Volume 0,Issue 12,2020 Table of Contents

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  • 1  Ginsenoside F2 Intervenes the NF-κB Pathway to Inhibit H2O2-induced Apoptosis
    LIU Di YU Zi-xiang ZHANG Hao ZHANG Han-xue KONG Fan-li FENG Xian-min
    2020, 36(12):1-6. DOI: 10.13982/j.mfst.1673-9078.2020.12.0537
    [Abstract](365) [HTML](306) [PDF 3.98 M](1024)
    Abstract:
    In this study, the effects of ginsenoside F2 on p65 protein in the NF-κB apoptosis signaling pathway were examined by qRT-PCR and Western blot techniques, and through measuring the effects of ginsenoside F2 on the release rate of lactate dehydrogenase (LDH) and and mitochondrial membrane potential (MMP) of apoptotic cells. It was found that the H2O2 injured cells had a significantly increased LDH release rate (by 42.72%), decreased mitochondrial membrane potential, and decreased relative fluorescence value (by 44.03%), and increased protein and mRNA expression of NF-κB p65 (as 122.73% and 1.66, respectively), compared with the control group (p<0.05). After pretreatment of cells with 1.25, 5, and 20 μmol/L F2, the LDH release rates of the injured group were significantly lowered (p<0.05), to 82.71%, 75.69%, and 69.61% respectively, while the mitochondrial membrane potential values were significantly increased (p<0.05) (with the corresponding relative fluorescence values as 60.22%, 62.76% and 70.96%, respectively). With the increase of F2 concentration, the protein expression of p65 in the NF-κB pathway decreased to 79.49%, 71.92% and 58.39%, respectively (p<0.05), and the mRNA expression was down-regulated to 1.30, 1.18 and 1.01, respectively (p<0.05). The results showed that ginsenoside F2 exhibited an anti-apoptotic effect though reducing the LDH release rate of apoptotic cells, increasing the mitochondrial membrane potential, and inhibiting the activation of NF-κB signaling pathway. This study provides an experimental basis for suppressing effect of ginsenosides on oxidative stress-induced apoptosis.
    2  Hypolipidemic Effects of Dietary Fiber from Suaeda sulsa in Hyperlipidemic Rats
    YIN Long-fei CHANG Zi-chen FAN Ying-ying WENG Zhi-chao ZOU An-ning PAN Jian-jian LIU Chun-yan
    2020, 36(12):7-12. DOI: 10.13982/j.mfst.1673-9078.2020.12.0320
    [Abstract](265) [HTML](228) [PDF 683.25 K](562)
    Abstract:
    To explore the hypolipidemic effects of the dietary fiber from Suaeda salsa on rats with hyperlipidemia, 56 male SD rats were randomly divided into 7 groups: normal group, Suaeda salsa dietary fiber prevention group, high-fat model group, positive control group, and three intervention groups with high, medium and low concentrations of dietary fiber in Suaeda salsa. After 6 weeks of intervention, the body weight, food intake, organ weight, periepididymal fat weight, liver coefficient, arteriosclerosis index and serum lipid levels of the rats in each group were measured. Results: Compared with the high-fat model group, the body weight, food intake, heart, liver, spleen, lung, kidney, periepididymal fat weight, liver coefficient, and arteriosclerosis index of the intervention group all decreased, with the largest decreases being 26.21%, 26.66%, 27.01%, 46.03%, 35.71%, 3.43%, 22.69%, 57.14%, 39.92% and 76.94%, respectively. In terms of blood lipids, the TC, TG, and LDL-C values of the higher-fat model group in the intervention group all decreased, with the largest decreases being 19.12%, 87.20%, and 60.50%, respectively. Compared with the positive group, LDL-C decreased by 38.16% and HDL-C increased by 27.01% in the high-dose group (p<0.05). Compared with the normal group, the organ weights of the prevention group were reduced to different extents. The TG and LDL-C values of the prevention group (68.85% and 31.64%, respectively) were lower, whilst the HDL-C increased by 12.88%, compared with those of the normal group. These results indicated that the dietary fiber of Suaeda salsa had desirable effects on monitoring body weight, food intake, organ weight, perididymal fat weight, liver coefficient and arteriosclerosis index of hyperlipidemic rats, and exhibited a lipid-lowering effect on hyperlipidemia.
    3  Inulin Regulating Action of Gut Mirobiota in Inflammatory Bowel Disease Mice
    WU Rui-li LIU Tong WANG Zhen CHENG Zheng-yu CHEN Tuo YANG Jia-li YANG Shao-qi
    2020, 36(12):13-21. DOI: 10.13982/j.mfst.1673-9078.2020.12.0598
    [Abstract](493) [HTML](289) [PDF 81.33 M](1099)
    Abstract:
    The effects of dietary inulin on gut microbiota in inflammatory bowel disease (IBD) in mice were investigated. The mice were fed dextran sulfate sodium (DSS) to establish IBD mice model. In this study, C57BL/6 mice were randomly divided into three groups: blank control group (CON) was administered with distilled water, model group (IBD) was treated with distilled water containing 2.5% DSS, as well as inulin treated with model group (INU) was administered with 2 g/kg inulin and 2.5% DSS. The body weight, fecal consistency and hematochezia of mice in diverse groups were monitored daily. After intervention, the pathological features of colon tissue were observed by hematoxylin-eosin staining, as well as intestinal flora diversity in feces of mice was analyzed by 16s rDNA high throughput sequencing. The results showed that inulin administration significantly increased the body weights (p<0.05), ameliorated diarrhea, hematochezia and colonic tissue damage, as well as reduced disease activity index in IBD mice (p<0.05). The sequencing results indicated that after inulin supplementation, the relative abundance of Lactobacillus and Bifidobacterium were increased to 28.70% and 0.06% (p<0.05), respectively, compared with IBD group, whilst the proportion of Proteobacteria was decreased to 0.66% in comparison with IBD group (p<0.05). In conclusion, inulin administration altered the composition of gut microbiota in IBD mice via increasing probiotic Lactobacillus and Bifidobacterium and decreasing Proteobacteria.
    4  Inhibitory Effect of Saffron Water Extract on Proliferation of Human Ovarian Cancer Cell Line HO-8910
    XU Jing CHANG Qing
    2020, 36(12):22-26. DOI: 10.13982/j.mfst.1673-9078.2020.12.0511
    [Abstract](322) [HTML](176) [PDF 925.16 K](1091)
    Abstract:
    The inhibitory effect of saffron water extract on the proliferation of HO-8910 human ovarian cancer cell was investigated. The experiment was divided into cell group, saffron water extract low-dose group (0.4 mg/L), medium dose group (0.8 mg/L) and high-dose group (1.0 mg/L). After HO-8910 cells were successfully cultured, they were treated with different concentrations of affron water extract. The proliferation ability of ovarian cancer cells and the content of extracellular regulated protein kinase (ERK), Bcl-2 and Bax protein were detected. The results showed that in the experimental concentration range, the growth rate of ovarian cancer cells was significantly inhibited with the increase of saffron water extract concentration. At 24 h, 48 h and 72 h, the proliferation rates of high dose group were 14.13%, 12.15%, and 11.16%, respectively, which were significantly lower than those of other experimental groups (p<0.05). Furthermore, the inhibition rates of saffron water extract on ovarian cancer cell apoptosis and invasion were 20.11% and 64.24%, respectively. The protein expression levels of ERK, Bcl-2 and Bax were 0.61, 0.48 and 0.95, respectively, which were significantly different than those of other experimental groups (p<0.05). These results indicated that saffron water extract could significantly inhibit the activity of ovarian cancer cells, reduce the proliferation and invasion ability of ovarian cancer cells, and its mechanism might be related to ERK signaling pathway.
    5  Analysis Microbial Community on the Surface of Large Yellow Croaker (Larimichthys crocea) Based on High-throughput Sequencing
    MAO Jun-long QI Xue-er ZHANG Bin SHUI Shan-shan
    2020, 36(12):27-35. DOI: 10.13982/j.mfst.1673-9078.2020.12.0565
    [Abstract](290) [HTML](280) [PDF 93.36 M](908)
    Abstract:
    To investigate the effect of theaflavin on the microbial composition on the surface of large yellow croaker (Larimichthys crocea) in low-temperature storage, microbial composition and changes in different samples were obtained by microbial extraction and high-throughput sequencing analysis after soaking the refrigerated and frozen yellow croaker with 0.3 mol/L theaflavin and 0.3 mol/L Vc solution. The results showed that the effective sequence range was 22879~55910, and the operational taxonomic unit (OTU) range was 28~49 in large yellow croaker. The number of OTUs in the frozen large yellow croaker after Vc soaking was the lowest. The Chao1 value, Shannon index, and Simpson index of refrigerated and frozen large yellow croaker treated with theaflavin were significantly changed compared with the blank group, among that Shannon index decreased by 17.80% and 13.79%, Simpson index increased by 50.80% and 71.72% respectively, indicating that theaflavin had a significant effect on the colony diversity and richness of bacteria on the surface of large yellow croaker. The surface colony distribution of the large yellow croaker was changed, the relative abundance of Myroides, Psychrobacter and Flavobacterium on the surface of refrigerated large yellow croaker treated with theaflavin decreased from 20.55%, 11.02% and 7.38% to less than 1%, and the growth of Acinetobacter was inhibited by theaflavin treatment. Taken together, theaflavin had a good antioxidative effect on the microbial composition on the surface of large yellow croaker with high-fat content, which could inhibit bacteria growth and prolong the storage time of large yellow croaker. The research provides a basic reference for the quality assurance of large yellow croaker and the development of compound biological preservative.
    6  Molecular Typing and Drug Resistance of Cronobacter spp. in Commercial Formula Rice Flour Products for Infants and Young Children
    LIANG An-li NONG Zhen-ni WEN Gui-zhen YANG Xian-biao HAN Zhi-chao XIE Si
    2020, 36(12):36-42. DOI: 10.13982/j.mfst.1673-9078.2020.12.0504
    [Abstract](218) [HTML](344) [PDF 767.82 K](694)
    Abstract:
    To understand the contamination, molecular typing and drug resistance of Cronobacter spp. in formula rice flour products for infants and young children, the formula products from six different manufacturers and brands with different ingredients were collected in the markets of Guangxi city for isolation of Kronobacter, and fusA gene amplification, sequencing and MLST database comparative analysis. The molecular typing of the isolates was detected by pulsed field gel electrophoresis (PFGE), and the minimal inhibitory concentration (Minimal Inhibitory Concentrations, MICs) of the isolates against 8 common antibiotics was analyzed by the broth microdilution method. Two hundred sixty-eight samples of formula rice flour products were collected and 32 strains of Cronobacter spp. were isolated, with the detection rate as 11.94%. The strain identification results showed 32 isolated strains, including 22 strains of C. sakazakii, 6 strains of C. malonaticus, 3 strains of C. dublinensis and 1 strain of C. muytjensii. The contamination of the formula rice flour products with different ingredients differed significantly, with those ingredients fortified with Huailian or fruits and vegetable having the highest contamination rates (17.78% and 15.38%, respectively). PFGE analysis showed that 32 strains were divided into 32 different molecular types, with the similarity in the range of 61.20%~92.30%. All the isolates were sensitive to ciprofloxacin, gentamycin and cefotaxime, with some (6.25%~43.75%) being moderately sensitive to chloramphenicol,tetracycline, trimethoprim/sulfamethoxazole, cefoxitin and nalidixic acid, and two being resistant to chloramphenicol. The results showed a certain degree of contamination of Cronobacter spp. in the formula rice flour products, especially those fortified with nutrients. The source of contaminated Cronobacter spp. is broad, with some strains from the formula rice flour products being moderately sensitive or even resistant to some antibiotics, indicating that the sensitivity of Cronobacter spp. to antibiotics was on a weakening trend.
    7  Antibacterial Activity of Trypsin Inhibitor from Potato
    LI Qi-meng LUO Zhi-gang LI Xiao-lin
    2020, 36(12):43-51. DOI: 10.13982/j.mfst.1673-9078.2020.12.0098
    [Abstract](189) [HTML](298) [PDF 9.16 M](1040)
    Abstract:
    In this study, the antibacterial activity and underlying mechanism of the potato trypsin inhibitor (PTI) was investigated. To evaluate the antibacterial activity of PTI, the inhibition zone diameter (DIZ) was determined through the filter paper diffusion method, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by the double microdilution method. The antibacterial mechanism of PTI was explored through observations by scanning electron microscopy, and measurements of cell membrane’s permeability and integrity, intracellular reactive oxygen content as well as inhibition rate of bacterial protease. The results showed that PTI exhibited significant inhibitory effects against Bacillus subtilis, Bacillus cereus and Pseudomonas aerimonas with the corresponding diameters of bacteriostatic zone as 12.56 mm, 12.35 mm and 11.76 mm, respectively, MIC ranging from 1.88 to 3.75 mg/mL, and MBC being the same for the three bacteria (3.75 mg/mL). PTI destroyed the morphology of bacterial cells and led to the increases of relative conductivity and leakage of nucleic acid in the bacterial suspension, which affected the membrane permeability of bacteria. Fluorescence microscopic images showed that PTI at the concentration of MIC destroyed the integrity of the bacterial cell membrane, promoted the production of intracellular ROS, causing oxidative damage to the bacterial cells. PTI showed a certain inhibitory effect on the activity of bacterial protease. Based on the experimental results, it is concluded that PTI probably exerts its antibacterial activity through such a multi-target synergistic effect.
    8  Enrichment and Microbial Degradation of 2,4,6-trinitrotoluene (TNT) in Four Aquatic Products
    LI Yu-nuo LI Da-jun SUN Ping LIU Yong-hao ZHANG Qiu-yu XU Miao
    2020, 36(12):52-59. DOI: 10.13982/j.mfst.1673-9078.2020.12.0519
    [Abstract](235) [HTML](245) [PDF 4.42 M](775)
    Abstract:
    To ensure the safety of aquatic products, an efficient extraction method for 2,4,6-trinitrotoluene (TNT) was established in this study. The TNT enrichment ability of four commercially available aquatic products: Ruditapes philippinarum, Mactra veneriformis Reeue, Solen strictus and Mercenaria mercenaria was analyzed by high performance liquid chromatography (HPLC). The TNT pollutants in water were degraded efficiently by microorganisms. The results showed that the extraction rate of this method reached 97.80%. Among the four aquatic products, Ruditapes philippinarum, Mactra veneriformis Reeue, Mercenaria mercenaria could accumulate TNT to different extents, with Mactra veneriformis having the highest concentration of accumulated TNT (76.26 ng/g). In order to degrade TNT pollutants in water, 9 aromatic compounds-degrading natural strains were selected for the biodegradation of TNT. The results showed that all the 9 natural strains could degrade TNT, with H5, LM1, and CT1 exhibiting higher efficiency, especially Vibrio H5 (which had the highest degradation efficiency, 80.90%, at 27 ℃ for 9 h). In this study, a simple, efficient and reproducible extraction-detection procedure with a good application prospect was established. In the meantime, the biodegradation method could efficiently removed TNT pollutants in water without secondary pollution, thereby ensuring the safety of water bodies.
    9  Optimization of Gallic Acid Production by Enzymatic Hydrolysis of Tara Tannin
    CHEN Pei-xu LIU Chun-li WANG Si-yuan YANG Qiu-ming ZHANG Yong-hui XIAO An-feng
    2020, 36(12):60-68. DOI: 10.13982/j.mfst.1673-9078.2020.12.0582
    [Abstract](442) [HTML](232) [PDF 36.04 M](793)
    Abstract:
    Gallic acid had wide application in food, chemistry and pharmaceutical industries. Compared with the traditional chemical production approach, the enzymatic hydrolysis had the advantages of environmental friendness and fewer by-product. In this work, a previously developed thermal stable tannase Tan1 was used for the simultaneous leaching-enzymolysis of Tara tannin and the hydrolysis conditions were optimized for the high efficiency enzymatic production of gallic acid. First, the preliminary hydrolysis conditions were optimized by single factor test as followed: Tara powder liquid ratio 1:30, reaction temperature 60 ℃, enzyme dosage 4 mL and reaction pH=5. Based on the single factor test, the Plackett-Burman design was performed to investigate the effects of different factors on the reaction conditions of tannase hydrolysis of Tara powder. It was found that temperature, pH and ratio of material to liquid were the significant factors that affect the hydrolysis process. Furthermore, the optimal hydrolysis conditions were optimized by response surface design as follows: Tara powder liquid ratio 1:40, reaction temperature 65 ℃, pH=4, the yield of gallic acid was 65.89%. The continuous feeding reaction was also investigated under the optimal hydrolysis conditions. The results indicated that Tara tannin could be hydrolyzed into gallic acid with high efficiency during six batch feeding process. This research laid the foundation for the industrialization of gallic acid produced by enzymatic hydrolysis of Tara tannin.
    10  Enzymatic Preparation of Phloretin from Naringin and Their Antioxidant Activity Analysis
    LI Hui-ling ZHOU Jin-lin LU Yu-jing CHEN Hong-ji YE De-xiao LIN Yu-cheng
    2020, 36(12):69-76. DOI: 10.13982/j.mfst.1673-9078.2020.12.0609
    [Abstract](481) [HTML](276) [PDF 16.50 M](837)
    Abstract:
    A highly efficient and environmentally friendly method for the preparation of high-value natural antioxidant phloretin was described in this work. Naringin dihydrochalcone was prepared from naringin which is a kind of natural citrus extract by one pot hydrogenation, and then was hydrolyzed by α-rhamnosidase and cellulase to product phloretin. The process conditions including pH, temperature and substrate to enzyme ratio of α-rhamnosidase and cellulase were optimized by single factor and orthogonal experiments. The antioxidant activity of phloretin, trilobin, naringin dihydrochalcone and naringin were also studied. The results showed that the optimum conditions of α-rhamnosidase were as follow: temperature of 60 ℃, pH of 4.0, and the substrate to enzyme ratio of 0.6:1. The optimum conditions of cellulase were as follow: temperature of 45 ℃, pH of 5.5, and the substrate to enzyme ratio of 0.3:1. Under these optimum conditions, the conversion of phloretin was 96.1%, which increased by 10.53% compared to the original method. The orders of antioxidant activity were as follows: the DPPH free radical scavenging capacity of phloretin (0.18±1.45) > trilobatin (0.3±1.63) > naringin dihydrochalcone (0.95±1.24) > naringin (8±1.97), the reduced iron ion capacity of phloretin (7.1±0.68) > trilobatin (2.51±0.75) > naringin dihydrochalcone (2.05±0.58) > naringin (0.11±0.92). The new preparation method of phloretin was mild, short-cycle, high-conversion and was easy to scale up. Phloretin produced by this method had a good antioxidant activity. This work will be helpful to the enlarge production and application of phloretin.
    11  Changing Trends in the Phenolic Substances and Antioxidant Activities of Chokeberry (Aronia melanocarpa) Subjected to in Vitro Simulated Digestion
    RAO Xue-tian ZENG Xin-an LIN Song-yi LIU Zhong-hua SUN Jia-jiang
    2020, 36(12):77-83. DOI: 10.13982/j.mfst.1673-9078.2020.12.0012
    [Abstract](328) [HTML](291) [PDF 5.22 M](1064)
    Abstract:
    The effects of in vitro simulated gastrointestinal digestion on the phenolic content and antioxidant activity of Chokeberry (Aronia melanocarpa) were investigated. The contents of total phenolics and flavonoids before and after digestion of the chokeberries were evaluated by the Folin phenol and aluminum chloride-sodium nitrite methods. The effect of gastrointestinal digestion on the antioxidant activity of chokeberry (Aronia melanocarpa) was examined by the DPPH· and ABTS+ free radical scavenging capacity assays. The experimental results showed that the contents of polyphenols and flavonoids in chokeberry showed different trends during the in vitro simulated digestion. The polyphenols of chokeberry exhibited higher stability during the simulated gastric digestion, with the flavonoid content increasing significantly (p<0.05) and no significant changes in DPPH· and ABTS+ scavenging activities (p>0.05). After the simulated intestinal digestion, the contents of polyphenols and flavonoids increased significantly (p<0.05) (by 1.33 and 1.38 times, respectively), with the DPPH· and ABTS+ scavenging rates decreasing by 36.84% and 8.55%, respectively (p<0.05). The pepsin, gastric acid, and trypsin in the gastrointestinal tract may promote the release of polyphenols and flavonoids in chokeberry to certain extents, whereas, trypsin can reduce the antioxidant activity of the fruit, which may be related to the decomposition of organic acids. The results of this study provide a scientific basis for the development and application of natural products of chokeberry.
    12  Acetylation Modification of the Polysaccharides from Portulaca oleracea L. and Their Antioxidant Activities
    LI Yin-Li ZHANG An-yong NIU Qing-chuan LI Yu-ping
    2020, 36(12):84-91. DOI: 10.13982/j.mfst.1673-9078.2020.12.0480
    [Abstract](311) [HTML](253) [PDF 8.18 M](1028)
    Abstract:
    Portulaca oleracea L. was used as the raw material. Polysaccharides from Portulaca oleracea L. (POP) were extracted by hot water, and acetylated with acetic anhydride to yield Ac-POP. Taking the degree of substitution as an index, the effects of reaction time, reaction temperature and material-liquid ratio on the degree of substitution of Ac-POP were investigated by the single factor experiments. The conditions for acetylation modification of POP were further optimized, and the antioxidant activities of POP and Ac-POP were evaluated. The experimental results showed that the optimal conditions for the acetylation modification of POP were: reaction time 2.78 h, reaction temperature 51.90 ℃, material-liquid ratio 1: 28.15 (g/mL). Under such optimal modification conditions, the degree of substitution of Ac-POP was 0.60. The infrared spectroscopy analysis of the original polysaccharide and acetylated polysaccharide showed that the acetylation of the polysaccharide from Portulaca oleracea L. was successful. The POPs before and after modification had a certain ability to scavenge free radicals and exhibited a certain dose-dependent relationship. In the range of 0.05~5.0 mg/mL, the maximum scavenging rates were 69.73% and 64.54% for POP and Ac-POP against DPPH free radicals, respectively, 43.48% and 25.04% against ·OH, respectively, and 78.86% and 79.16% against O2-·, respectively. As the concentration increased, the antioxidant activity of Ac-POP increased gradually. Antioxidant activity studies revealed that compared with POP, the scavenging capacities of Ac-POP against DPPH free radicals and ·OH decreased, but that against O2-· increased.
    13  Comparison of Biochemical Composition and Sensory Quality of Shuixian White Tea Made by Different Processes
    FENG Hua WANG Fei-quan ZHANG Bo ZHENG Hui CHEN Rong-bing
    2020, 36(12):92-102. DOI: 10.13982/j.mfst.1673-9078.2020.12.0941
    [Abstract](347) [HTML](210) [PDF 2.97 M](695)
    Abstract:
    The banjhi leaves of Fujian-shuixian tea cultivar were plucked as raw materials to produce white tea using the traditional white tea technology (CK) or the green leaf shaking technology (ST) during the withering process, respectively. The differences in the biochemical components, aroma components and sensory qualities of the two kinds of white tea were compared and analyzed, aiming to provide a reference for the development of high-aroma Shuixian white tea. The results showed that, compared with CK, ST decreased significantly the contents of tea polyphenols, flavonoids and caffeine, as well as the polyphenol-ammonia ratio and ratio of ester catechins to non-ester catechins, were reduced by ST, but increased the contents of free amino acids and theaflavins in Shuixian white tea (p<0.05). The types of aroma components in CK white tea and ST white tea were 104 and 107, respectively, with their relative contents as 79.72% and 78.33%, respectively (mainly alcohols). Compared with CK, ST decreased significantly the contents of clean-aroma or green-aroma substances such as hexanol, increased the content of floral -fruit fragrance substances such as geraniol in Shuixian white tea, and improved the aroma composition of Shuixian white tea. The sensory evaluation results showed that, ST could significantly improve the aroma and taste quality of the Shuixian white tea, and the resulting tea had a strong floral and fruity aroma and a mellow taste with fragrance. The comprehensive sensory evaluation score of ST white tea (93.10) was significantly higher than that of CK white tea (88.30) (p<0.05). In conclusion, compared with CK, ST increased the biochemical content and the content and composition of aroma components of Shuixian white tea, thereby enhancing the quality of aroma and taste. The Shuixian white tea produced by ST has excellent overall quality, which meets the quality requirements of high-aroma white tea.
    14  Comparison of Components in the Volatile Oil Extracted from Cortex Moutan by Five Methods
    ZHANG Shu-ya LI Yong-hui LI Jia SHENG Fei-fei ZHANG Miao-dan
    2020, 36(12):103-110. DOI: 10.13982/j.mfst.1673-9078.2020.12.0514
    [Abstract](464) [HTML](532) [PDF 2.22 M](904)
    Abstract:
    In this study, a gas chromatography-mass spectrometry (GC-MS) combined with retention index (RI) method was developed for the analysis of volatile oil extracted from cortex moutan by the following five extraction methods: water distillation, steam distillation, steam-alcohol lamp heating distillation, ether ultrasonic extraction, and supercritical CO2 extraction. The best method was selected through comparing the yield of the volatile oil, composition and extraction rate of paeonol. The oil yields obtained by the five methods were 1.03%, 2.97%, 4.45%, 2.85%, and 0.63%, respectively, with the types of extracted compounds as 21, 22, 22, 23, and 22, respectively (mainly phenols, alkanes, acids, esters, ketones, alcohols and aldehydes). The contents of paeonol obtained by the five methods were 76.34%, 72.49%, 91.54%, 60.04% and 75.9%, respectively. Taking the oil yield and paeonol extraction rate as the indices, the steam-alcohol lamp heating distillation method resulted in the highest extraction rate of volatile oil from cortex moutan, which could be used for the extraction of volatile oil from cortex moutan. Taking the extracted compounds as indices, a more comprehensive profile of the identified components was obtained by the supercritical CO2 extraction and the ether ultrasonic extraction.
    15  Deep Liquid Fermentation Increased the Content of Main Active Components and Antioxidant Capacity in the Fermentation Broth of Malus doumeri Fruits from Northern Guangdong Province
    CHENG Tian-de CHEN Qing-le LI Xue-ping
    2020, 36(12):111-117. DOI: 10.13982/j.mfst.1673-9078.2020.12.0606
    [Abstract](298) [HTML](191) [PDF 31.74 M](807)
    Abstract:
    The effect of deep liquid fermentation on the main active components and their antioxidant activities of fermented liquid of Malus doumeri fruits was investigated in this work. The deep liquid fermentation of Malus doumeri fruits from three different areas in northern Guangdong province was carried out by using LGG. The contents of total phenols, total flavones, total triterpenes, ORAC values, PSC, DPPH and ABTS radicals scavenging activities of fermented liquid of Malus doumeri fruits at different fermentation time were determined. There was no significant difference in the main active components and antioxidant activities of fermented liquid of Malus doumeri fruits from three different areas in northern Guangdong province and their trends were similar. The content of total phenols and triterpenes increased slightly with the increase of fermentation time, reached the maximum after 3~4 weeks, and then decreased slowly. The contents of total flavonoids increased gradually with the increase of fermentation time, and reached the maximum after 6 weeks (increased by 49.93% compared to control), then the content of total flavonoids decreased slightly. The ORAC value, PSC, DPPH and ABTS free radicals scavenging activities of fermented liquid of Malus doumeri fruits increased gradually with the prolongation of fermentation tim. The increase rate was high during initial four weeks, and then the increase rate gradually slowed down. The maximum increase rate of ORAC, PSC, DPPH and ABTS free radical scavenging activity were 6.81%, 9.29%, 56.42% and 102.30%, respectively. The deep liquid fermentation of Malus doumeri fruits which produced in northern Guangdong province was conducted by LGG, which can increase the contents of total phenols, total flavones, total triterpenes and increase their antioxidant capacities.
    16  Inhibitory Effect of Quercetin, Rutin and Gallic Acid on Xanthine Oxidase and Kinetic Characteristics
    CHEN Yu-cen WANG Ying-ying DU Ruo-tong LAI Hui-ning GUO Geng-cheng WU Yue WANG Yi-fan LUO Hong-yu
    2020, 36(12):118-124. DOI: 10.13982/j.mfst.1673-9078.2020.12.0608
    [Abstract](378) [HTML](264) [PDF 1.02 M](1566)
    Abstract:
    In order to understand the inhibitory properties of quercetin, rutin, gallic acid and its combination with vitamin C on Xanthine oxidase (XOD), a vitro inhibition model of XOD was established to evaluate the inhibitory effect of these three natural compounds on XOD at different concentrations. Allopurinol was used as the positive control. The inhibitory effects and kinetics of these three natural compounds on XOD at different concentrations were detected. The results showed that all the three substances had the inhibitory effect on XOD with concentration dependence, and the inhibitory effect was greatly related to the structure and their nature. The order of inhibition of XOD was as follow: quercetin > rutin > gallic acid. The IC50 values were (5.51±0.41) μmol/L, (48.66±0.49) μmol/L and >200 μmol/L for the three substances respectively. In this work, the inhibition effect of gallic acid was weak and it was demonstrated that vitamin C could assist gallic acid to participate in the reaction. The inhibition rate increased from 20.17% to 40.96%. It could achieve the dual effect of enhanced inhibition of XOD activity and stability. The types of XOD inhibition by quercetin, rutin, and gallic acid belong to different modes of atypical mixed inhibitors. This work will be of great significance to study the inhibition mechanism and application of these substances.
    17  Preservative Effect of High-Voltage Electrostatic Field Combined with Refrigeration on Fresh Prawn (Metapenaeus ensis)
    XIONG Yu-fei WANG Li-shuang WANG Jin YIN Yun-hou WANG Qi-jun
    2020, 36(12):125-132. DOI: 10.13982/j.mfst.1673-9078.2020.12.0177
    [Abstract](263) [HTML](244) [PDF 4.72 M](758)
    Abstract:
    In order to explore the effect of high-voltage electrostatic field (HVEF) technology on the quality of prawns (Metapenaeus ensis) during cold storage, three high voltages (8 kV, 12 kV, 16 kV) were selected under the experimental conditions of this study to treat the prawn continuously under low temperature storage conditions at 4 ℃, and the changes in of freshness indices such as color, texture, pH value, TVB-N value, TBA value and total number of colonies were measured on day 0, 2, 4, and 6 of the storage. The results showed that the samples in the HVEF treatment group showed better color and texture characteristics, and delayed effectively the decrease in hardness. Compared with the control group, HVEF treatment inhibited effectively the microbial growth in prawn and led to a decrease by 0.51~1.03 log?cfu/g. The TVB-N value of the control group exceeded 30 mg/100 g on the 4th day, while that of the 16 kV electric field group was only 24.67 mg/100 g on the 6th day, indicating that the HVEF treatment can effectively delay protein degradation. Other freshness indicators such as pH and TBA of the HVEF treatment group were significantly lower than those of the control group during the whole storage period (p<0.05). In addition, as the voltage value increased, the preservative effect was better. Comprehensive comparative analysis shows that the high-voltage electrostatic field has a good preservation effect on prawn, and its combination with refrigeration can extend the shelf life of the prawn by more than 2 days. This study provides a scientific basis for the improvement of high-voltage electrostatic field preservation equipment for keeping prawn fresh.
    18  The Drying Characteristic and Mathematical Modeling of Various Drying Method of Seahorse
    WU Jing-na CHEN Xiao-ting PAN Nan LIAO Deng-yuan ZHANG Jin-hua LIU Zhi-yu
    2020, 36(12):133-142. DOI: 10.13982/j.mfst.1673-9078.2020.12.0583
    [Abstract](275) [HTML](434) [PDF 702.30 K](803)
    Abstract:
    Drying of seahorse by hot air, vacuum and cold air, the drying characteristic, effective diffusion coefficients, activation energy and mathematical modeling were investigated at various conditions. Kinetics of seahorse at 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃ and 100℃ for hot air drying, 50 ℃, 60 ℃, 70 ℃, 80 ℃ and 90 ℃ for vacuum drying, and 20 ℃, 30 ℃ and 40 ℃ for cold air drying were obtained. With respect to R2, χ2 and RMSE, fitting of experimental data to 13 thin layer drying models resulted in Page and Midilli model were suitable model for hot air drying techniques, Page and Weibull model were suitable model for vacuum drying techniques, Page, Logarithmic and Weibull model were suitable model for cold air drying techniques. Effective diffusion coefficients Deff of hot air drying, vacuum drying and cold air drying varied between 1.1714×10-10 m2/s~6.7873×10-10 m2/s, 4.9252×10-10 m2/s~10.4920×10-10 m2/s and 2.3510×10-10 m2/s~4.0174×10-10 m2/s respectively. Activation energy values were 37.05 kJ/mol, 18.75 kJ/mol, and 20.55 kJ/mol respectively.
    19  Preparation Technology of Quinoa Eight-ingrediet Porridge
    LIANG Xia ZHOU Bai-ling WANG Hai-ping REN Yuan
    2020, 36(12):143-152. DOI: 10.13982/j.mfst.1673-9078.2020.12.0651
    [Abstract](282) [HTML](215) [PDF 2.19 M](719)
    Abstract:
    Quinoa was used as the main raw material to produce eight-ingrediet porridge. The nutritional evaluation of eight-ingrediet porridge was carried out by lysine AAS model recommended by FAO / WHO. The raw material ratio was optimized and the process parameters were optimized by orthogonal test and response surface methodology. The results showed that the best ratio of grains to beans, the ratio of quinoa, barley kernel and oat, the proportion of red kidney beans, white lentils, peanuts, mung beans and adzuki beans in beans were 60:40, 30:10:15 in grains, 15:10:5:5:5, respectively. Under these conditions, the lysine content of eight-ingrediet porridge, the lysine AAS, the sensory evaluation value were 4.61%, 83.82%, 80.4, respectively. The results of orthogonal test showed that the viscosity of eight-ingrediet porridge was the highest under the condition as follows: CMC of 0.02%, konjac powder of 0.08%, xanthan gum of 0.18%. The results of response surface methodology showed that the optimized process conditions were as follows: autoclaving time of 42 min, solid-liquid ratio of 32%, sucrose ester addition of 0.16%, sodium tripolyphosphate of 0.11%. There was a good correlationship between the predicted value and the actual value (R2 = 0.9248), and the sensory evaluation value was 85.5. Under the above conditions, the eight-ingrediet porridge was rich and full in taste and bright brown red in color, the grains were complete and chewy, the taste of beans was soft and a few grains have slight cracks, the eight-ingrediet porridge was viscous and has slight stratification after standing. The processing technology of quinoa eight-ingrediet porridge provided by this work could have a practical application in the diversified development of quinoa products.
    20  Processing Technology Optimization and Physicochemical Properties of Alum-free Fresh Potato/Cassava Starch Noodles
    SUN Zhen-xi MU Tai-hua MA Meng-mei CHEN Jing-wang
    2020, 36(12):153-160. DOI: 10.13982/j.mfst.1673-9078.2020.12.0546
    [Abstract](398) [HTML](188) [PDF 973.29 K](1022)
    Abstract:
    In order to optimize the processing technology of alum-free fresh potato/cassava starch noodles, the effects of addition ratio of sodium alginate, shaping time, refrigerated and frozen time, etc, on the texture properties, moisture content, and overall acceptability of alum-free fresh potato/cassava starch noodles were evaluated. In addition, effects of different retrogradation treatments on the breaking time, apparent and microstructure (scanning electron microscopy, Fourier infrared spectrum, small angle X-ray scattering) of alum-free fresh potato/cassava starch noodles were investigated, the mixture starches of potato and cassava (potato starch: cassava starch=1:1, W/W) was used as raw material, the fresh starch noodles without alum and with 0.30% alum were used as control. The results showed that the tensile strength (2.86 g/mm2), tensile deformation (63.88%), shear stress (39.89 g/mm2), shear deformation (37.76%), moisture content (60.40%), and overall acceptability of fresh potato/cassava starch noodles were the closest to those of fresh starch noodles with 0.30% alum after adding 1% sodium alginate, indicating 1% sodium alginate could be used as alum substitute for the production of fresh starch noodles. Furthermore, the optimal conditions for processing fresh potato/cassava starch noodles without alum were as follows: shaping time 1 min, cold storage at 4 ℃ for 24 h. The fresh potato/cassava starch noodles without alum obtained under this condition exhibited better elasticity and chew ability, longer breaking time and more uniform apparent structure. Therefore, the study can provide new basic data and theoretical support for the industry application of alum-free fresh wet potato starch noodles.
    21  Effects of Different Modifiers on the Characteristics of Potato Fermented Dough
    JIANG Peng-fei CHEN Ling GAO Jing-yan HUANG Zhen LIU Jia-yu FAN Ye-sheng YAN Xiao-meng WEN Cheng-rong
    2020, 36(12):161-167. DOI: 10.13982/j.mfst.1673-9078.2020.12.0518
    [Abstract](261) [HTML](194) [PDF 10.87 M](648)
    Abstract:
    Aiming at the issue that dough with a low gluten content is hard to ferment, this study investigated the effects of different proportions of pectin, sodium carboxymethyl cellulose, sodium stearyl lactate, monoglyceride and α-amylase on the fermentation volume, rheological properties and micro-morphology of fermented dough with the addition of 50.00% and 60.00% of mashed potato. The results showed that the increases in the fermentation volume of potato fermented dough with sodium stearoyl lactylate and α-amylase were higher than 20 mL, while those of other potato fermented doughs were less than 20 mL. The storage moduli of potato doughs with modifiers were all improved, except for those with α-amylase and monoglyceride (added at the ratio of 0.30%). The shear stabilities of potato fermented doughs were improved by modifiers, however, the initial viscosities of the doughs containing added α-amylase and 50.00% or 60.00% mashed potato were the lowest (1772.83 Pa·s and 1778.28 Pa·s, respectively). The network structures of the potato fermented dough were improved by pectin and carboxymethyl cellulose. Sodium stearyl lactate and monoglyceride were beneficial to the formation of gluten, while α-amylase was not conducive to dough network formation. Therefore, different modifiers influenced differently the properties and structures of potato fermented doughs. This study provides a theoretical reference for the application of potato in fermented wheat products.
    22  Optimization of the Spray-drying and Pulverizing Process of Rosa roxburghii Tratt Juice
    ZHANG Ting CHEN Si-qi DING Zhu-hong WANG Yi SONG Yu-ting YU Yi-hong ZHAO Xu-hai-cheng
    2020, 36(12):168-179. DOI: 10.13982/j.mfst.1673-9078.2020.12.0646
    [Abstract](364) [HTML](238) [PDF 93.55 M](827)
    Abstract:
    In order to investigate the effects of various process parameters on the quality of Rosa roxburghii Tratt juice during the spray-drying process, the process for spray-drying and pulverizing of Rosa roxburghii Tratt juice was optimized. Rosa roxburghii Tratt juice was used as raw material in this work. Inlet air temperature, feed concentration, feed flow and intake air flow were selected as process parameters for single factor test. On the basis of the single factor test, the powder collection rate, Vc content, flavonoid content and fuzzy mathematical comprehensive score were taken as the response values, and the response surface experimental design was carried out on the spray drying parameter conditions using the Box-Behnken central combination method. The results showed that the optimal parameters for the preparation of Rosa roxburghii Tratt fruit powder by spray drying method were as follows: inlet air temperature of 179 ℃, feed concentration of 5.9%, feed flow rate of 0.3 L/h, inlet air flow rate of 30 m3/h. Under these conditions, the Rosa roxburghii Tratt spray-dried powder had a product yield of 30.45%, and their Vc content, flavonoid content and sensory value were 753.96 mg/100 g, 277.70 mg/100 g and 85.95, respectively. It was consistent with the predicted value of the response surface model. The Rosa roxburghii Tratt fruit powder were uniform in powder quality, bright and shiny, and had a typical Rosa roxburghii Tratt aroma. The results could be used as theoretical basis for enhancing the spray drying technology of Rosa roxburghii Tratt and new products development.
    23  Preparation and Characterization of Eugenol/Starch Inclusion Compound Freeze-dried Powder
    WANG Na XIAO Yun-feng QIAN Xin-yu HAN Yun-qi
    2020, 36(12):180-187. DOI: 10.13982/j.mfst.1673-9078.2020.12.0586
    [Abstract](254) [HTML](201) [PDF 31.96 M](988)
    Abstract:
    The preparation technology of eugenol / starch inclusion compound freeze-dried powder was studied to improve its stability and accuracy in the application of medicine. The starch of naked oats was selected to encapsulate eugenol, and the preparation technology of the freeze-dried powder of eugenol starch inclusion compound was studied by ultrasonic method. The content of eugenol in the inclusion complex was determined by HPLC with inclusion rate as the index. The influence of the material ratio, ultrasonic temperature and ultrasonic time on the preparation of the inclusion complex was investigated by single factor test. The optimum technological conditions of the freeze-drying powder of eugenol starch inclusion compound were determined by the orthogonal test: the ratio of feeding materials was 10:0.8, the ultrasonic temperature was 50 ℃, the ultrasonic time was 50 minutes, and the inclusion rate was 44.54%. The order of influencing factors is: ultrasonic temperature>feeding ratio>ultrasonic time. The validation test for the preparation of eugenol/starch inclusion complex lyophilized powder was carried out by SEM, FT-IR and NMR The formation of eugenol/gelatinized starch inclusion complex freeze-dried powder was identified. In conclusion, the ultrasonic method was used to prepare eugenol/starch inclusion complex freeze-dried powder. The formation of eugenol/starch inclusion complex freeze-dried powder was verified. After the orthogonal experiment optimization of the preparation process, the inclusion rate reached 44.54%.
    24  Constructing a Comprehensive Evaluation Model for Assessing the Quality of Low-salt Emulsified Sausage with Soybean Protein Based on Principal Component Analysis
    ZHAO Chun-bo YU Xiao-ling LI Miao-yun XIAO Kang ZHANG Qiu-hui ZHAO Gai-ming
    2020, 36(12):188-197. DOI: 10.13982/j.mfst.1673-9078.2020.12.1231
    [Abstract](279) [HTML](260) [PDF 11.28 M](814)
    Abstract:
    In order to study the effect of soy protein on the quality of low-salt emulsified sausage, the influences of the proportion of KCl to replace salt (0%, 20%, 30%, 40% or 50%), and the amount of added soy protein (0%, 4%, 6%, or 8%) on the quality of the emulsified sausages were examined. The results indicated that the substitution by KCl at 20%~40% along with the addition of 6%~8% of soy protein significantly improved the yield and water retention rate of the emulsified sausage (p<0.05) (increased by 3.89% and 3.28%, respectively, compared to the blank group), decreased the redness and increased the yellowness of the sausage. In particular, the substitution by KCl by 50% and addition of 4%~8% of soy protein improved the hardness, springiness and chewiness of the sausage (p<0.05), with the hardness and springiness increasing by 19.37% and 5.00%, respectively. When the substitution of salt by KCl at 30%, adding 4%~8% of soy protein could reduce the resilience of the emulsified sausage (p<0.05). In terms of sensory scores, the addition of 4%~8% of soy protein significantly improved the tissue structure of the low-salt emulsified sausages but worsen significantly the color and mouthfeel of sausage. The amount of added soy protein was significantly correlated with the springiness, product yield, water holding rate and b value of the emulsified sausage, while the amount of salt substituted by KCl was insignificantly correlated with other quality indicators. It is recommended that the amount of KCl for substitution is 40% and the amount of soy protein for addition is 4%~6%. According to the results of the principal component analysis of the quality indices of emulsified sausages, a comprehensive evaluation model for assessing the quality of low-salt sausage with soybean protein was obtained. The results of this study provide a certain reference for the production of low-salt emulsified sausages.
    25  Design of Curved Sliding-cut Bay Scallop Sheller
    LI Lei WANG Jia-zhong YI Jing-gang GU Xiao-cui
    2020, 36(12):198-203. DOI: 10.13982/j.mfst.1673-9078.2020.12.0642
    [Abstract](347) [HTML](293) [PDF 36.68 M](605)
    Abstract:
    At present, the domestic scallop shelling and meat extraction are still mainly done by hand, and the processing environment is harsh and the production efficiency is low. In order to improve this situation, an artificial peeling machine for bay scallops is designed. It is based on the principle of manual cutter peeling off the shells, using elastic blades, and the blades to fit the scallop curved surface to peel off the adductor muscle is pushed by the cylinder. The roulette layout is adopted, it is mainly composed of shell cutting components and adductor muscle components. The measurement data was analyzed by MATLAB, the position of the adductor muscle and the cutting position of the shell cutting device are 8 mm away from the edge of the shell. The scallop shell body was curve-fitted by Origin to establish a geometric model of the scallop inner shell. The size of the scallop muscle peeling blade b=20 mm wide l=114 mm long, the average opening angle of the scallop β=27˚, and the bending angle range α=2˚~5˚. Simulation analysis with Adams. The test results show that the success rate of the bay scallop shelling machine is over 85%, and the shelling efficiency is 20 pieces/min. The shelling machine meets the requirements of scallop processing quality and production efficiency.
    26  Analysis on Improving Bread Quality and Nutritional Characteristics by Adding Coarse Grain Powder
    JIA Yan-jie SHEN Fei QIAN Zhi-wei JIANG Xiao-feng ZHANG Guan-qun
    2020, 36(12):204-212. DOI: 10.13982/j.mfst.1673-9078.2020.12.0588
    [Abstract](337) [HTML](250) [PDF 16.86 M](655)
    Abstract:
    Using quinoa flour, oat flour and high-gluten flour as the main raw materials, a new type of multigrain bread was prepared. Through single factor and orthogonal experiments, the effects of the amount of multigrain flour, yeast, xylitol, and butter on the sensory and specific volume of bread were studied, and the best process formula of quinoa-oat compound bread was determined: the ratio of quinoa flour to oat flour was 1:2, yeast addition 3.0%, xylitol addition 11%, butter addition 8%. Taking wheat bread as a comparison, the functional characteristics of multigrain bread such as anti-oxidation, in vitro digestibility, and pre-glycemic index were analyzed. The results showed that the antioxidant capacity of the multigrain bread was 0.054 mmol/g (calculated as FeSO4), which was much higher than 0.0048 mmol/g of the control bread; the amount of starch hydrolyzed in the multigrain bread tended to be stable after 90 min. Though the starch hydrolysis rate decreased after 30 minutes, it was always on the rise. The glycemic index of multigrain bread is determined to be 57.42, which is a medium glycemic index food. The results showed that the contents of protein, fat and total fiber were higher than those of wheat bread, and the nutritional value was higher. For ordinary bread, adding quinoa and oats to the bread can serve as a dietary supplement for antioxidants and delay the digestion of starch in the body. This provides technical support for the application of multigrain in bread.
    27  Analysis of Potato Flour Dosage on the Characteristics of Dough and the Quality of Steamed Bread
    CAI Sha CAI Fang HE Jian-jun SHI Jian-bin SUI Yong XIONG Tian CHEN Xue-ling FAN Chuan-hui MEI Xin
    2020, 36(12):213-219. DOI: 10.13982/j.mfst.1673-9078.2020.12.0547
    [Abstract](308) [HTML](278) [PDF 1.01 M](673)
    Abstract:
    Potato flour was added to the dough to enrich the nutrition and variety of steamed bread. The basic ingredients and characteristics of potato flour were investigated, and the effects of potato flour dosage on the dough characteristics and the quality of steamed bread were also examined. Results showed that the main component of potato flourwas starch, and the content was about 67.07%. The expansibility of potato flour in water holding capacity and water absorption were 3.57 g/g and 2.49 mL/g, respectively. The viscosity of the whole potato powder was 12.71 m2/s. Thephysical and chemical properties of the dough were enhanced when mixing with the potato flour. The addition of potato flour made the dough farinographical properties worse but mixing properties better. When the addition amount was 8%~15%, the gelatinization properties and tensile properties of the dough were better.With the increasing of potato flour, the whiteness of the surface and inside of potato steamed bread decreased.When the addition of potato flour was 5%~8%, the specific volume hardness and chewability of steamed bread were higherand the sensory scores were higher.In conclusion, in order to improve the dough characteristics, the recommended amount of potato flour is 8%~15%. To improve the quality of steamed bread, it is recommended to add 5%~8% potato flour.
    28  The Fermentation Kinetic Model and Antioxidant Activity of Kombucha-mongo Complex Wine
    LI Min-jie XIONG Ya
    2020, 36(12):220-226. DOI: 10.13982/j.mfst.1673-9078.2020.12.0655
    [Abstract](441) [HTML](362) [PDF 27.87 M](834)
    Abstract:
    Kombucha fermentation broth and Mongo juicy were used as raw materials to produce the Kombucha-Mongo complex wine. Antioxidant activities and fermentation kinetic model of the Kombucha-Mongo complex wine were investigated. The results of antioxidant activity showed that the contents of total polyphenol, DPPH? scavenging rate and Hydroxyl radicals scavenging rate were all increased firstly and then decreased, and their maximums were 799.61 mg/mL, 92.50% and 86.30% on the 8th day,respectively. Based on the SGompertz equation, fermentation kinetics model of growth of yeast was built, and the correlation coefficients was 0.98. The fermentation kinetics models of total sugar consumption, alcohol formation were built based on the Boltzmann equation and the Logistic equation, respectively, and their correlation coefficients were both more than 0.99. According to the non-linear fitting, the experimental values of the models had a good accordance with the predicted values. which could reflect the static dynamic characteristics of the Kombucha-Mongo complex wine fermentation very well, and the change in antioxidant activity of the Kombucha-Mango complex wine showed a peak type during fermentation, which could be provided as the theoretical basis for the fermentation of Kombucha mango complex wine.
    29  Monodisperse Droplet Generator (MDDG) Combined with Electrostatic Self-assembly to Produce Probiotic Microcapsules
    LUO Dan-yang HAN Kai-ning YANG Xiao-quan
    2020, 36(12):227-233. DOI: 10.13982/j.mfst.1673-9078.2020.12.0107
    [Abstract](191) [HTML](278) [PDF 1.19 M](937)
    Abstract:
    In this study, monodisperse droplet generator (MDDG) was utilized to produce multilayered probiotic microcapsules through using calcium alginate gel (-) (as the matrix), chitosan (+) and gum Arabic (-) (as the coating materials), and adopting a layer-by-layer approach based on electrostatic self-assembly. The results showed that the multilayered probiotic microcapsules had higher mechanical strength, and still maintained intact spherical structure after 9 h of culture in MRS liquid medium, with an increase (by 2.06 log cfu/g) in the number of probiotics contained in the microcapsules. In addition, multilayer structure prolonged the existence time of microcapsules prior to disintegration in the gastrointestinal juice. The single-layered calcium alginate microcapsules collapsed rapidly in the simulated intestinal fluid, with the amount of released probiotics reaching 8.23 log cfu/g after 1 h of digestion. Whereas, the probiotic microcapsules coated with chitosan, chitosan and gum arabic gum did not reach the corresponding logarithmic values (8.42 log cfu/g and 8.33 log cfu/g, respectively) until 3 h after digestion. Compared with the single-layer probiotics microcapsules, the multilayered microcapsules showed a higher storage stability at both 4 ℃ and 25 ℃, with the number of viable cells in the three-layered microcapsules coated with calcium alginate-chitosan-gum arabic decreasing from 8.90 log cfu/g to 8.81 log cfu/g after a storage at 4 ℃ for 12 days. The experimental results showed that MDDG combined with electrostatic-guided layer-by-layer self-assembly was an effective method for efficient preparation of homogeneous and stable probiotic microcapsules to enable the delivery of probiotics into the intestines.
    30  Development of Olive Fruit Wine and Analysis of Its Flavor Substances
    WEI Chun-hui ZHENG Zi-qiang GUO Yan LIU Yan-mei REN Zhi-qiang HUANG Zhi-guo DENG Jie
    2020, 36(12):234-242. DOI: 10.13982/j.mfst.1673-9078.2020.12.0501
    [Abstract](151) [HTML](332) [PDF 924.47 K](932)
    Abstract:
    In this research, olive fruit wine was produced via fermentation with olive fruit as the raw material. The effects of yeast inoculation amount, initial sugar content, fermentation time, fermentation temperature and initial pH value on the sensory quality of olive fruit wine were studied by the single factor tests. The optimal fermentation conditions of olive fruit wine were determined by the orthogonal experiments and verification tests. The results showed that the olive fruit wine had an alcohol content of (12.20±0.45)% vol, sugar content of 5.26 g/L and acidity of 5.46 g/L after the fermentation at the initial pH of 4.0, yeast inoculation amount of 7%, initial sugar degree of 22 °BX and 28 ℃ for 9 days. Under the optimal processing conditions, the finished wine was moderately astringent, rich in fruit aroma, and slightly yellow and translucent, with a refreshing aftertaste, therefore, its physical and chemical indices meet the relevant standards. Through the solid-phase microextraction and gas chromatography-mass spectrometry detection and analysis, it was found that olive fruit wine contained 74 flavor substances in olive fruit wine, including 26 esters, 13 alcohols, 4 alkanes, 12 alkenes, 1 phenol, 1 ether, and 17 other substances, among which, butyl acetate, phenylethanol, isoamyl alcohol, ethyl decanoate, ethyl laurate, phenylethyl acetate, and terpenes such as α-rhytene, α-pinene and β-elemene were significant contributors to the characteristic flavor of olive fruit wine, making the wine outstanding in style and unique in mouthfeel.
    31  Development and Evaluation of Multiplex PCR Detection Kit for Detection of Three Types of Diarrheagenic Escherichia coli
    ZHOU Yang WAN Qiang CAI Zhi-he LU Mian-fei YANG Xu-wei WU Qing-ping LI Jian-shun
    2020, 36(12):243-251. DOI: 10.13982/j.mfst.1673-9078.2020.12.0616
    [Abstract](209) [HTML](185) [PDF 16.39 M](607)
    Abstract:
    In order to develop a multiplex PCR detection kit for detecting three types of Diarrheagenic Escherichia coli (DEC), which includes Enteropathogenic E. coli (EPEC), Shigatoxin-producing E. coli (STEC) and Enterohemorrhagic E. coli (EHEC), multiplex PCR reaction system was optimized and their components of the kit were confirmed. The main detection reagents were produced into powder pattern by freeze drying technology, and the specificity, sensitivity, repeatability and shelf life of the kit were evaluated. The results showed that EP and ST reaction systems were successfully established for detection of three types of DEC. All standard strains and isolated strains belonging to the three types of DEC were detected positive and presented obvious specific amplification bands, while other types of DEC were all detected negative. The limit of detection of detection tube EP and ST in the kit were calculated to 1.5×103 cfu/mL and 2.1×103 cfu/mL, respectively, and the testing accordance rates were all 100%. The kit can be stored under 4°C condition for 12 months and transported under 42 ℃ condition for 120 h without efficacy loss. In conclusion, the kit had a good performance with stable and reliable detection results, and it could be applicable for rapid detection of three types of DEC in food samples. Key words:
    32  A Novel Quantum Dot Immunochromatographic Assay for Quantitative Detection of Enrofloxacin
    XIAO You-yu LU Fei ZHANG Chi WANG Chen ZHU Chen-chen LI Dong-yuan TANG Wei
    2020, 36(12):252-258. DOI: 10.13982/j.mfst.1673-9078.2020.12.0474
    [Abstract](270) [HTML](379) [PDF 1.63 M](937)
    Abstract:
    Enrofloxacin as a widely used antibiotic has attracted widespread attention due to its high positive rate in actual sampling. In this study, an immunochromatographic assay was developed for rapid and quantitative detection of enrofloxacin using quantum dot labeling and tracking. Quantitative detection of enrofloxacin was achieved through investigating the fluorescent quantum dot nanomaterials combined with active materials, developing reagents for sample pretreatment, and screening and optimizing concentrations to achieve the compatibility of quantum dot materials and food substrates. Through the optimization of the whole kit, the linear range of this detection method was 2~1000 ng/ml, the minimum detection limit was 1.80 ng/ml, and the precision was within 10%, with superior performance in accelerated thermal stability tests (stable for 10 days at 37 ℃). Compared with conventional liquid chromatography methods, this established method is simple and rapid with a good correlation among the detection results within the entire detection period of 20 min (correlation coefficient: 0.98). This research fills up the knowledge gap in quantitative detection of antibiotic residues in foods by combining quantum dots and immunochromatography technique, which allows rapid on-site screening of large-scale raw materials and promote the development of rapid food inspection technology.
    33  Determination of Multi-elements and Stable Isotope Ratios in Milk and Discrimination Their Geographical Origin
    HOU Jian-bo ZHANG Xiao-feng HONG Deng XIE Wen ZHANG Ming-zhe HAN Fang SHI Ying-zhu LU Shun QIU Hui
    2020, 36(12):259-266. DOI: 10.13982/j.mfst.1673-9078.2020.12.0593
    [Abstract](188) [HTML](176) [PDF 10.48 M](804)
    Abstract:
    In this paper, the inductively coupled plasma mass spectrometry (ICP-MS) was used for the determination of Li, Na and other 38 elements, the elemental analysis-isotope ratio mass spectrometry (EA-IRMS) and GasBench-IRMS were used for the determination of the stable isotope ratios of carbon, nitrogen, hydrogen and oxygen in milk, and for the feasibility assessment of milk geographical origin in different country. The milk sample was freeze-dried into a powder, and then determined by EA-IRMS or ICP-MS to obtain stable isotope ratios of nitrogen (δ15N) and mineral elements. The milk sample was detected by EA-IRMS or GasBench-IRMS to obtain stable isotope ratios of carbon, hydrogen and oxygen (δ13C, δ2H and δ18O). The milk samples were collected from Germany, Spain, Italy, Australia, New Zealand, China and Austria, and then the stable isotope ratios of carbon, nitrogen, hydrogen, oxygen and multi-elements were detected. The values of δ13C, δ15N, δ2H, δ18O and multi-elements were distinguished by multivariate statistical analysis (including ANOVA, Duncan’s multiple comparison,correlation analysis, principal component analysis, cluster analysis and discriminant analysis) using the SPSS software package for windows. The results showed that the As、Se、Rb、Sr、Mo、Cd、Cs、Ba、Tl、Bi、δ13C、δ15N、δ2H and δ18O were significantly different (p< 0.05),different clusters were observed in Germany and Italy, China, Austria Australia and New Zealand, and the accuracy of discrimination for milk geographical origin was 92.4% by the combined indicators of As, Se, Rb, Sr, Mo, Cs, Ba, Tl, δ13C, δ15N and δ2H.
    34  Preparation of Graphene-based Butyrylcholinesterase Biosensors for the Rapid Determination of Malachite Green in Sea Foods
    HAO Ya-ru LI Ting ZHANG Wei LI Shu-guo
    2020, 36(12):267-273. DOI: 10.13982/j.mfst.1673-9078.2020.12.0564
    [Abstract](205) [HTML](235) [PDF 32.00 M](688)
    Abstract:
    Graphene-based butyrylcholinesterase biosensors were prepared utilizing chitosan (CS) and graphene nanosheets (GS) composites to immobilized butyrylcholinesterase (BuChE) on the glass carbon electrode by crosslinking technology, the rapid and sensitive method for the determination of malachite Green (MG) in sea foods was developed. Effects of biosensor modified materials, electrolyte solution, enzyme activity and inhibition time on response current of enzyme biosensor were investigated. The optimum analytical parameters for determination of Malachite Green were determined as follows:the ratio of CS to GS was 1:2, the electrolyte solution was 0.1 mol/L PBS, the pH was 7, the inhibition time was 11 min, and the enzyme activity was 4.0 U/mL. Under optimum conditions, the response currents of the enzyme biosensor had a good linear relationship with MG concentration with a detection range from 1.00×10-7 mol/L to 1.10×10-6 mol/L. The linear equation was Ip=-6.97CMG+22.805 (R2=0.9885), with the limit of detection (LOD) as 2.80×10-8 mol/L (S/N=3). The addition standard recovery of the developed method was 96.36% to 99.78%. The developed method is simple, rapid and sensitive with good selectivity and excellent repeatability, which is practicable for rapid determination of MG or LMG in sea foods.
    35  Development and Validation of a Duplex PCR for the Simultaneous Detection of Atlantic Salmon (Salmo salar) and Rainbow Trout (Oncorhynchus mykiss) in Processed Fish Products
    HUANG Man-hong XIONG Xiong XU Wen-jie LI Yi CAO Min XIONG Xiao-hui
    2020, 36(12):274-282. DOI: 10.13982/j.mfst.1673-9078.2020.12.0580
    [Abstract](247) [HTML](292) [PDF 83.19 M](772)
    Abstract:
    Anovel method for rapid identification of Salmo salar and Oncorhynchus mykiss based on duplex PCR assay (conventional and fluorescent assays) was developed. Specifically, after sequence alignment, specific primers for S. salar and O. mykiss based on the COⅠ and Cyt b genes were designed and verified. The duplex PCR was optimized, and finally established. Only S. salar and O. mykiss amplified specific bands of 108 bp and 207 bp, while the other 23 non-target species were not successfully amplified. The optimal amount of primers for S. salar and O. mykiss were 0.1 μmol/L and 0.4 μmol/L, and the melting temperature was 81.5 ℃ and 85 ℃, respectively. Among the 29 commercial products, six products were identified as S. salar and three were identified as O. mykiss. Finally, theremaining 17 commercial samples were all tested as negative in the duplex PCR assay, and the results were consistent with DNA barcoding method. The results showed that the duplex PCR method for S. salar and O. mykiss was specific and feasible. This study provided reliable technical method and theoretical basis for the adulteration identification of S. salar and O. mykiss species. Key words:
    36  Determination of 78 Chemical Drugs Illegally Added in Health Food by Ultra-high Performance Liquid Chromatography-tandem Mass Spectrometry
    LIU Zi-xiong HUANG JING-hui TAN Gui-liang XIE Guo-dan LI Xue-yan WANG Qian-lei LI Xiang-li LIU Yan ZHANG Jing-qiang HU Min
    2020, 36(12):283-292. DOI: 10.13982/j.mfst.1673-9078.2020.12.0551
    [Abstract](229) [HTML](290) [PDF 2.29 M](803)
    Abstract:
    A method was developed for the determination of 78 chemical drugs illegally added in three types of health foods (slimming, anti-fatigue and sexual promoting health foods) by QuEChERS--ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted with methanol. The extracted solution was purified with QuEChERS approach. The seventy eight chemical drugs were then separated on a ACQUITY UPLC HSS T3 column (2.1×100 mm, 1.7 μm) through gradient elution with acetonitrile and 10 mmol/L of ammonium acetatesolution (0.1% formic acid) using as mobile phase and detected by MS/MS under multi-reactions monitoring (MRM) modes (ESI+ and ESI-)). The chemical drugswere quantified with external standard method. Under the optimal conditions, these chemical drugs were well separated, and had good linear relationship (r≥0.9991). The limits of detection (LOD) (S/N≥3) were 0.5 μg/kg~420 μg/kg. The average recoveries at three spiked levels were in the range of 59.9%~120.7%, with the relative standard deviation (RSD, n=3) of 1.3%~16.2%. This newly developed method was successfully applied for the determination of 57 health food samples, in which 14 chemical drugs were found in 41 samples. The developed method is rapid, simple, sensitive and highly efficient which can be used for the qualitative and quantitative determination of illegally added chemical drugs in the slimming, anti-fatigue and sexual promoting health foods.
    37  Analysis of Heavy Metals in Dried Edible Fungi Commercially Available in Beijing and Assessment of Health Risks via Consumption
    LI Bing-ru ZHANG Quan-gang YAO Zhen-zhen HE Zhao-ying GAO Yuan WANG Bei-hong ZHAO Fang LI Yang MA Zhi-hong
    2020, 36(12):293-299. DOI: 10.13982/j.mfst.1673-9078.2020.12.0587
    [Abstract](169) [HTML](426) [PDF 14.79 M](841)
    Abstract:
    The concentrations of 4 heavy metals Cd, Pb, As and Hg in eight kinds of dried edible fungi commercially available in Beijing were determined, and the potential health risks to the Beijing local residents via consumption of edible fungi were were analyzed based on the Nemorow complex pollution index (p) and target hazard quotients (THQ). The results showed that the concentrations of Cd, Pb, As and Hg in edible fungi were ND~9.332 mg/kg, ND~2.060 mg/kg, ND~24.690 mg/kg, 0.004~0.448 mg/kg, respectively. Most of the heavy metals in edible fungi were below the threshold levels of China quality standard for edible fungi, while the over-standard rates were 2.2%, 2.8% for Cd, As, respectively. The Agaricus blazeimuril is the most severely polluted edible fungi by heavy metals with p value of 1.41 (mild pollution level), and the p value of Agrocybe cylindracea is 0.95, reaching the food safety alert level, while the other six kinds of dried edible fungi were at safety level. The results of health risks associated with heavy metal were found that the THQ values of Agaricus blazeimuril for As and the TTHQ values of Agaricus blazeimuril, Armillaria mellea, and Dictyophora indusiate for 4heavy metals were all higher than 1. It was indicated that the local inhabitants were faced with potential health risk in some extent by ingesting heavy metals via consumption of these edible fungi, and Agaricus blazeimuril made more contribution to the Cd, Pb Hg. The above results showed that the dried edible fungi commercially available in Beijing were generally safe with low heavy metals exposure risk to the local population through consumption.
    38  Rapid Detection and Identification of Salmonella in Proficiency Testing Samples by TaqMan Real-Time Fluorescent PCR
    WANG Feng-jun YE Su-dan
    2020, 36(12):300-306. DOI: 10.13982/j.mfst.1673-9078.2020.12.0094
    [Abstract](253) [HTML](240) [PDF 3.28 M](730)
    Abstract:
    According to GB 4789.4-2016 standard, the conventional culture method was used to test the ACAS-PT526 proficiency test sample for Salmonella, and TaqMan real-time fluorescence PCR was used to detect and identify rapidly the pre-enriched culture. In this study, specific primers and probes were designed and synthesized through using the Salmonella specific gene hut gene as the target gene. The nucleic acid DNA of various foodborne strains was extracted for real-time fluorescent PCR reaction. Only Salmonella showed positive amplification, while non Salmonella species, negative control and blank control had no amplification signal, confirming thee relatively high specificity of the designed and synthesized primer probes. Secondly, after pre-enrichment, enrichment, isolation, purification, biochemical tests and serological identification of the proficiency test samples and spiked samples, as well as real-time fluorescent PCR detection of pre-enriched culture, the 18-D319 and spiked samples exhibited significant S-type amplification with the Ct value being 24.34 and 26.21, respectively (which were positive for Salmonella), whilst 18-M906 had no significant fluorescence signal with the Ct value higher than 40 (which was negative for Salmonella). Based on the determination using API20E reagent strips, 18-D319 was a subspecies of Salmonella cholerae in Arizona, with the percentage of identification as 99.90% and T value as 0.97. 18-m906 was Escherichia coli, with the percentage of identification as 99.80% andT value as 0.94. The results of real-time fluorescence PCR were consistent with those obtained by the conventional culture method, and the PCR method was simpler and more rapid, requiring only 12 hours from pre-enrichment to result determination, and leading to results with high accuracy and ability to detect multiple samples in one batch. This method allows rapid screening of Salmonella in a large number of samples and detection and verification of proficiency testing samples.
    39  Determination of Mercury Speciation in Aquatic Animals and Their Products by LC-hydride Generation-ICP
    XIONG Shan-bo XIAO Quan-wei YIN Hong-jun RAN Hong JIANG Xuan-hua ZHENG Shi-chao
    2020, 36(12):307-313. DOI: 10.13982/j.mfst.1673-9078.2020.12.0553
    [Abstract](158) [HTML](236) [PDF 26.39 M](632)
    Abstract:
    A simple and efficient method for the determination of methylmercury (MetHg) , Ethyl Mercury (EtHg) and inorganic mercury (Hg2+) in aquatic animals and their products was developed by combining Inductively coupled plasma with High-performance liquid chromatography hydride generation. Microwave acid extraction was used to pretreat the sample, optimize the chromatographic conditions and carrier concentration, and then verify the method's precision, detection limit, accuracy and standard recovery. The results showed that when the methanol content in the mobile phase was 5% and the l-cysteine content was 0.10%, the separation effect, the peak type and the instrument response value were good, and the Mercury memory effect was basically eliminated. The separation of inorganic mercury, methyl mercury and ethyl mercury was realized within 7 minutes. The linear relationship was good, r>0.9990, RSD%<10.00%. The quantitative limits (LOQ) were 0.023, 0.032 and 0.038 mg/kg, respectively. The recovery rate was 82.50%~98.40 %. The accuracy of the method was verified by two aquatic animal reference materials, BCR463 and TORT-3. The method is simple, effective, accurate and suitable for the determination of mercury species in aquatic animals and their products. It provides a new method for mercury speciation analysis.
    40  Chemical Structure Characterization and Biological Activity of Mumefural from Prunus mume: a Review
    ZOU Bo XU Yu-juan YANG Fan YU Yuan-shan YU Yang-yang
    2020, 36(12):314-319. DOI: 10.13982/j.mfst.1673-9078.2020.12.0590
    [Abstract](542) [HTML](313) [PDF 15.84 M](1104)
    Abstract:
    Prunusmume Sieb. Et Zucc is an important characteristic fruit in China, which is of high acidity and mainly used for processing into food or Traditional Chinese medicine. Mumefrual is the product in the processing process of Prunusmume. Recently, a lot of abroad studies have focused on the biological activity of Prunusmume products rich in mumefrual, such as juice concentrate. The chemical structure characterization, formation mechanism and biological activity of mumefrualand its derivatives were described in detail. The chemical structure of the mumefrual is 1-[5-(2-formylfuryl) methyl]-dihydrogen 2-hydroxypropane-1,2,3-tricarboxylate. Three kinds of its derivatives were found, which were esterified by the reaction of organic acids such as citric acid and malic acid with 5-hydroxymethyl furfural. In this paper, the main biological activity and its underlying molecular mechanisms such as improving blood flow, lowering blood pressure, inhibitory effects on influenza virus, and ameliorates cognitive impairment were discussed. In addition, this paper briefly introduced the mumefural purification technology, positive effects on fatigue and bowel movements, antioxidant activity, and contribution rate of biological activity of mumefural, how to improve the mumefural content in product, and mumefural identification problem. This review will provide inferences for Prunusmume deep processing.
    41  Research Progress on the Prevention and Control of Mycotoxins in Agricultural Products with Natural Plant Ingredients
    QIU Tao-tao WEN Fei-yan LI Cai-jian MAO Shi-hong
    2020, 36(12):320-327. DOI: 10.13982/j.mfst.1673-9078.2020.12.0533
    [Abstract](393) [HTML](165) [PDF 584.98 K](983)
    Abstract:
    Mycotoxins are secondary metabolites produced during the growth of fungi, and their pollution to agricultural products threatens directly the lives and health of humans and animals. The prevention and removal of mycotoxins is one of the key issues to be solved urgently to achieve high-quality development of the food and feed industries. At present, researchers have adopted a variety of strategies to prevent and control mycotoxin pollution to avoid health problems and economic losses, including inhibition of fungal growth and mycotoxins production, removal and degradation of mycotoxins in contaminated agricultural products, and decrease of the biological activities of mycotoxins. The use of natural plant compounds (NPC) to prevent and control mycotoxin pollution exhibits the advantages of high stability, safety and high inhibition efficiency, and has become a new research thrust. This article reviews the different strategies to prevent and control mycotoxins in agricultural products by using NPC in recent years, discusses the corresponding mechanisms of action, analyzes the advantages and limitations of using NPC to prevent and control mycotoxins at this stage, offers prospects on the applications in the food industry, and provides scientific reference for the development of new mycotoxin prevention and control reagents.

    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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