Volume 40,Issue 6,2024 Table of Contents

1 Effects of Noni Fruit Polysaccharide on Bile Acid Metabolism and Gut Microbiota of Mice Fed on a High-fat Diet

ZOU Jiaqi , WU Xiaoyong , PENG Zijun , WU Fangfang , ZHENG Chuanjin

2024, 40(6):1-11. DOI: 10.13982/j.mfst.1673-9078.2024.6.0655

[Abstract](113) [HTML](59) [PDF 22.36 M](1164)

Abstract:
To investigate the preventive effect and potential mechanism of noni fruit polysaccharides (NP) on metabolic disorders and obesity induced by long-term intake of high-fat diet (HFD), an HFD mouse model and a pseudo germ-free (PGF) mouse model were established by providing high-fat feed and intragastric administration of broad-spectrum antibiotics, respectively. The effects of NP intervention on the body weight, fecal total bile acid (TBA) levels, and gut microbiota composition were analyzed and compared. Results showed that the body weight of mice in the NP group decreased by 11.91% and fecal TBA increased by 29.58% compared to mice in the HFD group. However, the beneficial effects of NP were not observed in PGF HFD mice, indicating that the gut microbiota plays a key role in inhibiting body weight gain and promoting fecal TBA excretion by NP in HFD mice. Results of Spearman correlation analysis suggest that Faecalibaculum, Dubosiella, and Muribaculaceae among others promoted TBA excretion and inhibited body weight gain in HFD mice at weeks 4 and 12. These findings indicate that NP can promote TBA excretion and inhibit body weight gain in HFD mice by enhancing the proliferation of the beneficial gut bacteria.

2 Protective Effect of Sacha Inchi Oil on Aβ25-35-induced SH-SY5Y Alzheimer’s Disease Cells

ZENG Wenshen , LIU Bing , ZHANG Huan , PENG Luwei , LAI Lanyu , DU Bing , LI Pan

2024, 40(6):12-19. DOI: 10.13982/j.mfst.1673-9078.2024.6.0586

[Abstract](60) [HTML](39) [PDF 4.80 M](1132)

Abstract:
Human neuroblastoma cells (SH-SY5Y) were utilized to investigate the potential protective effects of sacha inchi oil against Aβ25-35-induced Alzheimer’s disease (AD) cells. Following exposure with Aβ25-35 and varying doses of sacha inchi oil, changes in antioxidant and anti-apoptotic indexes of the AD cell model caused by sacha inchi oil were measured. Results showed that sacha inchi oil, at doses ranging from 0 to 40 μg/mL, did not affect cell viability. However, doses ranging from 0 to100 μg/L exacerbated Aβ25-35-induced cell damage, with a 25 μg/L dose selected to induce the AD cell model. Post-cultivation, the effects of sacha inchi oil on the superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured. Flow cytometry was employed to assess the degree of apoptosis, mitochondrial membrane potential, and reactive oxygen species (ROS) levels. Western blot analysis was performed to measure Nrf-2, HO-1, Bcl-2, and Bax protein expression levels. Results showed that supplementation with 20 μg/mL and 40 μg/mL of sacha inchi oil decreased MDA levels by 24.24% and 42.73% (P<0.005) and the levels of ROS by 15.34% and 25.53% (P<0.005), and increased levels of SOD by 20.81% and 27.27% (P<0.005), respectively. Furthermore, sacha inchi oil modulated mitochondrial membrane potential, attenuated apoptosis, upregulated Nrf-2/HO-1 antioxidant pathway expression, increased Bcl-2 anti-apoptotic protein expression, and down-regulated Bax pro-apoptotic protein expression. In conclusion, sacha inchi oil demonstrates cell protection by mitigating oxidative stress damage and reversing apoptosis. Its mechanism may involve enhancing the Nrf-2/HO-1 antioxidant pathway and regulating apoptosis-related protein expression.

3 Exploring Protective Effect of Phellinus linteus Polysaccharides on Liver Injury in Exercise Fatigue Mice Based on Nrf2 Signaling Pathway

LI Kunzhan , WANG Ying , ZHENG Jia , LIU Hao

2024, 40(6):20-28. DOI: 10.13982/j.mfst.1673-9078.2024.6.1221

[Abstract](63) [HTML](49) [PDF 2.34 M](1167)

Abstract:
Ultrasound-assisted hot water extraction was utilized to obtain Phellinus linteus polysaccharides (PLPs), and its protective effect on liver injury in exercise-induced fatigue mice was investigated through modulation of the Nrf2 signaling pathway. Results showed a PLP extraction yield of 7.64%, with a purification efficiency of 23%. PLP administration led to a significant reduction in the liver coefficient of mice compared to the exercise-induced fatigue model group. Moreover, it increased swimming endurance times of the low-, medium-and high-dose groups by 15.58%, 34.69% and 53.06%, respectively. Compared to the sedentary control group, the model group exhibited significantly diminished activities of antioxidative enzymes in the liver, including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSHPx), alongside increased malondialdehyde (MDA) content; serum inflammatory factors such as tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6); and alanine transaminase (ALT) and aspartate transaminase (AST) activities. Conversely, the low-, medium-and high-dose groups demonstrated elevated antioxidant enzymes activity in the liver and reduced MDA content in comparison to the model group. Notably, the high-dose group exhibited significant reductions in serum TNF-α, IL-1β, and IL-6 levels by 50.54%, 50.51%, and 46.21%, respectively, alongside ALT and AST activities by 33.30% and 34.57%, respectively. Moreover, mRNA expression levels of Nrf 2, HO-1, and NQO1 were significantly lower in the model group compared to the sedentary group, while Keap1 mRNA expression was significantly higher. Post-PLP supplementation, mRNA expression levels of Nrf 2, HO-1 and NQO1 significantly increased in the low-, medium-and highdose groups, while Keap1 mRNA expression significantly decreased. These findings collectively suggest that PLPs enhance hepatic antioxidant capacity and reduce inflammatory factors in exercise-induced fatigue mice by activating the hepatic Nrf2 signaling pathway, thereby mitigating liver injury.

4 Screening and Activity Comparison of Anti-inflammatory Components of Walnut Proteins

HU Xia , HONG Zishan , DAI Jingjing , XIE Jing , TIAN Yang

2024, 40(6):29-42. DOI: 10.13982/j.mfst.1673-9078.2024.6.0780

[Abstract](54) [HTML](52) [PDF 10.53 M](1112)

Abstract:
The fractions of walnut proteins with the highest anti-inflammatory activity and the effect of gastrointestinal digestion on their properties and anti-inflammatory activity were studied. Six walnut protein protease hydrolysates were investigated for their anti-inflammatory activity using the lipopolysaccharide (LPS)-induced RAW 264.7 cell model. The protease hydrolysate demonstrating the strongest anti-inflammatory activity underwent fractionation using ultrafiltration technology, and the anti-inflammatory potential of fractions with different molecular weights was investigated. An in vitro simulated gastrointestinal digestion model was established to evaluate the effects on the degree of hydrolysis, peptide content, and anti-inflammatory activity of the most active fraction. Results indicated that all six protease hydrolysates inhibited nitric oxide (NO) release from LPS-induced RAW 264.7 cells. Notably, the alkaline protease hydrolysate exhibited the highest inhibitory effect, achieving an inhibition rate of 18.33% at a dose of 800 μg/mL. Within the alkaline protease hydrolysate, the fraction with molecular weight<1 ku demonstrated the most effective inhibition of NO release, with an inhibition rate of 25.25% at the same dose. Comparative analysis revealed that the peptide content of the<1 ku-simulated gastrointestinal digestion group increased from 5.56 g/100 g to 10.93 g/100 g. Likewise, the degree of hydrolysis increased from 1.82% to 7.54%, with an increase in the NO release inhibition rate from 24.75% to 46.50%. These results underscore the highest anti-inflammatory activity observed in the alkaline protease hydrolysate of walnuts with molecular weight<1 ku, which was further enhanced post-gastrointestinal digestion. This study provides foundational insights for the isolation and purification of anti-inflammatory peptides from walnuts, and offers a theoretical basis for the valorization of walnut by-products.

5 Hydrolysate of Oviductus Ranae Activates MAPK/ERK Signaling Apoptosis Pathway to Repair Corticosterone-induced Damage in HT-22 Cells

LI Weijia , MA Chao , LIU Mengmeng , PEI Ke , LIN Zhe , LV Guangfu

2024, 40(6):43-52. DOI: 10.13982/j.mfst.1673-9078.2024.6.0705

[Abstract](51) [HTML](38) [PDF 5.24 M](1105)

Abstract:
To examine the protective mechanism of oviductus ranae (OR) on hippocampal neuronal cells, this study explored the protective effect and mechanism of OR hydrolysate in a corticosterone (CORT)-induced mouse hippocampal neuron (HT-22) model of cell injury. HT-22 cells were co-cultured with CORT to establish an injury model, then further incubated with OR hydrolysate, followed by the addition of the ERK signaling pathway inhibitor PD98059. MTT assay, Hoechst 33258 staining, flow cytometry and Western blot were employed to assess cell apoptosis, protein expression, and MAPK/ERK signaling pathway activity. Results demonstrated that elevated levels of CORT induced damage in HT-22 cells, while OR hydrolysate enhanced cell viability by 62.5%~87.5%, and reduced apoptosis rates by 50%~70%. Moreover, OR hydrolysate upregulated BCL-2 and P-ERK1/2 protein expression, and downregulated BAX, Caspase-3 and Caspase-9 protein expressions. These findings indicate that high CORT levels promote apoptosis by inhibiting the MAPK/ERK signaling pathway, leading to HT-22 cell damage. OR hydrolysate regulates the expression of apoptosis-related proteins, (BLC-2, BAX, Caspase-3 and Caspase-9) by activating the MAPK/ERK signaling pathway, thereby inhibiting apoptosis and reducing neuronal damage. This mechanism represents a key pathway through which OR exerts anti-depressive effects.

6 Comparative Analysis of the Nutritional Components in Capitulums of Hangzhou White Chrysanthemum and Its F1 Hybrids

LYU Jin , LI Feng , MA Tiangui , ZHOU Hougao , WANG Fenglan , CHEN Yan , LUO Honghui , WU Qing

2024, 40(6):53-65. DOI: 10.13982/j.mfst.1673-9078.2024.6.0540

[Abstract](46) [HTML](37) [PDF 3.55 M](1135)

Abstract:
The nutritional components of flowers (capitulums) of Hangzhou white chrysanthemum and its F1 hybrid superior lines were analyzed using liquid chromatography-mass spectrometry (LC-MS) technology. The results showed that 502, 505, and 496 metabolites were detected in Hangzhou white chrysanthemum, Hang F1-17, and Hang F1-22, respectively. A total of 309 common metabolites were found in the three chrysanthemums. Compared to Hangzhou white chrysanthemum, according to the fold change, namely FC≥1.5 and ≤0.8, which indicated significant up-regulation and down-regulation, there were 135 and 206 significantly up-regulated metabolites detected in Hangzhou F1-17 and Hangzhou F1-22 respectively, and there were 144 and 154 significantly down-regulated metabolites, respectively. Among the significantly changed metabolites of Hang F1-17 and Hang F1-22, the relative contents of three flavonoid metabolites of kaempferol (FC of 16.77 and 18.69), luteolin (FC of 7.35 and 3.74), isorhamnetin (FC of 3.21 and 6.38); methionine (FC of 103.22 and 67.71), one of the essential amino acids for the human body; the main organic acids of malic acid (FC of 306.73 and 2.76) and citric acid (FC of 4.82 and 12.16); and chlorogenic acid (FC of 1.53 and 3.11), the main health component in chrysanthemum, have all been significantly up-regulated. Additionally, when compared to the female parent Hangzhou white chrysanthemum, components such as ursolic acid, vitamin A, and K3 were only detected in Hang F1-17, while components such as carnosol, myricetin, and vitamin B1 were only detected in Hang F1-22. These results indicate that relative contents of some main nutritional components in the F1 hybrids are obviously higher than that in the female parent, and some specific nutritional components are only detected in the F1 hybrids. Meanwhile, the anemone-typed capitulum of Hang F1-17 also provide references for the development of excellent tea chrysanthemum cultivars for both ornamental and food uses in the future.

7 Zeaxanthin-enriched Olive Oil Delays Aging Induced by D-galactose in Mice

YE Wenbin , CHEN Wendong , WANG Yu , HE Jiujun , HUANG Xinyi , DI Duolong

2024, 40(6):66-73. DOI: 10.13982/j.mfst.1673-9078.2024.6.0669

[Abstract](54) [HTML](44) [PDF 5.47 M](1110)

Abstract:
The effects of olive oil rich zeaxanthin (OZT) on aging mice were investigated. Divide mice successfully modeled in subacute aging into model groups, OZT High, middle and low treatment group, olive oil group (OL) , vitamin E positive (VE) control group. After continuous gavage for 28 days, to analysis the effects of different doses of OZT on body weight, major organ index, serum levels of SOD, CAT, GSH-PX, ALT, AST and MDA, IL-2, IL-4, IL10 and IFN-γ in aging mice. The results showed that the body weight of model group was significantly different from that of CK (0) mice (P<0.01), and the body weight of high, middle and low dose mice were significantly different (P<0.05), After oral administration, the hypoxia tolerance time and swimming time of OL group mice were the shortest, while the high dose OZT group mice had the longest time, compared with VE group, there was no significant difference (P<0.05); OZT could also decrease the activities of ALT, AST, SOD, CAT and GSH-Px in serum of senescent mice,and enhanced the production of IL-2, IL-4 and IFN-γ, the effects of high-dose OZT was significantly better than that of OL and similar to that of VE. In conclusion, OZT has a good intervention effect on the subacute aging model induced by D-galactose, which can effectively improve the anti-oxidation ability of mice, prolong the anti-hypoxia time and improve the anti-fatigue effect, and delay the aging effect.

8 Anti-proliferation Activity of Salidroside and the Aglycone Tyrosol in Triple-negative Breast Cancer Cells

WANG Yuanyuan , ZHENG Bisheng , XU Qiuxiong , LIU Ruihai

2024, 40(6):74-84. DOI: 10.13982/j.mfst.1673-9078.2024.6.0626

[Abstract](43) [HTML](44) [PDF 7.05 M](1119)

Abstract:
The high morbidity and mortality rates that are associated with breast cancer worldwide render the discovery of new drugs critical, and natural products with low toxicity, minimal side effects, multiple targeting, and good efficacy are hot topics in the development of such drugs. Two monomers derived from Rhodiola rosea L., salidroside and tyrosol, have shown good bioactivity. Thus, the ORAC method was used to determine the antioxidant capacity of these compounds, with the triple-negative breast cancer cell line, MDA-MB-231, used as an experimental model to investigate the anti-proliferation effects of the monomers. Cell scratch assay and flow cytometry were performed to detect cell apoptosis and cell cycle stage, and RT-qPCR was employed to further explore related mechanisms. The results showed that salidroside and tyrosol can significantly inhibit the proliferation of MDA-MB-231, with EC50 values of 63.55 and 127.35 μmol/L, respectively. Cell scratch assays showed significantly inhibited cell migration, and after 36 h, salidroside and tyrosol were shown to reduce the cell healing rate from 72.16 % to 27.86 % and 32.69 %, respectively, in the high-concentration groups, while cell cycle and apoptosis assays showed that both salidroside and tyrosol arrest the cell cycle at the G2 phase, promoting apoptosis. RT-qPCR showed that the anti-proliferation effects observed for salidroside are mainly due to up-regulation of the p53 and p21 genes and down-regulation of the Bcl-2, Bcl-xL, and CDK6 genes, whereas the efficacy of tyrosol is associated with up-regulation of the p53, p21, and Bax genes. These results provide theoretical support for further study into the bioactivity of salidroside and tyrosol and provide a theoretical basis for the development of anti-breast cancer drugs in the future.

9 Effect of α-Lactalbumin and Its Composition on Improving Sleep in Caenorhabditis elegans

LI Zhuobin , DENG Yiling , CHEN Caifeng , WU Tong , HOU Yanmei , ZHANG Yali , CHEN Yun , XIE Kui , CAO Yong , CHEN Yunjiao

2024, 40(6):85-95. DOI: 10.13982/j.mfst.1673-9078.2024.6.0761

[Abstract](53) [HTML](46) [PDF 6.76 M](1123)

Abstract:
With the incidence of insomnia increasing each year, there is an urgent need to develop active substances that can improve sleep. Caenorhabditis elegans was used to screen substances with the best sleep-improving effect from among four natural active substances (α-lactalbumin, γ-aminobutyric acid, L-theanine, and lily extract), and the mechanisms underlying their sleep-improving effects were examined. Finally, composites with sleep-improving effects were developed using these active substances. The results showed that all four natural active substances could reduce the levels of sleeprelated reactive oxygen species in C. elegans, and that α-lactalbumin had the best effect on improving sleep-related oxidative stress. Caenorhabditis elegans subjected to α-lactalbumin administration showed a 65.00% reduction in mitochondrial damage (P<0.05) and 4.10% increase in maximum lifespan under Pseudomonas aeruginosa PAO1 stress (P<0.05). Finally, the α-lactalbumin-containing composite with the best sleep-improving effect significantly increased sleep duration by 7.97% (P<0.05) and sleep frequency by 59.43% (P<0.05) during developmentally timed sleep, and reduced the movement speed of stress-induced sleep in C. elegans. In conclusion, α-lactalbumin had the strongest effect among the four active substances tested on improving sleep-related oxidative stress in C. elegans, and the mechanism of improving C. elegans sleep was related to mitochondrial repair. Composites containing α-lactalbumin showed sleep-improving effects in C. elegans.

10 Quercetin Ameliorates Hepatic Steatosis and Influences Tryptophan Metabolites in Obese Mice Induced by a High-fat Diet

GUO Qingjun , YANG Huifan , YANG Yunyan , LI Shuhuan , YANG Yihao , XIE Jiayu , SU Lijie

2024, 40(6):96-103. DOI: 10.13982/j.mfst.1673-9078.2024.6.0628

[Abstract](73) [HTML](43) [PDF 3.99 M](1117)

Abstract:
The purpose of this study was to investigated the ameliorating effect of quercetin on liver steatosis and its influence on tryptophan metabolites in obese mice induced by a high-fat diet. The obese mouse model was established using a high-fat diet. Male C57BL/6J mice were randomly divided into a control group (NC), a model group (HFD) and a quercetin intervention group (HFD+Q), with 10 mice in each group. The mice in the HFD+Q group were given 50 mg/kg.BW quercetin by gavage for 16 weeks. The body weights and liver weights of mice were measured. Fat deposition in the liver was detected tissue sections and oil red O staining. The ALT, AST, TC and TG levels were determined by ELISA. The relative expression levels of inflammatory cytokines, IL-1β, TNF-α and IL-6, and lipid metabolism-related genes, FAS, SREBP-1c and ABCA1, in the liver were determined by qPCR. The contents of serum tryptophan metabolites, indole-3-acetic acid (IAA) and indole-3-propionic acid (IPA), were determined by LC-MS targeted analysis. Quercetin intervention significantly (P<0.05) decreased the HFD-induced body weight gain, liver steatosis, and the levels of IL-6 (50.88%), IL-1β (42.52%), TNF-α (62.96%), FAS (80.36%) and SREBP-1c (23.54%), whilst increasing the mRNA expression level of ABCA1 (5.21 times) and the contents of tryptophan metabolites, indole-3-acetic acid (1.71 times) and indole-3-propionic acid (1.12 times). In conclusion, quercetin can reduce liver fat deposition, decrease the expression of inflammatory factors in the liver, ameliorate HFD-induced hepatic steatosis in obese mice, while increasing the contents of serum tryptophan metabolites such as indole-3-acetic acid and 3-indolepropionic acid.

11 Characteristics Analysis of Goat Yogurt Fermented by Three Groups of Multi-strain Probiotics

XU Shuangshuang , LYU Jiali , JU Rui , KANG Jie

2024, 40(6):104-113. DOI: 10.13982/j.mfst.1673-9078.2024.6.0663

[Abstract](49) [HTML](49) [PDF 5.98 M](1120)

Abstract:
In this study, three groups of probiotic combinations, Streptococcus thermophilus combined with 5 strains of Lactobacillus (SN_4), Streptococcus thermophilus combined with Lactobacillus bulgaricus (SN_2), and 5 strains of Lactobacillus combination (SN_3), were used to ferment goat milk. The number of viable bacteria, pH value, acidity, waterholding capacity during fermentation (0~12 h) and the texture properties, rheological characteristics, microbial community structure and functional differential metabolites at the curdling point were analyzed. The results showed that the curdling times of the SN_4, SN_2 and SN_3 yoghurts were 4.70 h, 5.60 h and 10.60 h, respectively, with the viable microbial number all reaching 109 CFU/mL or above. When fermentation reached the curdling point, both Streptococcus and Lactobacillus were detected. The water-holding capacity, textural characteristics and rheological properties of the goat yogurt fermented with SN_4 were the best, followed by the SN_2 yogurt. At the P level <0.05, the comparison of the SN_4 yoghurt with the SN_2 yoghurt revealed that 13 out of the 18 peptide differential metabolites, both the two carbohydrate differential metabolites, and 2 out of the 7 organic acid differential metabolites, were up-regulated. The comparison of the SN_4 yoghurt with the SN_3 yoghurt revealed that 5 out of the 18 peptide differential metabolites, 4 out of the 7 carbohydrate differential metabolites, and all the 6 organic acid differential metabolites, were up-regulated. There were 7, 5 and 4 differential metabolite pathways involved in SN_3 VS SN_2, SN_4 VS SN_2, SN_4 VS SN_3, respectively. The results showed that the properties of the goat yogurt fermented with SN_4 were better than those of the SN_2 and SN_3 yoghurts. The research results provide a theoretical basis and technical support for further research and development of multi-strain fermented yogurt with excellent sensory and functional properties.

12 Optimization of Fermentation Medium for the Production of Antibacterial Substances by Bacillus velezensis

LIU Jun , JIANG Yuqi , LIU Kang , DAI Hangpei , HUANG Cuixin , WANG Fengqing , LI Li , LI Zhongxuan , CHEN Xianxin , CHEN Ling

2024, 40(6):114-123. DOI: 10.13982/j.mfst.1673-9078.2024.6.0756

[Abstract](43) [HTML](38) [PDF 5.68 M](1124)

Abstract:
To improve the ability of Bacillus velezensis to produce inhibitory substances, the fermentation process was optimized using single-factor experiments, Plackett-Burman test, steepest ascent test, and the Box-Behnken design. The results showed that lactose and sodium nitrate were the optimum carbon and nitrogen sources for the fermentation medium. The Plackett-Burman test showed that the significant factors affecting were the inoculum, sodium nitrate concentration, and fermentation time. The steepest ascent test and response surface test determined the optimum conditions as 10 g/L lactose, 6.15 g/L sodium nitrate, 3% inoculum, a rotational speed of 220 r/min, 34 ℃, and 30.7 h of fermentation. Under these conditions, the diameter of the inhibition circle was 17.6 mm, which was 55% higher than the diameter before optimization. The biomass increased from 2.42×108 CFU/mL before optimization to 6.71×108 CFU/mL. The findings of this study are beneficial to the further development and utilization of B. velezensis as a potential probiotic and to improve the ability of the strain to resist food spoilage microorganisms.

13 Effect of Fermentation with Lactiplantibacillus plantarum PJ4-2 on the Quality of Pumpkin Juice Before and After Fermentation

LI Yaxin , DENG Lan , WANG Xiujing , YANG Shuangshuang , LI Wenyuan , HU Hong , ZHAO Yaran , ZHAO Qiang , LI Huamin , LIU Wenli

2024, 40(6):124-132. DOI: 10.13982/j.mfst.1673-9078.2024.6.0702

[Abstract](39) [HTML](49) [PDF 2.14 M](1132)

Abstract:
Cucurbita maxima pumpkin juice was fermented by Lactiplantibacillus plantarum PJ4-2, and theunfermented pumpkin juice was used as the control. The changes in physicochemical indexes, volatile flavor substances and sensory quality of the pumpkin juice after fermentation with L. plantarum PJ 4-2 were analyzed. The results showed that after a 12-h fermentation, the pH value of the pumpkin juice decreased to 4.52, the acidity increased to 10.70 mg/g, and the content of organic acid increased to 11.64 mg/g. A total of 40 volatile flavor compounds were identified from the unfermented and fermented pumpkin juices by headspace solid-phase microextraction and gas chromatography-mass spectrometry (HSSPME-GC-MS), including 11 aldehydes, 9 ketones, 11 alcohols, 4 olefins, 1 phenol, 1 ester, 1 acid and 2 other compounds. The concentration of volatile flavor substances increased by 67.60% after fermentation, and L. plantarum PJ 4-2 made an important contribution to the increase of pumpkin juice flavor. The odor activity value (OAV) analysis combined with the partial least squares discriminant analysis (PLS-DA) revealed that 2,3-butanedione (OAV=175.10, VIP=1.51) and 3-hydroxy- 2-butanone (OAV=10.18, VIP=1.40) were the potential characteristic markers for the aroma differences of pumpkin juice before and after fermentation, giving the fermented pumpkin juice a buttery aroma. The results showed that L. plantarum PJ4-2 had a good activity in pumpkin juice, and the resulting fermented pumpkin juice was rich in fruity aroma, had moderate sweetness and sourness, and gained higher overall acceptance, indicating that L. plantarum PJ4-2 was suitable for fermentation of pumpkin juice.

14 Optimization of Production Conditions for Kombucha Bacterial Cellulose by the Response Surface Method

WU Jiaqi , LI Li , BAI Jin , MA Sen

2024, 40(6):133-140. DOI: 10.13982/j.mfst.1673-9078.2024.6.0676

[Abstract](62) [HTML](46) [PDF 5.12 M](1129)

Abstract:
To improve the yield of bacterial cellulose (BC) during kombucha fermentation, the response surface method was employed to optimize the fermentation conditions using the dry weight of kombucha BC as an indicator, and the basic physicochemical properties of BC were measured. Using single-factor experiments and the response surface method, the optimal culture conditions for BC production by kombucha fermentation are as follows: tea volume fraction 0.83%, sucrose mass fraction 10.42%, liquid loading 70.22%, and culture temperature 29.33 ℃. The experimental results showed an actual yield of 4.21 g/L BC under these conditions, which is 60.08% higher than that obtained without optimization (tea volume fraction of 0.8%, sucrose mass fraction 6 %, liquid loading of 60%, culture temperature of 30 ℃, yield of 2.63 g/L). Measurement of the physicochemical properties of kombucha BC showed mass fractions of 3.01, 1.01, 85.67, and 6.1% for crude protein, crude starch, dietary fiber, and gray score, respectively. Scanning electron microscopy (SEM) indicated an ultra-network structure and a fiber diameter at the nanometer scale for kombucha BC, while tensile testing indicated a cellulose strength of approximately 2.28 MPa. X-ray diffraction analysis showed that the crystallinity of BC is 81.30%. Optimization based on the response surface method can thus effectively improve the yield of kombucha BC.

15 Formation Kinetics of Glyceryl Linolenate Isomers and Comparison of Different Acylation Positions on Thermotropic Isomers

LU Huimin , LI Yongfu , WU Yanxia , QIU Ju

2024, 40(6):141-148. DOI: 10.13982/j.mfst.1673-9078.2024.6.0710

[Abstract](43) [HTML](46) [PDF 2.16 M](1129)

Abstract:
The differences in the formation kinetics of trans linolenic acid in linolenic acid triglycerides during heating and the effects of linolenic acid at different acylation positions in the glycerides on the types of thermally isomerized trans products were studied. Using GC-FID to analyze the trans isomers of linolenic acid, it was found that there were 7 trans isomers in the linolenic acid triglyceride and 6 trans isomers in linseed oil, and the reaction was zero-order. The kinetic parameters of linolenic acid triglyceride and linseed oil were compared, and it was found that in linolenic acid triglyceride and linseed oil, the activation energies of C18:3-9t,12c,15c, C18:3-9c,12t,15c and C18:3-9c,12c,15t were 79.39, 106.49 and 82.33 kJ/mol, and 86.04, 115.84 and 102.85 kJ/mol, respectively; the activation energies of C18:3-9t,2c,15t and C18:3-9t,12t,15c were 180.57 and 233.55 kJ/mol, and 164.36 and 165.38 kJ/mol, respectively; the activation energies of C18:3-9t,12t,15t were 211.79 and 140.30 kJ/mol, respectively. With the comparison on the the isomer contents of monolinolenin, dilinolein and 1,3-dilinolenin revealed that Sn-1 and Sn-2 were more stable than Sn-1 and Sn-3; Sn-1 was more stable than Sn-1 and Sn-3, and Sn-1 and Sn-2. Therefore, the energy barrier of linolenic acid triglyceride was basically higher than that of linseed oil; In terms of acylation sites, Sn-1 and Sn-2 was more stable than Sn-1 and Sn-3, and Sn-1 was more stable than Sn-1 and Sn-3, and Sn-1 and Sn-2.

16 The Relationship between the Color and Chemical Composition of Fresh Tea Leaves and Their Suitability for Making Black Tea

CAO Huihua , JIANG Xinfeng , LI Chen , ZHANG Jiangen , WANG Lixian , TONG Zhongfei

2024, 40(6):149-157. DOI: 10.13982/j.mfst.1673-9078.2024.6.0556

[Abstract](65) [HTML](41) [PDF 1.85 M](1123)

Abstract:
Four tea varieties, namely Baiye No.1, Zijuan, Huangjinju and Fuding Dabai, were used as the research materials, the characteristics of tea buds and leaves were examined, the contents of biochemical components in the fresh leaves were determined, the correlation between the contents of different pigments and the contents of biochemical components was analyzed, and black tea was prepared for evaluation and verification. The results showed that Zijuan had the highest contents of chlorophyll a (1.21 mg/g) and anthocyanins (8.86 mg/g), which were 29.53, 6.47 and 4.32 times those of Baiye No.1, Huangjinju and Fuding Dabai, respectively. Correlation analysis revelaed that the content of pigments was negatively correlated with the content of amino acids, and positively correlated with the contents of water extract, tea polyphenols and caffeine. The principal component analyses of the contents of pigments and biochemical components of the new tea leaves revealed that the cumulative contribution rate of the first 3 principal components representing “Pigment Factor”, “Biochemical Factor” and “Taste Factor” was 96.90%, which could well distinguish the quality of black tea made with the fresh leaves of different colors (varieties). The quality scores of fresh leaves from high to low were Zijuan (T2) > Huangjinju (T3) > Fuding Dabai (T4) > Baiye No1 (T1), which was consistent with the black tea sensory evaluation results. Zijuan with high contents of chlorophyll a, chlorophyll b, carotenoid and anthocyanins, as well as high phenol-ammonia ratio, was more suitable for making black tea, indicating that the suitability of a tea variety for making black tea can be judged by the pigment content and biochemical component content of its fresh leaves. Taken together, this study can provide data support for the suitability of tea tree shoots with different colors.

17 Effect of Enzymatic Digestion Products of Konjac Glucomannan with Different Molecular Weights on Oxidation and Structural Properties of Myofibrillar Protein during Frozen Storage

GUO Bingbing , HU Ao , QUE Feng , WU Wenjin , XIONG Guangquan , SHI Liu , CHEN Sheng , GUO Xiaojia , WANG Chao , WANG Lan , LI Wei

2024, 40(6):158-168. DOI: 10.13982/j.mfst.1673-9078.2024.6.0659

[Abstract](46) [HTML](46) [PDF 3.59 M](1130)

Abstract:
Changes in the physical, chemical, and structural properties of myofibrillar protein of grass carp caused by adding konjac glucomannan enzymatic products EK1, EK2 and EK3 with molecular weights of 149.03, 118.75 and 36.48 ku, respectively, during the frozen storage at –18 ℃, were compared. The samples were analyzed for salt-soluble protein content, Ca2+-ATPase activity, total sulfhydryl groups, surface hydrophobicity, particle size, Zeta potential, SDS-PAGE, and UV and fluorescence spectra. The results manifested that the salt-soluble protein content and total sulfhydryl content in the EK3 group were at maximum at 1.51 mg/mL and 19.76×10-5 mol/g, respectively, after 20 d of freezing, compared with the blank control, commercial antifreeze, EK1, and EK2. At same time, the Ca2+-ATPase activity, in the EK3, were at maximum at 1.31 μmol Pi/(mg prot•h), while the Zeta potential were at minimum at 8 689.07 and –13.35 mV, respectively, after 30 d of freezing. After 30 d of freezing, the SDS-PAGE results showed that the EK3 group had the least degradation of myosin and actin, which inhibited the oxidation of myogenic fibronectin. Furthermore, the exposure of tryptophan and tyrosine residues was reduced in the EK3 group, which indicated that the stability of the protein spatial structure was maintained. Therefore, it was concluded that the addition of small molecular weight konjac glucomannan enzymatic digestion product EK3 (36.48 ku) had the best cryoprotective effect on myofibrillar protein in this experiment, which supports the use of small molecule polysaccharides as antifreeze agents for aquatic products.

18 Storage Quality of Ctenopharyngodon idellus Fillets Irradiated by High-energy Electron Beam

CHEN Minhui , CHEN Yulong , LI Jiahong , CHEN Feiping , YE Mingqiang , WANG Ling , QI Yingwei , LUO Zheng , DAI Fanwei

2024, 40(6):169-177. DOI: 10.13982/j.mfst.1673-9078.2024.6.0527

[Abstract](42) [HTML](47) [PDF 2.19 M](1127)

Abstract:
In this study, the preservative effect of high-energy electron beam irradiation technology on crisped grass carp fillets was investigated. Different irradiation doses (0, 1, 3, 5, 7 kGy) combined with vacuum packaging and storage under 4 ℃ refrigeration were applied, and the total colony count (aerobic plate count, APC), lipid oxidation products (thiobarbituric acid, TBARs), volatile basic nitrogen (TVB-N), texture (TPA), color and sensory scores were measured, to examine the effect of electron beam irradiation on the quality of fish fillet during cold storage. The results showed that the growth of microorganisms in the fillets could be inhibited to a great extent by irradiation, and the total colony number of the fillets could be kept below 106 CFU/g over the whole storage after the irradiation at a dose of 3~7 kGy, indicating that 3 kGy was the lowest effective dose for the fillets. Although the TBARs value of grass carp fillets increased after the irradiation, the irradiation could delay further increase of TBARs value during the late stage of storage. A dose at 5 kGy or lower could make the TBARs remaining at a relatively low level. Similarly, irradiation could delay the increase of the TVB-N content in grass carp fillets. The effects of irradiation on odor, texture and color of the fillets were insignificant. Taken together, under vacuum packaging and 4 ℃ cold storage, 3 kGy was the lowest effective dose for the fillets, and 5 kGy was the highest tolerated dose, with the irradiation at a dose of 3~5 kGy being the most suitable treatment for the storage and preservation of the crisped grass carp fillets. The results of this study provide a reference for the application of electron beam irradiation to the preservation of crisped grass carp fillets.

19 Storage Stability and in Vivo Antithrombotic Activity Evaluation of Collagen Peptide Functional Beverage

LIANG Ruihan , LI Bo

2024, 40(6):178-188. DOI: 10.13982/j.mfst.1673-9078.2024.6.0681

[Abstract](48) [HTML](42) [PDF 3.37 M](1116)

Abstract:
Antiplatelet functional foods can replace drugs in the prevention of thrombosis. Previous studies have shown that silver carp skin collagen peptides (SCPs) have a good antiplatelet activity, and the developed SCPs-based beverages are anticipated to play a role in the prevention of thrombus. In this study, the stability of SCPs powder and derived beverage under different storage conditions was investigated, and a tail thrombosis model was used to evaluate the antithrombotic activity of SCPs powder and derived beverage before and after the storage. The results showed that the peptide loss rate of the vacuum packed SCPs powder stored at room temperature (25 ℃ ) for two months was about 1.43%; The peptide loss rate of the derived SCPs beverage was about 5.90% after being stored at room temperature for three months, and was about 12.87% after being stored at a relatively high temperature (37 ℃ ) for three months, accompanied by the occurrence of the Maillard reaction, growth of bacterial colony and decline of sensory quality; The inhibitory rate of SCPs powder against the tail thrombus formation in mice was 66.4% when the feeding dose was 200 mg/kg•bw. The activity of SCPs powder after two months of storage at room temperature did not decrease significantly compared with that before the storage. The inhibitory rate of the derived SCPs beverage against the tail thrombosis in mice was 58.7%, which decreased to 45.3% after three months of the high-temperature storage, though a similar effect as that of aspirin at a dose of 25 mg/kg•bw was still detected. This study indicates that SCPs powder or liquid beverage are feasible product options, both of which can be used as dietary supplements for the prevention of thrombosis.

20 Functional Properties of Six Kinds of Dietary Fibers and Their Applications in Bread

YANG Shuo , ZHAO Xiujie , CAI Yongjian , DENG Xinlun , ZHAO Qiangzhong , ZHAO Mouming

2024, 40(6):189-197. DOI: 10.13982/j.mfst.1673-9078.2024.6.0633

[Abstract](59) [HTML](43) [PDF 3.22 M](1170)

Abstract:
The physiochemical and functional properties of bamboo fiber, wheat fiber, sugarcane fiber, pea fiber, soybean fiber, and cocoa fiber were compared and analyzed to investigate the effects of dietary fibers on the quality of frozen dough bread. The baking characteristics of frozen dough bread and its correlation with the properties of dietary fiber were determined. The dietary fibers were divided into three categories based on their properties. The first category included bamboo fiber, wheat fiber and sugarcane fiber, which had higher contents of insoluble dietary fiber (IDF) and cellulose, higher waterholding capacity and emulsifying capacity. The second category included pea fiber and soybean fiber, which had a higher hemicellulose content, and weaker water-holding and emulsifying capacities. The third category included cocoa fiber, which had a higher lignin content and lower IDF content while exhibiting the weakest water-holding and emulsifying capacities. The results of the baking characteristics showed that compared with the blank control group, the addition of a first-category fiber could significantly improve the bread baking quality, with the firmness of the sugarcane fiber-bread decreasing by 70.15 g, and the associated sensory score increasing by 3.76, indicating the greatest improvement of bread quality. The improvement induced by the second-category dietary fibers came second. After the third-category fiber was added, the firmness of the resulting bread increased by 74.46 g, and the associated sensory score decreased by 4.33, suggesting a negative effect on the bread quality. The correlation analysis results showed that the IDF content, water-holding capacity, and emulsifying capacity are all significantly correlated with bread’s firmness, elasticity, and sensory score (P<0.05).

21 Cluster and Principal Component Analyses of Key Nutritional Indicators for Mangoes at Different Harvest Maturities

DENG Hao , WU Guang , CHEN Xiaomei , GUO Li , YIN Qingchun

2024, 40(6):198-205. DOI: 10.13982/j.mfst.1673-9078.2024.6.0680

[Abstract](45) [HTML](38) [PDF 2.25 M](118)

Abstract:
Mango is a climacteric fruit, with significant differences in color, physicochemical, and nutritional indicators when harvested at different maturity levels. By comparing the main quality indicators of three mango varieties, Guifei (GF), Tainan (TN), and Jinhuang (JH), at different maturity levels, a comprehensive evaluation was carried out using cluster analysis (CA) and principal component analysis (PCA). The results showed that the comprehensive color index of GF and JH mangoes ranged from -0.01 to -0.35, indicating that the skin was predominantly green and that the color change was not as significant as that in the TN mango. The hardness of the three mangoes was also observed to decrease by 56.05, 48.58, and 69.69%, respectively, during the ripening process. The titratable acids decreased by 30.61, 61.29, and 85.06%, respectively, and the soluble solids, pH value, and solid-acid ratio gradually increased. The dominant sugar in mangoes was sucrose; the dominant organic acids were citric acid, adipic acid, and succinic acid. The predominant amino acids were alanine, glutamine, lysine, arginine, and aspartic acid. CA of the 15 key quality indicators revealed three categories, with PCA capturing 91.361% of the indicator information. Mathematical modeling confirmed that the quality ranking of fully matured mangoes ranked in the order GF>TN>JH. Notably, fully matured GF mangoes exhibited the highest quality, with an overall score 154.29% higher than 90% mature GF mango, making it an ideal variety for “tree-ripened” farm-picking activities.

22 Preparation and Stability of Anthocyanin W/O Pickering Emulsion from 'Blue Bird' Tropical Water Lily

ZHAO Xia , CHEN Yanfu , ZHOU Weijuan , ZHAO Ying

2024, 40(6):206-213. DOI: 10.13982/j.mfst.1673-9078.2024.6.0472

[Abstract](45) [HTML](43) [PDF 5.42 M](95)

Abstract:
The embedding technology of active ingredients needs to be explored due to the instability of active ingredients extracted from water lily. In this study, Nymphaea 'Blue Bird', a tropical water lily, is used as a target for the extraction of anthocyanin and its embedding in W/O pickering emulsions. W/O emulsions with different volume fractions of the aqueous phase were prepared, using the anthocyanin solution as the aqueous phase (W), soybean oil as the oil phase (O) and the emulsifier selected as the lipophilic emulsifier polyglyceryl ricinoleate (PGPR). The results showed that the W/O emulsions prepared at 30% and 50% of the aqueous phase volume fraction were stable after 15 d of storage at different temperatures, and the encapsulation efficiency of the anthocyanin was 75.97% and 78.12%, respectively, and the encapsulation stability within 15 d was good. The stability of W/O emulsions was investigated by preparing W/O emulsions at different shear rates. The apparent stability of W/O emulsions was achieved when the shear rate was 28 000 r/min, and the retention rate of centrifugation reached 97.40% after 120 min storage. In conclusion, the W/O pickering emulsion prepared in this manuscript was balanced and had a good encapsulation effect on anthocyanins.

23 Numerical Simulation of Dynamic Lateral Pressure during Vertical Silo Unloading Based on the Discrete Element Method

LIU Qiang , ZHANG Qianqian , XU Qikeng , DING Yonggang , SUN Qishuai , WANG Yifeng

2024, 40(6):214-220. DOI: 10.13982/j.mfst.1673-9078.2024.6.0405

[Abstract](48) [HTML](51) [PDF 4.18 M](73)

Abstract:
The dynamic lateral pressure when unloading vertical grain silos can render the process unsafe; thus, three types of grains (corn, wheat, and rice) were selected to simulate unloading using the discrete element simulation software, EDEM. The static lateral pressure distribution under the physical characteristics and contact properties of different stored materials was studied and compared with the specification value. The distribution patterns of dynamic lateral pressure and the corresponding overpressure coefficient, flow state, and velocity distribution relationships during unloading were analyzed together with the factors influencing the dynamic lateral pressure during unloading using gray relational analysis. The results showed that the maximum static lateral pressure for all three types of stored materials occurs towards the bottom of the silo wall and is greater than the specification value. Hence, the value calculated using the specification formula can be considered relatively conservative. Increased oscillation of the dynamic lateral pressure during unloading and the maximum dynamic lateral pressures of 6.08, 5.38, and 4.73 kPa observed for corn, wheat, and rice, respectively, at a depth of 0.8 m exceeds the correction coefficient for horizontal lateral pressure required in the specifications. Thus, the correction coefficient for horizontal lateral pressure required by the current code is unsafe. The main factors affecting the dynamic lateral pressure include the density of the stored material, the static friction coefficient between the stored material and the silo wall, and the collision recovery coefficient between the stored material and the silo structure. This paper can provide theoretical support for the analysis of the collision recovery coefficient between stored materials and silo structures for use in silo specifications.

24 Analysis of Key Aroma Compounds in Three Varieties of Wuyi Rock Tea Based on GC×GC-TOFMS-O

HU Tengfei , XIAO Han , XIE He , CHEN Guohe , OU Xingchang , JIANG Ronggang , WANG Chao , LI Qin , HUANG Jian'an , LIU Zhonghua , YU Liming

2024, 40(6):221-230. DOI: 10.13982/j.mfst.1673-9078.2024.6.0735

[Abstract](52) [HTML](56) [PDF 2.36 M](99)

Abstract:
The key aroma compounds of three varieties of Wuyi Rock Tea (RouGui, ShuiXian, and DaHongPao) processed at the same roasting temperature were determined and analyzed through sensory evaluation, comprehensive two dimensional gas chromatography-time-of-flight mass spectrometry-olfactometry (GC×GC-TOFMS-O), and odor activity value (OAV). In terms of aroma quality, RouGui was dominated by a cinnamon aroma with an accompanying floral aroma, ShuiXian was dominated by an orchid aroma, and DaHongPao produced a floral and fruity aroma. A total of 337 volatile compounds were detected across three types of tea, including 36 aroma active compounds and 26 key aroma compounds. Specifically, RouGui, contained 17 identified compounds, ShuiXian contained 16, and DaHongPao contained 18. Heatmap analysis showed eight key aroma compounds in RouGui, including geraniol, 3,5-diethyl-2-methyl-pyrazine, hexyl isovalerate, and hexanal; ten key aroma compounds in ShuiXian, including amyl hexanoate, β-ocimene, 6-methyl-5-hepten-2-one, indole, and 3-ethyl-2,5-dimethyl-pyrazine; and eight key aroma compounds in DaHongPao, including phenylethyl alcohol, methyl benzoate, undecanal, 2-methylpyrazine, and dodecanal. These aroma compounds are therefore considered to make important contributions to the aroma quality of the different varieties of Wuyi Rock tea.

25 Analysis of Volatile Flavor Substances in Different Dictyophora Cultivars by Gas Chromatography-ion Mobility Spectroscopy

AN Shiyu , TANG Pengyu , MENG Fanbo , HUANG Daomei , MO Xiaoyin , LIN Mao

2024, 40(6):231-242. DOI: 10.13982/j.mfst.1673-9078.2024.6.0700

[Abstract](46) [HTML](53) [PDF 4.96 M](105)

Abstract:
To study the flavor characteristics of different Dictyophora varieties, gas chromatography-ion mobility spectroscopy (GC-IMS) was used, combined with relative odor activity value analysis. The volatile flavor substances were analyzed in dried and fresh Dictyophora varieties. A total of 54 volatile flavor substances were identified, which included seven alcohols (4.51%~46.46%), eleven esters (8.00%~49.87%), six ketones (7.28%~18.76%), twenty aldehydes (14.86%~60.51%), two ethers (0.46%~6.41%), two pyridines (0.08%~0.49%), one furan (0.05%~0.30%), three sulfides (0.19%~3.44%), one olefin (0.06%~0.72%), and one carboxylic acid (0.17%~4.08%). GC-IMS fingerprint spectra showed that the characteristic peak regions were larger for Dictyophora acanthophora than for Dictyophora maxi. The main volatile flavor substances were different in different varieties of Dictyophora, with the most common being aldehydes, alcohols, and esters. Principal components analysis and Euclidean distance showed that there were differences in flavor between dried and fresh Dictyophora. Thus, GC-IMS enables visualization of flavor substances in different varieties of Dictyostelium. These findings provide some reference information for enriching the flavor quality characteristics of different Dictyophora varieties.

26 Effect of Different Spice Processing Treatments on the Volatile Flavor Components of Pot-stewed Goose Liver

LIN Wanling , ZENG Jiao , ZHENG Qiuchun , XUE Yingzhu , XIAO Liting , LIU Hanxu , LIU Yaqun , LUO Donghui , CAI Xueyuan

2024, 40(6):243-251. DOI: 10.13982/j.mfst.1673-9078.2024.6.0750

[Abstract](50) [HTML](33) [PDF 2.07 M](100)

Abstract:
Ordinary goose liver is highly nutritious, but its comprehensive utilization rate is low. Therefore, to improve the utilization value and optimize the marination process of goose liver, three different methods were used to spice ordinary goose livers, and the effects on the flavor of the pot-stewed goose livers were studied. The results showed that the sensory scores of goose livers marinated with crushed spices for 30 min (FS) were similar to those obtained for goose livers that were marinated traditionally with uncrushed spices for 60 min (WF). The sensory scores of goose livers marinated with crushed and ball-milled spices (FS+QM) were slightly worse than those obtained for WF. A total of 57 volatile flavor components were detected in the three kinds of goose livers, with 40 in WF, 42 in FS, and 36 in FS+QM, and significant differences were observed for some of the volatile components in the three kinds of goose livers, with relatively high contents and the most significant changes observed for aldehydes, alcohols, and ethers. Aldehydes were the key substances affecting flavor. Principal component analysis further showed significant differences in the key flavor substances of goose livers marinated under the three different processing methods, and that the grain size of the spices affects the types and contents of the flavor substances in braised goose livers. The results of the study indicate that replacing the traditionally used whole spices saves marinating time, thus providing a theoretical basis for improved processing of ordinary goose livers.

27 Detection of Sheep-derived Components in Sheep Plasma Using DNA Electrophoresis Image Analysis Based on the Python/RGB Module

CAO Shilin , ZHANG Chunhong , LAI Xinjue , YUAN Zhitao , HAO Jinheng , CHEN Hu , MA Junwei , LI Xinyao , YU Jieting , LUO Jiawei , CHEN Yinxi , ZHENG Shaopeng , ZHENG Kunwen , LIN Xiaoru , CHEN Wanjuan

2024, 40(6):252-259. DOI: 10.13982/j.mfst.1673-9078.2024.6.0629

[Abstract](32) [HTML](36) [PDF 2.31 M](85)

Abstract:
A novel method for determining the molecular weight and content of DNA in foods was developed using Python, and an image analysis method for DNA gels was established. Agarose gel electrophoresis was performed using DNA markers of different molecular weights and DNA standard samples, and gel images were captured for analysis with a selfdeveloped Python program. Image optimization was then performed using grayscale image conversion, Gaussian blurring, image thresholding, and contour detection, and the linear relationship between DNA concentration and RGB value was explored using the contour average, contour centerline, global data average, and global data integration methods, and the optimal processing method was selected. Pixel migration distance, RGB-grayscale value, RGB-vector, and RGB-brightness were used to determine the molecular weight and DNA content. A method for analyzing the molecular weight and content in DNA gel electrophoresis was established based on the Python/RGB color system. The relatively small error in the detection results demonstrates the feasibility of using Python/RGB to obtain information about DNA molecular weight and analyze content. Application of the gel image analysis method to detect sheep-derived components in the sheep plasma indicated 296 bp of the target protein, while 294 bp was obtained using the DNA detection method, indicating an error of only 0.99%. The results therefore indicate that the method may serve as a novel means of detecting meat-derived components.

28 Application of the HACCP System in Controlling the Formation of Bongkrekic Acid in the Production of Wet Noodles

XIAN Yanping , WANG Xin , XU Xiaoli , ZHU Guangfu , LIANG Ming , HOU Xiangchang , WU Yuluan

2024, 40(6):260-267. DOI: 10.13982/j.mfst.1673-9078.2024.6.0234

[Abstract](28) [HTML](39) [PDF 1.90 M](84)

Abstract:
Hazard analysis and critical control point (HACCP) is a preventive management system used in the control of food production and processing, which can effectively improve food safety management in food enterprises. Wet noodles are commonly associated with contamination issues; thus, a demonstration study was performed in a wet noodles production enterprise in Guangzhou, including a potential hazards analysis of contamination with Pseudomonas cocovenenans subsp. and its metabolites (highly toxic bongkrekic acid). The critical control points (CCP) of the production process were identified; CCP monitoring, correction, and verification procedures were established; and prevention and control measures were proposed. Finally, a HACCP plan was formulated. Application of the HACCP system can strengthen the management and control of the production process for wet noodles, ensuring the quality and safety of this food type.

29 Characteristics of an Emerging Food-borne Multidrug-resistant Atypical Enteropathogenic Escherichia coli Strain

HUANG Yuanbin , ZHANG Shuhong , YANG Guangzhu , WU Qingping , ZHANG Jumei , WU Shi , GU Qihui , YE Qinghua , ZHANG Youxiong , WEI Xianhu

2024, 40(6):268-278. DOI: 10.13982/j.mfst.1673-9078.2024.6.0692

[Abstract](41) [HTML](33) [PDF 3.36 M](99)

Abstract:
The phenotypic, biochemical, and genetic characteristics of an emerging food-borne multidrug-resistant atypical enteropathogenic Escherichia coli (aEPEC) strain were explored. An extended-spectrum β-lactamase (ESBL)-producing atypical aEPEC strain, E2892A1, carrying the plasmid-mediated colistin resistance gene mcr-1 was isolated from retail food. The biochemical characteristics were analyzed using the Analytical Profile Index 20E test. The minimal inhibitory concentrations of antibiotics were determined using the microbroth dilution method. Further, the genetic characteristics (antibiotic resistance genes, plasmid replicon types, and virulence genes) were analyzed using whole-genome sequencing (WGS), and the genetic evolutionary relationship was constructed based on core genome single nucleotide polymorphism cluster analysis. The results indicated that the aEPEC E2892A1 strain had a high prevalence of resistance to ceftazidine, ceftriaxone, tetracycline, ampicillin, and other commonly used antibiotics and was an ESBL-producing strain. WGS results showed that the strain was an aEPEC and carried 17 antibiotic-resistance genes, the virulence gene eae, and four plasmid replicon subtypes. This is the first report of multiple resistance genes (especially CTX-123 and mcr-1) co-existing in the same ESBL-producing aEPEC ST752 strain. Conjugation experiments confirmed that the mcr-1 gene could be transmitted horizontally to E. coli C600. The presence of such a strain in food poses a potential health threat to humans. Thus, continuous attention to its spread is essential. This study provides important basic data for monitoring the risk of highly virulent multidrug-resistant bacteria in food, which can aid the rational use of antibiotics and the formulation of clinical protocols for the treatment of food-borne diseases.

30 Establishment of Time-resolved Fluorescence Immunoassay for Progesterone Residues in Animal-derived Foods

LIU Bo , HUA Yantao , MA Nannan , ZHAO Xuan , CHEN Li'nan , YUAN Lipeng

2024, 40(6):279-284. DOI: 10.13982/j.mfst.1673-9078.2024.6.0672

[Abstract](31) [HTML](46) [PDF 1.93 M](82)

Abstract:
In this study, progesterone was taken as the research object, a new antigen was designed and prepared, and specific rabbit antibody was obtained through animal immunization. Based on the obtained antigen and antibody, key parameters, such as the concentration of antigen and antibody, the type of reaction buffer and its pH value, were further optimized. Finally, a time-resolved fluorescence Immunoassay (TRFIA) for rapid detection of progesterone residues in animal-derived foods was established for the first time in China. In this study, the optimal experimental conditions were determined as follows: the concentration of antigen was 0.30 μg/mL, the concentration of europium labeled antibody was 0.40 μg/mL, the pH of TBST working buffer was 7.2, and the standard curve was established. The linear range of the method was 0.46~6.94 μg/L, the IC50 reached 1.79 μg/L, the cross-reaction rate with testosterone was 1.25%, and there was no cross-reaction with estradiol, estriol and other hormones. The average spiking recovery rate of the actual samples was 82.0%~113.0%, and the coefficient of variation within and between batches was less than 5%. The correlation with the analysis results obtained by high-performance liquid chromatography was good (r2 = 0.988). The results indicate that the TRFIA detection method established in this study was accurate, reliable, specific, and sensitive, and can be used for the rapid detection of progesterone residues in animal-derived foods.

31 Detection of Phenylpyrazole Residues in Food by Ultra-high Performance Liquid Chromatography-tandem Mass Spectrometry

CHEN Li , ZHANG Qiheng , ZHU Zhengwei , WU Wanqin , JIANG Feng

2024, 40(6):285-294. DOI: 10.13982/j.mfst.1673-9078.2024.6.0652

[Abstract](42) [HTML](43) [PDF 3.53 M](155)

Abstract:
A food analytical method that combines QuEChERS pretreatment assay with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for the detection of eight phenylpyrazole residues in food; ethiprole, flufiprole, pyraflufen-ethyl, fipronil-desulfinyl, fipronil, fipronil-sulfone, fipronil-sulfide, and fipronil-detrifluoromethyl sulfoxide. Different food matrices were directly measured by salting-out and QuEChERS purification using 1% acetonitrile acetate and water as extraction solvents. Gradient elution was conducted using methanol and water as the mobile phase and scanning in the multiple reaction monitoring (MRM) mode was performed simultaneously in the positive and negative ion ESI modes. Matrix-matched standard solutions were used for quantitative analysis. The peak shape of phenylpyrazoles was sharp and symmetrical, showing good separation effects, good linearity within the 1~800 μg/L range, and correlation coefficients greater than 0.99. The detection limit of this method for eggs, poultry meat, milk, dates, Chinese cabbage, tea, and rice matrices ranged between 0.01~0.53 μg/kg, with the quantitation limit at 0.04~1.75 μg/kg, the standard recovery rates at 70.12~119.87%, and the relative standard deviation (RSD) from 1.01~9.91% (n=6). The developed QuEChERS-UHPLC-MS/MS method can be considered effective, accurate, and versatile, and it can be successfully applied for the simultaneous detection and analysis of different phenylpyrazole residues in food.

32 Analysis of Contamination, Drug Resistance, and Homology of Pseudomonas aeruginosa Isolated from Barreled Water in Ningxia

FENG Xiujuan , DONG Chuan , SU Yang , GAO Junfeng

2024, 40(6):295-302. DOI: 10.13982/j.mfst.1673-9078.2024.6.0698

[Abstract](34) [HTML](42) [PDF 1.99 M](76)

Abstract:
The study objectives were to comprehensively evaluate the pollution situation, drug resistance, and phylogenetic relationship of Pseudomonas aeruginosa strains in Ningxia barreled water production enterprises; identify the pollution source; and improve the product quality. Detection of P. aeruginosa was conducted in water samples from each production link of the enterprise. The isolates in the water samples were identified using a VITEK-2 microbial identification system, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and 16S rRNA gene sequencing. The antimicrobial resistance of P. aeruginosa was assessed using a compact VITEK 2 system, a phylogenetic tree was constructed using 16S rRNA gene sequencing data, and homology was analyzed using MALDI-TOF MS. The identification results of the VITEK-2 system, MALDI-TOF MS, and 16S rRNA gene sequencing were 100% consistent with the identification results of the 24 positive strains isolated using conventional methods. Two of the 24 P. aeruginosa strains, 5-B-1 and 7-C-5, were drug-resistant, and the drug resistance rate was 8.3%, indicating that the drug resistance level of waterborne strains was low. The mass spectrometry results showed that the positive strains from the same area were closely related. The phylogeny analysis showed that the isolates of P. aeruginosa were not related to the geographical region, but the strains of P. aeruginosa from the same source were in the same cluster, and the main source of P. aeruginosa was water. This study provides accumulated data for the contamination traceability of P. aeruginosa in barreled water and the theoretical basis for further research on contamination traceability of bacterial species.

33 Determination of Four Flavors in Rice by High-performance Liquid Chromatography Quadruple Rod/Electrostatic Field Orbital Trap High-resolution Mass Spectrometry

LIU Yun , LI You , ZHANG Shuran , LI Jingjing , DING Tao , LIU Han , ZHANG Junbei

2024, 40(6):303-310. DOI: 10.13982/j.mfst.1673-9078.2024.6.0670

[Abstract](46) [HTML](41) [PDF 2.67 M](91)

Abstract:
A method for determining four flavor compounds in rices by high-performance liquid chromatographyquadrurpole/electrostatic field orbitrap high-resolution mass spectrometry (HPLC-Q/Qrbitrap MS) was developed. The rice samples were soaked in a water solution, extracted by acidified acetonitrile, vortexed via oscillation for 12 min, and then centrifuged, the extract passed through a C18 solid-phase extraction column, and the effluent passed through a 0.45 μm filter membrane. The gradient elution was carried out with acetonitrile -0.1% (V/V) formic acid solution as the mobile phase, and Agilent EclipsePlus C18 (100 mm×2.1 mm, 1.8 μm) was used as the chromatographic column. The positive ion mode and Full MS/dd-MS2 scanning mode were used in the mass spectrometry. The corresponding peak area of parent ions extracted from the first-order mass spectrometry was quantified, and the secondary ions obtained by automatic trigger scanning were qualitatively confirmed. The samples were analyzed based on the external standard method. Under the established chromatographic conditions, four flavor compounds were well separated. The detection limits and quantification limits were 15 μg/kg and 50 μg/kg, respectively. Good linearity was obtained in the range of 5~500 ng/mL, and the correlation coefficients were all higher than 0.99. The average recoveries at three concentration levels were in the range of 79.0%~95.8% and the relative standard deviations (RSDs) were in the range of 3.1%~7.7%. The proposed method requires a simple sample treatment, and results in a high recovery rate and high stability. Therefore, can be used to screen and confirm four rice flavors, which is of great significance for regulation the application of the flavors in rice.

34 Research Progress on the Application of Sulfur Dioxide in the Preservation of Fresh Table Grapes

ZHANG Yifan , WU Peiwen , ZHU Benzhong

2024, 40(6):311-317. DOI: 10.13982/j.mfst.1673-9078.2024.6.0645

[Abstract](73) [HTML](51) [PDF 1.79 M](112)

Abstract:
Sulfur dioxide (SO2) is the widely used in the storage of grapes, offering advantages such as excellent antimicrobial effect, low cost, and significant fresh-keeping effects, thus, it is an ideal preservative. However, excessive SO2 can lead to serious damage to fresh grape fruits, with the common symptoms including fruit bleaching, increase of fruit falling, fruit cracking and flavor deterioration, causing high fruit loss during storage. At present, there is currently a lack of systematic induction and arrangement for the application outcome and working mechanism of SO2 preservation of table grapes. In order to solve this issue, this article reviews the effects of SO2 treatment on the postharvest diseases, sensory quality and physiological metabolism of fresh grapes, the antimicrobial mechanism and accumulation pathway associated with the application of SO2 in preseving table grapes, and the harms to the fresh grapes caused by excessive SO2 including fruit bleaching, fruit falling, and flavor deterioration during storage. Finally, the research and application trends of SO2 in the preservation of table grapes were prospected, with the aim to lay a theoretical foundation for the precise application of SO2 in grape preservation, and provide a corresponding reference for the advancement of storage and preservation technologies for table grapes in China.

35 Research Progress on the Extraction, Purification, Biological Activities and Stabilization Techniques of Cyanidin-3-glucoside

GAO Qi , SUN Mingyang , YUAN Xingling , PENG Xue , WANG Ning , XUE Youlin

2024, 40(6):318-326. DOI: 10.13982/j.mfst.1673-9078.2024.6.0409

[Abstract](42) [HTML](45) [PDF 1.91 M](83)

Abstract:
Cyanidin-3-glucoside (C3G) is one of the most widely distributed anthocyanins in nature. It is abundant in fruits, vegetables and cereals, and has many physiological functions such as anti-oxidant, anti-cancer, anti-inflammatory and visual health maintenance functions, thereby attracting much attention in the food and pharmaceutical industries. The extraction and purification are important steps in the utilization of C3G, but C3G tends to lose its original color and physiological value due to its vulnerability to external environments during storage and processing. In order to promote the application of C3G in the food field, this paper presents the contents of C3G in different foods as well as the common extraction and purification methods, summarizes the physiological functions biological activities of C3G such as anti-oxidant, anti-cancer, anti-inflammatory and visual health maintenance functions, and introduces the C3G stabilization techniques from the aspects of macromolecular complextion and molecular modification, which provides a theoretical basis for future research and comprehensive development and utilization of C3G.

36 Research Progress on the Application, Preparation and Modification of Curcumin

CHEN Yuchun , LIN Yong , LIU Yong , LIANG Jinglong

2024, 40(6):327-335. DOI: 10.13982/j.mfst.1673-9078.2024.6.0684

[Abstract](90) [HTML](44) [PDF 1.73 M](93)

Abstract:
Curcumin is a natural phenolic compound with many biological activities such as anti-inflammatory, anticancer and antioxidant effects. Curcumin has been well used in the food and feed industries. For example, it can be used as a coloring agent and preservative in food, and can replace antibiotics in the feed industry, offering a positive effect on improving the survival rate and meat quality of animals such as poultry, livestock and fish. However, there are some associated disadvantages such as high preparation and purification cost, low bioavailability and poor water solubility, which limited its applications. In order to solve these problems, researchers at home and abroad have done a lot of research on the extraction, synthesis and modification of curcumin, such as different extraction processes like supercritical extraction and flash extraction were ussed to extract curcumin; the development of different curcumin preparations like solid dispersions, liposomes, nanoparticles and polymeric micelles, and structural modifications of curcumin. Accordingly, this paper will review the applications, preparation methods and modification of curcumin, aiming to provide a reference for the efficient applications and related research of curcumin.

37 Research Progress on the Structures and Coloration Stability of Anthocyanins

LIANG Lu , SUI Yong , HUANG Shirong , CAI Fang , SHI Jianbin , CAI Sha , XIONG Tian , MEI Xin

2024, 40(6):336-346. DOI: 10.13982/j.mfst.1673-9078.2024.6.0582

[Abstract](82) [HTML](45) [PDF 1.76 M](171)

Abstract:
With the improvement of living standard, people pay increasing attention to nutrition and diet while placing greater emphasis on the safety of the food ingested. Anthocyanins, as one type of safe and non-toxic natural pigments, play a very important role in the field of food coloring and functional food development under the current social hotspot of nutritious diets. However, anthocyanins have multiple phenolic hydroxyl groups, which present problems such as poor structural stability, susceptibility to degradation and low bioavailability, resulting in limitations in food processing and other applications. The color diversity of anthocyanins is closely related to their structure. On the basis of the relationship between the structure and color of anthocyanins, this article mainly reviews the correlation between their basic structure and color, and discusses the effects of different processing methods on the color stability of anthocyanins. Meanwhile, this article elaborates the opportunities to improve the stability of anthocyanins via the combination of anthocyanins with starch, protein, dietary fiber, and pectin, which provides a reference for deeper studies on anthocyanins and the development of safer and more environmentally friendly functional food products.

38 Progress of Research on the Chemical Constituents and Biological Activity of Areca-nut

LIU Shuwei , ZHANG Tiantian , WANG Yan , WU Tianming

2024, 40(6):347-355. DOI: 10.13982/j.mfst.1673-9078.2024.6.0570

[Abstract](89) [HTML](50) [PDF 2.28 M](633)

Abstract:
Areca-nut is a popular chewing item in tropical Asia and China. It is reported in the domestic and international literature that areca-nut contains alkaloids, flavonoids, tannins, terpenes, steroids, fatty acids and other chemical constituents, and has functions such as antiparasitic, anti-depressive, anti-fatigue, antioxidant, anti-aging, antibacterial, antiviral, anti-inflammatory, disgestion-promoting, hypoglycemic, and cardiovascular disease-ameliorating effects. With the expansion of the areca-nut sales market and the improvement of people's health consciousness, the side effects of arecanut continue to be amplified, but there is still no authoritative conclusion on the specific substance foundation of its activity and side effects. Exploring the substance source of the bioactivity and side effects of areca-nut has become the key to the sustainable development and food safety of the areca-nut industry. This article provides a theoretical support for subsequent research on areca-nut through reviewing the research on the chemical composition and biological activity of areca-nut.

39 Advances in the Development of a Digital Twin to Empower the Pre-prepared Cold Food Chain

KUANG Hongyun , HAO Hao , YOU Shisheng , SU Xing

2024, 40(6):356-363. DOI: 10.13982/j.mfst.1673-9078.2024.6.0359

[Abstract](58) [HTML](49) [PDF 1.80 M](131)

Abstract:
The COVID-19 pandemic and stay-at-home economy have contributed to a new consumer trend of “convenience dining,” as represented by pre-prepared foods. Digital technologies have given rise to new application and value creation scenarios, driven innovation across operations, processes, and organizational management, and empowered industrial upgrading. Thus, problems related to the lack of pre-cooling at the origin and poor information in the cold supply chain for pre-prepared foods in China were analyzed, including insufficient cold chain support facilities, irregular cold chain operations, last-mile distribution, and sales losses. The digital twin model can simulate and predict changes in the quality of pre-prepared foods during the cold chain process, while the introduction of technologies such as the Internet of Things and blockchain can enable transport monitoring and the traceability of products. This study proposes leveraging digital twin technology to establish a digital cold chain tracking and tracing system for pre-prepared foods. It aims to develop supply, digital, trust, and benefit chains within the cold pre-prepared food supply chain, exploring a digital pathway tailored to the development of pre-prepared foods in China. Ultimately, this initiative seeks to drive digital transformation and industrial development within the pre-prepared foods and cold supply chain sector.

Home

About the journal

Notes for submission

Acceptable topics

Author garden

Open access

中文

Volume 40,Issue 6,2024 Table of Contents