness of the control group by 42%. It had a strong antibacterial effect on F.semitectum and A.alternate and has a better antibacterial effect on A.alternate. Appropriate ozone treatment had a good effect on the post-harvest low-temperature storage quality of melon and extended its shelf life.
    19  Enhancement of Chilling Tolerance of Hami Melon Fruits in Postharvest Storage Period by Using Nitric Oxide Fumigation
    WANG Lu-yang WU Bin JING Yuan-yuan HU Jiang-wei ZHANG Ping
    2018, 34(4):114-120. DOI: 10.13982/j.mfst.1673-9078.2018.04.019
    [Abstract](587) [HTML](187) [PDF 730.64 K](805)
    Abstract:
    The effects of nitric oxide (NO) fumigation on chilling tolerance of Hami melon fruit in postharvest storage were investigated. The muskmelon fruit, 'Xizhoumi25' muskmelon, was used as a test material and was fumigated with 60 μL/L NO for 3 h and stored at (1 ± 0.5℃), (3 ± 0.5℃) and (5 ± 0.5℃), respectively. The chilling injury incidence and chilling index were counted. The activities of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), the production rate of superoxide anion (O2ˉ·) and the content of hydrogen peroxide (H2O2) were determined regularly. The results showed that NO treatment could increase the activities of SOD and POD and inhibit the production rate of O2ˉ·. At the storage temperature of 1℃, the incidence of chilling injury was the highest and the occurrence of chilling injury was reduced by NO treatment. At the storage temperature of 3℃, the chilling injury incidence occurred slightly in the control fruit , but the chilling injury was inhibited by NO-treatment. When the storage temperature was 5℃, the chilling injury and disease symptoms occurred in the late storage period, and the chilling injury and disease were alleviated by NO treatment. The antioxidant enzyme activity was increased and the accumulation of reactive oxygen species (ROS) were inhibited by NO fumigation, thus reducing the chilling injury of fruits. The storage quality of Hami melon fruit could be maintained, and the occurrence of chilling injury could also be inhibited by the NO fumigation treatment at 3 ℃.
    20  Muscle Fatty Acids Analysis of Yunnan Wuding Chicken, Yanjin Silky Fowl and Daweishan Miniature Chicken
    XIAO Zhi-chao GU Da-hai YANG Xiao-li DONG Xiao-zhu ZHANG Ci ZHANG Guan-tao YANG Shi-bo LIAO Guo-zhou
    2018, 34(4):121-128. DOI: 10.13982/j.mfst.1673-9078.2018.04.020
    [Abstract](760) [HTML](207) [PDF 511.48 K](779)
    Abstract:
    In this study, the total lipid was extracted by solvent extraction from breast and leg meat of Wuding chicken, Yanjin silky fowl and Daweishan miniature chicken.s. The fatty acids composition and contents were analyzed by use gas chromatography-mass spectrometry (GC-MS) after methyl esterification. Results showed that totally 20 kinds of fatty acids were identified in the breast and leg meat of Wuding chicken, Yanjin silky fowl and Daweishan miniature chickens, mainly including cis-9-oleic acid methyl ester, linoleic acid methyl ester, stearic acid methyl ester, palmitic acid methyl ester and arachidonic acid. The fatty acids contents of breast meats in Wuding chicken (28.470 mg/g) and Yanjin silky fowl (25.042 mg/g) were 28.470 and 25.042 mg/g, respectively, which were significant higher than that in Daweishan miniature chicken (16.769 mg/g). The fatty acids content of leg meat in Daweishan miniature chicken (51.10 mg/g) was significant higher than that in Wuding chicken (40.994 mg/g) (p<0.05).The same fatty acid composition in the three kinds of chickens was found with the similar saturated and unsaturated fatty acids proportion. However, the fatty acid contents in the three kinds of chickens had significant difference, and the fatty acids contents of leg meats were significant higher than those of breast meat in the three kinds chickens (p<0.05).
    21  Optimization of Enzymolysis Parameters of Highly Soluble Egg White Protein Powder and Its Application in Immunoregulation in Vitro
    PENG Qi MA Mei-hu JIN Yong-guo
    2018, 34(4):129-136. DOI: 10.13982/j.mfst.1673-9078.2018.04.021
    [Abstract](565) [HTML](220) [PDF 652.15 K](999)
    Abstract:
    Egg white is rich in proteins and has high biological values and biological activities, which has been served as an excellent food resource. However, the egg white protein products have not yet been fully developed. Here, orthogonal experiment was designed by selecting four factors, including hydrolysis time, hydrolysis temperature, pH and enzyme dosage based on single factor experiments. The solubility and dispersibility of egg white protein powder were traced as evaluation indicators for optimizing enzymatic process. The results showed that the optimal solubility and dispersion time of egg white protein powder reached 96.6% and 39.6 s, respectively when the ratio of neutral protease to papain, the enzyme amount , the hydrolysis temperature , enzymatic hydrolysis time and pH being of 1:2, 800 U/g, 53.5 ℃, 90 min and 5.5, respectively. Furthermore, the effects of simulate gastrointestinal digestion products (SGDP) derived from highly soluble egg white protein powder on the RAW264.7 macrophages was studied by cell experiment. The results showed that SGDP significantly increased the level of acid phosphatase (ACP) and lysozyme (LZM) intracellular. Meanwhile, the role of SGDP in immunoregulation was confirmed by the enhanced proliferation potential (proliferation index 1.28) and cytokine release. This study can provide an important reference for the development of egg protein products with highly soluble and function.
    22  Fatty Acid Analysis and Microcapsule Preparation of Camellia Oil
    ZHOU Dan WANG Jie PENG Yin SHI Qing-long GE Fa-huan
    2018, 34(4):137-142. DOI: 10.13982/j.mfst.1673-9078.2018.04.022
    [Abstract](582) [HTML](230) [PDF 525.51 K](718)
    Abstract:
    The fatty acid composition of camellia oil was analyzed by GC-MS. It was mainly composed of palmitate, stearic acid, oleic acid, linoleic acid and linolenic acid, of whichthe content of unsaturated fatty acid reached more than 80%. The microencapsulation of camellia oil was prepared by spraying drying using soybean protein isolate and maltodextrin as wall materials. The effects of emulsifying temperature, the ratio of SPI to MD, the wall materials concentrations, and the ratio of oil to wall materials on the encapsoluation efficiency were examined based on single factor and orthogonal experiments. The optimum process conditions were as follows: emulsifying temperature 75 ℃, SPI/MD 0.6, the wall materials concentrations 13%, and core material: wall material 1.5:1. Under the optimal conditions, the encapsulation efficiency of camellia oil microencapsulation was 83.83%. The structure of microcapsules was observed by a scanning electron microscope (SEM) and the size distribution of camellia oil microcapsules was 8.43μm measured by a laser particle, which confirmed the structure integrality and better integrality of microcapsules.
    23  Optimization of polysaccharide extraction from Mulberry Fungus and Evaluation of Its Probiotic and Antioxidant Activities
    ZHANG Jing-han YAO Zhong SUN Yun ZHU Ben-wei YUAN Heng YAO Yuan YAO Jing
    2018, 34(4):143-149. DOI: 10.13982/j.mfst.1673-9078.2018.04.023
    [Abstract](787) [HTML](192) [PDF 611.34 K](832)
    Abstract:
    The extraction process of of Mulberry fungus polysaccharide (MFP) sampled from Kunming, Yunnan Province, were optimized and the probiotic and antioxidant activities of the extracted polysaccharides were analyzed in this study. By single factor test combined with response surface methodology, the optimized water extraction conditions of MFP were obtained. When the extraction was performed with the solid-liquid ratio of 1:108 (m/V) at 100℃ for 3.5 h, the polysaccharide yield was 6.96%. After 10 repeated extractions, the polysaccharide yield was as high as 34.18%. High performance gel permeation chromatography (HPGPC) analysis showed the average molecular weight of MFP was 2.09×107 u. The monosaccharide composition analyzed by ion chromatography showed that MFP mainly contained glucose, xylose and mannose, their molar mass ratio was 1.18: 0.65: 2.88. Fourier transform infrared (FT-IR) results showed that the polysaccharide contained β-glucopyranoside bonds. The experimental data of the effects of MFP on probiotics indicated that MFP had prebiotic activity that could effectively promote the proliferation of Bifidobacterium bifidum and Bifidobacterium adolescentis. Furthermore, the in vitro antioxidant activity experiment showed that MFP at the concentration of 10 mg/mL had strong ABTS?+ and ?OH radical scavenging ability and the scavenging rates were 98.93% and 71.28%, respectively.
    24  Scaling-up Cultivation of Phaeodactylum tricornutum in Open Raceway Pond and Optimization of the Culture Conditions for Fucoxanthin Accumulation
    SONG Pei-qin LIU Lu WEI Dong
    2018, 34(4):150-158. DOI: 10.13982/j.mfst.1673-9078.2018.04.024
    [Abstract](721) [HTML](279) [PDF 949.76 K](1047)
    Abstract:
    As a kind of carotenoid which existed in various marine microalgae, fucoxanthin had many biological activities including scavenging free radicals, anti-cancer, anti-obesity and other physiological activities, especially in anti-tumor and slimming effect. Phaeodactylum triconutum (P. tricornutum) had the capability to accumulate plenty of fucoxanthin, while the environment and nutritional factors have a significant effect on the growth of microalgae and the content of fucoxanthin. In this study, effects of different salinity (20, 25, 30), pH values (7.5, 8.0, 8.5) and nitrogen source types (urea, ammonium bicarbonate) on the OD value, cell concentration, dry cell weight, fucoxanthin content of P. tricornutum were investigated in outdoor mass culture. The results showed that maximum cell concentration was 6.01×106 /mL, which was obtained in the culture medium with salinity of 20. There was no significant effect of different salinity on the increase of fucoxanthin content of P. tricornutum. Optimal pH value of the culture medium for P. tricornutum was 8.0. Maximum cell concentration and fucoxanthin content were 5.8×106 /mL and 17.79 mg/g, respectively. Compared with ammonium bicarbonate, urea as a nitrogen source was more suitable for the growth of P. tricornutum and the final cell concentration reached 4.1×106 /mL. However, in terms of fucoxanthin accumulation, ammonium bicarbonate as nitrogen source was more advantageous since the maximum fucoxanthin content reached 9.96 mg/g. Therefore, the optimum culture conditions in open raceway pond for P. tricornutum were summed up to be salinity of 20, pH 8.0 and ammonium bicarbonate as the nitrogen source.
    25  Effects of Different Extraction Methods on Physicochemical Properties and Anti-glycation Activity of Pectin Extracted from Hawthorn
    HOU Yu-ting SU Jin-fang CHEN Shi-yue HU Feng-qing ZHU Ru-gang
    2018, 34(4):159-166. DOI: 10.13982/j.mfst.1673-9078.2018.04.025
    [Abstract](950) [HTML](203) [PDF 588.56 K](779)
    Abstract:
    In this study, the pectin was extracted from dry hawthorn powder by three different extraction methods (hot water extraction, ultrasonic-assisted hot water extraction and xylanase-assisted hot water extraction) to investigate the effects of different extraction methods on the pectin extraction yield and physicochemical properties(including total sugar content, total phenol content, galacturonic acid content, degree of esterification and viscosity), and anti-glycation activity. The results showed that the enzyme-assisted hot water extraction had the highest extraction yield of 17.7%, and the corresponding degree of esterification and viscosity were also the highest. However the operation process of this method was tedious. The extraction yield of hot water extraction was the second highest (10.1%), and the total phenol content and the degree of esterification were the lowest. Although the ultrasonic-assisted hot water extraction had the lowest extraction yield of 6.4%, the contents of total sugar and polygalacturonic acid were the highest. In vitro anti-glycation activity of pectin extracted by ultrasonic-assisted hot water extraction was the strongest, and the inhibition rates of glycation in BSA-fructose and BSA-MGO analog system were 82.7% and 79.8%, respectively. The activity of anti-glycation was directly proportional to the content of galacturonic acid. Thus, the different extraction methods had great influence on the extraction yield, physicochemical properties and anti-glycation activity of hawthorn pectin.
    26  Gelatinization Characteristics of Potato Starch by Microscopic Observation Combined with Target Recognition Technology
    YUAN Bo TAO Jin-xuan LIU Hong-sheng
    2018, 34(4):167-171. DOI: 10.13982/j.mfst.1673-9078.2018.04.026
    [Abstract](597) [HTML](274) [PDF 635.69 K](1266)
    Abstract:
    A novel method of microscopy observation combined with target recognition based on Artificial Neural Network (ANNs) was developed to study the gelatinization characteristics of starch, and the on-line detection of the gelatinization characteristics of potato starch was realized by machine learning algorithm. In this paper, a detector based on deep neural network (starch-SSD) was designed to monitor the morphological changes of potato starch with the increasing of temperature. The starch birefringence characteristics were automatically identified first and then, the number of starches with birefringence characteristics in each micrograph during the process of gelatinization was calculated. The gelatinization temperature of starch and the degree of gelatinization (DG) at different temperatures were determined according to the change of birefringence. Results showed that compared with the traditional methods based on artificial vision observation, the proposed method had the advantages of high precision and fast speed. In addition, this method overcame the uncertainty of artificial subjective judgments and provided a uniform standard for judging the gelatinization characteristics of starch by microscopic. This study would provide the possibility of on-line monitoring during the industrialized production of starch products.
    27  Separation Process of Pea Protein Peptide with Enzymolysis Combined Extrusion
    LI Hui WANG Qi GUAN Jian WANG Xin-shuo ZHOU Quan-cheng
    2018, 34(4):172-178. DOI: 10.13982/j.mfst.1673-9078.2018.04.027
    [Abstract](602) [HTML](243) [PDF 558.30 K](784)
    Abstract:
    The purpose of this paper was to optimize the enzymolysis conditions of pea protein with enzyme combined extrusion by response surface methodology, so as to obtain the optimal antioxidant peptide with high free radicals scavenging capacity and an accurate enzymolysis prediction model. The enzymolysis conditions of neutral protease were optimized with the scavenging ratio of O2-.as evaluation index and with water content of 30% pea protein as raw by response surface methodology. The optimal enzymolysis conditions were as follows: enzyme amount 12.23% (E/S), temperature 40.23℃, pH 6.99, and substrate concentration 6.92% (g/mL). Under these conditions, the O2-.scavenging rate was 75.93%. The separation and determination of molecular weight of enzymolysis products were studied by the combination of dialysis and HPLC. The enzymolysis liquids with molar weights <1 ku, 1~3.5 ku, 3.5~7 ku, and<7 ku were separated. The results showed that the antioxidant activity of enzymolysis liquid less than 1 ku was the strongest, reaching 78.31%. The molecular weight was concentrated in about 200 ~ 800 u as 2 ~ 8 peptide. It is confirmed that the prediction model is accurate and reliable, and hydrolysates has high antioxidant activity, which can provides the reference value for the development of related production and process products. Dialysis can significantly improve the free radical scavenging rate.
    28  Response Surface Methodology for Optimization of Extraction Process of Total Flavonoids from Camphor Leaves by an Ionic Liquid/Aqueous Two-phase System
    LIU Bao-liang CAO Gui-ping
    2018, 34(4):179-187. DOI: 10.13982/j.mfst.1673-9078.2018.04.028
    [Abstract](704) [HTML](287) [PDF 606.12 K](857)
    Abstract:
    Flavonoids of camphor leaves was extracted by an ionic liquid/aqueous two-phase system in this paper. First, the stability of aqueous two-phase was investigated. Based on single-factor tests, Box-Benhnken center composite experiment was carried out with three factors and three levels of experimental design using extraction time, extraction temperature and pH as the influence factors. Besides, the content of flavonoids was determined by Al(NO3)3-NaNO2-NaOH spectrophotometric method. For a stable ionic liquid aqueous two-phase system, the phase-forming salt is ammonium sulfate ( (NH4)2SO4); the addition amount is 0.8 g; and the volume ratio of the [Bmim] BF4 to water was 2: 2. Response surface analysis showed that for 0.1 g of camphor leaves powder, the influence of factors that affected the extraction rate of flavonoids were in a descending order of extraction time, extraction temperature and pH. The optimized extraction conditions were as follows: extraction time 3.7 h, extraction temperature 82℃, and the solution acidity 9.6. Under the optimum conditions, the extraction rate of flavonoids reached 10.62%. At the same time, the secondary mathematical model for extraction of total flavonoids from camphor leaves with ionic liquid aqueous two-phase system was established, which has a good predictive effect on target product extraction, and provided theoretical guidance for the scale-up experiment or large-scale production of this system.
    29  Effects of Vacuum Freezing Combined with Hot Air Drying on the Quality of Strawberry
    ZHANG Li-hui LIU Du-juan LIAO Li WANG Chao AN Ke-jing QIAO Yu
    2018, 34(4):188-197. DOI: 10.13982/j.mfst.1673-9078.2018.04.029
    [Abstract](585) [HTML](209) [PDF 40.55 M](937)
    Abstract:
    The effects of vacuum freezing combined with hotair drying at different time and temperature on the quality of strawberry were investigated in this study, and the effects of the temperature and time of hot air on the quality of strawberry were compared with those of dried strawberry, such as color, anthocyanins, hardness, odor, volatile matter and moisture fluidity. Results showed that vacuum freezing combined with hot air drying (60 oC for 2.5 h, 70 oC for 2 h or 80 oC for 1.5 h) could better maintain the color of strawberry and reduce the loss of anthocyanin, and the hardness was moderate. According to the analysis of volatile flavor compounds by electronic nose and GC-MS, the volatile substances in strawberry were better preserved by vacuum freezing combined with hot air drying at 80 oC for 1.5 h. In addition, the results of low field nuclear magnetic resonance showed that the vacuum freezing combined with hot air drying at 80 oC for 1.5 h resulted in weaker moisture fluidity, which was similar to that of the lyophilized samples, and the structure of strawberry was well preserved. Consequently, vacuum freezing combined with hot air drying at 80 oC for 1.5 h had better advantages in maintaining the color, nutrition quality and volatile components of strawberry.
    30  Establishment of Growth Predictive Model of Staphylococcus aureus in Liangpi
    MENG Yun MA Jun-wei LIAO Chao ZHANG Kai-li TIAN Hui-li MI Wei-yu JI Hua WANG Zhou-ping
    2018, 34(4):198-205. DOI: 10.13982/j.mfst.1673-9078.2018.04.030
    [Abstract](697) [HTML](422) [PDF 683.32 K](769)
    Abstract:
    The growth curve of Staphylococcus aureus was fitted based on the Baranyi model, modified Gompertz model and Huang model to investigate the growth of Staphylococcus aureus in a traditional food Liangpi by determining the growth data at 5 oC, 10 oC, 15 oC, 20 oC and 25 oC. The correlation coefficients and parameters of the three models were compared, and the maximum specific growth rate (μmax) and lag phase (λ) obtained by the primary model were used to establish a temperature-dependent secondary model. The results showed that the bias factor (Bf) and accuracy factor (Af) of the primary model established by the modified Gompertz model were within a reasonable range. The square root model of temperature was established by using μmax and λ fitted by the modified Gompertz model, and the fitting R2 is 0.80 and 0.88, indicating that the Modified Gompertz model was most suitable for fitting growth curve. In addition, the variance analysis of the secondary model showed that the model could effectively predict the growth of S.aureus in Liangpi. This study provided theoretical basis for the quantitative risk assessment of S. aureus in Liangpi.
    31  Study on Hot-air Drying Characteristics and Dynamic Model of Daqu
    XIA Yu LUO Hui-bo ZHOU Ping HUANG Dan DENG Bo SHEN Cai-ping WU Jie-feng ZHANG Man
    2018, 34(4):206-214. DOI: 10.13982/j.mfst.1673-9078.2018.04.031
    [Abstract](641) [HTML](212) [PDF 720.18 K](815)
    Abstract:
    The hot-air drying dynamics model of Daqu during the period of drainage and cooling was established in this study to explore the correlation between hot-air drying and the lethality of Daqu pest by investigating the hot-air drying characteristics, the effective diffusion coefficient (Deff) and the activation energy (Ea) of Daqu. The results demonstrated that the drying stage of Daqu was mainly the deceleration-drying stage. The effect of drying temperature on Deff was obviously greater than the drying air speed, indicating the temperature had a great influence on the dehydration of Daqu, and the Ea was 59.744 kJ/mol. In addition, eight typical drying model equations were selected to describe the drying curve of Daqu during the desiccation-cooling period. The Midilli model had superior fitting effect and high fitting accuracy, and the Daqu pests in external and internal environment would completely die after hot-air drying process. Therefore, the paper investigated the drying technology of Daqu with external heating process, and the Daqu pests were effectively exterminated. The obtained results provided a theoretical basis for research and production control of hot-air drying process of Daqu.
    32  Effects of Sugar Addition on the Lipid Oxidation Stability and Sensory Quality of Cantonese Sausage
    LIU Yu-bin GE Ya-zhong SUN Wei-zheng
    2018, 34(4):215-220. DOI: 10.13982/j.mfst.1673-9078.2018.04.032
    [Abstract](705) [HTML](233) [PDF 411.38 K](1178)
    Abstract:
    Effects of different sugar dosages on the lipid hydrolase activity, lipid oxidation and sensory quality of Cantonese sausage was evaluated. The results showed that neutral lipase, acid lipase and phospholipase activities significantly decreased during the whole processing (p<0.05). Neutral lipase activity was higher than those of acid lipase and phospholipase. The amount of sugar addition significantly affected the changes of the three lipase activity during processing. The three lipase activities in the high-sugar addition group were slightly higher than those in the low-sugar addition group When the sugar addition amount was 3%, neutral lipase, acid lipase and phospholipase activities after baking were reduced by 77%, 81% and 96%, respectively. When the sugar addition amount was 12%, activities of neutral lipase, acid lipase and phospholipase were reduced by 67%, 65% and 78%, respectively. After the baking, the peroxide value, carbonyl value and hexanal content of the low-sugar addition group were higher, indicating that the reduction of the sugar addition leads to the increase of lipid oxidation. Sensory analysis showed that the reduction in sugar content caused more salinity and a more intense rancidity flavor which could affect the overall acceptability of Cantonese sausage products.
    33  Simultaneous Determination of Carbamazepine and Its Metabolites in Animal Matrix Using Ultra Performance Liquid Chromatography Tandem Mass Spectrometry
    YANG Sheng-ru YAO Xi-mei ZOU Jian LIU Hong-bin
    2018, 34(4):221-226. DOI: 10.13982/j.mfst.1673-9078.2018.04.033
    [Abstract](775) [HTML](259) [PDF 577.19 K](858)
    Abstract:
    Carbamazepine is a drug for the treatment of psychiatric illnesses, such as epilepsy, trigeminal neuralgia and so on. However, it also can stimulate the release of antidiuretic hormone, causing side effect of water-sodium retention. Water-sodium retention can lead to tissue edema and weight disorders, which provides the possibility of water retention and antidiuretic by illegal water injection in the breeding process. Therefore, it is of great significance to detect carbamazepine in animal tissues for cracking down on illegal water injection. A multiresidue method based on ultra performance liquid chromatography tandem mass spectrometry was developed for the determination of carbamazepine and its metabolites in animal matrix. In this method, samples were extracted by acidified acetonitrile, and purified by Oasis PRiME HLB SPE column, and then carbamazepine and its metabolites were analyzed by Acquity UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm) using methanol and 0.1% formic acid as the mobile phases. The signals were acquired through the MRM mode. All analytes could be well-separated by a gradient program during 8 minutes. The calibration curves of carbamazepine and its metabolites had a good linear in a concentration range of 1.0~50.0 μg/L with the correlation coefficient more than 0.999, and the limits of quantitation were all less than 1.0 μg/kg in animal matrix. The recoveries of 1.0, 10, 20 μg/kg fortified samples ranged from 72.3% to 106.8%, with RSDs of 1.43% to 10.3%. The new method provides a certain reference for the prevention of illicit drug addition and water injection in animal products.
    34  Determination of Abamectin Residues in Cabbage and Orange by Ultra Performance Liquid Chromatography
    QIN Guo-xin LAO Shui-bing MO Ren-fu ZHOU Qi-feng HE Jie YANG Yu-xia LUO Li-hong LI Tao
    2018, 34(4):227-231. DOI: 10.13982/j.mfst.1673-9078.2018.04.034
    [Abstract](1020) [HTML](233) [PDF 457.74 K](956)
    Abstract:
    A determination method for abamectin residues in cabbage and orange was established in this study by using ultra high performance liquid chromatography- ultraviolet (UPLC-UV). Samples were extracted with acetonitrile, and mixed with ethylenediamine-N-propylsilane (PSA) and C18 matrix dispersion scavenger for purification by using a ACQUITY UPLC BEH C18 column (2.1×100 mm, 1.7 μm). The column temperature was set as 35 ℃, the mobile phase was composed of acetonitrile-water (70:30, V/V) with a flow rate of 0.25 mL/min, and the ultraviolet detection wavelength was set as 245 nm. Abamectin had different matrix effects on cabbage and orange samples and therefore, external standard of the blank matrix-matched calibration curves was used for quantification. The results showed that abamectin had good linear relationship in the range of 0.25~10 mg/L, and the correlation coefficients were all more than 0.9999. In the range of 0.05~0.5 mg/kg, the average addition recovery was 83.0%~100.2%, and the relative standard deviation (RSD) was 1.17%~1.30%. The limits of detection (LOD) of abamectin in cabbage and orange (S/N=3) were 0.0109 mg/kg and 0.0160 mg/kg, respectively. The proposed method was simple, accurate and sensitive, which could be used for the analysis of abamectin in cabbage and orange.
    35  Changes of Aroma Substances during the Roasting Process of Xinglong Coffee
    WANG Ying DONG Wen-jiang FU Hong-yan CHU Zhong HU Rong-suo ZONG Ying
    2018, 34(4):232-241. DOI: 10.13982/j.mfst.1673-9078.2018.04.035
    [Abstract](744) [HTML](199) [PDF 785.56 K](1058)
    Abstract:
    The volatile components of different roasting degrees (JQ, Q, QZ, Z, ZS, S, JS, FZ) of coffee beans from Xinglong, Hainan province were analyzed in this study by headspace-solid phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS) combined with electronic nose. The results showed that 61, 68, 72, 72, 72, 68, 70 and 70 compounds were identified from JQ, Q, QZ,Z,ZS,S,JS and FZ samples, respectively. The main volatile components were pyrazines and acids in JQ, Q and QZ samples, which exhibited the nutty and sour flavor. The Z and ZS samples were mainly composed of furans, pyrroles and ketones, which had the caramel and burning flavor. And the S, JS and FZ samples were mainly composed of phenols and pyridines that were contributing to the smoky flavor and the pleasant flavor of clove. The electronic nose could be used to analyze the aroma of coffee with different roasting degrees, and the response of other 4 sensors to 8 different roasting coffee samples was significantly different except for the LY2/gCT and LY2/AA. This study clearly manifested the changing rules of aroma components of coffee beans from Xinglong, Hainan province, and provided theoretical support for the improvement of roasting technology of Xinglong coffee.
    36  Simultaneous Determination of Chloropropanolate and Glycidyl Ester in Food by Gas Chromatography-Tandem Mass Spectrometry
    LIU Qing RUAN Jun ZENG Guang-feng ZHANG Yang-zi WEI Wen-xin WANG Zhi-yuan CHEN Wen-rui KANG Wen-yu
    2018, 34(4):242-248. DOI: 10.13982/j.mfst.1673-9078.2018.04.036
    [Abstract](922) [HTML](215) [PDF 511.17 K](1041)
    Abstract:
    A gas chromatography-tandem mass spectrometry (GC-MS/MS) method was established for the simultaneous determination of 3-chloropropanol ester (3-MCPDE), 2-chloropropanol ester (2-MCPDE) and gycidyl ester (GE) in various fatty foods in this study. The 3-MCPDE, 2-MCPDE and GE in vegetable oils, bakery foods, fried- puffed foods and milk powder were determined by GC-MS/MS after the optimization of extraction, transesterification and derivatization of samples and conditions of GC-MS/MS. The limits of quantitation (LOQs) of the four types of food products were 10, 20, 50 and 100 μg/kg, respectively, and the total mean recoveries were in the range of 68.9% ~116.5% with the relative standard deviation (RSD n=6) of 2.11%~13.90%. The results showed that the samples had good linear correlation within a wide linear range, and the correlation coefficients (R) were higher than 0.99. The proposed method had the advantages of high extraction efficiency, good purification effect, high detection sensitivity and accuracy, which could be used for qualitative and quantitative determination of 3-MCPDE, 2-MCPDE and GE in vegetable oils, milk powder, fried- puffed foods and bakery foods.
    37  Establishment and Optimization of an In-vitro Method for Screening Anti-hyperuricemic Peptides
    YANG Liu KANG Xiao-yan LIANG Ming ZHANG Ting REN Jiao-yan
    2018, 34(4):249-257. DOI: 10.13982/j.mfst.1673-9078.2018.04.037
    [Abstract](815) [HTML](179) [PDF 779.40 K](887)
    Abstract:
    Because UV spectrophotometry, NBT/PMS colorimetry, fluorescence analysis, MTS/PMS reduction and other xanthine oxidase (XO) inhibitory activity assays had limitations for the detection of peptides, a method for the screening and determination of anti-hyperuricemic peptides in vitro was established and optimized in this study. The in vitro xanthineoxidase inhibitory activity of peptides was determined by double enzymecoupling method combined with high performance liquid chromatography (HPLC). The optimal reaction conditions were determined by double-enzyme coupling method. The optimum reaction conditions were as follows: 0.22 mmol/L xanthine, 0.52 u/mL xanthine oxidase (XO), Tris-HCl pH 8.0, reaction temperature 30℃, and reaction time 20 min for catalytic reaction. Meanwhile, the optimal conditions for the determination of uric acid by HPLC were determined as follows: 95% 15 mmol/L NH4H2PO4 and 5% methanol at pH 6.5, 1 mL/min of flow rate, column temperature 25℃, and detection wavelength 290 nm. The results of double-enzyme coupling assay combing with HPLC method showed a good stability and higher accuracy than single HPLC and double-enzyme coupling detection method with the accuracy more than 95%. Double-enzyme coupling method combined with HPLC could effectively and accurately detect the activity of peptide-reduced uric acid. This novel detection method demonstrated that reduced glutathione (GSH) and oxidized glutathione (GSSG) had xanthine oxidase inhibitory activity which could be used as uric acidlowering peptides.
    38  Determination of Ascorbic Acid Content in Food by the Optimized HPLC Method
    CUI Ling-jun SUN Hai-xin LI Jie ZHAO Mei-li ZHOU Yan-pei
    2018, 34(4):258-263. DOI: 10.13982/j.mfst.1673-9078.2018.04.038
    [Abstract](1193) [HTML](319) [PDF 511.53 K](948)
    Abstract:
    A method for the simultaneous determination of L-ascorbic acid, D-ascorbic acid and dehydroascorbic acid in food was established in this paper by optimizing and improving the sample extraction, extraction agent and mobile phase. Compared with mechanical homogenate, the liquid nitrogen freeze-grinding pretreatment could significantly improve the extraction rate, reduce the dosage of chemical reagents and simplify the pretreatment process for fruit and vegetable samples. 0.019 mol/L sodium thiosulfate was added as a protective agent in the metaphosphoric acid to protect L-ascorbic acid from being oxidized. The results showed that the experiment did not be protected from light, and the extract remained stable within 24 h at 4 oC. The baseline separation for different configurations of ascorbic acid in high concentration could be achieved by using potassium dihydrogen potassium–decylamine as the buffer solution. Ascorbic acid showed a good linear relationship in the range of 0.5 mg/L to 200 mg/L and the detection limit was 0.04 mg/100g. The average recoveries were 99.7%~107.3% and the relative standard deviation was 3.80% (n=5). Consequently, it was of great significance to establish a standardized operating procedure for accurately determining the content of active ascorbic acid in food.
    39  Development of a Double-Antibody Sandwich Enzyme Linked Immunosorbent Assay for Detection of Staphylococcal Enterotoxin P
    DU Xuan ZHAO Yan-ying LIU Ji LONG Hu WANG Hong-zhi TIAN Wan-fan TANG Jun-ni
    2018, 34(4):264-269. DOI: 10.13982/j.mfst.1673-9078.2018.04.039
    [Abstract](591) [HTML](286) [PDF 447.40 K](883)
    Abstract:
    A double-antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) method was developed for detection of a new staphylococcal enterotoxin P (SEP). The experimental conditions were evaluated through the index of sensitivity, intra-assay variation, inter-assay variation and spike recovery by optimizing the concentration of monoclonal antibody and antiserum, the horseradish peroxidase (HRP) labeled goat anti-rabbit IgG (IgG/HRP), different types of buffer, blocking time, antigen incubation time, IgG / HRP incubation time, and TMB chromogenic time. Our results were as follows: the optimal concentration of anti-SEP monoclonal antibody 3.28 μg/mL, the concentration of anti-SEI rabbit serum 3.14 μg/mL, the dilution of enzyme-labeled secondary antibody 1: 3000,the blocking time 1 h, the antigen incubation time 90 min, the secondary antibody incubation time 30 min and the TMB chromogenic time 15 min. And 1 × phosphate buffer solution (pH 7.4) was shown as the best buffer. The regression equation of this method was y=0.0313x+0.0262 with R2of 0.9946. The sensitivity of the developed method was 1.80 μg/mL. The precision within the batch variation was less than 6 %, and inter-assay variation was less than 15 %. The recovery rates for LB broth, beef and cooked rice were more than 90%. Thus, this study successfully established a DAS-ELISA method for rapid detection of newly identified staphylococcal enterotoxin P.
    40  Matrix Effects of Pyrethroid Pesticides in Aquatic products using Gas Chromatography
    LI Li-chun LIU Shu-gui YIN Yi ZHENG Guang-ming MA Li-sha DAI Xiao-xin SHAN Qi ZHAO Cheng
    2018, 34(4):270-280. DOI: 10.13982/j.mfst.1673-9078.2018.04.040
    [Abstract](828) [HTML](140) [PDF 786.30 K](727)
    Abstract:
    A rapid method was developed for the detection of 9 pyrethroid pesticides in aquatic products in this study. The matrix effects of Ctenopharyngodon idellus, Carassius auratus, Hypophthalmichthys molitrix, Oreochromis spp and Penaeus orientalis on 9 pyrethroid pesticides were studied, and the effects of matrix types, pesticids concentration and matrix concentration on the matrix effects were analyzed. The results showed that the 9 pyrethroid pesticides had a good linear relationship with the concentration in range of 5.0~750 ng/mL (tefluthrin of 2.5~750 ng/mL, pemethrin of 10~750 ng/mL) with the correlation coefficients of 0.9996~0.9999. The average recoveries of standard addition were 80.1±2.95%~116±2.45 % with the concentration of 5.0, 50 and 100 μg/kg, and the intra-day and inter-day precision were 0.272%~10.7 % and 0.164%~12.8 %, respectively. Different five kinds of aquatic products had different degree of matrix effects on 9 pyrethroids, and the matrix effects were in the range of 0.906~2.45. The matrix effects increased with the increase of matrix concentrations, and the Oreochromis spp, Hypophthalmichthys molitrix and Penaeus orientalis improved the matrix effects. In addition, the concentrations of target analysis had a significant influence on its matrix effect, and the matrix effect decreased with the increase of pesticide concentrations. Therefore, the matrix additive method should be used to reduce or eliminate the matrix effect to ensure the accuracy of quantitative result.
    41  Detection of Six Steroid Hormone Residues in Butter Samples by Gel Permeation Chromatography Purification and Gas Chromatography-Mass Spectrometry
    ZHAO Chao-min GU Shu-qing ZHENG Jiang DENG Xiao-jun YUE Zhen-feng LAI Fu-rao MIN Tian LIU Shao-jie
    2018, 34(4):281-286. DOI: 10.13982/j.mfst.1673-9078.2018.04.041
    [Abstract](581) [HTML](212) [PDF 639.70 K](767)
    Abstract:
    A gel permeation chromatography purification (GPC)-gas chromatography-mass spectrometry (GC/MS) method was developed for the determination of 6 steroid hormone residues (androsterone (A), dehydroepiandrosterone (DHEA), testosterone (T), progesterone (P), estrone (E1) and β-estradiol (β-E)) in butter samples. The butter samples were extracted by oscillation with ethylacetate/cyclohexane (1:1, V/V). The extract was purified and degreased by GPC column. The GPC concentrate was evaporated to dryness under a stream of nitrogen. Derivatization of the residue was carried out with pyridine and aceticanhydride. Finally, the derivative was separated using a GC column (HP-5MS, 30 m×0.25 mm, 0.25 μm), and the qualitative and quantitative analysis was conducted under the model of selective ion monitor (SIM). Steroid hormone residues were quantified using external standard method, which had good linearity in the concentration range of 10-500 μg/kg with correlation coefficiency larger than 0.999. The quantification limit was 4-10 μg/kg. At the spike levels of 10 μg/kg, 50 μg/kg and 200 μg/kg, the recoveries of hormones were in the range of 77.2-112% and the relative standard deviation (RSD) was from 4.2% to 10%. The above results showed that the method was accurate, reliable and suitable for the determination of 6 hormone residues in butter samples.
    42  Review: Freshness Indicator Intelligent Packaging
    LI Yang FENG Gang WANG Lei-ming ZHANG Xi
    2018, 34(4):287-293. DOI: 10.13982/j.mfst.1673-9078.2018.04.042
    [Abstract](1118) [HTML](455) [PDF 452.14 K](1501)
    Abstract:
    Food freshness indicator intelligent packaging is developed based on characteristic color reactions, temperature-activated biological reactions and enzyme activations caused by characteristic gas and specific reagents released during the storage process of food products, and thus can be used to help consumers intuitively, accurately and scientifically judging the quality and freshness of foods. Food freshness indicators had important application values in real life. In this paper, based on the induction and analysis of the domestic and foreign freshness indicator intelligent packaging, the instruction principle research status and indications of the freshness indicator were explained from two aspects: the food freshness indicator application type and the freshness indicator substrate. The production process and material selection of the agent substrate, summarized the existing research results, pointed out the problems that still existed in the research and the direction of future research prospects and put forward reasonable research suggestions, aiming to study food freshness indicator technology more deeply and provide the reference.

    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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