Volume 36,Issue 2,2020 Table of Contents

1 Serum Uric Acid Lowering Effect of Lactobacillus plantarum UA149 on Hyperuricemic Rats

NIU Chun-hua , XIAO Ru-xue , ZHAO Zi-jian , GAO Lei , CUI Wei-dong , LIANG Tie , LIN Li , LI Sheng-yu

2020, 36(2):1-6. DOI: 10.13982/j.mfst.1673-9078.2020.2.001

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Abstract:
In order to screen Lactobacillus plantarum with assistant uric acid-lowering function, five species of L. plantarum independently isolated and identified by us were evaluated its ability to degrade purine nucleosides in vitro. L. plantarum UA419, a strain with strong degradation ability of purine nucleoside, was further studied. The L. plantarum UA419 was given to the hyperuricemia rats (induced by potassium oxonate combined with fructose) by gavage for continuous 2 weeks. The uric acid, xanthine oxidase and inflammatory factor levels in serum were measured and western bolt was used to explore the mechanism of the strain’s lowering uric acid. The results showed that L. plantarum UA419 could significantly reduce serum indexes, including uric acid (39.71%), xanthine oxidase (15.36%), leukotrienes (25.81%), thromboxane (38.40%) and inflammatory factor levels (IL-1 26.89%, IL-8 10.40%, IL-6 17.29%, IL-1β 20.95% and TNF-α 23.09%). L. plantarum UA419 might be a promising agent for gouty treatment to inhibit renal NF-κB/NLRP3 inflammasome activation via the AMPK/SIRT1 pathway. These results indicated that L. plantarum UA419 plays an assistant uric acid-lowering effect.

2 Promoting Apoptosis of Lycium barbarum Polysaccharides of Hepatocarcinoma Cells in Rats

HAN Yong-hong , LIU Xing-xiang

2020, 36(2):7-11. DOI: 10.13982/j.mfst.1673-9078.2020.2.002

[Abstract](400) [HTML](348) [PDF 613.50 K](590)

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To investigate the effect and mechanism of Lycium barbarum polysaccharides on apoptosis of model rats with hepatocarcinoma. Forty-five healthy male SD rats were selected, with 5 as the normal group, and the remaining 40 rats divided into liver cancer model group, drug control group, low- and high-dose intervention groups. The cell proliferation, apoptosis and cycle distribution of the rats in each group were observed, and the expressions of PTEN, p-Akt, mTOR, Bcl-2, Bax and caspase-3 were detected. The results showed that the proportion of cells at the G1 phase in the high-dose intervention rats was 57.59%, which was higher than those of the model group, drug control group and low-dose intervention group (p<0.05). The proliferation rate and apoptotic rate of the rats in high-dose intervention group were 8.53% and 47.68%, respectively, which were better than those of the model group, drug control group and low-dose intervention group. The relative expression of PTEN, p-Akt, mTOR, Bcl-2, Caspase-3 and Bax in the high-dose treated rats was 0.98, 1.05, 1.11, 1.26, 1.19 and 0.98, respectively. The interventional effect was greater than that of the drug control group and low-dose intervention group (p<0.05). The results showed that the Lycium barbarum polysaccharides could significantly regulate the proliferation, apoptosis and cell cycle distribution, as well as the expression of PTEN, p-Akt, mTOR, Bcl-2, caspase 3 and Bax in the rats with hepatocarcinoma. Lycium barbarum polysaccharides could block the cell cycle distribution, inhibit the proliferation and promote cell apoptosis of hepatocarcinoma cells, which provides a theoretical basis for the clinical treatment of hepatocarcinoma.

3 Protective Effect of the Ethanolic Extract from Gynura procumbens against Ulcerative Colitis

MA Si-meng , QIN Qiu-fang , MA Min-jie , LI Yu-sang , LI Xiao-jun , TANG He-bin

2020, 36(2):12-17. DOI: 10.13982/j.mfst.1673-9078.2020.2.003

[Abstract](343) [HTML](207) [PDF 996.88 K](647)

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The purpose of this experiment was to examine the therapeutic effect of the ethanolic extract from Gynura procumbens against ulcerative colitis. In this experiment, BALB/c male mice and SD male rats were used to establish animal models with mild and severe ulcerative colitis, respectively, through intraintestinal administration of TNBS-50% ethanol solution. Then, different doses of Gynura procumbens extract and its effective components (alone or in combination) were administered separately, and H&E and PAS staining techniques were used to evaluate colonic injury-related pathological changes. The results showed that compared with the mild ulcerative colitis model group, the glycogen content of the low-dose and high-dose Gynura procumbens group decreased by 147.14% and 178.89%, respectively, with the goblet cell content of these two groups increased by 15.39% and 36.77%. Compared with the severe ulcerative colitis model group, the glycogen content of Gynura procumbens group increased by 45.00% with the goblet cells increasing by 95.62%. The Gynura procumbens extract can be used to treat mild and severe ulcerative colitis as a potential drug for further development.

4 Inhibition of Proliferation and Apoptosis of Cervical Cancer Hela Cells by Treating with Moringa Oleifera Lam Alkaloids

LUO Feng-xian , XIE Jing , QIAN Ying-yan , YANG Ming-rong , TIAN Yang

2020, 36(2):18-24. DOI: 10.13982/j.mfst.1673-9078.2020.2.004

[Abstract](349) [HTML](246) [PDF 1005.38 K](697)

Abstract:
The aim of this study was to investigate the effects of Moringa Oleifera. Lam (M. oleifera) alkaloids on proliferation and apoptosis of cervical cancer Hela cells and its possible mechanism. Following 48h of treatment with M. oleifera alkaloids at various doses (20~320 μg/mL) , the proliferation, apoptosis and protein expression level of Hela cells were detected by MTT assay, colony formation assay, flow cytometric analysis and western blot. The results showed that the survival rate of Hela cells decreased gradually with the increase of M. oleifera alkaloids concentration. When the concentration of M. oleifera alkaloids was 160 μg/mL, the cell survival rate was 35.87% (p<0.001), the survival rate of human normal colon cell NCW460 is 91.91%. Colony formation experiments showed that M. oleifera alkaloids (40~160 μg/mL) significantly inhibited the colony formation of Hela cells, and the inhibition rates were 26.04% (p<0.05), 37.19% (p<0.01) and 67.77% (p<0.001), respectively. When the concentration of M. oleifera alkaloids was 80 μg/mL, the morphology of Hela cells changed significantly. Further flow cytometry analysis showed that the number of apoptotic cells in Hela cells increased with the increase of the concentration of M. oleifera alkaloid. When the cells were treated with 160 μg/mL of M. oleifera alkaloids for 48 h, the number of apoptotic cells was 42.1% (p<0.001). Further experiments showed that at 48 h, M. oleifera alkaloid up-regulated the ratio of Bax/Bcl-2 and the expressions of Caspase9 and down-regulated the expressions of P-Stat3 and CyclinD1 at the protein level in Hela cells. Our results indicate that M. oleifera alkaloids inhibits cell proliferation of Hela cells through the induction of apoptosis, which is mediated via inhibition of the Stat3-related pathway.

5 Hypoglycemic Effects of Extracts of Penthorum chinense Pursh in High Fat Diet and Streptozotocin-induced Type Ⅱ Diabetic Rats

HU Ji-lei , ZHENG Le-yu , TANG Wei , XU Ya-xin , FAN Xi , XIE Hui-bo

2020, 36(2):25-31. DOI: 10.13982/j.mfst.1673-9078.2020.2.005

[Abstract](489) [HTML](290) [PDF 994.77 K](739)

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The hypoglycemic effect of extract of Penthorum chinense Pursh (PCP) on a high fat diet and streptozotocin (STZ)-induced diabetic rats was investigated. The efficacy of orally administer PCP (545 mg/kg/day) for 4 weeks were evaluated in high-fat diet and STZ (35mg/kg.) induced diabetic rats, and metformin (500 mg/kg/day) was used as a positive control. A range of parameters, including blood glucose and lipid were tested to evaluate its anti-hyperglycemic effects. Moreover, superoxide dismutase (SOD), malonaldehyde (MDA), glutathione peroxidase (GSH-Px), and catalase (CAT) were performed to determinate their antioxidant activities. The fasting blood glucose and HbAc1 level of PCP treatment group decreased by 43.93% and 77.05%, respectively, when compared with the diabetic rat group (p<0.05). The activities of antioxidant enzymes including GSH-Px, SOD and CAT were significantly improved by 76.32%, 42.75% and 32.12% (p<0.05), respectively. PCP was also found to reduce the levels of MDA (p<0.01). Meanwhile, the histology results showed the extract of PCP could protect against liver and pancreas damages. This study showed that the extract of PCP modulated hyperglycemia in high-fat diet and STZ-induced diabetic rats, which might be attributed to enriching antioxidant enzymes activities.

6 Relieving Physical Fatigue of Sea Cucumber Peptide Complex

WANG Min , LI Li-jie , ZHANG Zeng-liang , LU Sai , ZOU Sheng-can

2020, 36(2):32-37. DOI: 10.13982/j.mfst.1673-9078.2020.2.006

[Abstract](310) [HTML](335) [PDF 643.10 K](623)

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The was investigated effect of the compound of sea cucumber peptide, Maca powder, Wolfberry extract and Rhodiola rosea extract on relieving physical fatigue. Four hundred of healthy male mice were divided into 4 batches (N=100), on which weight loading swimming experiment, serum urea nitrogen test, blood lactic acid test, and liver glycogen test after exercise were conducted respectively. Each batch was randomly divided into 10 groups (n=10), one of which was used as the negative control group, and the other 9 groups as the low, medium and high dose of three experimental groups (sea cucumber peptide complexes, sea cucumber peptide, plant extracts). Low (0.2 g/kg?bw), medium (0.4 g/kg?bw), and high (1.2 g/kg?bw) doses are equivalent to 5, 10, and 30 times the recommended doses of the human body. The drug was administered by intragastric administration once a day for 30 days, and the control group was given an equal amount of distilled water. The changes of exhaustive swimming time, serum urea nitrogen content, lactate levels and hapatic glycogen content after exercise in each group were compared. Compared with the control group, the weight loading swimming times of the groups administered the medium and high-dose sea cucumber peptide complexes was extended by 80.06% (p<0.05) and 99.13% (p<0.01) respectively. In the meantime, the serum urea concentrations after exercise decreased by 26.21% (p<0.05) and 30.74% respectively (p<0.05), the area under the curve of blood lactic acid were reduced by 26.90% (p<0.05) and 32.11% (p<0.05) respectively. It can be seen that the sea cucumber peptide has better effect on relieving fatigue by compounding with Maca powder, Wolfberry extract and Rhodiola rosea extract.

7 Comparison of in Vitro Antioxidant Activities of Fermented Meat Polypeptides Extracted with Different Methods

LI Miao-yun , WU Hui-lin , ZHU Yao-di , XIAO Kang , REN Hong-rong , ZHAO Gai-ming , HAO Yun-peng , MA Yang-yang

2020, 36(2):38-45. DOI: 10.13982/j.mfst.1673-9078.2020.2.007

[Abstract](249) [HTML](246) [PDF 885.14 K](573)

Abstract:
Taking acidified meat as the research object, the antioxidant activity of the peptides from acidified meat after microwaving, steaming, deep frying and grilling was studied. Comparison was made on the extraction rate of polypeptide, thiol (-SH) content, scavenging abilities of 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) and hydroxyl (-OH) radicals, metal ions (Fe2+) chelating ability, inhibitory effect against lipid oxidation, and ability to remove nitrite. The results showed that the content of -SH in the crude peptide extract from acidified meat after microwaving, steaming, deep frying, and grilling was 25.41, 22.89, 26.62, and 24.60nmol/mg, respectively. The antioxidant capacity significantly increased with an elevated concentration of crude peptide extract. At the same concentration, the antioxidant capacity of the crude peptide extract from the acidified meat after different heating methods varied.. When the mass concentration of the crude peptide extract was 5 mg/mL, the scavenging rates of DPPH and -OH radicals of the crude peptide extract from acidified meats decreased in this order: steaming>grilling>microwaving>deep frying>raw. Their corresponding Fe2+-chelating abilities were 50.61%, 52.67%, 48.76%, 50.58%, 57.77%, respectively. Their corresponding lipid oxidation-inhibiting rates were 47.33%, 57.60%, 44.26%, 49.03%, 51.63%, respectively. and nitrite clearance rates were 68.81%, 75.37%, 70.05%, 74.86% and 76.01%, respectively, after the reaction with linoleic acid for 144 h. In summary, compared with the raw acidified meat, the antioxidant activity of the crude peptide extract was improved after one of the above heat treatments, with steaming being the best. Therefore, the suitability of the heat treatment methods for the extraction of the antioxidative polypeptides from acidified meat decreased in this order: steaming>grilling>microwaving>deepfrying .

8 Comparison of Physicochenical Properties of Soaked Glutinous Rice from Different Varieties

HAN Xue-qin , LIU Lei , HUANG Li-xin

2020, 36(2):46-52. DOI: 10.13982/j.mfst.1673-9078.2020.2.008

[Abstract](314) [HTML](383) [PDF 971.30 K](945)

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In order to study the effect of soaking treatment on the physicochemical properties of rice, three types of rice were selected, and their physicochemical properties and viscosity curve were investigated. Changes of moisture content and the final water content of rice during soaking (20 ℃~35 ℃) were measured, and the Peleg equation was used to fit the measured water absorption data. Infrared spectrum and X-ray diffraction were used to study the change of order structure and crystalline structure of rice before and after soaking. The study found that the Vietnamese rice and Yangtze River rice had greater water absorption, and the final water content reached 36.34% (20 ℃) and 34.64% (28 ℃), respectively, and temperature had little effect on it. Black fragrant rice had a small water absorption rate and water absorption, and its final water content reached 31.99% (35 ℃) and temperature had greater influence on it. In addition, the Peleg equation can be used to predict the approximate moisture content of rice during soaking. The ratios of the absorbance of the bands at 1047 cm-1 and 1022 cm-1 of rice before and after soaking was between 0.89 and 0.92, which was no significant difference. X-ray diffraction showed that water molecules mainly enter the amorphous region and the sub-crystalline region of rice, and the sub-crystalline region of the Vietnamese rice and Yangtze River rice became smaller, while that of the black fragrant rice was increased. This research can provide guidance for the processing of rice flour.

9 Extraction, Separation and Antioxidant Activity of Polyphenols from Mango Pomace

HU Hui-gang , ZHAO Qiao-li

2020, 36(2):53-62. DOI: 10.13982/j.mfst.1673-9078.2020.2.009

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Using mango pomace as the raw material, the extraction method and process conditions of crude polyphenols were determined by single factor experiments. Crude polyphenols were extracted with organic solvents of different polarities to screen the components with the highest contents. These screened components were separated and purified by HPD100 macroporous resin. Furthermore, the purified components were qualitatively analyzed by LC-Q-TOF-MS, and comparison was made on the in vitro antioxidant activities of the extraction phases obtained by different solvents and the purified components. The results showed that ultrasonic-assisted extraction was more effective, with the optimal extraction conditions as: ethanol concentration 80%, extraction time was 1.5 h, extraction temperature was 60 ℃, ultrasonic power was 250 W, and the liquid-to-material ratio 30:1 (V/W). Under these conditions, the yield of polyphenols was 9.68%. The content of polyphenols extracted by ethyl acetate was the highest (254.41 mg/g). A total of 17 compounds were identified from the purified components obtained by resin, which mainly included flavones, flavonols, phenolic acids and tannins, and had excellent antioxidant activities. The IC50 values for the DPPH, ABTS+, hydroxyl and superoxide anion radical scavenging assays were 0.191×10-3, 0.081, 0.43 and 0.63 mg/mL, respectively. These results indicated that the purified components in the ethyl acetate phase were the material basis for the antioxidant activities of mango pomace.

10 Comparison of Dried Alpinia officinarum Hance Quality Dried at Different Heat Pump Temperatures

YU Yang-yang , TANG Dao-bang , WEN Jing , WU Ji-jun , AN Ke-jing , ZOU Ying

2020, 36(2):63-69. DOI: 10.13982/j.mfst.1673-9078.2020.2.010

[Abstract](295) [HTML](305) [PDF 1013.74 K](529)

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The effects of different heat pump drying temperatures (45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃) on the color, active substances and volatile components of the Alpinia officinalis with a moisture content of 8±0.5% were analyzed through using sun-drying as the control approach. The results showed that the color of Alpinia officinalis dried at 50 ℃ was the closest to that of sun-dried Alpinia officinalis, with the △Ｅ as 2.16±0.2 and rehydration rate as 2.39±0.03 (the highest). The rehydration ratio decreased with an increase of the heat pump drying temperature; Drying at 50?C led to the highest contents of total phenols and flavonoids (19.33±0.21 mg/g and 8.44±0.19 mg/g, respectively). When the heat pump temperature exceeded 50 ℃, the contents of total phenols and flavonoids decreased with an increase of the heat pump temperature. The effect of heat pump drying temperature on the content of galangin was not significant. The content of galangin in the Alpinia officinarum dried at 50 ℃ was 6.29±0.07 mg/g, and this content in the Alpinia officinarum dried by heat pump was higher than by sun-dyring (5.54±0.1 mg/g). The Alpinia officinalis dried in the sun, at 45 ℃, at 50 ℃, at 55 ℃, at 60 ℃, and at 65 ℃, respectively, had 81, 69, 74, 78, 82 and 85, types of volatile substances, and 42, 39, 37, 32, 34 and 31 olefin substances. Drying at 45 °C led to the highest content of eucalyptol (37.41%), and the content of eucalyptol decreased with the increase of heat pump temperature. Based on the color, quality and flavor of the dried Alpinia officinalis, the optimum temperature for heat pump drying was 50 ℃. The results reported in this paper provide a theoretical basis for the control of drying conditions of Alpinia officinarum by heat pump.

11 Simulated Gastrointestinal Digestion Increase the in Vitro Antioxidant Activity of Cordyceps militaris Proteins

CHEN Meng-fei , ZHOU Juan-juan , WU Shu-jian , XIE Yi-zhen , WU Qing-ping , DING Yu

2020, 36(2):70-77. DOI: 10.13982/j.mfst.1673-9078.2020.2.011

[Abstract](502) [HTML](263) [PDF 1022.49 K](693)

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Physicochemical properties and antioxidant activity of Cordyceps militaris proteins and their simulated gastrointestinal digestive products were investigated. Molecular weight distribution and amino acid composition of the proteins and digestive products were measured by SDS-PAGE and acid hydrolysis method, respectively. Antioxidant activity of Cordyceps militaris proteins and their simulated gastrointestinal digestive products was evaluated by in vitro chemical methods. Oxidative damaged PC12 cell model induced by H2O2 was established. After treatment with the digestive products, cell viability was measured by CCK-8. The results showed that after digestion, the molecular weight distribution shifted from 10~120 ku to 8~15 ku; the IC50 values of DPPH clearance rate of Cordyceps militaris proteins and their digestive products were 1.55 and 1.06 mg/mL, respectively. The IC50 values of Fe2+ chelating power were 1.32 and 0.18 mg/mL, respectively. The ORAC values were 467.27±46.53 and 948.80±24.02 μmol TE/g respectively when the sample concentration was at 0.3 mg/mL. The cell viability of PC12 cells injured by H2O2 was significant improved (p<0.05) after pre-treated with 100 μg/mL digestive products. Both of Cordyceps militaris proteins and their digestive products possess high lipid per-oxidation inhibition ability and low ferric reducing power. Thus, more peptides with lower molecular weight were generated after simulating gastrointestinal digestion of Cordyceps militaris proteins. Of note, the antioxidant activity improved significantly. It is therefore plausible to further purify and characterize the antioxidant peptides in simulated gastrointestinal digestive products of Cordyceps militaris proteins.

12 Quality Improvement of Hakka Rice Wine of by Adding Monascus

ZHENG Min-yi , HONG Ze-chun , ZHAO Wen-hong , QIAN Min , LING Hui-fang , BAI Wei-dong

2020, 36(2):78-84. DOI: 10.13982/j.mfst.1673-9078.2020.2.012

[Abstract](230) [HTML](209) [PDF 921.00 K](688)

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The effects of different koji recipes on the organic acids as flavor substances during the brewing of Hakka rice wine were studied by HPLC. The effects of Monascus on the flavor and total amount of organic acids during brewing were also investigated. The total amount of organic acids in the three wine samples differed significantly on Day 30 after fermentation: the rice wine with the yeast and the koji (wine sample Ⅱ) the highest (33.83 g/L), the wine with Monascus alone (the wine sample III) the second highest (27.72 g/L), and the wine complex with Monascus, yeast and koji (wine sample Ⅰ) the least (22.67 g/L). The ratio of volatile acid to non-volatile acid in the wine samplesⅠ, Ⅱ and Ⅲ were 1:4, 1:1 and 2:1, respectively; The lactic acid content in the wine samples differed largely, with the wine sample I having the highest amount (11.40 g/L), and thewine sample Ⅲ had the least (6.02 g/L); the acetic acid content in the three kinds of wine resembled (about 5.5 g/L); the wine samplesⅠ and Ⅱ had a similar succinic acid content (about 5 g/L); The wine samples Ⅱ and Ⅲ had a relatively high propionic acid content with none detected in wine sample I. In addition, small amounts of malic acid and citric acid were detected in the wine sample I. The results showed that adding an appropriate amount of Monascus during Hakka rice wine brewing would help maintain the acidity balance of Hakka rice wine and enhance the sense of taste.

13 Suitability of Different Potato Varieties for Processing Noodles

ZHANG Yi-jie , QI Yan-long , SONG Yu , SHEN Hong-fei , FENG Huai-zhang

2020, 36(2):85-93. DOI: 10.13982/j.mfst.1673-9078.2020.2.013

[Abstract](355) [HTML](173) [PDF 908.80 K](833)

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Due to the existence of many potato varieties, the quality of different raw materials will affect the quality of potato noodles. The purpose was to study the suitability of different potato varieties for processing noodles and guide the potato industry to select processing and planting varieties. The maximum-minimum normalization method was used to transform each quality index of potato dough and potato noodles into a one-dimensional comprehensive evaluation index, which was compared with 40 varieties of potato raw materials (starch, vitamin C, soluble protein, reducing sugar, crude fiber, potassium, ash, dry matter, free amino acid). Fitting and regression models were established for hardness, elasticity, cohesion, chewiness, stickiness and resilience. Forty potato varieties were classified into three categories according to processing suitability by clustering method. The results showed that the determinant coefficient R2 was 0.911, the adjusted determinant coefficient R2 was 0.904, the random error estimate was 123.113, the determinant coefficient R2 was 0.973, the adjusted determinant coefficient R2 was 0.971, and the random error estimate was 432.226; K-means clustering algorithm was used. According to processing suitability, 40 potato varieties were divided into three categories: the most suitable, the basically suitable and the unsuitable. Among them, 12 varieties were suitable for processing, including 05-44-1, Ke 9, 79(2), C11, D17, C3, T3, Zhuang 3, Hui 2, T4, L7 and Hei. The basically suitable varieties were L0524-2, Ji 8, T2, F5, Hong, Zheng 7, S3-28, Zhong901, S4-32, Zhong13, T5, Ji 12, Gannong 5, Jin 18, F6, T18 and 78. The comprehensive quality evaluation model obtained in this study had high fitting degree, small error and reliable effect. It can be used to evaluate the quality of potato noodles. The K-means clustering results are consistent with the actual application, which can provide reference for the selection of processing varieties in Xinjiang.

14 Evaluation on Antioxidant and Anti-inflammation in Vitro of Extracts of Three Solanum Nigrum L. Berries

GUO Rui , LI Yao , WANG Ping

2020, 36(2):94-101. DOI: 10.13982/j.mfst.1673-9078.2020.2.014

[Abstract](524) [HTML](249) [PDF 957.88 K](1255)

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Solanum nigrum L. berries have been widely used for anti-pyretic and diuretic in China. Antioxidant and anti-inflammation activities in vitro of extracts of Solanum nigrum Linnaeus (SNL), Solanum diphyllum Linnaeus (SDL) and Solanum alatum Moench (SAM) berry which were prepared by petroleum ether (PE), ethyl acetate (EtoAc) and n-butanol (n-BuOH). The antioxidant activites were evaluated by FRAP and DPPH· scavenging assays. Vitamin C was used as positive control. The results showed that DPPH· scavenging IC50 and FRAP values of SNL-EtoAc extract were 119.43±1.19 μg/mL and 2.674±0.071 mM FeSO4/L, respectively, indicating that it had the highest antioxidant activity. The anti-inflammation effect of different extracts was determined by hyaluronidase and lipoxygenase inhibition. SAM-PE extract had the highest anti-inflammation activity, which IC50 were 810.67±79.02 and 781.28±28.01 μg/ml, respectively. Diclofenac sodium and 4,4'-(2,3-Dimethyltetramethylene) dipyrocatechol were used as anti-inflammatory positive control. SNL had the highest content of total phenols (27.16±0.14 mg/g). SAM had the highest content of total flavonoids (18.59±0.14 mg/g). The results provided a theoretical supporting for developing natural antioxidant and anti-inflammatory resources.

15 Antioxidant Components Release of Rosa roxburghii Tratt by in Vitro Simulated Gastrointestinal Digestion

LI Yi , HE Jun , ZHANG Peng-min

2020, 36(2):102-107. DOI: 10.13982/j.mfst.1673-9078.2020.2.015

[Abstract](480) [HTML](263) [PDF 838.47 K](1127)

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The changes in contents of polyphenols, flavonoids and their antioxidant activities in Guizhou Rosa Roxburghii Tratt were studied by in vitro simulated gastrointestinal digestion to investigate the relationship between antioxidant components and antioxidant activity of Rosa Roxburghii Tratt. In vitro simulated gastric digestion and in vitro simulated intestinal digestion were performed. NaNO2-Al(NO3)3 colorimetric method, forin-phenol colorimetric method were used to detect the content of polyphenols, flavonoids. DPPH free radical scavenging rate and Prussian blue method were used to detect the antioxidant activities. The results showed that compared with the control, the content of polyphenols and flavonoids, DPPH free radical scavenging rate and reducing power of Guizhou Rosa Roxburghii Tratt increased significantly during simulated gastric digestion. The simulated gastric digestive group showed a significant increase within 0.5 h, and kept constantly during last stage. The content of polyphenols and flavonoids, DPPH free radical scavenging rate and reducing power increased by 1.48, 1.35, 1.14, and 1.48 times, respectively. That in the gastric acid control group increased by 1.28, 1.21, 1.07, and 1.41 times, respectively. The simulated intestinal digestion group showed a significant upward trend within 1 h and kept constantly during last stage. The content of polyphenols and flavonoids, DPPH free radical scavenging rate and reducing power increased by 1.07, 1.65, 1.28, and 1.07 times, respectively. The results showed that pepsin, gastric acid, bile salts and pancreatic enzyme could promote the release of antioxidant compoumds and increase the antioxidant activity of Guizhou Rosa Roxburghii Tratt.

16 Comparative Analysis of Nutritional Composition of Sea Cucumber Body Wall Cooked by Different Ways

WANG Zhi-yuan

2020, 36(2):108-113. DOI: 10.13982/j.mfst.1673-9078.2020.2.016

[Abstract](281) [HTML](309) [PDF 667.62 K](647)

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To explore the effects of different cooking methods on nutrient composition of sea cucumber body wall. The changes of appearance, body wall tissue, water loss rate, weight loss rate, shrinkage rate, nutrient composition of body wall and texture of sea cucumber were compared under different cooking methods. The results showed that the contents of water, water-soluble protein, collagen and polysaccharide in the body wall of sea cucumber in high pressure cooking group were 84.27%, 0.58%, 1.73%, 0.76%, 2.73%, respectively. The contents of water, water-soluble protein, collagen and polysaccharide in the body wall of sea cucumber in atmospheric pressure cooking group were 87.58%, 0.36%, 1.92% and 1.92%, respectively. The contents of water, water-soluble protein, collagen and polysaccharide were 86.62%, 0.46%, 1.82% and 0.81% respectively. The contents of water, water-soluble protein, collagen and polysaccharide in the body wall of sea cucumber in Chongtang cooking group were between the high-pressure cooking group and the atmospheric cooking group, with statistical difference (p<0.05). According to the above results, the body wall tissue of sea cucumber cooked with Chongtang is relatively complete, the nutrient components of body wall are retained more, and the texture of sea cucumber body wall is less affected, which meets the requirements of sea cucumber cooking.

17 Improving on Postharvest Quality of Munag Grape Berries Fumigated by Sulfur Dioxide (SO2)

LI Jie , WEI Jia , ZHANG Zheng , LI Jiang , WU Bin

2020, 36(2):114-121. DOI: 10.13982/j.mfst.1673-9078.2020.2.017

[Abstract](398) [HTML](243) [PDF 1017.36 K](648)

Abstract:
In order to investigate the effect of postharvest quality and texture characteristics changes of munag grape after fumigation by SO2, the changes of fruit quality indexes during storage were determined. Texture parameters of munag grape were determined by Texture multifaceted analysis (TPA method) and studied by correlation analysis. The results showed that when the fumigation concentration of SO2 was 3000 μl/L, the residue of SO2 in the fruit was 7.55 mg/kg, which is in line with the developed countries in Europe and America on table grape import and export food standards. The browning degree of grape stem and stalk after SO2 fumigation was 2.60% lower than that without fumigation. SO2 fumigation treatment could inhibit chlorophyll decomposition. Its content in stems decreases from 0.091 mg/g to 0.037 mg/g without SO2 fumigation treatment, while decreases to 0.052 mg/g after SO2 fumigation treatment, showing a significant difference (p<0.05). SO2 fumigation treatment could keep the content of soluble solid and titratable acid stable, maintaining postharvest quality of grapes. When the soluble solid content reached the maximum value, SO2 fumigation treatment was 4.2% higher than untreated. At the end of storage, the titratable acid content of SO2 treated fruits was 11.60% higher than that of untreated fruits. TPA method was used to determine the texture parameters of the fruit after SO2 treatment, and it was found that SO2 treatment could well maintain the texture parameters of the fruit. The fruit firmness decreased slowly and was 4.29 N/cm2 at the end of storage. At the end of storage, the cohesiveness was 0.78, showing a significant difference (p<0.05). Elasticity, gumminess and chewiness decreased by 3.8%, 18.1% and 3.68% respectively compared with that at 0 d. The correlation analysis between texture parameters and quality of fruits after SO2 fumigation showed that the texture parameters of fruits could well evaluate the quality of fruits in post-harvest storage. Through the above experimental results, it was clear that 3000 μL/L of SO2 short time fumigation could maintain the quality of munag grape.

18 Screening of a Marine Lactobacillus plantarum with Cholesterol-lowering Effect

WAN Jing-liang , LUO Man , HUANG Shi-xin , WANG Qing-hua , TANG Xu , XU Chang-an

2020, 36(2):122-128. DOI: 10.13982/j.mfst.1673-9078.2020.2.018

[Abstract](514) [HTML](172) [PDF 920.70 K](661)

Abstract:
In this work, a strain of lactic acid bacteria HJ-S2 with high effective cholesterol-lowering was isolated from Beak Whale viscera using o-benzaldehyde method, and the probiotic performance of Lactobacillus plantarum HJ-S2 were investigated in vitro. Acid-resistant and cholestate-tolerant were carried out to detect the probiotic performance of the strain, and antibacterial effect on pathogenic bacteria and adhesion ability to human colon cancer cell HT-29 were also studied. Morphology, API50CH and 16S rDNA were used to identify the strain. The results showed thatthe cholesterol-lowering rate of this lactic acid bacteria HJ-S2 was 48.82% in vitro. Under being cultured for 3 h at pH 3 or in solvent containing 0.3% bile salt, the tolerance rate reached 82.73% and 80.62% respectively. The result of antibacterial analysis suggested metabolites of the strain HJ-S2 have certain inhibitory effect on E.coli, S.areaus and Salmonella. Analysis of adhesion to human colon cancer cell HT-29 of 132.52. The strain was identified as Lactobacillus plantarum and labled as HJ-S2 (CGMCC NO: 17720). The Lactobacillus plantarum HJ-S2 has effective high cholesterol-lowering and can provide a reference for further mircro-ecologicol agent development.

19 Identification of Soybean Trypsin Inhibitor-degrading Bacillus pumilus Strains and Their Extracellular Proteins

LIU Jia-wei , HUANG Kun-lun , LIANG Zhi-hong

2020, 36(2):129-136. DOI: 10.13982/j.mfst.1673-9078.2020.2.019

[Abstract](358) [HTML](266) [PDF 886.34 K](720)

Abstract:
Soybean trypsin inhibitor (STI) was used as the sole carbon source, three strains of bacteria capable of degrading soybean trypsin inhibitors were isolated from the interior of soybeans. The 16S rDNA sequence analysis revealed that the strains were Bacillus subtilis LZ013-1, Bacillus pumilus LZ013-2 and Paenibacillus sp. 013-3. Further studies showed that the supernatant of LZ013-2 exhibited a high activity for degrading soybean trypsin inhibitors, and the rate of trypsin inhibitor inhibition was reduced by 73.60% in 2 h. LZ013-1 and LZ013-2 were used in the fermentation of soybean meal, and were s found to degrade trypsin inhibitors efficiently. The trypsin inhibitor activity of the untreated soybean meal was 22.26 mg/g, which was reduced to 0.50 mg/g and 0.63 mg/g, respectively, after liquid fermentation with LZ013-1 and LZ013-2 strains, and decreased to 1.06 mg/g and 1.03 mg/g, respectively, after solid-state fermentation with LZ013-1 and LZ013-2 strains. The proteins with degrading activity were separated from the supernatant of the sample obtained via fermentation with LZ013-2 strain by ammonium sulfate fractionation and gel column chromatography. The separated proteins were identified by mass spectrometry. Two kinds of active proteins were screened and identified as peptidase S8 (Uniprot ID: A0A2T0DB16) and peptidase M84 (Uniprot ID: A8FIH7).

20 Bacterial Diversity Analysis of Infant Food Based on 16S rRNA High-throughput Sequencing

WANG Ming-qiu , YANG Shuo , LIU Yan , XIN Rui-peng , LI Shi-yao , ZHANG Li

2020, 36(2):137-143. DOI: 10.13982/j.mfst.1673-9078.2020.2.020

[Abstract](298) [HTML](287) [PDF 1.01 M](745)

Abstract:
In order to investigate the bacterial community structure in infant formula milk and rice flour, and provide theoretical basis for the quality control and supervision of infant food production, the 16S rRNA V4-V5 regions of bacteria from 14 infant food samples were sequenced based on ion torrent PGM platform. A total of 13,805 different OTUs were obtained by sequencing analysis, belonging to 2 kindoms, 10 phyla, 20 classes, 50 orders, 84 families and 144 genera. The results showed that the bacterial community diversity of the infant milk powder samples was higher than that of the rice flour, and the difference within group of milk powder was smaller than that of rice flour. The absolute dominant flora in goat milk powder belonged to Fimicutes (65.58%) and Proteobacteria (16.01%) on phylum level, Streptococcus (24.86%) and Lactococcus (21.44%) on genus level. While, Cyanobacteria (41.79%) was the most dominant in rice flour samples, followed by Fimicutes (30.99%) and Proteobacteria (24.48%), which might be related to the different raw materials of two products. In addition, foodborne pathogens such as Salmonella (8.75%) and Listeria (3.61%) existed in most of the rice flour samples, and the difference of abundance was significant (p<0.05) between the milk powder and rice flour samples, which indicated that infant rice flour products might have potential food safety risks. Therefore, the enterprises and food supervision department should pay more attention to the quality control of infant rice flour production.

21 Formation of Listeria monocytogenes Biofilm Promote by Environmental Factors

CHEN Qian , GUO Ai-ling , GU Li-hong , LIU Wu-kang , ZHANG Xin-shuai , RUAN Yao

2020, 36(2):144-151. DOI: 10.13982/j.mfst.1673-9078.2020.2.021

[Abstract](454) [HTML](398) [PDF 0.00 Byte](0)

Abstract:
The effects of environmental factors including pH, NaCl, common carbohydrates and an environmental bacteria (Ralstonia insidiosa) on the formation of biofilms by Listeria monocytogenes in normal nutrient and nutrient-poor conditions were investigated. The activity and structure of the single and double strain biofilms by Listeria monocytogenes and Ralstonia insidiosa were observed using Confocal laser scanning microscope (CLSM).The results showed that weak acid, alkaline conditions, low concentration of NaCl and Ralstonia insidiosa could significantly promote the formation of biofilm by Listeria monocytogenes. However, compared with that in normal nutrient, biofilm formation in the nutrient-poor condition was reduced. Several kinds of carbohydrates commonly found in foods (glucose, sucrose, xylitol, galactose and konjac powder) also have a certain promoting effect, especially xylitol and konjac flour, which could cause growth rates up to 75.00% and 96.67%, respectively. The results of CLSM indicated that the biofilm of Listeria monocytogenes and Ralstonia insidiosa were different, but the number of viable cells was relatively high. The formation of biofilms by pathogenic bacteria had a great threat to food safety, and many environmental factors had the effect of enhancing the formation of biofilms, which should cause concern in industries such as food production.

22 Celery Leaf Improve the Gel Properties of Fish Cake

YI Shu-min , LYU Ke-ming , ZHANG Shi-wen , LI Jian-rong , LI Xue-peng , XU Yong-xia , MOU Wei-li , SHEN Lin , XIE Jing , GUO Xiao-hua , YU Jian-yang

2020, 36(2):152-158. DOI: 10.13982/j.mfst.1673-9078.2020.2.022

[Abstract](302) [HTML](259) [PDF 897.92 K](655)

Abstract:
In order to investigate the effect of celery leaf on the gel properties of fish cake, 8%, 10%, 12% and 14% of the celery leaf were added to the fish cake, and the sample without the celery leaf as the control group. The nutrient contents, pH, color, texture, sensory evaluation, and microstructure of sample were measured. The results were shown that the protein, fat and calcium contents of Nemipterus virgatus surimi were 18.32%, 2.48%, 60 mg/100 g respectively. The dietary fiber, total acid and calcium contents of celery leaf were 3.23%, 1.51%, 457.40 mg/100 g The values of L*, a*, whiteness and pH of the fish cake were decreased significantly, the texture and sensory evaluation were increased and then decreased with the increase of celery leaf additions. Compared with the control group, the hardness, adhesion and chewiness increased by 35.33%, 29.77% and 29.73%, respectively, with the addition of 10% celery leaf. The fish cake was uniform and dense in microstructure. When the addition of celery leaf was 10%, the gel properties of fish cake were the best. The aim was to provides theoretical basis for the development of surimi-based production and increase the quality and nutrition of traditional surimi-based production.

23 Quality Improvement of Dried Chicken Meat Gruel Slice with Lycopene

WU Bin , LIU Xue-ming , WANG Xu-ping , WANG Yu-tao , LI Ming-yuan , CHENG Jing-rong , ZHU Ming-jun

2020, 36(2):159-165. DOI: 10.13982/j.mfst.1673-9078.2020.2.023

[Abstract](315) [HTML](279) [PDF 748.00 K](647)

Abstract:
The effects of lycopene on the chicken jerky qualities, including color, texture, lipid and protein oxidation, antioxidant capacity and sensory characteristics were evaluated. The results showed that lycopene could improve the color and texture of the product effectively, considering the increment of a* value and springiness, and the decrement of b* and L* value. The addition of lycopene led to a concentration-dependent inhibition of the lipid and protein oxidation. The antioxidant activity was significantly improved when the lycopene concentration increased. With a lycopene dosage of 0.90 g/kg, a highest sensory acceptance of the product was obtained. The developed product had 0.74 mg/kg MDA, 0.14 nmol/mg prot. carbonyl, and 270.66 nmol/mg prot. sulfhydryl groups. Besides, it exhibited excellent antioxidant activity in vitro (ABTS scavenging ability of 195.16 μmol/mg prot., DPPH scavenging ability of 131.74 μmol/mg prot., and FARP vale of 44.39 μmol/mg prot.). The above results indicate that lycopene has the potential to improve the quality of processed meat products and is expected to be a natural meat additive for the development of functional meat products.

24 Quality Improvement and Digestion Rate Reduction of Inulin Biscuit

ZHANG Can , ZHANG Kang-yi , ZHU Xiao-peng , GUO Dong-xu , KANG Zhi-min

2020, 36(2):166-171. DOI: 10.13982/j.mfst.1673-9078.2020.2.024

[Abstract](382) [HTML](265) [PDF 818.45 K](919)

Abstract:
Soluble dietary fiber can inhibit the hydrolysis and digestion of starch, in order to study the effect of inulin on the quality of biscuits, the formula of inulin biscuits was optimized by uniform design method, and the effect of inulin on biscuit digestion was studied by simulating the digestion process of human gastrointestinal tract. The results showed that the best formula was as follows: low-gluten flour 100g, water 20 g, xylitol 15.05 g, inulin 12.60 g, oil (butter: corn oil = 1:1) 31 g, baking soda 0.5 g, salt 0.5 g. In addition, fat content was 16.54%, protein 3.33%, dietary fiber 6.87%, and carbohydrate 56.63%. The results of in vitro digestion showed that the content of the fast-digested starch decreased from 14.51% to 3.06%, and the content of the slow-digested starch and resistant starch increased by 3.67% and 0.20%, respectively. The in vitro digestibility of inulin biscuits was lower than that of blank biscuits, and the inulin biscuit was predicted to have a blood sugar index of 68.36, which is a medium glycemic index food. Therefore, inulin can inhibit the hydrolysis and digestion of starch and reduce the glycemic index of high-fat biscuits. The application of inulin is of great significance for the development of low and medium glycemic index products.

25 Development and Characterization of Protein-based Porous Materials

YU Yang-yang , GU Li-rong , LAI Fu-rao , YIN Shou-wei

2020, 36(2):172-178. DOI: 10.13982/j.mfst.1673-9078.2020.2.025

[Abstract](358) [HTML](335) [PDF 1.19 M](710)

Abstract:
Pickering High Internal Phase Emulsion (HIPEs) template stabilized by self-assembled gliadin particles (GP) was used to prepare porous materials with open-cell structure and the physical performance were characterized. Using GP as a particulate emulsifier, HIPEs template was prepared with the mixture of acrylamide and polyethylene glycol as water phase and n-dodecane as oil phase. Furthermore, the effects of protein concentration and oil phase volume on the properties of porous materials were also studied. The result showed that under pH 4, GP concentrations of 1.5%, 2.0% and 2.5% and oil phase volume of 75%, 80% and 85% can be used to prepare stable hydrophilic porous materials using HIPEs templates. When the concentration of GP increased from 1.5% to 2.5%, the particle size of the emulsion in HIPEs decreased, the pore wall of the internal structure became thicker, the apparent density increased, and the compressive modulus increased from 15.16 MPa to 18.01 MPa. Besides, porous material prepared by 2.0% GP concentration had good moisture holding capacity, with the water absorption rate of 10.18 g/g. In addition, as the oil phase volume increased from 75% to 85%, the particle size distribution of the emulsion became more uniform, the pores of the material D3,2 increased from 19.94 μm to 23.59 μm, the apparent density decreased, and the compressive modulus decreased from 22.58 MPa to 14.67 MPa. By using HIPEs template stabilized by GP, hydrophilic porous materials with open-cell structure and good mechanical properties were successfully prepared, which is of great significance for the application of porous polymeric materials in food and biomedicine.

26 Salmon Collagen Oligopeptide Calcium Increase Bone Mineral Density of SD Rat

ZHANG Jiang-tao , WANG Yue-qun , BI Yuan , ZHOU Ming , QIN Xiu-yuan , ZHANG Rui-xue , LU Lu , GU Rui-zeng , LIU Wen-ying

2020, 36(2):179-185. DOI: 10.13982/j.mfst.1673-9078.2020.2.026

[Abstract](412) [HTML](238) [PDF 884.95 K](788)

Abstract:
Salmon bone collagen oligopeptide was prepared from salmon bone and chelated with calcium ion as salmon collagen oligopeptide calcium and used as test substance. Sprague-Dawley rats were orally administered with low, medium and high doses of test substances, and a blank control group and a calcium carbonate positive control group were used. The body weight, calcium absorption rate and retention rate, femur dry weight, femur length, bone density and other important indicators were measured to evaluate the bone mineral density of the salmon collagen oligopeptide calcium. The results showed that the total protein content of salmon collagen oligopeptide calcium was 65.37%, the chelation rate was 52.56%, and the chelate yield was 43.12±0.13%. There was no significant difference in body weight between the experimental groups (p>0.05). The calcium absorption rates of the middle and high dose groups and the calcium carbonate group were 39.18%, 40.52%, 38.38%, respectively, and the retention rate was 38.80%, 39.27%, 37.58%, respectively, which were significantly higher than the blank control group 36.31, 35.91 (p<0.05), respectively. The high dose group was significantly better than the calcium carbonate group with the same calcium content (p<0.05). In addition, the femoral dry weight and midpoint diameter of the femur were 0.57 (g) and 2.40 (mm), respectively. The proximal, distal and midpoint density of the femur were 0.19, 0.22, 0.17 (g/cm2), respectively. These were higher than that in the blank group (p<0.05) and there was no significant difference from the calcium carbonate group. It indicated that the salmon collagen oligopeptide calcium had a good calcium-absorbing effect and a bone density-enhancing function, which provided a good theoretical foundation for the development and utilization of related new functional foods.

27 Processing Technology of Non-fried Yellow Peach Chips

JIN Li-mei , LIAO Zi-zhao , SUI Shi-you , CHEN Wen-lu , LI Ting , HU Ya-guang , WEI Chun-hong

2020, 36(2):186-193. DOI: 10.13982/j.mfst.1673-9078.2020.2.027

[Abstract](300) [HTML](284) [PDF 968.49 K](787)

Abstract:
In order to develop non-fried fruit and vegetable chips, the fluidization-microwave-baking combination processing technology to prepare yellow peach chips with yellow peach as the raw material was studied. The color difference, vitamin C content, sensory score and brittleness were set as evaluation indexes, and the yellow peach qualities affected by the factors including fluidization temperature, fluidization wind speed, microwave power, microwave time, baking temperature and time were evaluated, using single factor and orthogonal experiment to optimize the experimental parameters for each stage. The experimental results showed that the best parameters were fluidization temperature 55 ℃, fluidization wind speed 300 m3/h; The microwave power 400 W, microwave time 600 s and water content of yellow peach about 20% during fluidization and microwave conversion; Baking temperature 65 ℃ and baking time 35 min. The yellow peach chips obtained by this process had good taste and color, wihe the sensory score was 91 and brittleness reached 469 g. This research provides a theoretical basis for the processing of non-fried fruit vegetable chips and broadens the idea for the development of fruit and vegetable dry products.

28 Preparation Modified Starch by Using Concentrated Alkali

CHEN Yan-fang , ZHANG Ben-shan

2020, 36(2):194-200. DOI: 10.13982/j.mfst.1673-9078.2020.2.028

[Abstract](470) [HTML](466) [PDF 907.91 K](1160)

Abstract:
Using corn starch as the raw material, sodium trimetaphosphate, sodium hypochlorite, acetic anhydride, propylene oxide, 3-chloro-2-hydroxypropyltrimethylammonium chloride as the modifiers, the modified starch was prepared in the aqueous phase with the mass fractions of the 3%, 6% and 10% sodium hydroxide solutions. The physicochemical properties of the modified starch were studied as well. According to the consumption of sodium hydroxide solution in the reaction process and the total volume of starch milk after the reaction, the utilization efficiency of the reaction tank and the change of water consumption were calculated. The results showed that the preparation of wet modified starch with 10% concentrated alkali can improve the utilization efficiency and production capacity of the reaction tank by 5%~22%, reduce industrial wastewater discharge by 8%~34%, and the use of concentrated alkali was particularly effective in preparing high-efficiency water-saving acetate starch and cationic starch. The process breaks through the bottleneck of preparing low-concentration alkali (mass fraction of 2%~4%) to prepare wet modified starch, which provides a theoretical basis for the production of wet modified starch with concentrated alkali in food and industry.

29 Development of A Dandelion Beverage

ZHANG Ping , LIANG Yin-ku , LI Yun-xiang , GAO Fei-xiong

2020, 36(2):201-209. DOI: 10.13982/j.mfst.1673-9078.2020.2.029

[Abstract](401) [HTML](258) [PDF 1.57 M](1089)

Abstract:
By comparing the material ratio, extraction time and extraction temperature in the extraction process, the optimum conditions for the dandelion water extraction process were as follows: the ratio of material to liquid was 1:30, the extraction time was 30 min, and the extraction temperature was 80 ℃. The optimal composition of dandelion beverage was determined by single factor and response surface optimization test design: 1.6 g of honey, 0.03 g of citric acid and 0.04 g of stevioside per 100 mL of finely filtered dandelion juice. By analyzing and testing the nutrients and active substances of the finished dandelion beverage, the results show that the dandelion beverage has a pH of 4.4, a reducing sugar content of 8.16 g/L, and a protein content of 10.4 mg/L. The beverage contains 17 free amino acids, of which 4 essential amino acids; 10 known active ingredients, 5 phenolic acids, 5 flavonoids. The optimized dandelion beverage extraction process is reasonable, feasible, nutritious and has certain health care functions.

30 Preparation of Lactone Hazelnut Curd

WAN Yu-rong , GUO Yang , MAI Xin-nian , LIU Xue-yan , QIU Yu-xin , BAO Yi-hong

2020, 36(2):210-217. DOI: 10.13982/j.mfst.1673-9078.2020.2.030

[Abstract](374) [HTML](276) [PDF 879.87 K](803)

Abstract:
In this study, In order to improve the solidification and sensory evaluation effect of hazelnut lactone tofu, the processing of lactone hazelnut tofu was investigated by using hazelnut and soybean as the raw materials and glucono-δ-lactone (GDL) as the coagulant.Based on the hardness, elasticity, cohesiveness and resilience as the indices, four factors i.e. the yellow bean-hazelnut ratio, dose of gluconolactone, coagulation temperature and pH were screened by single factor experiments. The optimized processing conditions were established through combining orthogonal tests, sensory evaluation and quality-structure analysis. Comparisons were also made on the quality and structural indices of lactone hazelnut tofu and other tofu products commonly found in the market. The results showed that when the soybean to hazelnut ratio was 10:3, GDL dose for addition was 1.3% (GDL/ soybean), coagulation temperature was 85 ℃, and coagulation pH was 6.5, the hardness of lactone hazelnut tofu reached 1±0.21, with its elasticity as (6.3±0.16) mm, cohesiveness as 0.54±0.01, and resilience as 1.12±0.21. The hardness of the commercial tofu was 1.4±0.12/100 g, which was similar to that of the lactone curd (whose sensory score was the highest). The optimization of the quality and textural conditions not only improved the solidification of lactone hazelnut curd tofu, but also increased the sensory score of this tofu (with the best quality and texture).

31 Optimization of Extraction Technology of Isoflavones from Soybean Umbilicus

ZHOU Wen-hong , GUO Mi-mi , BI Yan-hong , WANG Zhao-yu , DUAN Zhang-qun

2020, 36(2):218-223. DOI: 10.13982/j.mfst.1673-9078.2020.2.031

[Abstract](314) [HTML](347) [PDF 904.99 K](737)

Abstract:
In order to improve the utilization rate of soybean umbilicus in soybean processing industry and to give full play to the nutritional value of soybean umbilicus, a high performance liquid chromatography (HPLC) method for the determination of isoflavones in soybean umbilicus was established based on the national standard method for the determination of isoflavones in soybean. In this experiment, the optimal extraction process of soybean isoflavone was achieved by single factor experiments and orthogonal experiments, when soybean umbilicus and ethanol-water solution served as the raw material and extraction solvent, respectively. The results showed that the order of factors on the extraction rate of soybean isoflavones was: Extraction temperature (B)>Extraction time (C)>Solid-liquid ratio (D)>Ethanol concentration (A). And the optimum conditions were as follows: the ethanol concentration was 80%, the extraction temperature was 80 ℃, the extraction time was 1.5 h, and the ratio of material to liquid was 1:35 (g/mL). Under this condition, when the soybean isoflavones were extracted for three times, the highest extraction rate of 10.88±0.120 mg/g could be obtained. This method is accurate and efficient, and more than 90% of soybean isoflavones can be extracted from raw materials. The extraction process is stable and feasible, which can provide theoretical basis for the extraction of isoflavones from soybean umbilicus.

32 Specificity Analysis of Essential Oil from Pericarpium Citri Reticulatae ‘Chachiensis’

HE Jing , CHEN Gu , HE Qian-xian , YING Fan

2020, 36(2):224-231. DOI: 10.13982/j.mfst.1673-9078.2020.2.032

[Abstract](386) [HTML](383) [PDF 1.18 M](1099)

Abstract:
In this study, the essential oil of Pericarpium Citri Reticulatae (PCR) from Guangdong (Pericarpium Citri Reticulatae ‘Chachiensis’, PCR-C) and from Si Chuan (C), Zhe Jiang (Z) and Guang Xi (G), were extracted by steam distillation. The content of essential oil extracted from PCR-C was much higher than those of the other PCRs (p<0.05). A total of 111 components were identified in essential oils through GC-MS analysis, of which 48 components were identified for the first time from PCR-C. The compositions of essential oil were statistically analyzed using Principal Component Analysis (PCA) and heatmap, and significant differences were found not only in the components with relatively high contents such as D-limonene, γ-terpinene and 2-(methylamino)-methyl ester, but also in the minor components with relatively low contents such as α-farnesene, terpinol and caryophyllene. Partial least squares discriminant analysis (PLS-DA) of essential oil in PCR aged for one and two years revealed for the first time that the major contributors to the difference between PCR-C and PCR also included (-)-carvone (0.03%~0.23%), (E, E, E)-2,6,10-trimethyl-2,6,9,11-dodecanetetraen-1-al (0.03%~0.80%), 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, (0.04%~0.34%), 4-methyl-1-(1-methylethyl)-bicyclo-hexanene (0.51%~0.84%) and 6,6-dimethyl-2-methylene-bicyclic heptane (1.42%~2.28%). Among which, carvone, (E, E, E)-2,6,10-trimethyl- 2,6,9,11-dodecanetetraen-1-al and perillaldehyde were only detected in the PCR-C, while the contents of 4-methyl-1-methylethyl- bicyclo-hexanene and 6,6-dimethyl-2-methylene-bicyclic heptane were significantly higher in PCR-C than that in PCRs. In addition, the PLS-DA analysis of the high-quality PCR-C aged for 1-5 years revealed a large difference in the essential oils between the PCR-C aged for 1 year and PCR-C aged for 2-5 years. These results suggested that the first two years of aging were the key period for the formation of specific flavor substances of PCR-C, and for studying the mechanism underlying PCR-C aging.

33 Analysis of Flavor Components of Different Mulberry Cultivars

LU Yan , ZENG Xia , ZHENG Ke-ming , CAO Jian-ping

2020, 36(2):232-240. DOI: 10.13982/j.mfst.1673-9078.2020.2.033

[Abstract](522) [HTML](487) [PDF 995.06 K](834)

Abstract:
The physicochemical characteristics and flavor components of different mulberry varieties were investigated. The moisture, ash content, total acid, soluble solids, pH and the contents of C, H and N were determined. Organic acids in different mulberry varieties were analyzed by HPLC. Volatile aroma constituents were detected by SPME and GC-MS. The results indicated that the physicochemical characteristics of different mulberry varieties were significantly different. The contents of moisture, ash, total acid, soluble solids and pH were 66.65%~84.83%, 0.63%~1.21%, 0.037%~0.062%, 8.7~18.2 °Brix and 4.31~6.06, respectively. The constituents and contents of organic acids with different mulberry varieties were different obviously. The content of tartaric acid was highest with white mulberry, purple mulberry, black pearl, Dashi and mulberry 283. While tartaric acid wasn't detected and the content of citric acid was highest in mulberry 32109. Ninety-nine volatile aroma components containing alcohols, esters, aldehydes, ketones, alkenes, acids and alkanes were identified from six mulberry cultivars. According to the above analyses, Dashi was suitable for processing for its high acidity and high moisture content. White mulberry was sweet and had high ratio of total soluble solids, black pearl and mulberry 283 had rich aroma constituents, moderate sour and sweet taste, which were suitable for fresh-eating. Mulberry 32109 had low ratio of total soluble solids, moderate acidity and enough aroma, and was more suitable for further processing. Purple mulberry could be used for making wine, for its high ratio of total soluble solids and proper acidity.

34 Determination and Comparison of Biochemical Components and Aroma Substances in the Pu-erh Teas with Mellow Flavor and Floral-fruity Aroma

NIAN Bo , JIAO Wen-wen , HE Ming-zhu , LIU Qian-ting , ZHOU Ling-xia , JIANG Bin , ZHANG Zheng-yan , LIU Ming-li , MA Yan , CHEN Li-jiao , LIU Fu-qiao , RONG Yu-ting , ZHAO Ming

2020, 36(2):241-248. DOI: 10.13982/j.mfst.1673-9078.2020.2.034

[Abstract](375) [HTML](186) [PDF 952.04 K](662)

Abstract:
Pu-erh teas with the floral-fruity flavor and mellow flavor produced by the same manufacturer were used as the materials. The quality characteristics and chemical basis for these two kinds of pu-erh teas were studied and compared by spectrophotometry, high performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), and sensory evaluation. Sensory analysis revealed that the floral-fruity pu-erh tea had a rich and sour taste with a floral or caramel aroma; the mellow pu-erh tea was rich in mellow and aged flavor. The analysis results showed that the contents of water extract, free amino acids, soluble sugars, gallic acid, theaflavins, thearubigins and epigallocatechin in the pu-erh tea with floral-fruity flavor were higher than those in pu-erh tea with mellow flavor (p<0.05); whereas, the content of epicatechin in the mellow-flavored pu-erh tea was higher than that in the floral-fruity flavored pu-erh tea (p<0.05). A total of 532 compounds were detected by GC-MS, with 55 being significantly different (vip>1.00, p<0.05, FC>1.50). The floral-fruity flavored pu-erh tea had significantly higher contents of the compounds with floral or ripen fruit aroma including (3R,6S)-2,2,6-trimethyl-6- vinyltetrahydro-2H-pyran-3-ol, phenylethyl alcohol, trans-linalool oxide (furanoid), benzyl alcohol, linalool and geraniol, compared with the pu-erh tea with mellow flavor. Whereas, the levels of methoxybenzene and alkanes compounds such as 1,2,3-Trimethoxybenzene and 1,2, 3-trimethoxy-5-methyl-benzene., which exhibited mellow and aged flavor, were significantly higher in the mellow flavored pu-erh tea than in the tea with floral-fruity flavor, In summary, the contents of biochemical components such as gallic acid, water extract, and free amino acids, as well as the relative contents of compounds with flower and ripe fruit aromas such as (3R,6S)-2,2,2, 6-trimethyl-6-vinyltetrahydro-2H-pyran-3-ol, in the floral-fruity flavored pu-erh tea were higher than those in the mellow flavored pu-erh tea (p<0.05) . Whereas, the relative contents of methoxybenzene and alkane compounds with mellow flavor in the floral-fruity flavored pu-erh tea were lower. These compositions were responsible for the rich, sour and mellow taste, and the flower or fruit aroma of the floral-fruity flavored pu-erh tea. In general, the floral-fruity flavored Pu'er tea is a novel Pu'er tea product rich in constituents with a unique aroma.

35 Comparative Analysis of Organic Acids in Wine Grape Fruits from Xinjiang

WANG Jing , WAN Zhi-bo , XU Chao-li , ZHANG Ke , WANG Wen-xuan , ZHANG Zhen-zhen

2020, 36(2):249-254. DOI: 10.13982/j.mfst.1673-9078.2020.2.035

[Abstract](432) [HTML](294) [PDF 654.72 K](819)

Abstract:
The organic acid content of Cabernet Sauvignon grapes in four small producing areas in Xinjiang and four kinds of red wine grape fruits (Cabernet Franc, Syrah, Petit Verdot and Matheran) in the northern foothills of Tianshan mountains were studied. Four organic acids (oxalic acid, tartaric acid, malic acid and citric acid) in the growing cycle of cabernet sauvignon fruits were analyzed by RP-HPLC. The results showed that the total organic acid content in Cabernet Sauvignon fruit decreased with the increase of grape ripen, while the contents of oxalic acid and citric acid were lower, and their changes were no significant difference. The total organic acid contents of Cabernet Sauvignon grapes in four small regions of Xinjiang were significantly different in the range of 3.97~7.96 mg/g (p<0.05). The total organic acid content of Cabernet Sauvignon produced in Wujiaqu of the northern foot of Tianshan mountain reached 7.96 mg/g, in which oxalic acid, tartaric acid and malic acid were 0.55 mg/g, 4.66 mg/g and 2.47 mg/g, respectively, and the total content of organic acid of Cabernet Sauvignon produced in The 67th Regiment area of Ili Valley was decreased to 3.97 mg/g. Through principal component analysis of organic acid substances in different wine grapes from the same origin, it was found that the relative content of tartaric acid in Syrah and Matheran was higher, the relative contents of oxalic acid and citric acid in Cabernet Sauvignon were higher, and the relative contents of malic acid in Cabernet Franc and Petit Verdot were higher. The results showed that the organic acid content of Cabernet Sauvignon had some differences in different producing areas, and the organic acid accumulation characteristics of different varieties in the same producing area were also different. The results in this work could provide a theoretical basis for research on "high sugar and low acidity" in Xinjiang.

36 Development of a Real-time RPA Assay for Pathogenic Yersinia enterocolitica Detection

LIU Jing-wen , HUANG Cheng-dong , LING Li , WANG Ju-fang , LI Zhi-yong

2020, 36(2):255-262. DOI: 10.13982/j.mfst.1673-9078.2020.2.036

[Abstract](356) [HTML](193) [PDF 1.08 M](908)

Abstract:
A real-time recombinase polymerase amplification (RPA) assay for pathogenic Yersinia enterocolitica detection was established in this work. According to the sequences of Yersinia enterocolitica pathogenic ail (Attachment Invasion Locus) gene, the specific primer and exo probe were designed and the detection could be finished within 20 mins at 37 ℃. This real-time RPA assay showed a good specificity and the detection limit of the target DNA was 0.1 ng/μL. In stability study, the assay was performed at the DNA concentration of 10 ng/μL, 0.1 ng/μL, 0.01 ng/μL and 0.001 ng/μL in octuplicate. The concentration of 0.01 ng/μL and above could be detected. The relative standard deviation (RSD) of threshold time and maximum fluorescence values of the eight parallels at 0.1 ng/μL DNA were the lowest (≤7.06%). In artificially contaminated powdered milk and beef samples with an initial bacterial concentration of 3 CFU/25 g, the pathogen can be detected using this real-time RPA method after incubation for 20 hours. The detection of 20 different real samples showed that the results of real-time RPA assay were consistent with that of GB 4789.8-2016, which is the national standard of China to detect Yersinia enterocolitica. This real-time RPA assay is helpful for the rapid field inspection at room temperature when conducting qualitative detection of pathogenic Yersinia enterocolitica.

37 Rapid Identification of Monofloral Honeys with Non-sugar Substances

FAN Jia-hui , YUE Jin-ping , YANG Yun-ge , I Yi-han , REN Hong

2020, 36(2):263-270. DOI: 10.13982/j.mfst.1673-9078.2020.2.037

[Abstract](390) [HTML](285) [PDF 948.09 K](688)

Abstract:
In order to quickly identify four common monofloral honeys (Medlar honey, Chaste honey, Jujube honey and Locust honey), non-sugar substances were used in this work. The non-sugar substances of honey were extracted by solid phase extraction (SPE) and sugar was removed. The determination of honey floral origin was carried out by high performance liquid chromatography (HPLC) combined with chemometrics. The non-sugar characteristic markers of these four monofloral honeys were found. The contents of rutin, methyl syringate and ferulic acid were significantly different among the four monofloral honeys. P-hydroxybenzoic acid and abscisic acid can be considered as floral origin markers of medlar honey with an average content of 0.59 μg/g and 0.42 μg/g, respectively. The average content of p-coumaric and cinnamic acid in chaste honey is 0.08 μg/g and 0.05 μg/g, respectively, which can be used as potential flower origin markers for chaste honey. Ferulic acid and isoferulic acid can be the characteristic markers of jujube honey with an average content of 0.40 μg/g and 0.76 μg/g, respectively. The characteristic markers of locust honey are rutin and methyl syringate with an average content of 0.08 μg/g and 0.14 μg/g, respectively. HPLC fingerprint combined with chemometrics (principal component analysis and discriminant analysis) was used, and the four monofloral honeys were successfully distinguished according to their floral origins. This study has important reference value for the determination of honey authenticity, which lays a foundation for the subsequent identification of honey.

38 Detection of the Freshness of Yanbian Yellow Beef by Hyperspectral Imaging

ZHAO Jian

2020, 36(2):271-276. DOI: 10.13982/j.mfst.1673-9078.2020.2.038

[Abstract](305) [HTML](266) [PDF 1.00 M](667)

Abstract:
In order to improve the quality and safety of Yanbian yellow beef, hyperspectral imaging technique was used to detect its freshness. Hyperspectral images of Yanbian yellow beef sample were collected by the imaging system, and then subjected to black-and-white correction. The processed hyperspectral images were denoised via the combined use of S-G filter and mean filter before being processed by principal component analysis to reduce dimension. The total volatile basic nitrogen (TVB-N) content of Yanbian yellow beef was determined by the semi-micro nitrogen determination method. The strong classifiers of Yanbian yellow beef were established through multiple BP-ANN weak classifiers. The TVB-N content of Yanbian yellow beef was placed as an input into the strong classifier and taken as the index, and then the freshness of Yanbian yellow beef was detected according to the classification results. The results showed that at the wavelength of 700~750 nm, the TVB-N content was the highest, suggesting a higher degree of internal damage in meat and poorer freshness of meat. On the 10th to 11th day, the TVB-N content of the Yanbian yellow beef changed significantly. After the hyperspectral image was denoised, the signal frequency fluctuated from-15 dB~15 dB to-5 dB~5 dB, and the fluctuation of signal frequency gradually decreased and tended to be stable. These results indicate that the proposed method was highly accurate with high denoising ability: The detection method can effectively remove the noise existing in the image, and the accuracy of this method was as high as 99%.

39 Nutrient Composition and Hazard Factors of the Edible Bird's Nest

MEI Xiu-ming , WU Xiao-xiao , QIAO Ling , LI Yuan , ZHANG Chi

2020, 36(2):277-282. DOI: 10.13982/j.mfst.1673-9078.2020.2.039

[Abstract](1014) [HTML](1375) [PDF 583.85 K](1103)

Abstract:
In this paper, five brands of edible bird's nest were tested for their nutrients composition and hazard factors. The nutrient composition included water content, ash content, protein content, fat content, total sugar content, sialic acid content, amino acid composition and content, and conventional element composition and content. The hazard factors included the type and content of heavy metal elements and the content of nitrite. Results showed that the water content of the five brands of edible bird's nest was 14.05%~15.21%, the ash content was 3.38%~4.91%, the protein content was 66.61%~67.97%, the fat content was 0.15%~0.21%, the total sugar content was 17.12%~25.47%, the sialic acid content was 12.21%~12.82%, and the total amino acid content was 57.80%~61.40%. The major elements Na, Mg and Ca were detected in bird's nest. The results of the hazard factors determination were that the heavy metal elements Hg and As were not detected in edible bird's nest. The contents of Zn, Cr, Cd and Pb did not exceed 1.15 μg/g in the five brands of edible bird nests. The content of nitrite was 11.38 mg/kg~14.89 mg/kg. Based on the determination of basic nutrients and hazard factors in bird's nest and the relevant reference data, it could provide a scientific basis for the establishment of quality evaluation standards and supervision program for bird's nest.

40 Rapid and Quantitative Analysis of Exogenous Maltodextrin in Pueraria lobata Extract by Mid-infrared

LI Yan-qing , DING Shan-shan , GUO De-hui

2020, 36(2):283-291. DOI: 10.13982/j.mfst.1673-9078.2020.2.040

[Abstract](469) [HTML](160) [PDF 1.00 M](844)

Abstract:
Due to the requirements of the production process and storage of Chinese herbal extracts, a certain amount of maltodextrin is added. At present, there is no standard method for determining the content of maltodextrin in Chinese herbal extracts in China and overseas. This study aimed to establish a method for rapid determination of the maltodextrin content in the mixed Pueraria extract powder. Using 88 samples of Pueraria lobata extract powders containing different contents of maltodextrin as the experimental materials, and the mid-infrared spectra of samples with known maltodextrin contents were collected. Baseline correction and normalization pretreatment were performed on the infrared spectra, and the quantitative model was established based on the partial least squares regression method. The results showed that the quantitative model had good prediction effect, and the prediction model had strong stability and high prediction precision with the decision coefficient (R2) as 0.9819 and standard deviation as 3.205. The mid-infrared spectroscopy technique can quickly quantify the content of maltodextrin in Pueraria lobata extract, and effectively monitor the extract market to avoid substituting shoddy products for quality products, thereby providing technical support to the market supervision department.

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Volume 36,Issue 2,2020 Table of Contents