Volume 38,Issue 8,2022 Table of Contents

1 Changes of Urine Metabolism and Gut Microbiome in Rats after Intragastric Administration of Quinoa Saponins

ZHANG Ruoyu , YAN Fei , LI Xuening , CAO Yuqing , YU Yuan , FENG Jing , XUE Peng

2022, 38(8):1-9. DOI: 10.13982/j.mfst.1673-9078.2022.8.0999

[Abstract](296) [HTML](202) [PDF 2.09 M](634)

Abstract:
The saponins from Chenopodium quinoa were used as the material for 90-day oral exposure to healthy adult Sprague Dawley rats to evaluate the effects of the saponins on rats’ kidneys in combination of gut microbiome with urine metabolomics studies. Rats (n = 48, half male and female) were divided into the high-dose (500 mg/kg saponin) treatment group, medium-dose (50 mg/kg saponin) treatment group, low-dose (5 mg/kg saponin) treatment group and blank control group. After oral gavage, the intestinal fluids were collected from the rats for examining the effects of saponins on intestinal flora by 16S rDNA, and analyzing rats’ urine metabolomics by UPLC-MS. Partial inflammatory changes were observed in the kidney slices of male and female rats in both the medium- and high-dose groups. The results of metabolomics showed that there was insignificant difference between the medium- and low-dose groups. 101 kinds of differential metabolites were found in the urine of female rats while 29 kinds of differential metabolites were found in the urine of male rats after administration of the high dose of quinoa saponins, with metabolic processes such as vitamin B6 metabolism, ammonia cycle and tryptophan metabolism being affected. The gut microbiome analysis revealed the significant differences in the diversity of gut microbiome between the treatment group and the control. In summary, quinoa saponins at a low dose had insignificant toxicity, but exhibited potential non-contact nephrotoxicity at medium-high doses.

2 Bifidobacterium lactis XLTG11 Alleviates Cyclophosphamide-induced Immunosuppression in Mice

LI Wenwen , MA Weiwei , MA Qing , ZHANG Zhenhua , HUANG Lili

2022, 38(8):10-16. DOI: 10.13982/j.mfst.1673-9078.2022.8.1372

[Abstract](329) [HTML](265) [PDF 1.68 M](531)

Abstract:
The effects of Bifidobacterium lactis XLTG11 on immune function utilizing an immunosuppressed mouse model that was constructed using cyclophosphamide (CTX) were investigated. The blank control and model groups were given normal saline, the positive control group was given levamisole hydrochloride (LEV) (10 mg/kg), and the experimental groups were given B. lactis XLTG11 at different concentrations (1×109, 1×108, 1×107, or 1×106 CFU) for 28 consecutive days; subsequently, immunological indices were measured. All mice dosed with B. lactis XLTG11 resisted CTX damage to the thymus; their thymic indices increased by 37.37%, 43.43%, 56.56%, and 84.84% (p<0.05), respectively, compared with those of the model group. Additionally, the experimental groups showed increases in plantar thickness of 38.24%, 50.00%, 55.89%, and 94.12% (p<0.05), respectively. Higher villus height and goblet cell number in the small intestines (p<0.05) were also observed, with those of the 1×109 CFU group increasing by 20.82% (p<0.01) and 51.23% (p<0.01), respectively. Moreover, elevated serum immunoglobulin and cytokine levels were detected (p<0.05). IgA, IL-2, and TNF-α levels increased the most; in the 1×109 CFU group, IgA increased by 20.03% (p<0.01), IL-2 by 35.94% (p<0.01), and TNF-α by 14.50% (p<0.05). Therefore, B. lactis XLTG11 enhanced the immune function of immunocompromised mice in a dose-dependent manner. Our findings can serve as a theoretical basis for the development and use of probiotic health foods.

3 Protective Effect of Coreopsis tinctoria Nutt. Ethanol Extract against Acrylamide-induced Liver Injury

GAO Juanjuan , LI Shuang , MA Rui , SHAO Lei , XIE Aidi , WANG Zhen , ZHAO Yi , LI Yuxin , HAN Haixia

2022, 38(8):17-26. DOI: 10.13982/j.mfst.1673-9078.2022.8.0273

[Abstract](224) [HTML](214) [PDF 1.26 M](506)

Abstract:
The ethanol extract of Coreopsis tinctoria Nutt. was applied to human hepatocellular carcinoma HepG2 cells and mouse liver to evaluate its protective effect against acrylamide (ACR)-induced injury. Cell survival rate was used to evaluate the protective effect of C. tinctoria ethanol extract against HepG2 cell injury, whereas body weight change, liver function, and liver pathological sections were used to evaluate the protective effect of C. tinctoria ethanol extract against mouse liver injury. Antioxidant indices were also determined to evaluate the underlying protective mechanisms. The results indicated that after preincubation with C. tinctoria ethanol extract (2.00 mg/mL), the survival rate of ACR-injured HepG2 cells increased by 12.81%; intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) decreased by 57.67% and 4.68 nmol/mg, respectively; and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) levels increased by 4.68, 10.48, and 13.81 U/mg, respectively. The weight gain of mice in the low-dose (0.25 g/kg), medium-dose (0.25 g/kg), and high-dose (0.25g/kg) groups of C. tinctoria ethanol extract were 2.2~2.5 times that of the ACR group. In the high-dose group (1.0 g/kg), serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) decreased by 27.76 and 46.79 U/L, respectively; MDA decreased by 1.86 nmol/mg, whereas SOD and GSH-Px increased by 56.73 and 330.44 U/mg, respectively. Hematoxylin and eosin staining results of liver tissue showed that the hepatic lobule structure and hepatocyte morphology of mice had improved to varying degrees with low, medium, and high doses of C. tinctoria ethanol extract, with significant alleviation of the injury to liver tissue. In conclusion, C. tinctoria ethanol extract could prevent the ACR-induced injury of HepG2 cells and mouse liver tissue, and the underlying mechanism was related to its antioxidant capacity.

4 Effects of a Red Ginseng and Donkey-Hide Gelatin Composite Beverage on Hematopoietic Ability and Immunomodulatory Function in Mice

LIU Huiping , DENG Yudi , TU Yali , YIN Hantong , WANG Linqing , WEI Xi , YANG Xiaona , LIAO Wenzhen , JIANG Liang

2022, 38(8):27-34. DOI: 10.13982/j.mfst.1673-9078.2022.8.1211

[Abstract](259) [HTML](216) [PDF 1.33 M](499)

Abstract:
Red ginseng and donkey-hide gelatin peptide were used as the main functional raw materials to develop a functional composite beverage, into which auxiliary materials were added, including collagen peptide, yeast β-glucan, N-acetylneuraminic acid, chicken peptide, longan powder, red date powder, and γ-aminobutyric acid, according to the National Solid Beverage Standards. The antioxidant effects of the beverage were detected in vitro, and a mouse model of Qi and blood deficiency was constructed to determine the effect of the beverage on immune function. The results show that the total antioxidant capacity of the beverage at 100 mg/mL was 0.25 U/mL. In addition, the beverage restored the number of leukocytes, lymphocytes, and platelets in mice with Qi and blood deficiency. The beverage also significantly alleviated spleen damage, reduced MDA contents, and enhanced the activities of antioxidant enzymes (superoxide dismutase and glutathione peroxidase), thereby reducing oxidative damage. Furthermore, the beverage could significantly improve antioxidant capacity, hematopoietic ability, and immunomodulatory function in mice. Overall, the functional beverage had abundant beneficial effects and shows promise as a marketable multifunctional food in the future.

5 Cloning, Heterologous Expression, and Enzymatic Characteristics of the Bile Salt Hydrolase Gene from Enterococcus faecium 132

YANG Lingshuang , XIE Xinqiang , LI Ying , ZHANG Jumei , DING Yu , WU Qingping , WANG Juan

2022, 38(8):35-43. DOI: 10.13982/j.mfst.1673-9078.2022.8.1167

[Abstract](371) [HTML](201) [PDF 1.15 M](555)

Abstract:
The bile salt hydrolase (BSH) activity of a potentially cholesterol-lowering strain, Enterococcus faecium 132, was studied. The target gene was cloned and expressed in Escherichia coli BL21, and its enzymatic characteristics were examined. The BSH activity of E. faecium 132 lysate was determined using the ninhydrin method, and its specific enzyme activity was 0.55 U/mg. The bsh gene of E. faecium 132 was cloned into the expression vector pET-28a(+) for heterologous expression in BL21. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that the molecular weight of the resulting enzyme was approximately 37 ku. The recombinant BSH showed optimal hydrolytic activity (6.59 U/mg) when glycocholic acid (GCA) was used as a substrate at a pH of 5.50 and temperature of 30 ℃, while also exhibiting good thermal and pH stability within a temperature range of 4~30 ℃ and pH range of 5~7. The effect of different metal ions on enzyme activity indicated that BSH activity was activated by Na+, Ca2+, and Mg2+, unaffected by Mn2+ or Fe2+, but inhibited by Ni2+, Al3+, Li2+, CO2+, and Zn2+, with enzyme activity decreasing to < 10%, and an almost complete loss of enzyme activity. Enzymatic kinetics revealed that the Vmax of this enzyme was 6.44 μmol/(min•mg), and the Km value was 3.16 mmol/L. Therefore, through the cloning and heterologous expression of the bsh gene in E. coli BL21, significant improvements can be made to E. faecium 132 BSH activity, and various bile salts were strongly hydrolyzed, thus implying that this recombinant BSH can be used in the development and application of cholesterol-lowering functional foods.

6 Isolation, Screening, and Probiotic Function Evaluation of Lactic Acid Bacteria with Cholesterol-lowering Effects from the Intestinal Tract of Seabass

SONG Yingli , LI Anzhang , XU Shuaishuai , MA Li’an , ZHU Honghui

2022, 38(8):44-52. DOI: 10.13982/j.mfst.1673-9078.2022.8.1121

[Abstract](202) [HTML](194) [PDF 1.17 M](538)

Abstract:
This study focused on the screening and isolation of lactic acid bacteria with high-efficiency cholesterol-lowering effects from the intestines of healthy seabass. The assessments of in vitro probiotic effects were carried out through strain identification, together with the evaluation of acid resistance, bile salt tolerance, hydrophobicity, self-cohesion, and the antibacterial properties of their metabolites. Bile salt hydrolase (BSH) assays and in vitro cholesterol reduction tests were performed, which led to the isolation of a high-efficiency cholesterol-lowering strain ZG2YLu05. This strain exhibited crude BSH activity with a value of 0.82 µmol/(h•mL), and a cholesterol removal rate of 50.09%. The acid-resistance survival rate of the strain was 83.33% when cultured at pH 3.0 for 8 h, while the bile salt-tolerance survival rate was 89.31% when cultured in 0.3% bile salt concentration for 8 h. The hydrophobicity of the strain in dimethylbenzene was 46.82% and its self-cohesion was 92.93% when left to stand for 24 h, which indicates that the strain has potentially good adhesion properties. The metabolites of the strain also showed significant inhibition of Escherichia coli, Staphylococcus aureus, and Salmonella. The strain was identified as Lactiplantibacillus pentosus through morphological observations and 16S rDNA sequencing. Therefore, this strain can be used as a potential cholesterol-lowering lactic acid bacteria for the development of complementary lipid-lowering probiotic preparations.

7 Identification and Traceability Analysis of Bacteria in the Main Ingredients of Zigong Leng-chi Rabbit

YUAN Xianling , ZHENG Yidan , LUO Yi , LIN Hongbin

2022, 38(8):53-65. DOI: 10.13982/j.mfst.1673-9078.2022.8.1344

[Abstract](162) [HTML](167) [PDF 739.88 K](618)

Abstract:
The number of microorganisms in chilled rabbit meat, chili pepper, Chinese prickly ash, star anise, sesame, cumin, aromatic ginger, spices, cinnamon, and process water used in the production of Leng-chi rabbit was determined, and the main species of bacteria in these raw materials and various auxiliary materials were identified using a traditional culture method combined with 16S rDNA sequencing. Subsequently, traceability analysis was performed by constructing a phylogenetic tree. The results showed that a total of 76 bacterial strains from 20 genera were isolated from the raw and auxiliary materials. The materials were ranked according to the total number of colonies as follows: rabbit meat > cumin > chili pepper > spices > process water > aromatic ginger > star anise > cinnamon > Chinese prickly ash > sesame. The materials were ranked for the number of bacterial genera present, as follows: raw meat > chili pepper, cumin > spices, process water > Chinese prickly ash, star anise, sesame, cinnamon > aromatic ginger. Additionally, the ranking for number of bacterial species present was: spices > raw meat > cinnamon > chili pepper > star anise > aromatic ginger > cumin, Chinese prickly ash > sesame, process water. The bacterial diversity was high in the raw and auxiliary materials for Leng-chi rabbit. Bacillus was common in all materials; however, raw meat contained the most bacteria. This study provides an in-depth understanding of the contamination of raw and auxiliary materials used in the production of Leng-chi rabbit. Thus, it provides a theoretical basis for controlling the species and quantity of bacteria from each source and improving production process management and safety.

8 Effects of Plasma Treatment on the Endogenous Enzyme Activity and Quality of Foxtail Millet

QIN Jiale , LI Zhongyan , LIU Qian , ZHANG Ying , WANG Langhong , ZENG Xin’an

2022, 38(8):66-72. DOI: 10.13982/j.mfst.1673-9078.2022.8.1307

[Abstract](208) [HTML](154) [PDF 2.94 M](518)

Abstract:
The effects of dielectric barrier discharge-atmospheric cold plasma (DBD-ACP) on the lipoxygenase and lipase activities and the physiochemical properties (chromaticity, total yellow pigment content, and DPPH free radical scavenging capacity) of foxtail millet (Mizhi, Shaanxi) were investigated. DBD-ACP was found to have a significant inactivation effect on the activities of endogenous enzymes in foxtail millet (p<0.05). For example, treatment at a voltage of 25 kV for 12 min decreased the relative activities of lipoxygenase and lipase to 31.15% and 25.22%, respectively. The chromaticity indicators (L and b*) of millet did not change significantly (p>0.05) after DBD-ACP treatment under 15 kV and 25 kV for 12 min; whereas increasing the voltage to 35 kV under the same treatment time led to a significant increase in the L value from 58.27 to 62.68, and a decrease in the b* value from 43.06 to 38.74 (p<0.05). These results were consistent with the changes in the total yellow pigment content of foxtail millet, indicating that the DBD-ACP treatment had a certain destructive effect on the pigment components in millet at excessively high voltages. The changes in the DPPH scavenging ability, malondialdehyde (MDA) production, and morphology of foxtail millet were further studied. The results showed that there were no significant changes in DPPH scavenging ability, MDA production, and morphology of foxtail millet after DBD-ACP treatment (p>0.05). These results suggest that DBD-ACP can be used for the inactivation of lipoxygenase and lipase, while also maintaining the appearance quality of foxtail millet to some extent. This study provides a theoretical basis for the application of DBD-ACP technology in the inactivation of endogenous enzymes to delay the aging of millet and stabilize its appearance quality.

9 Screening and Identification of Zearalenone-Degrading Bacteria and Preliminary Extraction of Zearalenone-Degrading Enzyme

LIU Chen , XIE Yanli , CAO Rongyao , CHENG Sizhong

2022, 38(8):73-79. DOI: 10.13982/j.mfst.1673-9078.2022.8.1110

[Abstract](223) [HTML](155) [PDF 948.23 K](532)

Abstract:
A zearalenone (ZEN)-degrading bacterial strain was screened from soil using the enrichment culture method. ZEN was coated onto an inorganic salt medium as the sole carbon source in the initial screening, and the degradation rate of ZEN in the fermentation broth of the strain was used as the evaluation index in the second screening. The strain with the highest degradation rate was named A.lwoffi.Haut.1, which showed a degradation rate of 93.54% after co-incubation with 5 μg/mL ZEN in the fermentation broth for 48 h at 37 ℃. The strain was identified through 16S rDNA gene sequencing analysis, physiological and biochemical experiments, and observation of colony morphology, followed by the preliminary localization of its degradation active substances. Finally, the effectiveness of the tannic acid-polyethylene glycol and salt precipitation methods for crude ZEN-degrading enzyme extraction in cell-free supernatant was tested. A.lwoffi.Haut.1 was identified as a strain of Acinetobacter lwoffii. The highest ZEN-degradation rate of A.lwoffi.Haut.1 in cell-free supernatant was 82.31%, which decreased to 20.10%, 41.67%, and 18.68% after treatment with heat, protease K, and protease K+SDS, respectively, thus indicating that extracellular enzymes were the main degradation active substances. The degradation rate of the crude enzyme solution extracted using 15 mg/mL of tannic acid and 10 mg/mL of polyethylene glycol solution was 64.33%, and that using salt precipitation with 60% ammonium sulfate was only 20.30%. Therefore, the tannic acid-polyethylene glycol method was highly effective for the extraction of degradation enzymes. This study provides a research basis for investigating the bacterial degradation mechanism of ZEN and a new research material for ZEN biodegradation.

10 Optimization of Preparation Techniques for Oligopeptides from Mauremys mutica and Its Potential to Inhibit SARS-CoV-2

SU Keying , YANG Guizhuo , DAI Pangcong , LI Li , XU Xiaofei , ZHANG Xuewu

2022, 38(8):80-88. DOI: 10.13982/j.mfst.1673-9078.2022.8.1176

[Abstract](188) [HTML](164) [PDF 1.56 M](467)

Abstract:
This study aimed to explore the possibility of using Mauremys mutica oligopeptides as raw materials to develop a drug targeting the SARS-CoV-2 virus. M. mutica oligopeptides were prepared through the combined enzymatic hydrolysis of M. mutica meat using flavoenzyme and papain, and the optimal enzyme ratios, enzyme dosage, pH, and enzymatic hydrolysis time were determined using single-factor and orthogonal experiments. After separating the oligopeptide fractions via high-performance liquid chromatography-mass spectrometry (HPLC-MS), Peak Studio and Peptide Ranker were used for peptide sequence analysis and peptide activity prediction, respectively, to screen for oligopeptides with high bioactivity. Finally, the binding ability of oligopeptides with high predicted activity against the SARS-CoV-2 spike protein receptor-binding domain (RBD) was evaluated using molecular docking. The results show that the highest degree of hydrolysis (DH; 42.56%) was obtained when M. mutica meat was treated with a flavoenzyme: papain ratio of 7:3 and an enzyme dosage of 7% at pH 5.5 for 4 h. According to Peak Studio analysis, 510 peptides with an average local confidence (ALC) of > 90% were discovered. Six oligopeptides with high Peptide Ranker scores (LDFFK, LDFFKAL, FRVL, AFRVL, AGGKPFQ, and SPFRVT) were screened to dock with S protein. Their docking scores ranged from -138.50 to -169.68, and the lowest docking score (-169.68) was exhibited by LDFFKAL. Therefore, a high DH of M. mutica meat could be attained after process optimization, and a high inhibitory potential for SARS-CoV-2 was observed in the resulting M. mutica oligopeptides.

11 Microbial Distribution and Traceability Analysis in the Production of Capsule-type Health Food Products

ZHANG Yiyu , CHEN Ling , ZHENG Yuqing , LIU Tingting , ZHOU Jinzhen , LU Yongcheng , CHEN Jianyu , YAO Fei , GUO Weipeng

2022, 38(8):89-96. DOI: 10.13982/j.mfst.1673-9078.2022.8.1058

[Abstract](155) [HTML](178) [PDF 1.04 M](422)

Abstract:
Microbiological contamination of human hands and the equipment surfaces in the different production stages of the health food capsule was investigated. The changes in the hygiene and sanitation of the workshop were monitored. The typical contaminating microorganisms were isolated and identified to monitor the composition of microbial flora in each stage and evaluate the effectiveness of the microbial control system in the industrial production process. The results showed that the detection values of coliform and Staphylococcus aureus in 34 smear samples of human hands were < 10 CFU/ hand with the total colony count being 10~107 CFU/hand; in 132 smear samples of equipment surfaces, the detection values of coliform and Staphylococcus aureus were < 0.4 CFU/ cm2 (equipment surface) with the total colony count being 10~104 CFU/cm2; 46 strains of microorganisms (including 44 strains of bacteria and 2 strains of fungi) were isolated from the samples for strain identification. The dominant species was Paenibacillus sp., accounting for 60.87%, followed by Acinetobacter sp., Bacillus sp. and Brevibacterium sp., all accounting for 4.35%. The traceability analysis of the isolated Paenibacillus sp. was performed based on the 16S rRNA gene sequences and MALDI-TOF protein fingerprint revealed cross-contamination of Paenibacillus sp. between the human hands and equipment surfaces. Also, Paenibacillus sp. was colonized on the surfaces of the containers used for turnover materials, which had potential risks to production quality control.

12 Antioxidant Activity and Key Components of Three Grades of Black Tea

LE Ting , WANG Weiwei , WANG Wei , ZHANG Jianyong , XUE Jinjin , YANG Liuyan , JIANG Heyuan

2022, 38(8):97-104. DOI: 10.13982/j.mfst.1673-9078.2022.8.1175

[Abstract](245) [HTML](175) [PDF 4.28 M](1178)

Abstract:
Three grades of black tea were investigated to determine their antioxidant activity and main chemical components. The results showed that the antioxidant activity of black tea samples increased with increasing tea grade, with a significant difference between special-grade and second-grade black teas (p<0.05). In addition, antioxidant activity also varied significantly among five different categories of black tea. Composition analysis revealed that the levels of caffeine, polyphenols, catechins, non-ester catechins, gallic acid, and theaflavins increased gradually with increasing tea grade; whereas the polyphenol and ester catechin levels were consistent with the changes in antioxidant activity among the five different categories of black tea samples. Correlation analysis indicated that the antioxidant activity of black tea was significantly positively correlated with the levels of polyphenols, catechin, non-ester catechin, ester catechin, gallic acid, and theaflavins. Among them, the correlation of polyphenols with the four indicators of antioxidant activity were highly significant (p<0.01), and the correlation coefficients with T-AOC and DPPH exceeded 0.9. In conclusion, the grade of black tea can influence its antioxidant activity, while polyphenols and its derivatives can serve as key components for determining the grade and antioxidant activity of black tea.

13 Metabolite Difference Analysis for Guizhou Specialty Honey Based on GC-MS Untargeted Metabolomics

YAO Dan , LI Ying , LI Huajun , YU Yinglong , HE Xingjiang , ZHAN Hongping , ZHOU Wencai , WAN Wei , WEI Xiaoping

2022, 38(8):105-115. DOI: 10.13982/j.mfst.1673-9078.2022.8.1212

[Abstract](269) [HTML](430) [PDF 2.22 M](553)

Abstract:
Two kinds of mature Apis cerana honey, specifically blueberry and wild rose honeys, were chosen to represent Guizhou specialty honey, while vitex and osmanthus honeys were chosen as controls. Gas chromatography-mass spectrometry (GC-MS)-based untargeted metabolomics was employed to perform clustering and functional enrichment analyses on the metabolites of the specialty honey, followed by the screening of differential metabolites and functional annotations. Among the four honeys, the analysis detected a total of 90 metabolites and enrichment in 210 pathways, of which the top 20 pathways belonged to three types: carbohydrate metabolism (8), overview (9), and membrane transport (3). Norepinephrine (NE) was detected in all four honeys and was enriched by saliva, gastric acid, and pancreatic secretions. Additionally, twelve significantly different metabolites (VIP>1, log2FC>1 and p<0.05), including 2-ketobutyric acid, stearic acid, and inositol, were detected. Moreover, 2-ketobutyric acid and 3-hexanedioic acid were found to be characteristic substances that were unique to blueberry and wild rose honeys, respectively. The abilities of the honeys to improve human digestion, absorption, and protein synthesis were ranked in the following order: osmanthus honey > vitex honey > blueberry honey > wild rose honey. Thus, by analyzing the differences in nutritional components from a metabolomics perspective, the characteristic substances in blueberry and wild rose honeys were preliminarily determined. Therefore, the results provide a reference for identifying the authenticity and traceability of honeys.

14 Comparison of the Chemical Constituents and In Vitro Hypoglycemic Effect of Polygonatum from Different Origins

MA Juan , ZHANG Yiwen , DONG Chenyang , CHAI Yangyang , GUO Qingqi

2022, 38(8):116-126. DOI: 10.13982/j.mfst.1673-9078.2022.8.0983

[Abstract](381) [HTML](260) [PDF 1.16 M](564)

Abstract:
The main chemical components of Polygonatum from six different origins, Yunnan and Guangxi (Polygonatum kingianum), Hunan and Anhui (Polygonatum cyrtonema), and Heilongjiang and Liaoning (Polygonatum sibiricum) were compared. Their hypoglycemic properties were analyzed based on the inhibition rates against α-glucosidase and α-amylase and the glucose dialysis delay indices of their extracts. A screened Polygonatum was incubated in vitro with the feces of diabetic mice, and through 16S rDNA sequencing, the regulation of the composition and structure of the intestinal flora of diabetic mice were analyzed. There were significant differences (p<0.05) among the components of the Polygonatum from different origins. The inhibitory rates of the aqueous extract of Guangxi Polygonatum kingianum were 98.36% against α-glucosidase and 91.85% against α-amylase, which were significantly higher than those of other origins (p<0.05). The glucose dialysis indices exhibited an increasing trend. After comprehensive analysis, Polygonatum kingianum from Guangxi was selected for in vitro incubation. The abundances of beneficial bacteria such as Proteobacteria and Bifidobacterium increased, whilst the abundances of harmful bacteria such as Prevotellaceae_NK3B31_group and Ruminococcus_2 decreased. These results revealed that the water extract of Guangxi Polygonatum kingianum can significantly improve the diversity of the intestinal flora of diabetic mice, and adjust the structure of the intestinal flora. The study provides a theoretical reference for the regional differences in the chemical composition of Polygonatum and its hypoglycemic function and regulatory effect on the intestinal flora in diabetic mice.

15 Analysis of Chemical Constituents in Different Parts of Hellgrammites Based on UHPLC-Q-TOF-MS/MS

LIU Haibo , RAN Junfeng , REN Yan , TIAN Yubo , WU Faming , MAO Yu , GOU Yan , SI Dandan

2022, 38(8):127-137. DOI: 10.13982/j.mfst.1673-9078.2022.8.0937

[Abstract](175) [HTML](202) [PDF 2.19 M](592)

Abstract:
UHPLC-Q-TOF-MS/MS was used to analyze the chemical constituents of the different parts of hellgrammites such as head, thorax and abdomen. The differential material contents were detected. The distribution patterns of the chemical constituents of hellgrammites was discussed. The ultra high performance liquid chromatography conditions were: Waters acquity BEH amide column, 100 mm × 2.1 mm, 1.7 μm; mobile phase, 25 mmol/L aqueous ammonium acetate solution and acetonitrile in gradient mode, flow rate 0.2 mL/min; column temperature, 30 ℃. Mass spectrometry conditions were: Triple TOF 6600 high resolution tandem mass spectrometry, electrospray ionization (ESI) ion source, and data collection in positive and negative mode. A total of 25 compounds were identified in hellgrammites by means of positive and negative ion mass spectrometry information and element composition analysis. Among which, 19 compounds in the head, 21 compounds in the thorax and 19 compounds in the abdomen (including nine amino acids, six organic acids, five nucleosides and five other compounds), with 19 compounds being reported for the first time in hellgrammites. The contents of the differential constituents in different parts of hellgrammites were determined by HPLC. The results showed that there were significant differences in the contents of the differential components in the head, thorax and abdomen (p<0.05). This research showed an analytical method with high sensitivity, and high degree of separation for rapid analysis of the chemical composition of hellgrammites and identification of the differential compounds in different parts, which provides a basis for fundamental research of hellgrammites’ substances and the selection of their usable parts.

16 Analysis of Structure Difference and Molecular Evolution of Xylan 1,4-β-Xylosidase Based on Sequence Alignment

LIN Yanling , CAI Yuchen , LI Lijun , NI Hui

2022, 38(8):138-147. DOI: 10.13982/j.mfst.1673-9078.2022.8.0902

[Abstract](227) [HTML](235) [PDF 4.86 M](1065)

Abstract:
Xylan 1,4-β-xylosidase (EC 3.2.1.37) is an exohydrolase that has become more widely used in industry in recent years. At present, there has been a relative lack of research on the structure of xylan 1,4-β-xylosidase.In order to analyze the evolutionary relationship and structural differences of xylan 1,4-β-xylosidase, MEGAX10.1.8 was used to compare the multiple sequences of xylan 1,4-β-xylosidase gene sequences and construct a phylogenetic evolutiontree. The analysis of results showed that xylan 1,4-β-xylosidase could be divided into two categories, from which 12 representative sequences were screen and selected for the comparison and alignment of multiple amino acid sequences. Only 15 relatively conserved sites were found, showing non-conservative characteristics. The physicochemical properties and signal peptides of the enzymes corresponding to the 12 sequences were predicted and analyzed by bioinformatics tools. The prediction results showed that all enzymes were hydrophilic, and possessed intracellular and extracellular secretion modes. Modell 9.24 and Phyre2 were used to construct models for the tertiary structure. According to the modeling results, xylan 1,4-β-xylosidase was divided into three representative structures: β-folded barrel, bowl-like structure, and (α/β)8 barrel structure. Molecular docking was used to assist the calculation of the size of the binding pocket, and it was speculated that the size of substrate has a certain degree of effect on the morphology of its characteristic structure. Based on the study of the structural pattern of xylan 1,4-β-xylosidase, point mutations can be precisely designed, blindness can be reduced, and desired physicochemical properties can be obtained, to provide bioinformatics guidance for further research on the modification of xylan 1,4-β-xylosidase, then offers a basis for further study on the relationship between the structure and function of xylan 1,4-β-xylosidase, thereby further broadening the application of xylan 1,4-β-xylosidase in food, medicine and other fields.

17 Effect of Light Sources on Chilled Meat Preservation during Storage

ZHAO Lijun , ZHAO Ke , AI Mingyan , ZHAO Gaiming , ZHU Yaodi , WANG Na , LI Miaoyun , HAO Yanan

2022, 38(8):148-152. DOI: 10.13982/j.mfst.1673-9078.2022.8.0868

[Abstract](164) [HTML](172) [PDF 539.57 K](656)

Abstract:
Two different parts of chilled meat (longissimus dorsi and hindquarter) were used as the main experimental materials to investigate the effects of light sources (including pink light, pink purple light, and ultraviolet light) on the color, oxymyoglobin content, thiobarbituric acid (TBA) value and total plate count of the chilled pork samples, with aim to screen out the most beneficial light souce for chilled pork. The results showed that during cold storage, the pork refrigerated under pink light had higher color score, a* value, oxygenated myoglobin content, and overall decreasing rates of the three indices (38.64%~40.00%,10.36%~13.61%, and 25.88%~34.98%, respectively), compared with the pork samples refrigerated in dark or under pink purple light or ultraviolet light. Compared with the other light sources, the pink light source was more conducive to stabilizing the color of the chilled pork, and under this light source, the degree of lipid oxidation of the chilled pork was lower (overall increasing rates of TBA value: 41.38%~86.57%). It is suggested to place chilled pork under pink light in the display cabinet during the actual sale to improve the fresh-keeping effect of chilled pork.

18 The Fresh-keeping Effect of Antibacterial Houttuynia Cordata Extract-chitosan Composite Film on Blueberries Stored at A Low Temperature

HUO Ruobing , LI Yang , XU Tonghui , LI Qingpeng , WANG Leiming , ZHANG Qunli , CHEN Chunsheng

2022, 38(8):153-162. DOI: 10.13982/j.mfst.1673-9078.2022.8.1057

[Abstract](263) [HTML](180) [PDF 1.64 M](539)

Abstract:
In order to improve the preservation of blueberries, antibacterial composite films containing different concentrations of Houttuynia cordata extracts were prepared in this study. The tensile strength, elongation at break, light transmittance, water vapor transmittance and antibacterial rate of the films were examined. The blueberry fruits were coated with a film and stored under refrigeration conditions (at 4 ℃), and the indices such as firmness, weight loss, total soluble solids (TSS), titratable acid (TA), content of anthocyanins, ascorbic acid (Vc) content, malondialdehyde (MDA) content and polyphenol oxidase (PPO) activity were determined.. The study showed that when the concentration of Houttuynia cordata extract was 0.06 g/mL, the antibacterial rate increased to 77.40%, the tensile strength of the film increased to 21.92 MPa, the elongation at break was 17.13%, the light transmittance was 80.20%, and the vapor transmission rate was 2.55×10-10 g/(m•s•Pa), indicating the best overall performance; after 20 days of storage, the firmness of the blueberry fruit was 1.17 kg/cm2, the weight loss rate was 5.80%, and TSS content was 0.13%, TA was reduced to 4.57×10-2 mmol/g, the anthocyanin content increased to 2.40 mg/g, Vc content was 19.50 mg/100 g, MDA content was 13.30 μmol/g, PPO activity was 3600 U/min•mg. The research has shown that the addition of Houttuynia cordata extract at 0.06 g/mL could effectively improve the comprehensive performance of the antibacterial composite film, provide a greater preservative effect on blueberries, thus effectively maintain the quality of blueberries and extend their shelf life by almost 10 days.

19 Effect of High Hydrostatic Pressure Processing on the Quality of Compound Yam Puree during Storage

WANG Zhiying , LI Qin , CHEN Yun , WU Yan , ZHAO Liang , WANG Yongtao , LIAO Xiaojun

2022, 38(8):163-173. DOI: 10.13982/j.mfst.1673-9078.2022.8.1242

[Abstract](157) [HTML](184) [PDF 1.04 M](530)

Abstract:
Compound yam puree prepared using yam, okra, and kiwifruit was subjected to a comparative analysis between the effects of high hydrostatic pressure (HHP) treatment (400 MPa/5 min, 400 MPa/10 min, 500 MPa/2 min) and thermal processing (TP, 97 ℃/2 min) on the microbial and quality (nutrient composition, antioxidant activity, endogenous enzyme activity, and particle size) indicators of the puree during storage at 4 ℃ for 24 days. Results showed that HHP treatment inhibited the growth of microorganisms during storage, and the total number of bacterial colonies in samples treated with 400 MPa/5 min and 500 MPa/2 min was less than 1 lg CFU/g; mold and yeast were not detected in any sample. Compared with TP, the total phenolic content of HHP-treated compound yam puree increased by 60.66%~227.54%, which indicated a strong antioxidant capacity during storage. The ∆E of the HHP-treated group was significantly lower than that of the TP-treated group during storage, with the TP group reaching 25.26 and the HHP (500 MPa/2 min) group reaching just 5.44 after 24 days. Therefore, HHP caused less damage to the color of the compound fruit and vegetable puree during storage. However, because HHP could not effectively inhibit the activity of pectin methylesterase, the particle size and viscosity of the HHP-treated compound yam puree were higher than those of TP-treated puree during storage. In conclusion, HHP treatment can meet the requirements of commercial application for compound fruit and vegetable puree but has limited inhibitory efficiency for endogenous enzyme activity.

20 Photothermal Stability Analysis of Vitamins in Neutral Double Protein Drinks under Different Storage Conditions

YAO Lina , ZHENG Bo , TAO Wenchu , ZHAO Fangfang , ZHOU Xiaoyue , BEN Dongxu , LI Yanjun , SHU Zhicheng

2022, 38(8):174-182. DOI: 10.13982/j.mfst.1673-9078.2022.8.1079

[Abstract](194) [HTML](309) [PDF 1023.85 K](579)

Abstract:
Enhancing the stability of vitamins in foods and beverages is important to ensure the quality of products and the compliance of the declared values on the label with regulatory requirements. In this study, neutral double protein drinks was used as the research object, the effects of storage temperature (37 ℃ and 55 ℃), light conditions (natural light and xenon lamp irradiation) on the stability of vitamins in the drinks were systematically investigated. The results showed that during the 3-month storage at room temperature, the content of VE essentially remained unchanged, with the attenuation rates of VA, VD, nicotinamide, VB1, VB2 and VB6 being 5.45%, 8.74%, 8.99%, 18.13%, 21.40% and 33.72%, respectively. As the temperature increased to 37 ℃ or 55 ℃, the changes in the attenuation rate for VE were the smallest, followed bynicotinamide, VB2 and VB6. The storage at 55 ℃ for 2 months led to the increases in the average attenuation rates of VA and VB1 to 89.23% and 83.33%, respectively. The sensitivities of VA and VB1 to light differed. The attenuation rates of VE, VA, VD, nicotinamide, VB1,VB2 and VB6 after 3 months of natural light were 1.28%, 15.03%, 8.68%, 14.42%, 7.92%, 86.41% and 35.27%, respectively. However, after 5 days of xenon-lamp light irradiation, the contents of VE and VB6 changed insignificantly, with the attenuation rate of nicotinamide being relatively small (9.32%), and the attenuation rate of VB2 as high as 76.62%. The comparison results showed that VE and nicotinamide exhibited higher photostability. VA, VD and VB1 were more sensitive to ultraviolet light than to visible light, whilst VB6 was more sensitive to visible light. This study provides basic data for the development and application of high-quality beverages.

21 NO Fumigation Regulates Active Oxygen Metabolism and Mitigates Browning in Fresh Lycium barbarum Fruit during Cold Storage

WANG Xue , LI Qian , LIU Caihong , GULIDAN•Taledawu , LIU Fenglan , LONG Yang , WANG Jing

2022, 38(8):183-192. DOI: 10.13982/j.mfst.1673-9078.2022.8.1024

[Abstract](142) [HTML](162) [PDF 866.20 K](487)

Abstract:
In order to explore the effect of NO fumigation on the reduction of active oxygen metabolism and browning during cold storage of fresh Lycium barbarum fruits, “Ningqi No.7” Lycium barbarum fruits were used as the experimental materials, and fumigation of "Ningqi No.7" was conducted using 300 μL/L NO (0 μL/L as the control) for 3 h followed by storage at 3±0.5 ℃. The results showed that: NO fumigation treatment could significantly inhibit the increase in browning degree of fresh Lycium barbarum fruits (p<0.05). At the end of storage, the NO treated fruits had higher glutathione (GSH) content, peroxidase (POD) activity and superoxide dismutase (SOD) activity (increased by 32.65%, 0.03% and 0.21% respectively), and lower L-glutathione oxidized (GSSG) content, hydrogen peroxide (H2O2) content, superoxide anion (O2-) formation rate and catalase (CAT) activity (decreased by 18.97%, 28.21%, 42.99% and 0.08%, respectively), compared with the control group. Compared with day 0 of the storage, the activity of ascorbate peroxidase (APX) increased by 5.33% in the control group but decreased by 29.39% in the treatment group, whereas, the activity of glutathione reductase (GR) decreased by 31.52% in the control group but increased by 1.22% in the treatment group. Throughout the storage, the ascorbic acid (ASA) content and GSH/GSSG ratio were significantly (p<0.05) higher for the fruits treated with NO than for the control group. The above results showed that the 300 μL/L NO fumigation accelerated the scavenging rate of active oxygen species and maintained the integrity of cell membranes, thereby delaying the browning of fresh Lycium barbarum fruit.

22 Analysis of Physicochemical Properties of Wheat Flour Starch with Different Particle Sizes

LIN Jiangtao , SUN Lingling , YUE Qinghua

2022, 38(8):193-198. DOI: 10.13982/j.mfst.1673-9078.2022.8.1163

[Abstract](167) [HTML](264) [PDF 3.28 M](639)

Abstract:
The damaged starch content, gelatinization characteristics, particle morphology, crystal structure, digestion characteristics, freeze-thaw stability, and thermal characteristics of starch from wheat flour at different particle sizes was analyzed to explore the changes in the characteristics of starch. The results showed that as particle size decreased, damaged starch content increased by 78.11% and freeze-thaw stability increased from 33.35% to 49.19%. Regarding gelatinization characteristics, the viscosity and attenuation values showed a trend of initial decrease followed by increase, whereas the gelatinization temperature showed no significant change. The starch granules became increasingly dispersed from an agglomerated state, and surface was roughness increased. The relative crystallinity of starch first increased and then decreased, reaching a peak value of 21.78% when the grain size was 12XX/--, and exhibited a high diffraction peak intensity at medium particle size. The rapidly digestible starch content first increased and then decreased, slowly digestible starch content decreased by 22.01%, and resistant starch content was 59.88% at medium particle size. Considering starch thermal characteristics, the peak temperature increased with decreasing particle size; when the particlesize of wheat flour was 13XX/--, the initial temperature was 58.55 ℃ and the final temperature was 69.72 ℃. In conclusion, the starch characteristics of wheat flour were generally superior at medium particle size. Our findings can provide a theoretical basis for the starch production requirements of wheat flour at different particle sizes.

23 Enhancement of Wheat Dough Characteristics and Steamed Bread Quality Using Compound Modifiers

LIU Yilin , LI Bing , WU Hong

2022, 38(8):199-207. DOI: 10.13982/j.mfst.1673-9078.2022.8.1216

[Abstract](232) [HTML](162) [PDF 4.27 M](1140)

Abstract:
To improve the processing characteristics of wheat dough and the quality of steamed bread, sodium stearoyl lactate (SSL), L-ascorbic acid, and β-glucanase were chosen as compound modifiers and their composition was optimized. First, single factor experiments were conducted using wheat dough characteristics and steamed bread quality as evaluation indexes. The results showed that the addition of the three modifiers had a significant effect on wheat dough characteristics or steamed bread quality. Considering this, hardness was taken as the response value to perform response surface experiments with three factors and three levels. The optimal formula for the compound modifier was determined as addition of 0.16% SSL, 160 mg/kg L-ascorbic acid, and 80 mg/kg β-glucanase. After adding the compound modifiers, the hardness of steamed bread decreased by 38.4% to 875.58 g, whereas its specific volume increased by 12.7% to 3.01 mL/g, thus indicating that the improvement effect of compound modifiers was superior to that of a single emulsifier on steamed bread. In addition, compound modifiers enhanced the rheological and tensile properties of wheat dough, as well as its water holding capacity, suggesting that compound modifiers have the potential to slow down the aging rate of products and prolong shelf life.

24 Spray Drying Optimization of Food for Special Medical Purposes Based on Vc and Oil Encapsulation Rates and Product Storage Stability

DUAN Yingyu , LIU Lei , GAO Zihao , ZHANG Ruifen , ZHANG Mingwei

2022, 38(8):208-217. DOI: 10.13982/j.mfst.1673-9078.2022.8.1323

[Abstract](154) [HTML](186) [PDF 935.77 K](635)

Abstract:
The effects of different processing parameters on the quality of powdered total-nutrition food for special medical purposes (FSMP) during the spray drying process were investigated to obtain the optimal preparation process for the spray-dried powder of total-nutrition FSMP. Using vitamin C (Vc) and oil encapsulation rates as evaluation indexes for powder quality, the spray drying processing parameters were optimized based on the Box-Behnken central composite method. The effects of spray drying parameters, such as inlet air temperature, injection speed, injection concentration, and air velocity, on the quality of powdered total-nutrition FSMP were investigated to determine the optimal spray drying process conditions. The storage stability of total-nutrition FSMP prepared by spray drying under different accelerated test conditions (high temperature, high humidity, and bag opening) were studied using the conventional dry mixing method as the control. The results showed that the optimal process conditions for wet spray drying of total-nutrition FSMP were injection concentration at 24%, inlet temperature of 132 ℃, injection speed of 13.5 mL/min, and air velocity of 30 Hz. The Vc and oil encapsulation rates of total-nutrition FSMP prepared using this process were 79.72% and 92.25%, respectively, and the blend uniformity was up to 99.68%. The results of accelerated testing demonstrated that compared to conventional dry mixing, this technique could effectively slow down lipid oxidation and the loss of Vc content, while also improving the storage stability of the powder. Therefore, our findings can provide technical support for improving the quality of powdered total-nutrition FSMP.

25 Comparison of the Quality Characteristics of Powder from Different Sweet Potato Varieties

ZHAO Shishan , CAI Fang , SUI Yong , XIONG Tian , CAI Sha , ZOU Haofeng , ZHOU Deshun , CHEN Xueling , HE Jianjun , MEI Xin

2022, 38(8):218-228. DOI: 10.13982/j.mfst.1673-9078.2022.8.1152

[Abstract](185) [HTML](179) [PDF 793.24 K](548)

Abstract:
The nutritional quality and physicochemical characteristics of powder from 19 different varieties of sweet potato were compared and analyzed. The results showed that the 19 types of sweet potato powder could be divided into seven categories, among which the top three varieties with the best nutritional quality were Q7007>GanziC702>Ningzi 8. Cluster analysis showed that the different varieties could be classified according to their similarities in performance into four classes: Class I, seven varieties with medium water holding and swelling capacities, and low oil holding capacity; Class II, three varieties with high water holding capacity and low oil holding capacity; Class III, five varieties with low water and oil holding and swelling capacities; Class IV, four varieties with high oil holding and swelling capacities. The gelatinization onset temperature (To), peak temperature (Tp), end temperature (Tc), and enthalpy (ΔH) ranged between 73.47 ~83.00 ℃, 80.63~88.10 ℃, 86.87~92.90 ℃, and 0.79~3.77 J/g, respectively. Xushu 22 had the highest To, Tp, and Tc, whereas Sushu 32 had the lowest values. Correlation analysis showed that there was a significant negative correlation between protein content and swelling capacity, whereas water and oil holding capacities were significantly correlated with anthocyanin and β-carotene levels, respectively, thus demonstrating that there was a close relationship between the nutritional quality and physicochemical properties of sweet potato powder. Therefore, the different varieties of sweet potato powder can be processed and utilized according to their nutritional quality, physicochemical characteristics, and properties, to provide a theoretical basis for the promotion of sweet potato resources and product development.

26 Effects of Matcha Powder on Dough Rheological Properties and Noodle Quality

WANG Jinping , CAO Meng , WANG Xuefei , WANG Baogang , ZHOU Feng , WEI Huajian

2022, 38(8):229-235. DOI: 10.13982/j.mfst.1673-9078.2022.8.0381

[Abstract](191) [HTML](188) [PDF 689.99 K](551)

Abstract:
In order to expand the application of matcha powder in flour products, mixed flours were produced using wheat flour and matcha powder as the main raw materials. The gelatinization properties of the mixed flours were measured, and a farinograph was used to measure the effects of the different mixed flours on the rheological properties of the resulting dough. Finally, the cooking and texture properties of the prepared matcha noodles were determined. The experimental results showed that at a matcha powder content of 6%, the peak viscosity of the mixed flour, trough viscosity, and gelatinization temperature were 1043/cP, 486/cP, and 87.18 ℃, respectively, accelerating the water absorption, expansion, and gelatinization properties of the mixed powder. At this point, the setback viscosity value decreased from 686/cP to 586/cP, thereby inhibiting aging of the mixed dough. The dough formation and stabilization times were 7.07 min and 10.6 min, respectively, and the gluten network structure of the mixed dough was moderate. When the matcha powder content was 4%~6%, the matcha noodles had a tea aroma, the maximum sensory score was 82, and no significant changes were observed in the cooking loss and water absorption rates. With 6% matcha powder content, the noodle hardness, adhesiveness, and elasticity were 4852/g, 2728/g and 0.089, respectively, which suggested that the noodles were of good quality. Taken together, these findings indicate that the maximum amount of added matcha powder should be 6%.

27 Effect of Mulberry Polyphenols on the Flavor of Cantonese Sausage

HOU Yuxue , LIU Xueming , CHENG Jingrong , ZHU Mingjun

2022, 38(8):236-246. DOI: 10.13982/j.mfst.1673-9078.2022.8.1107

[Abstract](172) [HTML](164) [PDF 1.13 M](450)

Abstract:
Plant polyphenols have recently attracted attention because of their effective inhibition of peroxidation in meat products; however, the resulting flavor changes have rarely been reported. In view of this, different doses of mulberry polyphenol extracts (0.5 and 1.0 g/kg) were added to Cantonese sausages, and the changes in the compositions and amounts of volatile flavor substances, free fatty acids, and free amino acids were studied. The effect of mulberry polyphenol on the sensory components of Cantonese sausages was also investigated. The results showed that after the addition of mulberry polyphenols, the number of volatile flavor substances in Cantonese sausages decreased from 49 to 32, and free fatty acidcontent decreased significantly. It is worth noting thatowingto enhanced proteolysis, the addition of mulberry polyphenols promoted the release of taste-activeamino acids (Glu and Arg) in Cantonese sausages. At the end of storage (10 days), the free amino acid content of Cantonese sausages with 1.0 g/kg of mulberry polyphenols added reached 5904.91 mg/100 g, which was 10.82% higher than that of the control. In general, the addition of mulberry polyphenols inhibited the formation of some volatile flavor substances, suppressed the unpleasant pork smell, and promoted the release of taste-active amino acids but had little effect on the composition of free fatty acids in Cantonese sausages.

28 Physicochemical Properties and Volatile Composition Analysis of Jasminum sambac (L.) Ait. Dried by Different Methods

SHENG Jinfeng , CHEN Kun , TANG Yayuan , WANG Xuefeng , HE Xuemei , ZHOU Zhugui , LING Dongning , LEI Yawen , LI Li , YI Ping , ZHENG Fengjin , YE Dongqing , TANG Jie , SUN Jian

2022, 38(8):247-259. DOI: 10.13982/j.mfst.1673-9078.2022.8.1033

[Abstract](231) [HTML](365) [PDF 733.05 K](854)

Abstract:
Fresh double-petalled jasmine was used as the raw material for the comparative analysis of the color, physicochemical composition, antioxidant capacity, amino acid components and volatile aroma components of the flowers dried by hot-air drying (HD), microwave drying (MVD), microwave combined with hot-air drying (MVD+HD), and vacuum freeze-drying (FD). The results showed that the jasmine dried by FD had the highest L*, lowest a*and ΔE, highest contents of chlorophyll and total phenolics, and highest hydroxyl radical-inhibitory ability. The jasmine dried by MVD+HD had the highest total amino acid content, essential amino acid content and essential amino acids ratio (8.32 mg/g, 2.67 mg/g and 32.09%, respectively). The relative contents of alcohols in the dried flowers were the highest. Among the four groups, the relative contents of alcohols, esters and aldehydes of the FD group were 53.37%, 5.40% and 17.99%, respectively. The HD group had the highest relative contents of ketones, alkanes and acids, and the MVD group had the highest relative contents of alkenes and other kinds of volatiles, indicating that FD could retain the main aroma substances of jasmine flower to the greatest extent, whilst HD caused the largest loss. In general, the jasmine dried by FD had the best color and aroma and could be developed into high-end jasmine products. Whereas, MVD+HD could preserve the aroma and nutritional quality of jasmine , thereby being suitable for industrial production and used as an ideal drying method for drying jasmine flowers.

29 GC-MS Analysis of the Changes in Volatile Oils before and after Compounding of Perilla Leaf and Tangerine Peel

WANG Yin , ZHANG Lizhong , WU Yi

2022, 38(8):260-265. DOI: 10.13982/j.mfst.1673-9078.2022.8.0188

[Abstract](216) [HTML](170) [PDF 547.48 K](541)

Abstract:
Steam distillation was performed to extract the volatile oils of Perilla leaf, tangerine peel, and the compound of Perilla leaf and tangerine peel (hereinafter referred to as the compound) to investigate changes in volatile oils before and after the compounding of Perilla leaf and tangerine peel. The volatile oils were analyzed by gas chromatography-mass spectrometry to compare the differences in their composition and content. A total of 20, 22, and 31 components were identified from the volatile oils of Perilla leaf, tangerine peel, and the compound, respectively, and the total mass fractions of the detected substances were 97.77%, 99.76%, and 97.94%, respectively. Four components in the volatile oils of Perilla leaf (menthol, β-bourbonene, trans-nerolidol, and humulene epoxide II) were not detected in the volatile oils of the compound, whereas the content of β-copaene increased significantly after compounding. Five components in the volatile oils of tangerine peel (2-carene, p-cymene, isoterpinolene, 4-terpenol, and germacrene) were not detected in the volatile oils of the compound, and the content of cyperenone increased significantly after compounding. Six additional components were detected in the volatile oils of the compound (4-carene, o-isopropyl benzene, decanal, γ-elemene, neryl acetate, and nerolidyl acetate). The results showed that there were significant changes in the components of volatile oils before and after compounding of Perilla leaves and tangerine peel. This study provides new insights for the further development of Perilla leaf and tangerine peel.

30 Analysis of Volatile Components in Anemarrhena asphodeloides and Its Processed Products Based on HS-SPME-GC-MS and PCA

LIU Tianqi , JIANG Hanmei , TIAN Yu , LIU Jinmin

2022, 38(8):266-272. DOI: 10.13982/j.mfst.1673-9078.2022.8.1123

[Abstract](132) [HTML](194) [PDF 501.92 K](394)

Abstract:
To provide theoretical guidance for the edible and medicinal uses of Anemarrhena asphodeloides, its volatile components and processed products were analyzed and compared. The volatile components of raw, salt-processed, and wine-processed A. asphodeloides were analyzed and identified usingheadspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The relative percentage of each component was calculated by area normalization and principal component analysis (PCA) was performed. A total of 70 volatile components were identified from the three types of A. asphodeloides, including 28, 28, and 29 components in raw, salt-processed, and wine-processed A. asphodeloides, respectively. The compound with the highest relative content was phenethyl alcohol, accounting for 12.19%, 9.64%, and 20.36%, respectively. Only salt-processed A. asphodeloides contained limonene, hexanoic acid, and α-terpineol, which have lipid-lowering, analgesic, anti-inflammatory and anticonvulsant effects. The volatile components common to all three products of A. asphodeloides were n-hexanal and benzyl alcohol β-caryophyllene, the levels of which differed significantly across the different samples. PCA was performed on the volatile components and their levels using SPSS 21.0. The results showed that the comprehensive score of volatile components insalt-processed A. asphodeloides was the highest, where as the scores of raw and wine-processed A. asphodeloides were lower. There were significant differences in the composition and levels of volatile components between raw A. asphodeloides and its products, among which salt-processed A. asphodeloides scored the highest.

31 Correlation Analysis between Consumer Liking and Key Sensory Attributes of Ultra-high Temperature (UHT) Pure Milk

SU Yufang , WANG Houyin , HUANG Wenqiang , ZHAO Lei , WU Ziyan , SHI Bolin , ZHONG Kui

2022, 38(8):273-279. DOI: 10.13982/j.mfst.1673-9078.2022.8.1029

[Abstract](284) [HTML](175) [PDF 665.14 K](676)

Abstract:
Fourteen kinds of ultra-high temperature (UHT) milk products in the market were used as the research object and studied using the 9-ponit liking scale, check-all-that apply (CATA) and just-about-right scale, while partial least squares (PLS) regression analysis was performed to study the differences in consumer liking and sensory attribute acceptability of different types of UHT milk samples. Results indicated that the overall liking scores of different UHT milk samples ranged from 4.07 to 6.25, and the skim milk samples and part of the whole milk samples had the lowest liking scores (<5), with insignificant differences detected between the whole milk samples and low-fat milk samples (p>0.05). There were significant differences (p<0.05) in the acceptability of five key sensory characteristics, milky aroma (MA), sweetness (SW), residual flavor (RF), thickness (TH) and smoothness (SM) among the different milk samples. Seven key sensory acceptability indices that caused the liking differences were screened out by PLS, which were MA, SW, TH, SM(-), SW(-) and MA(-). Weak SW and MA as well as insufficient smoothness were the key sensory characteristics that led to the low overall liking scores for low-fat milk and part of whole milk samples. This study could provide a basic theory and data reference for subsequent studies on consumer liking and product sensory quality of UHT pure milk. Key words: ultra high temperature (UHT) milk; consumer hedonic test; sensory attribute, just about right (JAR) scale; partial least squares (PLS)

32 Separation and Determination of Florfenicol Enantiomers Using Ultra-performance Convergence Chromatography

ZHANG Wenhua , WANG Ying , HOU Jianbo , TAO Hongxia , HU Qili , WANG Liangli , XIE Wen , XU Dunming

2022, 38(8):280-287. DOI: 10.13982/j.mfst.1673-9078.2022.8.1339

[Abstract](141) [HTML](242) [PDF 798.62 K](358)

Abstract:
A new method was established for the separation and determination of two florfenicol enantiomers using ultra-performance convergence chromatography (UPC2). The chromatographic separation conditions were optimized, and the stability of standard solutions of (-)-florfenicol and (+)-florfenicol enantiomers were observed. The separation process was carried out in Waters Acquity Trefoil CEL2 (150×3.0 mm, 2.5 µm) chiral columns. The mobile phase used carbon dioxide and methanol at a flow rate of 1.0 mL/min with gradient elution. The UV detection wavelength was set to 224 nm, the injection volume was 5 µL, the system backpressure was 17.2 MPa, and the column temperature was maintained at 40 ℃. The method validation results indicate that the limit of detection (LOD, S/N=3) for both enantiomers was 2.00 mg/L, and the calibration linear range was between 4.00 and 400.00 mg/L, with correlation coefficients (r2) > 0.9993. Repeated measurements of the peak area using 10 mg/L standard solutions of each florfenicol enantiomer showed relative standard deviations (RSD, n=6) of 0.65 and 0.81%, respectively. This method was then used to separate and measure commercially available standard florfenicol racemates. The results indicate that (+)-florfenicol was not detected in the three standard florfenicol racemates, but (-)-florfenicol (9.20~10.00 mg/L) was detected in all of them. The separation and content determination of the two florfenicol enantiomers were completed within 6.0 min. Therefore, this is a rapid, high-resolution, eco-friendly method that can be used for the separation and determination of florfenicol enantiomers.

33 Safety Evaluation of Curcumin-mediated Photodynamic Treatment of Oysters

ZHI Jinjin , WANG Zhiguang , WU Shuangjie , LI Zhaojie , XUE Changhu , TANG Qingjuan

2022, 38(8):288-296. DOI: 10.13982/j.mfst.1673-9078.2022.8.1241

[Abstract](173) [HTML](173) [PDF 1.43 M](521)

Abstract:
The food safety of oysters treated with curcumin-mediated photodynamic non-thermal sterilization was evaluated using the acute and 28-day oral toxicity tests. The results showed that the acute oral median lethal dose (LD50) of photodynamically-treated oysters in mice was higher than 40 g/kgbw, which was classified under the practically non-toxic category, and compared with the control group, there were no obvious abnormalities in hematology, organ index, and histopathology. After repeated intragastric administration of photodynamically-treated oysters at the selected dose of 10 g/kgbw for 28 days, no significant abnormal changes were found in the indices of the rats, including their growth and development, body weight, food utilization rate, urology, hematology, serum biochemistry, organ index, and histopathology. The results indicate that photodynamically-treated oysters showed no acute or subacute toxicity within the range of the experimental dosages, and had high food safety, thus providing a theoretical basis for the promotion and application of this technique in shellfish processing.

34 Comparison of Micro-biochemical Identification Kits for Yersinia enterocolitica from Different Manufacturers

YANG Xuwei , LIN Guoqiang , LU Mianfei , LI Yanchang , CAI Zhihe , WU Qingping

2022, 38(8):297-301. DOI: 10.13982/j.mfst.1673-9078.2022.8.0897

[Abstract](151) [HTML](159) [PDF 338.93 K](404)

Abstract:
This study aimed to evaluate the performance of the micro-biochemical identification kit for Yersinia enterocolitica developed in our laboratory (termed EasyID). Thirty six strains of Y. enterocolitica (including two standard strains and nineteen isolated strains of Y. enterocolitica; five isolated strains of Y. flexneri; five isolated strains of Y. intermedia; five isolated strains of Yersinia Klebsiella) were used to evaluate the three kinds of Y. enterocolitica identification reagent kits: EasyID, traditional liquid biochemical tube (HKM) and other domestic brands (termed KIT). The results showed that the identification results of the thirty six tested strains exhibited overall coincidence rates of 99.69% and 98.15%, respectively, for the “dry” identification kits, EasyID and KIT, compared with those of the traditional liquid identification kits. Compared with KIT, EasyID had a higher coincidence rate with HKM; the three identification kits, EasyID, HKM and KIT, had overall compliance rates of 99.37%, 99.07%, and 97.83%, respectively, compared with the standard requirements, with the EasyID having the highest conformity rate, followed by HKM then KIT. Conclusion: The reliability of EasyID Yersinia enterocolitica microbiochemical identification kit was superior to KIT and comparable to HKM. In terms of ease of use, EasyID involving one-step sampling technique was superior to HKM and KIT.

35 Establishment of a Loop-mediated Isothermal Amplification (LAMP) Method for the Rapid Detection of Hazelnut Components in Plant-based Protein Beverages

XIAO Jian , LIANG Meidan , XIAN Yanping , LIU Donghao , LAO Jiaqian , CAO Xiafei , HUANG Zhishen , LI Lili

2022, 38(8):302-308. DOI: 10.13982/j.mfst.1673-9078.2022.8.1209

[Abstract](140) [HTML](176) [PDF 739.94 K](396)

Abstract:
To address the widespread adulteration of plant-based protein beverages, a loop-mediated isothermal amplification (LAMP) method was developed for the rapid detection of hazelnut components. The conserved sequence (No. 19517533~19519500 bp) of chromosome Ca8 (accession number: LR899430.1) in European hazelnut was adopted to design the specific primers for the LAMP detection of hazelnut components. The reaction system was optimized and the specificity, sensitivity, and stability of the LAMP method were verified. Using real-time polymerase chain reaction as the reference method, McNemar's test was performed to verify the performance indexes and accuracy of the LAMP method for 32 plant-based protein beverages. The LAMP method had strong specificity, and no positive amplification results were obtained for 33 plant ingredients except hazelnut. The reproducibility test was stable (Ct value, RSD=5.41%), and the lower limit of detection was 0.1% (by mass fraction). The results indicated that the LAMP method had a specificity and sensitivity of 100%, with no false positives or false negatives. In conclusion, the LAMP detection method had the advantages of simple operation, fast and efficient detection (<2 h from sample processing to final results), and high accuracy. Hence, it can be applied to the rapid detection of hazelnut components in plant-based protein beverages.

36 Application of Agrocybe aegerita Lectin 2 for Detecting GlcNAcylated Plasma Proteins Inpatients with Breast Cancer

CHEN Liqiong , GUAN Xin , HUANG Zhuanglin , ZENG Shuxian , ZHANG Wenxin , LIANG Yi

2022, 38(8):309-318. DOI: 10.13982/j.mfst.1673-9078.2022.8.1187

[Abstract](171) [HTML](196) [PDF 1.18 M](361)

Abstract:
The level of terminal β-N-acetylglucosamine (GlcNAc) - modified protein in plasma was detected using enzyme-linked immunosorbent assay (ELISA) with reverse Agrocybe aegerita lectin2 agglutinin (AAL2). The protein and GlcNAcylated protein levels of three candidate tumor biomarkers - plasma protease C1 inhibitor (C1Inh), serpin B4, and serotransferrin (TF) - in plasma were determined by western blotting and reverse AAL2-based ELISA. When compared to healthy volunteers (HE),in the breast cancer (BC) group, the protein levels of C1Inh and TF in plasma decreased significantly, whereas the level of serpin B4 protein increased significantly, and the level of GlcNAcylated protein showed the opposite trend (p<0.05). Additionally, between the HE group and early-stage BC samples, the area under the receiver operating characteristic (ROC) curve (AUC) for C1Inh, serpin B4, and TF proteins was 0.66, 0.62, and 0.73, respectively, whereas that for GlcNAcylated C1Inh, serpin B4, and TF was 0.69, 0.76, and 0.83, respectively. The combined detection of GlcNAcylated serpin B4 and TF showed improved performance for differentiating BC from HE, with the AUC for HE/early-stage BC samples, HE/limited-stage disease, and HE/extensive-stage disease increasing to 0.89, 0.89, and 0.94, respectively. This study provides a theoretical basis for the detection of GlcNAcylated protein in plasma using reverse AAL2-based ELISA, and GlcNAcylated serpinB4 and TF can serve as potential diagnostic markers of BC.

37 Preparation of Nano-immunosensor for Rapid Determination of Allergen β-Lactoglobulin in Dairy Products

YAN Rongrong , LI Shuguo

2022, 38(8):319-326. DOI: 10.13982/j.mfst.1673-9078.2022.8.1001

[Abstract](133) [HTML](202) [PDF 692.77 K](389)

Abstract:
In this study, a nano-immunosensor was constructed through using chitosan, graphene and gold nanoparticles as the composite modification material to immobilize β-lactoglobulin (β-LG) antibody, to establish a rapid method for the determination of β-LG. The nano-immunosensor was characterized by cyclic voltammetry, using 1.0 mmol/L K3[Fe(CN)6] as the probe, and the experimental conditions were optimized. The optimal conditions were as follows: amount of the composite modification solution, 5 μL; pH of electrolyte solution, 7.0; loading amount of antibody, 40 ng; incubation temperature, 37 ℃; incubation time, 30 min. There was a good linear relationship between the immune-response current of the nano-immunosensor and the logarithm of β-lactoglobulin mass concentration at 2.5~100 ng/mL, with a limit of detection of 0.75 ng/mL. The nano-immunosensor exhibited good stability, specificity and reproducibility, and had a recovery rate of the spiked standard between 88.59% to 97.64% when it was applied to the determination of lactoglobulin in dairy products. The recovery rate was good, and the results were more accurate than those obtained by ELISA. Therefore, this methods can be used for rapid and accurate determination of β-lactoglobulin allergen in dairy products.

38 Research Progress on the Effects of Thermal and Non-thermal Processing Technologies on the Allergenicity of Aquatic Products

CHENG Junhu , MA Xiaoran , CHEN Lu , YU Huaning , LI Jilin

2022, 38(8):327-333. DOI: 10.13982/j.mfst.1673-9078.2022.8.1059

[Abstract](238) [HTML](163) [PDF 539.13 K](450)

Abstract:
China is the largest country in aquaculture and total consumption of aquatic products, and the allergic problem caused by aquatic products has attracted more and more attention. In recent years, incidence of allergy caused by the intake of aquatic product has increased gradually. This paper reviews recent research on the allergen reduction of aquatic products by thermal processing technologies (steaming, boiling and high temperature pressure), non-thermal processing technologies (ultra-high pressure, cold plasma, ultrasound and irradiation), and the combination of the two processing technologies. It is pointed out that thermal processing technologies mainly reduce allergenicity via denaturing the proteins, whilst non-thermal processing technologies reduce allergenicity via masking or destroying the antigenic epitopes of allergens. These results provide an important basis and technical reference for further development of hypoallergenic aquatic products. Continuing investigations on the mechanisms underlying the allergic reactions caused by allergens, and accelerating the development of the application of hypoallergenic aquatic processing technologies in practical production, are both conducive to controlling and reducing the risks associated with aquatic product allergy.

39 Research Progress on Chemical Constituents and Biological Activities of Gynura procumbens

WU Lei , CAO Mingyuan , WU Jing , GU Zhen , HU Juwu , FU Shuigen , HUANG Binhua

2022, 38(8):334-351. DOI: 10.13982/j.mfst.1673-9078.2022.8.1120

[Abstract](269) [HTML](243) [PDF 1.12 M](598)

Abstract:
Gynura procumbens (Lour.) Merr, known as Man San Qi, is an annual herb belonging to the family Asteraceae and is widely distributed in Southeast Asia and several regions in China, including Guangdong, Jiangxi, and Guizhou. G. procumbens has been widely used as a “medicine and food homology” plant in folk medicine in China and some Southeast Asian countries. It is characterized by a bitter flavor and cold nature, which can be used to promote blood circulation and detoxification. G. procumbens is rich in bioactive constituents, including flavonoids, phenols, alkaloids, fatty acids, terpenoids, and steroids. Modern medical research has shown that G. procumbens has a high medicinal value with a wide variety of biological activities, such as antioxidation, anti-inflammation, anticancer, antihyperglycemia, antihypertension, and liver protection. With reference to domestic and foreign literature, this study summarized the research progress on the chemical constituents and biological activities of different parts of G. procumbens including its roots, stems, and leaves, to provide a reference for novel healthcare products based on the medicine and food homology of G. procumbens and a basis for the comprehensive utilization and further development of G. procumbens.

40 Research Progress on the Action Mechanisms of Plant Essential Oils against Microorganisms and Its Application in Berry Preservation

LI Dehai , JIANG Shasha

2022, 38(8):352-360. DOI: 10.13982/j.mfst.1673-9078.2022.8.0026

[Abstract](209) [HTML](241) [PDF 1.22 M](487)

Abstract:
The pulp of berry fruits is juicy and rich in nutrition; however, it isprone to pathogen growth after harvest, which can lead to spoilage and deterioration. Thus, antimicrobial research on pathogenic microorganisms in berries is key to berry preservation. Plant essential oilsare important secondary metabolites of natural plants with a wide range of antimicrobial activities. The sources and main active components of natural plant essential oils are summarized in this paper. Recent researchon the antimicrobialmechanisms of natural plant essential oils againstpathogenic microorganisms was collated to review the research progress on the application of different essential oils in the preservation of berry fruits and evaluate the safety of plant essential oils in berry preservation. Our findings canprovide a new approach for the replacement of traditional preservatives with natural biological resources.

41 Research Progress on the Effects of Ultrasonic Treatment on Thawing Process and Post-thaw Quality of Livestock Meat

WU Ping , YAO Fang , WANG Zhengyun , LIU Ping , ZHENG Haisong , SUN Zhiyuan , XU Jiaman

2022, 38(8):361-371. DOI: 10.13982/j.mfst.1673-9078.2022.8.1104

[Abstract](233) [HTML](339) [PDF 1.18 M](751)

Abstract:
Ultrasonic processing technology belongs to the category of physical processing technologies. In recent years, it has been widely used in the field of food processing, such as cleaning, enzymolysis, separation, extraction, pickling and emulsification, because of its green and pollution-free advantages. With the deepening of research of food ultrasonic processing technology, researchers also found that ultrasound can be used to promote and monitor the thawing process of frozen animal meat products. In this paper, the principle of ultrasonic technology and the mechanism underlying its potential thawing action are reviewed. The effects of ultrasonic treatment on thawing efficiency, water holding capacity, texture, freshness, tenderness and fatty acid composition of frozen livestock meat products are analyzed in detail. In addition, the feasibility of low loss and fast real-time monitoring of material thawing process by using the ultrasonic echo signal state is discussed. This paper not only provides theoretical and practical bases for the application of ultrasonic technology in the study on rapid thawing of frozen livestock meat products, but also offers a novel research idea for the development of ultrasonic monitoring technology in the thawing process of frozen animal products。

Home

About the journal

Notes for submission

Acceptable topics

Author garden

Open access

中文

Volume 38,Issue 8,2022 Table of Contents