Volume 37,Issue 2,2021 Table of Contents

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  • 1  Nanoemulsion Improves Oral Bioavailability and Transdermal Absorption Efficiency of Oxyresveratrol
    LI Jun WANG Qun LIU Guo MIAO Jian-yin XIE Lin CAO Yong
    2021, 37(2):1-10. DOI: 10.13982/j.mfst.1673-9078.2021.2.0657
    [Abstract](479) [HTML](535) [PDF 55.61 M](914)
    Abstract:
    In this study, a nanoemulsion was prepared to improve the solubility of oxyresveratrol (OXY) in aqueous solutions. The effect of nanoemulsion on the bioavailability of OXY was evaluated through in vitro dissolution test, lipolysis test transmembrane transport test in Caco-2 monolayer model, and transdermal absorption test. The results showed that the bioavailability of OXY-loaded nanoemulsion and OXY itself was61.22% and 23.47%, respectively, in the fed state, and 56.12% and 22.45%, respectively, during the fasting state. The nanoemulsion increased the diffusion rate of OXY in the epithelial cells of the small intestine from medium to rapid, and the diffusion type was passive diffusion with an apparent permeability coefficient Papp (AP-BL) as 1.69×10-5 cm/sec, Papp (BL-AP) value as 8.94×10-6 cm/sec, and ER=Rpapp(AP-BL)/(BL-AP) as 1.89. The transdermal absorption of OXY-loaded nanoemulsion and OXY at the 6 h was 51.76 and 5.73 g/cm2 skin, respectively. Conclusions: The bioavailability of the OXY-loaded nanoemulsion was 3 times higher than that of the compound itself. Nanoemulsion significantly improved the absorption (by 2~4 times) and transmembrane transport efficiency of OXY (p<0.05) in the small intestinal epithelia cells. This study laid a research foundation for the application of OXY and provided a theoretical basis for enabling its efficacy.
    2  Improvement of Lipid Metabolism by DHA Liposomes
    YANG Rui-li LU Na ZHANG Hui ZHOU Sai-nan ZHANG Qing XUE Chang-hu TANG Qing-juan
    2021, 37(2):11-20. DOI: 10.13982/j.mfst.1673-9078.2021.2.0781
    [Abstract](463) [HTML](308) [PDF 64.52 M](877)
    Abstract:
    To explore the effects of DHA liposomes on lipid metabolism, HepG2 cells were induced by free fatty acids. After the intervention of DHA liposomes, the contents of TG and TC were detected. The mRNA expression of Fatty acid synthase (FAS) and Sterol regulatory element binding protein 1 (SREBP-1) were detected by RT-PCR. Then male C57BL/6J mice (6 weeks old) were housed and randomly devided into control group (C), model group (M), TG-DHA emulsion (O-DHA), TG-DHA liposome (L-DHA). After 12 weeks, the protein expression levels of FAS, CPT-1 were determined by immunohistochemistry, the enzyme activity of Fatty acid synthase (FAS), malic enzyme (ME), carnitine palmitoyltransferase 1 (CPT-1), lipoprotein esterase (LPL) were detected using ELISA. The results showed that DHA liposomes significantly reduced the TC and TG contents (p<0.05) by 62.91% and 48.73% respectively; significantly reduced the mRNA expression levels of FAS (48.62%) and SREBP-1 (38.53%) (p<0.05). The results of animal experiments showed that DHA liposomes significantly reduced theepididymal fat content (14.26%) of high-fat diet mice (p<0.05); significantly reduced the protein expression levels of FAS (74.29%) (p< 0.05) and increased the protein expression levels of CPT-1 (1.70 folds) (p<0.05). DHA liposomes could significantly inhibited the activities of FAS, ME (p<0.05), reduced by 30.33% and 11.79% respectively; and promoted the activities of CPT-1, LPL (p<0.05), increased by 10.08% and 15.12% respectively. This study showed that DHA liposomes can improve lipid metabolism disorder induced by high-fat diet, and provide theoretical basis for the development and utilization of deep-sea fish oil.
    3  Regulatory Effect of Pea Oligopeptide on PI3K/AKT/FOXO1 Signaling Pathway in Liver of Type 2 Diabetic Mice
    WANG Sai SUN Wan-ting WANG Meng DONG Lei-chao CHEN Xuan-hong NAN Xi-jun JI Wei ZHOU Quan-Cheng
    2021, 37(2):21-27. DOI: 10.13982/j.mfst.1673-9078.2021.2.0713
    [Abstract](420) [HTML](257) [PDF 11.76 M](789)
    Abstract:
    The purpose of this study was to investigate the effect of pea oligopeptide on the protein expression of phosphatidylinositol 3-kinase/protein kinase B/FoxO1 (PI3K/ AKT/ FoxO1) in the liver of mice with type 2 diabetes mellitus (T2MD). Mice were intraperitoneally injected with streptozotocin (STZ) to establish a type 2 diabetic mouse model, and the mice were fed with metformin and pea oligopeptide for 4 weeks, respectively. The results showed that the diabetes indications of mice in the pea oligopeptide group were improved in a dose-dependent manner compared with the model group. In the high-dose group, blood glucose was decreased by 23.97%, body weight were increased by 12.24%, and the expressions of PI3K, AKT and FOXO1 proteins in the liver were increased by 278.49%, 21.78% and 80.41%, respectively. Cytopathological observation showed that the high dose group could regulate cell morphology and improve glycogen accumulation. Therefore, pea oligopeptidatin can regulate the PI3K/AKT/FOXO1 signaling pathway in the liver of mice with type 2 diabetes, which can not only reduce liver cell damage, but also improve some indicators of type 2 diabetic mice. This paper broadens the idea of high-value utilization of pea protein, and provides practical reference for the application of pea oligopeptide in the field of diabetes, which can supplement and improve the diabetes theory of pea oligopeptide.
    4  Discussion on the Risk of Body Colitis Caused by Food-grade κ-Carrageenan
    ZHANG Hui LIU Fang YANG Rui-li TANG Qing-juan
    2021, 37(2):28-35. DOI: 10.13982/j.mfst.1673-9078.2021.2.0786
    [Abstract](461) [HTML](257) [PDF 38.46 M](764)
    Abstract:
    To investigate whether various dosages of marketed food-grade κ-carrageenan could induce colitis in the organisms, the subtype and molecular weight of purchased carrageenan sample were detected. 72 6-week-old C57BL/6J mice were randomly divided into 6 groups and fed the normal diet (NC), the normal diet mixed with the dosages of 0.05% (0.05% CGN), 0.5% (0.5% CGN), 1% (1% CGN), 2.5% (2.5% CGN) and 5% (5% CGN) of the carrageenan sample for six weeks, respectively. The related colitis markers of mice were measured after sacrifice. The characteristic analysis of carrageenan indicated that the sample belonged to κ type food-grade carrageenan. The animal experiment showed that different dosages of carrageenan intervention had no significant effects on the thymus index, spleen index, colon microstructure and length, and release of prostaglandin E2 (PGE2) in colon (p>0.05). The protein expression of tumor necrosis factor-α (TNF-α) and the activity of myeloperoxidase (MPO) in the colon of 0.05% CGN and 2.5% CGN group mice respectively decreased by 63.14% and 29.50%, compared to the control group (p<0.05, p<0.01). There was no significant difference between the other dosage groups and the control group (p>0.05). The protein expression of Toll-like receptor 4 (TLR4) in colonic epithelium of mice in 1% CGN group was higher than that in control group (66.67%, p<0.05) and there was no significant difference between the other carrageenan intervention groups and the control group (p>0.05). The research results suggested that supplementation of 0.05%~5% food-grade κ-carrageenan in diet had no colitis effect for mice. The results show that the adults who consume carrageenan-processed-food daily are not at risk for colitis.
    5  Pericarpium Citri Reticulatae Phenolic Compounds Regulate AHR and NF-κB Pathways Against Benzopyrene-Induced Lung Epithelial Cell Injury
    GAO Chao LIU Jie HU Feng-xia
    2021, 37(2):36-43. DOI: 10.13982/j.mfst.1673-9078.2021.2.0720
    [Abstract](352) [HTML](200) [PDF 40.19 M](867)
    Abstract:
    To study the mechanism of benzo-α-pyrene (Bap) induced inflammatory injury in pulmonary epithelial cells and explore the protective effect of pericarpium citri reticulatae phenolics, the phenolics in pericarpium citri reticulatae was isolated and their anti-inflammatory potency in Bap induced human lung epithelial type II cells (A549) was explored. The expressions of inflammatory factors and the protein expression in NF-κB, aryl hydrocarbon receptor (AHR) pathways were detected, and the protective potency of the phenolics was explored. Six phenolics were isolated and their structures were identified, among whichaspidin BB can reduce by 3.74% apoptosis in Bap-induced A549 cell. Further, aspidin BB inhibited the secretion of NO and the inflammatory factors (IL-1β, IL-6 and TNF-α) by 49.22%, 26.79%, 37.86% and42.94% respectively. Western blotting results showed that aspidin BB significantly inhibited the activation of AHR and NF-κB pathways induced by Bap stimuli. The phenolics isolated from the pericarpium citri reticulatae can regulate the AHR and NF-κB pathways to attenuate the inflammatory and oxidant damages induced by the Bap stimuli.
    6  Puerarin Improves Oxidative Stress in Rats with Gestational Diabetes Mellitus
    NIE Xiao-xia WANG Cui-xiang
    2021, 37(2):44-48. DOI: 10.13982/j.mfst.1673-9078.2021.2.0509
    [Abstract](203) [HTML](214) [PDF 739.00 K](603)
    Abstract:
    The effect of puerarin extract on oxidative stress in gestational diabetes model rats was studied. Gestational diabetes model rats were established and puerarin extract was used for intervention. Fasting blood glucose (FPG), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor (TNF-α), Quinone oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1) and nuclear factor E2 related factor 2 (Nrf2) proteins were detected. Results were showed that the FPG, LDL-C and HDL-C of high dose puerarin group were 9.05 mmol/L, 0.79 mmol/L and 0.72 mmol/L respectively, which were significantly different with other groups (p<0.05). The MDA, NO and SOD were 7.15 nmol/mg, 90.76 μmol/L and 9.29 U/mg respectively, The levels of IL-6, CRP and TNF-α in puerarin high-dose group were 135.51 ng/L, 7.18 mg/L and 15.06 μg/μL respectively, which were lower than those in model groups (p<0.05). Puerarin extract can reduce fasting blood glucose and improve MDA, NO and SOD levels.
    7  Optimization of Spore Germination Conditions of Clostridium sporogenes
    HUANG Zhong-min GUO Nai PAN Zhi-li AI Zhi-lu LEI Meng-meng SUO Biao
    2021, 37(2):49-55. DOI: 10.13982/j.mfst.1673-9078.2021.2.0783
    [Abstract](576) [HTML](591) [PDF 44.61 M](842)
    Abstract:
    To study the optimum conditions for the spore germination of Clostridium sporogenes under different temperature, time and pH values,in this study, the spore suspension of Clostridium sporogenes was prepared by activating the passaged Clostridium sporogenes solution for 7 days, centrifugation for several times, and adding sterile water. The treatment temperature was 70 ℃~90 ℃, and the treatment time was 5~25 ℃. The germination rate of Clostridium sporogenes was observed and calculated by plate counting method, and the optimal values of three conditions affecting the germination rate of Clostridium sporogenes were studied by response surface methodology. Through the analysis of the quadratic multiple regression equation, the best conditions for spore germination of Clostridium sporogeneswere obtained as follows: when the temperature was 80.90 ℃, the time was 20.72 min, and the pH value was 4.69, the highest germination rate of Clostridium sporogenum could reach 80%. In this paper, combined with the mechanism of spore germination, the optimum germination conditions of spores were used to make the spores germinate under mild conditions, which laid the foundation for the new sterilization method of "germination first and then killing"; and provided a new idea and feasibility of low-intensity sterilization for the difficult problem of spore killing, which was of great significance to the application of low-intensity sterilization in the sterilization of low acid canned food.
    8  Identification of Micro RNA-like RNAs and Their Target Genes from Fusarium oxysporum F. sp. cubense Race 4
    LI Jing-yu XU Lin-bing YING Fan XIAO Wei-qiang CHEN Gu
    2021, 37(2):56-63. DOI: 10.13982/j.mfst.1673-9078.2021.2.0300
    [Abstract](279) [HTML](352) [PDF 2.37 M](953)
    Abstract:
    Fusarium wilt has seriously threatened the development of the banana industry. In order to analyze the miRNA-like (milRNA) and its regulatory function in the Fusarium oxysporum F. sp. cubense race 4 (Foc4), three Foc4 mycelia small RNA sequencing libraries were constructed. Totally 11,783,990 raw reads were obtained by sequencing, of which 3,351,578 valid reads can be used for subsequent milRNA identification. Through the comparison with the plant miRNAs in miRbase and the reported fungal milRNAs, seven conservative milRNAs and three novel milRNAs were identified. A total of 53 pairs of milRNA-mRNAs were identified through degradome sequencing to predict milRNA target genes. Through GO and KEGG enrichment analysis of target genes, milRNA was found in association with multiple metabolic pathways, including purine metabolism, glycerophospholipid metabolism, thiamine metabolism, and tricarboxylic acid cycle pathways, and would have an important impact on fungal growth and development. In the meantime, milRNA targeted the ABC transporter CDR4 and spore wall mature protein DIT1, thereby probably influencing the pathogenic process of Foc4. This study is the first to analyze milRNA-targeted genes in the pathogen Foc4 via degradome sequencing after milRNA was obtained by high-throughput sequencing, which provides an important reference for studying the regulatory functions of fungal milRNA and new ideas for the prevention and treatment of Fusarium wilt.
    9  Optimization of the Conditions for Synergistic Production of Esters by Esterifying Bacteria of Luzhou-flavor Liquor
    HUANG Zhi-guo PU Ling-ping LUO Hui-bo LIN Feng ZHANG Su-yi CHENG Guo-fu DENG Jie
    2021, 37(2):64-71. DOI: 10.13982/j.mfst.1673-9078.2021.2.0750
    [Abstract](318) [HTML](293) [PDF 13.92 M](871)
    Abstract:
    In order to increase the yield of ethyl hexanoate and ethyl butyrate in Luzhou-flavor liquor, Clostridium beijerinckii, Clostridium guangxiense and Clostridium sartagoforme with better ester-producing performance that have been screened from Luzhou-flavor pit mud were used as test materials. The 3 strains were subjected to a mixed culture experiment, and the compounding conditions of each strain were optimized by the Box-Behnken response surface test design method, and the best compounding conditions were determined. The results showed that the three strains had a certain synergistic effect between two of them, and the mixed fermentation effect of adding 3 strains at the same time was the best. The content of ethyl caproate and ethyl butyrate was significantly higher than the results of other cooperative fermentation experiments (p<0.05); the optimalratio of inoculation amount of 3 strains in compound fermentation was Y1:Y2:Y3 = 4:1.5:4.5. Under the optimized culture conditions, the yield of ethyl caproate could reach 32.25 mg/100 mL, which was 0.63 times higher than that before optimization (19.78 mg/100 mL); the yield of ethyl butyrate could reach 117.68 mg/100 mL, 1.59 times higher than that before optimization (45.37 mg/100 mL). The content of ethyl caproate and ethyl butyrate after optimization was significantly higher than that before optimization (p<0.05). The results showed that the synergistic effect of microorganisms could be used to improve liquor flavor.
    10  CRISPR/Cas9-assisted Construction of Engineered Low-fructose-utilization Saccharomyces cerevisiae
    CHEN Hong ZHAO Feng-guang LI Zhan-sheng YANG Jia-ming HAN Shuang-yan
    2021, 37(2):72-78. DOI: 10.13982/j.mfst.1673-9078.2021.2.0277
    [Abstract](411) [HTML](279) [PDF 29.98 M](980)
    Abstract:
    The production of D-psicose using D-fructose as the raw material and Saccharomyces cerevisiae as the host has inherent advantages in food applications. In order to reduce the consumption of fructose by the hostSaccharomyces cerevisiae itself, the hexokinase isoenzyme 2 (hxk2) gene was editedin Saccharomyces cerevisiae. In this study, CRISPR/Cas9 technology was used to construct Cas9 and gRNA co-expression plasmid pYES2-CG-?hxk2, and using Saccharomyces cerevisiae BY4741 as the starting strain and URA3 as the selection marker, hxk2-deficient strain BY4741-?hxk2 was obtained by high-efficiency electroporation-induced transformation and intracellular homologous recombination technology. On this basis, a fructose fermentation experiment was conducted to evaluate the consumption rate of D-fructose in the mutant strain BY4741-?hxk2. The experimental results showed that the fructose consumption rate in the BY4741-?hxk2 strain after 14 h of fermentation was 3.35 mg/h (which decreased by 6.42% compared with wild strain BY4741). In addition, the OD600 nm of BY4741-?hxk2 was 8.65 after 22h of fermentation (which increased by6.40% compared with BY4741). This research shows that deleting the hexokinase hxk2 gene can reduce the utilization of fructose by Saccharomyces cerevisiae to a certain extent, and the defective strain exhibited advantages in growth compared with the wild type. These findings lay a foundation for the subsequent production of D-psicose by Saccharomyces cerevisiae using BY4741-Δhxk2 as the host.
    11  Changes of Molds in Jingwei Fuzhuan Brick Tea during Fermentation
    WU Jin-jin LYU Jia-li HU Xin SHI Chao-ye
    2021, 37(2):79-86. DOI: 10.13982/j.mfst.1673-9078.2021.2.0789
    [Abstract](335) [HTML](212) [PDF 79.65 M](956)
    Abstract:
    Fuzhuan brick tea originated in Jingyang, Shaanxi province and belongs to post-fermented tea. Molds play important roles in the fermentation of Fuzhuan brick tea. Jingwei Fuzhuan brick tea is a typical representative of Fuzhuan brick tea. In this work, the changes of culturable molds in 12 different stages (0th d, 2nd d, 4th d, 6th d, 8th d, 10th d, 12th d, 14th d, 16th d, 18th d, 23th d, 28th d) during the fermentation of Jingwei Fuzhuan brick tea were analyzed. The results showed that there were eight kinds of molds involved in the fermentation process, which were Aspergillus cristatus, Aspergillus costiformis, Penicillium citrinum, Fusarium equiseti, Aspergillus niger, Aspergillus oryzae, Alternaria alternate and Cladosporium cladosporioides. In the early stage of fermentation, Penicillium citrinum was the dominant mould group, and there were a small amount of Aspergillus cristatus, Aspergillus niger, Alternaria alternate and Cladosporium cladosporioides. On the 8th day of the middle fermentation period, there was still a large amount of Penicillium citrinum, and a small amount of Aspergillus costiformis and Aspergillus niger were also detected. After that, Aspergillus cristatus began to grow in large quantities and occupied a dominant position in the middle and late fermentation period. At the end of fermentation, Aspergillus cristatus were to be 134000 CFU/g and accounted for 99.99% of all molds. Fungal flora is rich in the early stage of Jingwei Fuzhuan brick tea fermentation. With the fermentation progress, Aspergillus cristatus gradually become the dominant flora.
    12  Expression of Nicotinamide Phosphoribosyltransferase in Escherichia coli and Catalytic Synthesis of Nicotinamide Mononucleotide
    LIAO Yi-bo WU Min-hui LING Shu-li LIN Ying
    2021, 37(2):87-93. DOI: 10.13982/j.mfst.1673-9078.2021.2.0239
    [Abstract](376) [HTML](250) [PDF 1.37 M](1270)
    Abstract:
    Nicotinamide phosphate ribose transferase (Nampt) is an important enzyme in the bioenzymatic synthesis of nicotinamide ribotide (NMN), and is used to catalyze the synthesis of NMN from nicotinamide (NAM) and phosphoribosyl pyrophosphate (PRPP). In this study, Nampt from Meiothermus ruber was expressed intracellularly in the Escherichia coli expression system, and the expressed product was purified for the examinations of enzymatic properties and catalysis for the synthesis of NMN. Recombinant strains were induced in shake flasks at a low temperature (16 ℃) for 21 h. The fermented cells were collected and disrupted ultrasonically. After the disruption, the supernatant was purified by Ni-NTA chelation affinity chromatography. SDS-PAGE results showed that the size of the expressed and purified product was about 55 ku (which was consistent with the expected protein molecular weight). The optimal reaction temperature of the recombinant Nampt was 45 ℃, with the optimal pH as 6. Enzyme kinetic analysis showed that the Km, Vmax, and kcat of the enzyme on the substrate NAM were 0.39 μmol/L, 3.20 μmol / (mg·min), and 1.39 1/s, respectively. The enzyme was used to catalyze the production of NMN, and the product NMN yield could reach 30 mg/L with an addition of the substrate PRPP within the 10 min reaction. In this study, a Nampt with excellent enzymatic properties and thermal stability was successfully expressed, and applied to a single enzyme-catalyzed production of NMN with a higher yield and production efficiency. This research has laid the foundation for the application of bioenzymatic synthesis of NMN.
    13  The Correlation between Structural and Antigenicity Changes of Goat Casein by Heat Treatment
    XUE Hai-yan FAN Jiao-jiao HE Bao-yuan CAO Ge LI Jing-ying SONG Hong-xin
    2021, 37(2):94-102. DOI: 10.13982/j.mfst.1673-9078.2021.2.0751
    [Abstract](329) [HTML](286) [PDF 40.61 M](1026)
    Abstract:
    The heat treatment of α-casein (α-CN) and β-casein (β-CN) in goat milk was explored by circular dichroism, fluorescence spectroscopy and other methods to analyze the effects of their structure and antigenicity. The results showed that with the increase of the heat treatment temperature of the casein, the natural structure of α-CN and β-CN was destroyed, caused molecular cross-linking or aggregation, and changed the molecular weight. The content of free carbonyl in the molecule increased. At 134 ℃, the carbonyl content increased by 134.72% and 110.98%, respectively. The free sulfhydryl content decreased continuously. The maximum fluorescence absorption intensity of the hydrophobic probes increased by 50.38%, and 9.61%, respectively. The temperature rise caused hydrophobic groups or disulfide bonds to be exposed, resulting in increasing hydrophobicity of the proteins. Circular dichroism results showed that the degree of curl or elastic structure in the secondary structure undergoes complex transformation, which changes the spatial structure of the protein. α- spirals were increased, β- turns and irregular curls were decreased. The antigenicity of casein decreased with increased temperature. After simulated gastrointestinal digestion, the antigenicity was reduced by 80.63% and 84.12%, respectively, at 134 ℃. Therefore, heat treatment can reduce the antigenicity of goat milk casein. And the change of antigenicity are inversely proportional to the change of free carbonyl content of protein. In addition, it is also positively correlated with the content of irregular curls and β-turns in the secondary structure.
    14  Evaluation of Bioactive Components and Antioxidant Activity of Gardenia Fruit Oil
    ZHU Ying-jie YANG Ya-jie LI Qun-he ZOU Ying LUO Zi-sheng
    2021, 37(2):103-113. DOI: 10.13982/j.mfst.1673-9078.2021.2.0776
    [Abstract](367) [HTML](224) [PDF 34.91 M](925)
    Abstract:
    Gardenia fruit oil was extracted with hexane, ethyl acetate and ethanol combined with ultrasonic assisted extraction. The yield, oil composition, bioactive components and free radical scavenging ability of the three crude oils and ethanol extracts were analyzed. Under the same conditions that the solid-liquid ration was 1:8, the temperature was 40 ℃, the spending time was 20 minutes and ultrasonic intensity was 200 W, the oil yield extracted with ethanol was 13.26%, slightly lower than that of hexane (14.86%) and ethyl acetate (13.84%). The by-product ethanol colloid phase (ECP) was stratified at 4 ℃ from ethanol extraction, and the yield was 9.68%. The total tocopherol content in the crude oil of Gardenia fruit that extracted by ethanol was 1.62 μg/mg, which was 1.27 times of that obtained by n-hexane. The total sterol content was 22.63 μg/mg in the crude oil extracted by ethanol, which was 1.29 times of that obtained by ethyl acetate. The main aromatic components in the crude oil extracted by ethanol were volatile vanillic acid, syringic acid, and syringol. Different from the three crude oils, γ-linolenic acid (1.50%) and trans-linoleic acid (1.14%) were detected in ECP. The IC50 values of DPPH clearance and ABTS in ECP were 0.61 mg/mL and 0.40 mg/mL, respectively, which were significantly lower than the test results in crude oil(7.62~10.31 mg/mL). In addition, crocetin and eight sugar derivatives were preliminarily identified in the ECP by the method UPLC-Triple-TOF/MS. The experimental results showed that gardenia fruit extracted with ethanol had higher economic value, for the reasons that it had sweet fragrance, rich types and higher contents of omega-6 fats, higher contents of active substances such as tocopherol and sterol, and strong free radical scavenging ability related to crocetin and its derivatives in the by-product.
    15  Dual Inhibitory Effects of Aqueous Tree Peony (Paeonia suffruticosa Andr.) Extract on Renin and ACE
    GAO Yi-fang LIU Xue-ting YAN Zhong-li YANG Wen-qing LI Xi-xi WANG Chang-lu LI Feng-juan
    2021, 37(2):114-119. DOI: 10.13982/j.mfst.1673-9078.2021.2.0683
    [Abstract](342) [HTML](218) [PDF 1.23 M](613)
    Abstract:
    The inhibitory effects of aqueous tree peony (Paeonia suffruticosa Andr.) extracts on renin and angiotensin converting enzyme (ACE), two key enzymes in the renin-angiotensin system, were investigated in this research. Tree peony samples with typical colors were selected and compared with herbaceous peony (Paeonia lactiflora Pall.) samples on the renin- and ACE-inhibitory activities and antioxidant activities of aqueous sample extracts were determined. The correlations between the contents of total phenolics or flavonoids and the functionalities were also analyzed. Results showed that the aqueous extracts of red tree peony and herbaceous peony exhibited excellent renin- and ACE-inhibitory activities, while the aqueous extract of white tree peony exhibited very weak inhibitory effects on renin and ACE activities. The IC50 value of the extract with the highest inhibitory activity was 0.08 mg/mL for renin and 0.23 mg/mL for ACE. In addition, the aqueous extracts of red tree peony and herbaceous peony had ABTS free radical scavenging capacities in the range of 115.89~121.75 mg TE/g DW, DPPH radical scavenging capacities in the range of 192.67~200.46 mg TE/g DW, iron ion reduction capacities in the range of 119.86~208.94 mg TE/g DW, and total phenolic content in the range of 99.29~122.45 mg GAE/g DW. However, the antioxidant capacity and total phenolic content of the white tree peony extracts were much lower than those of the red ones. Correlation analysis revealed that the renin-/ACE-inhibitory activities, DPPH/ABTS free radical scavenging capacities, and iron reduction ability of the different aqueous extracts were significantly positively correlated with their total phenolic contents (p<0.01), with the correlation coefficients being 0.99, 0.91, 0.99, 0.99 and 0.98, respectively. This research indicated that the aqueous extracts of the dark colored tree peony tended to show stronger renin-and ACE-inhibitoryactivities, with phenolic compounds as potentially important active substances. These results would provide more fundamental theoretical support for exploring novel blood pressure-regulating agents and fulfilling the high-value utilization of various tree peony flowers.
    16  Enzymatic Synthesis of Myristoyl Cyanidin-3-O-Glucoside in a Mixed Solvent System
    ZHANG Ping-ling ZHAO Zhen-gang
    2021, 37(2):120-128. DOI: 10.13982/j.mfst.1673-9078.2021.2.0365
    [Abstract](281) [HTML](226) [PDF 28.68 M](746)
    Abstract:
    In order to improve the stability and lipophilicity of cyanidin-3-O-glucoside (C3G), immobilized lipase Lipozyme 435 was used in this study to catalyze the acylation of C3G by methyl myristate. The acylation in a single organic solvent and a mixed organic solvent was investigated. Then, the acylated derivative of C3G was separated and purified by semi-preparative liquid chromatography, and its structure was characterized by HPLC-MS/MS and NMR techniques. The optimal synthesis conditions of myristoyl C3G were obtained in 20% pyridine-tert-amyl alcohol by single factor experiments and orthogonal experiments. The results showed that the conversion rate in a mixed solvent system (tert-amyl alcohol plus 20% V/V of pyridine petroleum ether, n-hexane or isooctane) was significantly improved (p<0.05) compared to that in a single organic solvent. The 20% pyridine-tert-amyl alcohol combination was the best reaction medium and allowed the increase of the conversion rate from 10.13% to 15.62%. The acylation most likely occurred on the 6″-OH of the glucose residue of C3G to yield cyanidin-3-(6″-myristoyl)-glucoside. The highest conversion rate for myristoyl C3G was achieved (33.25%) under the optimal synthesis conditions: 60 ℃; reaction time, 22 h; molar ratio of C3G to methyl myristate, 1:250; enzyme concentration 20 mg/mL. This study provides a useful reference for further research on the stability and biological activity of anthocyanins, and to expands the application of anthocyanins in lipophilic matrices.
    17  Effect of Aging Treatment on Starch Content, Gelatinization and Digestibility of Corn
    ZHANG Ming-dan WANG Min CHEN Guang-xuan PENG Dan-dan LIU Ya-nan LIU Na
    2021, 37(2):129-137. DOI: 10.13982/j.mfst.1673-9078.2021.2.0759
    [Abstract](383) [HTML](301) [PDF 11.33 M](1066)
    Abstract:
    In order to provide theoretical reference for the application of corn starch and the reasonable storage of corn, the effects of aging on starch content, amylase activity, starch gelatinization characteristics and Starch digestibility of corn seeds with artificial aging treatment under the environment of high temperature and high humidity were explored. The correlation between starch content, total amylase activity, α-amylase activity, starch debranching enzyme activity, starch gelatinization characteristics, starch digestibility of corn seeds and artificial aging under the environment of high temperature and high humidity(42 ℃, 100% RH) was analyzed using Zheng Dan 958, Wei Ke 702 and Xun Dan 29 as materials. The results showed that there was significant inverse correlation between the corn starch content, amylopectin content, ready digestible starch, total amylase, alpha amylase, starch branching enzyme activity and artificial aging (p<0.05), the decrease rate of total starch content and amylopectin content were 3.98%~7.07% and 4.20%~6.37%,respectively, and the decrease rate of enzyme activity was 40.47%~55.71%. The artificial aging was significant positive correlation with amylose content, Slowly Digestible Starch, Resistant Starch, peak time (p<0.05), the increase rate of amylose content was 13.92%~20.89%, and the increase range of peak time was 0.47 mim~0.66 min. However, it decreased the starch peak viscosity, trough viscosity, breakdown value, final viscosity, seatbcack viscosity (p<0.05), the peak viscosity, trough viscosity, final viscosity, disintegration value and reduction value of Zheng Dan 958 starch were all higher than those of Wei Ke 702 and Xun Dan 29 at 0 and 8 days of artificial aging.
    18  Comparison of Fruit Quality and Characteristics at Different Growth Stages of Kumquat from Rongan
    LI Jun FU Man-qin XU Yu-juan WU Ji-jun YU Yuan-shan WEN Jing
    2021, 37(2):138-146. DOI: 10.13982/j.mfst.1673-9078.2021.2.0762
    [Abstract](274) [HTML](307) [PDF 52.80 M](1035)
    Abstract:
    A study on the dynamic change of the physicochemical properties and the active ingredients of kumquat fruits at different growth stages was carried out with Guangxi Rongan specialty Fortunella margarita (Lour.) 'Youpi' (YP) and Fortunella margarita (Lour.) 'Cuipi' (CP).The results showed that from September to December, the physical and chemical indexes such as single fruit weight, juice yield, pH value, soluble solids, and sugar-acid ratio of kumquat increased, and the fruit seed rate and titratable acid content decreased. The main sugar content rose from 39.04 and 32.38 mg/g to 111.23 and 137.11 mg/g, respectively. The main organic acids were ascorbic acid, malic acid and oxalic acid, the ascorbic acid content increased first and then decreased. In October, kumquat ascorbic acid content peaked (48.23 and 23.20 mg/g, respectively). While malic acid and oxalic acid contents continued to decline. Compared with September, the total flavonoid contents of YP and CP kumquat decreased from 3.45 and 2.14 mg RE/g to 1.21 and 0.76 mg RE/g respectively in December, in which the characteristic flavonoid fortunellin content increased significantly. The total phenol content and antioxidant activity decreased significantly. Between the twovarieties, there were no significant differences in mature single fruit weight, titratable acid, TFs, and hesperidin content, and the fruit seed rate, ascorbic acid, fortunellin, TPs content, and total antioxidant capacity of YP were significantly higher than those of CP. While the juice yield, fruit juice pH, soluble solids, sugar-acid ratio, fructose, glucose, sucrose, malic acid, oxalic acid, and rutin content of YP were significantly lower than those of CP. This study clarified the fruit quality characteristics of the two kinds of kumquat at different growth stages and provided a theoretical basis for the development and utilization of kumquat fruit.
    19  Effect of Sustained Release of Plant Essential Oil Carried by Diatomaceous Earth on Preservation of Raspberry
    ZHANG Li-hui FAN Kai LIAO Li QIAO Yu ZHANG Jin-mu CHEN Xue-ling
    2021, 37(2):147-154. DOI: 10.13982/j.mfst.1673-9078.2021.2.0621
    [Abstract](285) [HTML](328) [PDF 2.04 M](1003)
    Abstract:
    In order to prolong the storage time of raspberries and maintain the fruit quality, each of three plant essential oils, eugenol, carvacrol or linalool carried by diatomaceous earth was applied to keep the raspberries fresh via sustained release over a 27 day storage at 4 ℃. The preservative effect of the sustained -release essential oil was evaluated based on the measurements taken every 3 days of fruit decay rate, mass loss and nutrient composition and antioxidant enzymes. Results showed that compared with the blank group, the sustained release of each essential oil reduced effectively the fruit decay rate, mass loss rate, soluble solids content, titratable acid content, reducing sugar content and Vc content, and maintained SOD and POD activities of raspberries during storage, thereby delaying the senescence and membrane lipid peroxidation of raspberries during storage; Compared with the blank group, the sustained release of carvacrol carried by diatomaceous earth extended the shelf life of raspberries by 12 days. After the 27 day storage, the decay rate and mass loss rate of raspberries were only 34.43% and 2.45%, respectively, with the soluble solids content, titratable acid content, reducing sugar content and Vc content in raspberries as 3.28%, 0.35%, 0.78% and 0.37 g/kg, and the SOD and POD activities as 143.32 U/g and 0.89 U/g. The results indicated that the sustained-release of carvacrol carried by diatomaceous earth exhibited a greater preservation effect on raspberries.
    20  The Fresh-keeping Effect of Different High-oxygen Packaging Methods on Non-heading Chinese Cabbage
    WANG Ping WANG Ling YU Xin CHEN Yu-long GUO Jing CHEN Fei-ping LUO Zheng YIN Juan
    2021, 37(2):155-163. DOI: 10.13982/j.mfst.1673-9078.2021.2.0680
    [Abstract](242) [HTML](331) [PDF 26.37 M](788)
    Abstract:
    Using fresh non-heading Chinese cabbage as the test material, and biaxially oriented polypropylene film (BOPP) and low-density polyethylene (LDPE) for the packaging of fresh non-heading Chinese cabbage under a high oxygen (>80%) environment, the changes in gas composition of the packaging bag, and the nutritional quality, antioxidant activity and lignin content of the fresh cabbage stored at 4 ℃ were examined. The results showed that during storage, high-oxygen packaging could effectively retard the rapid increase of the respiration rate of cabbage, accelerate the increase in total phenolic content of cabbage, and increase the antioxidant capacity of cabbage. On the 8th day of storage, the total phenolic contents of the cabbage packed by BOPP-H and LDPE-H were 1.75% and 6.27% (both were higher than that of the control group). In the earlier storage stage, the activity of catalase (CAT) was stimulated to increase, while in the late storage stage, the activity of superoxide dismutase (SOD) increased, the accumulation of H2O2 decreased, and synthesis of lignin was reduced. On the 8th day of storage, the lignin contents of the cabbage packed by BOPP-H and LDPE-H were 5.70% and 1.43% (both were lower than that of the control group), with that of LDPE-H packaging being 2.40% lower than that of BOPP-H packaging. The above results indicate that high-oxygen packaging is beneficial to the storage and preservation of cabbage, and LDPE-H packaging can maintain the total phenol content and reduce lignin synthesis more effectively than BOPP-H packaging.
    21  Storage Quality Improvement of Fresh-Cut Broccoli by Cold Plasma Treatment
    ZHANG Yong ZHANG Zhi-wei CHENG Chen-xia ZHANG Xin-fu YANG Shao-lan
    2021, 37(2):164-170. DOI: 10.13982/j.mfst.1673-9078.2021.2.0806
    [Abstract](327) [HTML](300) [PDF 38.26 M](1059)
    Abstract:
    In this work, the effect of CP treatment on the vegetable storage quality of fresh-cut broccoli (Brassica oleracea) was evaluated. The results showed that compared with the control, the CP treatment could effectively sterilize the bacteria on the broccoli surface. The hardness, chewiness and viscous force of fresh-cut broccoli treated with CP treatment on 5thd were44.45 kg/cm2, 12.51 and 139.88 mJ, respectively. While those of the control group were 34.84 kg/cm2, 7.71 and 83.63 mJ, respectively. It indicated that CP treatment could significantly inhibit the texture change of broccoli. The ethylene production rate of fresh-cut broccoli increased at first and then decreased during the storage time, which was significantly inhibited by CP treatment. According to the principal component analysis and linear discriminant analysis of electronic nose detection, the volatile compound of fresh-cut broccoli was significantly different between CP treatment group and control group during the storage time. The cluster analysis showed that the storage quality of fresh-cut broccoli with CP treatment on 15thd was equivalent to that of the control fresh-cut broccoli on 11thd. So, the storage life of fresh-cut broccoli could be effectively prolonged by CP treatment, and the vegetable quality could be maintained better.
    22  Effects of High Energy Electron Beam Irradiation on the Preservation of Spaghetti Squash
    LI Yang SHA Fei GAO Yue-xia LI Jia-jia PENG Xue REN Ya-mei
    2021, 37(2):171-182. DOI: 10.13982/j.mfst.1673-9078.2021.2.0694
    [Abstract](280) [HTML](306) [PDF 55.03 M](807)
    Abstract:
    In order to study the effects of high electron beam irradiation on preservation and storagequality of spaghetti squash, the four sides of the spaghetti squash were irradiated with different doses of high-energy electron beam: 0 kGy (CK), 0.4 kGy, 0.6 kGy and 0.8 kGy, then stored at 9±1 ℃, RH 65%~70% for use. Effects of different high-energy electron beam doses on the storage quality of different parts of the spaghetti squash were studied. Results showed that the respiration intensity of mature spaghetti squash was promoted by the irradiation, whose respiration intensity was 2.75 times that of the control (p<0.05).The nutrient consumption of different parts was accelerated, and the weight loss rate was 2.90 times higher than that of control. Damage of cell membrane integrity led to more MDA accumulation, which promoted maturity, accelerated the process of softening and aging, decreased its hardness, brittleness and moisture content, decreased taste and flavor quality, and increased decay rate. On the 15th day of storage, the hardness of control was 2.25 times that of the irradiated spaghetti squash, and the rotting rate of the irradiated spaghetti squash was 2.16 times that of control at the end of storage (p<0.05); however, the contents of titratable acid and Vc were not affected by the irradiation dose (p>0.05). In a word, the doses of 0.4 kGy, 0.6 kGy and 0.8 kGy irradiation for 4 times had a positive and negative impact on the quality of spaghetti squash. The dose could accelerate the ripening of spaghetti squash which could not mature normally due to climatic reasons, earlier harvest or needs for urgent eating. Further research can reduce the irradiation dose or times, which is expected to be used for the postharvest storage and preservation of the spaghetti squash.
    23  Optimization of Soy Isoflavone Aglycone Production from Soybean Milk Fermented by Lactobacillus plantarum 58
    HUANG Yu-jun ZHOU Fan LI Ying-hua YU Jun-juan GU Rui-xia
    2021, 37(2):183-190. DOI: 10.13982/j.mfst.1673-9078.2021.2.0796
    [Abstract](299) [HTML](229) [PDF 4.19 M](793)
    Abstract:
    In this work, the growth and β-glucosidase production of Lactobacillus plantarum 58 in different carbon sources were analyzed to optimize carbon source of the strain, and then the best time for inoculation to soymilk was obtained. On the basis of single-factor experiments (such as inoculation amount, sugar content, fermentation time, and fermentation temperature), the response surface experiment was designed according to the Box-Behnken central combination principle. The soy isoflavone aglycone content was used as an indicator to further optimize the fermentation conditions of soybean milk by Lactobacillus plantarum 58. The results showed that the optimal carbon source for the growth and β-glucosidase production of Lactobacillus plantarum 58 was lactose, and the enzyme activity reached 0.66 U/mL, which was significantly higher than that of fructose, sucrose, glucose and maltose (p<0.05). The strain cultured in a lactose carbon source for 18 h couldproduce the best enzyme activity (0.75 U/mL), and the growth was good. Results of response surface optimization experiments showed that the optimal conversion condition of soy isoflavones wasas follows: inoculum amount of 3.80%, sugar content of 5.80%, fermentation temperature of 38.10 ℃, fermentation time of 9.80 h.Under this condition, the predicted value of soy isoflavone aglycone content reached 68.63 mg/L, which was not significantly different from the experimental value 68.16 mg/L, indicating that the construction of the secondary model was scientific and accurate. Compared with the soy isoflavone aglycone content (59.64 mg/L) before optimization, it increased by 15.07%. The results of this work could be helpful to the conversion of soy isoflavone glycosides in lactic acid bacteria fermented soymilk to high bioactivity and availability of soy isoflavone aglycones.
    24  Effect of Electromagnetic Cylinder Variable Temperature Coupling to Hot Air Drying Technology on the Formation of Chestnut-like Aroma Green Tea
    CHEN Jia-yu ZHANG Ming-ming JIANG Yong-wen YANG Yan-qin YUAN Hai-bo LIU Zheng-quan
    2021, 37(2):191-204. DOI: 10.13982/j.mfst.1673-9078.2021.2.0745
    [Abstract](292) [HTML](334) [PDF 4.70 M](700)
    Abstract:
    In order to investigate the effect of electromagnetic cylinder variable temperature coupling hot air drying technology on the formation of chestnut-like aroma in green tea, the effects of different combinations of drum variable temperature , drying time, and coupling to hot air were investigated. The qualitative and quantitative analyses of aroma components were implemented by using infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS), and the key compounds for chestnut-like fragrance were further screened by multivariate statistical analysis. The results showed that the best quality of chestnut-like aroma was obtained when the drying temperature of the electromagnetic drum was 180 ℃/170 ℃/160 ℃, coupling to hot air at 110 ℃ maintaining for 6 min. In addition, an effective discriminant model of green tea with chestnut-like aroma was established by partial least squares-discriminant analysis (PLS-DA) (R2Y=0.997, Q2=0.774). Based on VIP>1 and p≤0.05, 27 key differential compounds were screened out. Their distribution was further determined using hierarchical cluster analysis (HCA), and it was found that the contents of 27 volatiles were generally higher in chestnut-like aroma green teas than non-chestnut-like aroma green teas. In addition, the quality of chestnut-like aroma in green teas was influenced by the tenderness of the raw materials, too. Better quality of chestnut-like fragrance was obtained using green tea with a single bud than that with a bud and one leave. In general, as a promising processing technology, the electromagnetic cylinder variable temperature coupling to hot air drying technology provides theoretical reference and technical support for the processing of chestnut-like green tea.
    25  Comparative Analysis of Different Vacuum Freeze Drying Processes on Quality of Osmanthus fragrans
    CHEN Bai-nan YANG Hao BAO Yun-hui ZHAO Dou CHEN Hong-guo ZENG Xiang-ling YANG Jie
    2021, 37(2):205-212. DOI: 10.13982/j.mfst.1673-9078.2021.2.0743
    [Abstract](619) [HTML](345) [PDF 4.65 M](787)
    Abstract:
    To obtain high quality dried Osmanthus fragrans flowers, the eutectic point and co-melting point of flowers were measured byelectrical resistance method. The effects of material thickness, pre freezing temperature and time, partition heating program on the freeze-drying efficiency of O. fragrans flowers were analyzed. And the rehydration ratio, active components and microstructure of O. fragrans flowers dried by vacuum freeze of different processes and hot air were compared. The results showed that the eutectic point was -19 ℃ and the co-melting point was -17 ℃. When the pre-freezing temperature was maintained at -25 ℃ for 2.5 h, the pre-freezing requirement reached. The material thickness and partition heating program in the drying stage were important factors affecting the drying efficiency. Compared with hot-air drying treatment, vacuum freeze-drying maintained good tissue shape with the rehydration ratio 4.16 ~ 4.56 g/g. The total flavonoid content in vacuum freeze-drying ranging from 35.90 to 38.42 mg/g·DW and the contents of aroma active compounds were all significantly higher than hot-air dried O. fragrans flowers. The effects of different vacuum freeze-drying processes on the content of total flavonoid and aroma active compounds in O. fragrans flowers were not significant. The rehydration ratio of fast heating vacuum freeze-drying O. fragrans flowers was 4.16 g/g, significantly higher than that of hot-air dried flowers 2.98 g/g, but lower than the slower heating vacuum freeze-dried flowers. Microstructure analysis showed that the slower the heating process, the smoother the petal surface. High quality of the dried O. fragrans flowers could be obtained using partition heating program at - 10 ℃ for 1 h, 5 ℃ for 1 h, 20 ℃ for 1 h, and 35 ℃ for several hours. This study laid a foundation for the storage and preservation of fresh flowers, and the production and utilization of high-quality dried O. fragrans.
    26  Optimization of Extraction Process and Component Analysis of the Flavonoids from Broussonetia papyrifera Leaves
    ZHANG Xing-rong ZHANG Xue-lin HE Lian-zhi XU Hui ZHENG Xiao-ga LI Feng HUANG Yan-hong
    2021, 37(2):213-220. DOI: 10.13982/j.mfst.1673-9078.2021.2.0671
    [Abstract](329) [HTML](353) [PDF 46.86 M](880)
    Abstract:
    In order to investigate the optimal extraction process and the main components of flavonoids from the leaves of Broussonetia papyrifera, single factor experiments and response surface methodology (RSM) analysis were conducted to examine the effects of ethanol concentration, extraction time, extraction temperature and liquid-material ratio on the yield of flavonoids, as well as the flavonoid composition of the extract. The results showed that when the ethanol concentration was 30%, extraction time was 2.5 h, the extraction temperature was 69 ℃, and liquid-material ratio was 9%, the yield of flavonoids in Broussonetia papyrifera leaves was 37.33 mg/g; UPLC-MS (UPLC-MS/MS) was used for component analysis, a total of 11 species of flavonoids were identified: scutellarin, orientin, apigenin-7-O-glucuronide, kaempferol, apigenin, cynaroside, galangin, apigenin-7-glucoside, (1ξ)-1,5-anhydro-1-(5,7-dihydroxy-4-oxo-2-phenyl-4h-chromen-8-yl)-d-glucitol, 6-O-phydroxybenzoylaucubin, and isovitexin. The Box-Behnken Design of response surface methodology was used to optimize the ethanolic extraction of total flavonoids form Broussonetia papyrifera leaves, while determiningthe best extraction process for the total flavonoids. The process was simple and easy to implementwith good stability, which can provide guidance and +referencefor the industrial production of flavonoids from Broussonetia papyrifera leaves.
    27  Extraction of Lignans from Schisandra chinensis by Magnetic Agitation Assisted Supercritical CO2
    BI Jin-long LIANG Zheng-ji ZHANG Xian-feng YANG Qing WANG He-fei PAN Xin-yue QIN Mei-qiong WANG Zhi-bing
    2021, 37(2):221-230. DOI: 10.13982/j.mfst.1673-9078.2021.2.0717
    [Abstract](324) [HTML](209) [PDF 26.92 M](928)
    Abstract:
    In this study, a magnetic stirring assisted supercritical CO2 extraction method was established and applied to the extraction of eight lignans from the fruit of Schisandra chinensis. The target analytes were separated and determined by high performance liquid chromatography (HPLC). Specifically, supercritical CO2 was used as extraction solvent, the sample was pre-impregnated with ethanol solution, and the contact between samples and supercritical CO2 was promoted by magnetic stirring to improve mass transfer efficiency. Then, various factors affecting the extraction efficiency of lignans were optimized, and compared with the traditional methods. The experimental results showed that the good linear relationship for analytes was obtained in the linear range (r>0.9998). The limit of detection and limit of quantification were 21.30~990.20 ng/mL and 60.80~2992.80 ng/mL, respectively. The spiked recoveries were between 75.00% and 97.78%. The analysis results were satisfactory. Compared with other methods, the extraction yield obtained by this method was significantly higher than that obtained by microwave extraction and thermal reflux extraction, and comparable to that obtained by the pharmacopoeia method. Although a small amount of organic solvent was used in the extraction process, the ratio of solid to liquid was only 1:2, which is 1/25~1/50 of other methods. This method has the advantages of large sample handling capacity, simple operation, environmental protection and high extraction efficiency, and certain potential in industrial production and application. It can be used for the extraction and separation of lignans in traditional Chinese medicine.
    28  Optimization of Low Temperature Vacuum Frying Lotus Seed
    WANG Hai-lan TANG Jin-song YAO Fang QI Xing-pu SHI Shuai
    2021, 37(2):231-237. DOI: 10.13982/j.mfst.1673-9078.2021.2.1033
    [Abstract](292) [HTML](376) [PDF 37.18 M](1007)
    Abstract:
    In this work, the optimum technology of low temperature vacuum-frying lotus seeds was investigated by response surface methodology. The effects of single factor on the hardness and oil content of vacuum-frying lotus seeds were evaluated. The regression models were established by box Behnken design and used to analyze the effects of vacuum degree (0.085~0.095 MPa), frying temperature (80~90 ℃) and frying time (15~25 min) on the quality of lotus seed snack food, and the optimum technology parameters were selected. The results showed that, R2 of the two regression models were 0.9987 and 0.9930, respectively, which both were close to 1. The fitting degree of the regression models was good. The optimal technological parameters of low-temperature vacuum-frying method were obtained as follows: frying temperature of 80 ℃, frying time of 25 min, frying vacuum degree of 0.095 MPa, lotus seed moisture of 55%, thickness of 1/2. The sensory characteristics of low-temperature vacuum-frying lotus seeds were significantly better than those of normal pressure frying lotus seeds. Therefore, it could be feasible to optimize the low-temperature vacuum-frying process of lotus seeds by response surface methodology, and the sensory characteristics of lotus seeds fried under the optimized process were better than that of normal pressure frying method.
    29  Dynamic Changes in Quality and Composition of Oolong Tea Made with Fresh Bixiangzao Summer Tea Leaves during Processing
    SONG Jia-yan HE Jia-xing OU Yi-ling JIANG Ping-li BO Jia-hui GONG Lian-jin XIAO Li-zheng
    2021, 37(2):238-248. DOI: 10.13982/j.mfst.1673-9078.2021.2.0688
    [Abstract](410) [HTML](223) [PDF 628.99 K](639)
    Abstract:
    Using three- four fresh leaves of Bixiangzao summer tea leaves as the raw materials, oolong tea was produced following the procedure involving withering, shaking, kill-green (de-enzyming), rolling and drying steps. The biochemical components of the samples generated from the tea processing and the dry tea samples were analyzed, and the aroma components were detected by solid phase microextraction-gas chromatography-mass spectrometry (SPME/GC-MS). Combined with sensory evaluation, the dynamic changes of quality components and quality formation of Bixiangzao fresh leaves during oolong tea processing were examined. The results of sensory evaluation showed that the oolong tea had amellow taste and a floral aroma. Quality component analysis showed that tea polyphenols, catechins, caffeine, soluble sugars, flavonoids and water extracts showed an overall downward trend (decreases by 5.32%, 3.96%, 0.48%, 0.38%, 22.35%and 2.77%, respectively, from fresh leaves to dried tea),whilst the content of free amino acids showed an overall upward trend (an increase by 12.88%from fresh leaves to dried tea). The analysis of volatile components revealed that the overall contents of volatile components (hydrocarbons, ketones, aldehydes and other substances) showed an upward trend, whilst the contents of alcohols, esters and phenols showed an overall downward trend. Among them, trans-nerol, phenylethanol, dihydrolinalool, benzaldehyde, β-ionone, indole, α-farnesene, α-ylenoleneand geranyl acetone can be used as the characteristic aroma components of Bixiangzao summer oolong tea. The processing of oolong tea promotes the gradual decrease of bitter and astringent tastes and greenish substances, and the gradual increase of sweet, mellow, and floral and fruity substances, which is conducive to the formation of the taste and aroma of this kind of tea, and provides a scientific reference for the utilization of summer tea resources.
    30  The Optimization of Processing Technology Based on Fuzzy Mathematic Evaluation and Aroma Component Analysis of Grape Distilled Wine in Xinjiang
    SONG Jing-jing LI Ning TONG Wen-jie ZHAO Hao WANG Wei-xiong ZHANG Hai-jun YANG Hua-feng LIU Xiu-hai LU Pi-chao WU Yun
    2021, 37(2):249-260. DOI: 10.13982/j.mfst.1673-9078.2021.2.0768
    [Abstract](318) [HTML](400) [PDF 15.48 M](1031)
    Abstract:
    Three processing technologies of flavored Lycium barbarum and Glycyrrhiza grape distilled wine were optimized by fuzzy mathematic evaluation combined with headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). Subsequently, the volatile aroma components of flavored Lycium barbarum and Glycyrrhiza grape distilled wine and the effects of characteristic compounds on overall flavor were explored through principal component analysis. The results showed that the sample with Lycium barbarum and Glycyrrhiza extracts had the highest comprehensive score, and showed rich variety of aroma, strong characteristic flavor, meaning a consistent result between HS-SPME-GC-MS analysis and fuzzy mathematics evaluation, thus the best processing technology for grape distilled wine was Lycium barbarum and Glycyrrhiza extraction. 72 volatile compounds were obtained from three kinds of grape distilled wine and base liquor, the results of principal 17 kinds of common volatile compounds and 5 kinds of volatile compounds for three kinds of grape distilled wine analysis showed that, esters, alcohols, acids and aldehydes components were the important components that affected the aroma of flavored Lycium barbarum and Glycyrrhiza grape distilled wine. The key characteristic compounds were: ethyl caprylate, ethyl caprate, ethyl caproate, ethyl laurate, isoamyl alcohol, phenethyl alcohol, octanoic acid.
    31  Analysis of Differences in Quality Characteristics of Meat from Different Parts of Xinjiang Brown Cattle
    ZHAO Gai-ming ZHANG Gui-yan RU Ang LI Jia-qi ZHU Chao-zhi NAI Bi-jiang LIU Jian-ming
    2021, 37(2):261-267. DOI: 10.13982/j.mfst.1673-9078.2021.2.0631
    [Abstract](741) [HTML](451) [PDF 10.36 M](968)
    Abstract:
    In order to investigate the differences in quality characteristics and processing suitability of the meat from different parts of Xinjiang brown cattle and provide a theoretical basis for the refining process of Xinjiang brown beef, meat samples from seven parts of Xinjiang brown cattle including beef lint, outer ridge, beef brisket, shoulder, beef tendon, rump and cucumber strips were selected for nutrition and meat eating quality in this experiment. The results showed significant differences in the quality characteristics of the meat samples from the above-mentioned parts of Xinjiang brown cattle. The beef lint had a higher collagen content (13.02%) and showed better gelling and emulsifying properties; The outer ridge had a higher fat content (2.31%) with greater tenderness but poor water retention; The beef brisket had a small thawing loss (1.79%) but large cooking loss (37.27%); The shoulder meat had good gelling and emulsifying characteristics with tenderness; The beef tendon had a relatively high water content (76.48%) is high with a small thawing loss (1.70%); The rump meat had a relatively high collagen content (18.49%) with good water retention; The cucumber strips had the highest nutritional quality with better tenderness and less cooking loss (30.49%). The results showed that the meat samples from different parts of Xinjiang brown cattle differed in quality characteristics and require their own suitable processing methods.
    32  Analysis of Meat Quality and Meat Production Performance of Free-range Chickens
    HAN Ming-sheng MA Si-yu LIU Xiao-he HE Gui-wen YANG Ya-jin GUO Ai-wei
    2021, 37(2):268-274. DOI: 10.13982/j.mfst.1673-9078.2021.2.0808
    [Abstract](273) [HTML](423) [PDF 2.81 M](1023)
    Abstract:
    In this work, the meat quality and meat production performance of free-range chickens were evaluated. Ten healthy free-range chickens from 12 weeks of age were randomly selected, and 10 healthy caged chickens from 12 weeks of age were used as the control group. The chickens were slaughtered in accordance with "poultry performance terms and methods". The breast muscle and thigh muscle were collected for meat quality analysis. The cooking loss, pH, redness (a*), yellowness (b*), lightness (L*), electrical conductivity and, fat and protein content in muscle, abdominal fat rate and slaughter performance were determined. The results showed that the cooking loss, pH45 min, pH24 h, b*45min, protein, fat, EC24 h of free-range chicken breast muscle were 23.36%, 5.65, 5.65, 17.67, 83.16%, 3.89%, 6.80 mS/cm, respectively. The cooking loss, pH45 min, pH24 h, b*45 min, protein, fat, EC24 h of leg muscles were 24.21%, 5.88, 5.84, 16.80, 72.81%, 13.37%, 5.00 mS/cm, respectively. The abdominal fat rate, slaughter rate, total eviscerated rate, breast muscle rate, and leg muscle rate of free-range chickens were 3.31%, 91.43%, 64.90%, 22.76%, and 23.13%, respectively. Compared with caged chickens, free-range chickens had better slaughter performance, meat color, freshness, and free-range chicken muscles had the characteristics of low fat.
    33  Analysis and Evaluation of Nutritional Contents in Muscle of Guizhou Sansui Duck Cultured with Different Methods
    YANG Li-ping WANG Xiu-jun LIU Lin-xin YU Pei CHEN Yan-hong NIE Qian-li YANG Wan-yun YAO Bi-qiong
    2021, 37(2):275-282. DOI: 10.13982/j.mfst.1673-9078.2021.2.0741
    [Abstract](254) [HTML](346) [PDF 4.97 M](829)
    Abstract:
    To study the nutritive value of Sansui duck (scattered culturing) and Sansui duck (enterprise management culturing) in Guizhou, using the national standard method to determine the composition and content of the basic nutrients, mineral elements and amino acids of these two duck meats, nutrient components in muscle of them were analyzed and the nutritive quality of the meat were evaluated in this study. The results showed that the moisture (76.30%), crudeprotein (21.36%), and mineral (649.02 mg/100 g) content in the Sansui duck (scattered culturing) muscle were significantly higher than those in Sansui duck (enterprise management culturing) muscle; but the crudefat (2.12%) in the Sansui duck (scattered culturing) muscle was lower than that in Sansui duck (enterprise management culturing) muscle (p<0.05). They have the same cholesterol content (64.00 mg/100g). Lead and cadmium were not detected. A total of 16 amino acids were detected in muscle proteins of Sansui duck cultured with different methods , and the total amino acid (19.14 g/100 g), total essential amino acid (8.28 g/100 g), essential amino acid index (76), biological value (71) and nutritional index (0.16) of Sansui duck (scattered culturing) were higher than those of Sansui duck (enterprise management culturing), the content of delicious amino acids (8.70g/100g) was lower than that of Sansui duck (enterprise management culturing). Amino acid score (AAS) analyses showed that the first limiting amino acid in muscle of Sansui duck cultured with different methods were Met+Cys. The ratio of essential amino acids to total amino acids and the ratio of essential amino acids to nonessential amino acids of the two kinds of Sansui duck cultured with different methods met WHO/FAO standard.18 and 20 fatty acids were detected in two kinds of duck meat, respectively. The contents of saturated fatty acid (0.77%), monosaturated fatty acid (0.86%) and polyunsaturated fatty acid (0.36%) in Sansui duck (scattered culturing) were significantly higher than those in Sansui duck (enterprise management culturing) (p<0.05). Sansui duck (scattered culturing) has high the nutritional value of basic nutritional components and amino acid, and Sansui duck (enterprise management culturing) has high delicate amino acid and reasonable fatty acid quality.
    34  Changes of Chilled Duck Meat Quality under Different Cold Chain Storage and Transportation Conditions
    GUO Xing-yue ZHANG Yu-jie OUYANG He-yi AI You-wei LEI Fei-fei HOU Wen-fu
    2021, 37(2):283-289. DOI: 10.13982/j.mfst.1673-9078.2021.2.1005
    [Abstract](281) [HTML](275) [PDF 26.60 M](864)
    Abstract:
    In order to study the effect of different cold chain storage and transportation conditions on the quality of chilled duck meat. Sensory evaluation, total bacterial count and total volatile base nitrogen (TVB-N) value were used as evaluation criteria to study the effects of different packaging methods, transportation time, transportation temperature and vibration intensity on the quality of chilled and fresh duck meat. The results show that The TVB-N value of modified atmosphere packaging (53% O2+47% CO2) at the end of storage and transportation was only 12.78 mg/100 g, which was still in the second grade freshness, which could maintain the original quality of chilled duck meat better than vacuum packaging and modified atmosphere packaging. The sensory score of 1 h transportation group decreased slowly during the whole experiment, and the sensory score was still above 8 at the end of the experiment. Transportation temperature had a significant effect on the total number of colonies in the later stage of storage and transportation (p<0.05). Low temperature (4 ℃) transportation can effectively maintain the quality of products, and the storage period is 1~2 days longer than that of high temperature transportation. Vibration intensity had a significant effect on the total number of colonies (p<0.05), but 3 Hz amplitude had little effect on the quality of duck meat. At the end of storage, the total number of colonies was 5.04 lg CFU/g and TVB-N value was 11.01 mg/100 g. The research provides a reference for the selection of cold chain transportation conditions for cold fresh duck meat.
    35  Comparison of Fatty Acid Composition and Principal Component Analysis of Beef Cattle in Western Area of Yellow River
    ZHENG Ya WANG Xiao-xuan HU Sheng-hai TIAN Jia-chun
    2021, 37(2):290-297. DOI: 10.13982/j.mfst.1673-9078.2021.2.0983
    [Abstract](389) [HTML](429) [PDF 4.03 M](1083)
    Abstract:
    To research the difference of fatty acid composition between Simmental and Angus cattle in western area of yellow river, the content of fatty acid in samples was determined by gas chromatography and evaluated by principal component analysis. Nine Simmental bulls and nine Angus bulls were selected. All animals were provided the same diet and management. Nine bulls per breed at approximately 18 months of age were randomly selected and then slaughtered. Cattle were slaughtered after being fasted for 12 h. The fatty acid content of the longissimus dorsi muscle was measured. The results showed that 17 kinds of fatty acids were identified in the two kinds of cattle, including 5 saturated fatty acids and 12 unsaturated fatty acids. Among the saturated fatty acids, palmitic acid was the highest, which was 21.81% and 23.54% respectively. The content of unsaturated fatty acids in Angus beef was 7.10% higher than that in Simmental. The contents of four unsaturated fatty acids (myristic acid, eicosapeenoic acid, arachidonic acid and DHA) in Angus cattle were significantly higher than those in Simmental cattle. Based on principal component analysis, seven core fatty acids were extracted as the characteristic fatty acids in two kinds of cattle. A comprehensive mathematical model was established as F=0.590×F1+0.154×F2+ 0.124×F3. In terms of fatty acid composition and comprehensive score, Angus was better than Simmental cattle. Fatty acid determination and principal component analysis revealed the characteristics and differences of fatty acid composition in the two kinds of beef, which provided theoretical basis for the rational development and utilization of excellent beef cattle products in western area of yellow river.
    36  Research Progress of Cellulose Modification and its Application in Meat Products
    MI Hong-bo LI Yi DENG Ting-yue YI Shu-min LI Xue-peng CHEN Jing-xin LI Jian-rong
    2021, 37(2):298-307. DOI: 10.13982/j.mfst.1673-9078.2021.2.0632
    [Abstract](398) [HTML](445) [PDF 3.66 M](1087)
    Abstract:
    Cellulose is a kind of abundant and renewable resource in nature. However, it is difficult to dissolve natural cellulose in most solvents due to its intra- and inter-molecular hydrogen bonding and its highly crystalline aggregate structure, which limits the development and application of cellulose. The modification of cellulose, while being capable of retaining its original characteristics, enabled new properties such as reduced crystallinity and degree of polymerization through introducing active functional groups such as hydroxyl, amide, and amino groups, thereby endowing products with high quality during food production and extensive attention from domestic and international scholars. This article summarizes the types and characteristics of modified cellulose, as well as the interactions between modified cellulose and meat proteins and its application in meat products. The currently existing problems and the future development directions were also put forward to provide references for further research on modified cellulose and promote the value-added utilization of cellulose.

    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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