Volume 36,Issue 1,2020 Table of Contents

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  • 1  Effect of Probiotic Intervention Frequency and Cycle on Serum Antioxidant Capacity in Rats with Hyperlipidemi
    HUANG Yu-jun YAO Yao ZHOU Fan GU Rui-xia
    2020, 36(1):1-7. DOI: 10.13982/j.mfst.1673-9078.2020.1.001
    [Abstract](584) [HTML](308) [PDF 811.53 K](971)
    Abstract:
    In this study, a rat model of hyperlipidemia was established, and the Lactobacillus plantarum 67 with high in vitro antioxidant capacity was preserved separately in the laboratory. According to the “intermittent fasting” method, an intervention with the Lp 67 strain being intervened 5 times per week (the 5 : 2 intervention group) or being intervened once per two days (the every other day intervention group) were established. The levels of serum GSH-Px, T-SOD, CAT and MDA and the T-AOC ability of these two groups were measured in different periods of intervention, and compared with those of the other groups, to explore the influence of probiotic intervention frequency and cycle on the serum antioxidant capacity of hyperlipidemic rats. Compared with the model group, the intervention group had significantly increased levels of serum GSH-Px and T-SOD (p<0.05), significantly decreased MDA level (p<0.05), and insignificantly improved T-AOC ability (p>0.05). The CAT level significantly reduced (p<0.05) for the 5:2 intervention group but insignificantly reduced (p>0.05) for the every other day intervention group. In general, the every other day intervention of the Lp 67 strain continuously for 8 weeks was more effective, which increased the GSH-Px level, T-SOD level, CAT level, and T-AOC ability by 93.08 nmol/mL, 13.05 U/mL, 5.97 U/mL, and 0.50 U/mL, respectively, while decreasing the MDA level by 10.04 nmol/mL. The experimental results showed that the frequency and cycle of probiotic intervention had significant effects on the antioxidant capacity of hyperlipidemic rats.
    2  The Total Saponins of Panax japonicus Improved the Apoptosis of Natural Aging Rats
    WANG Rui WANG Jia-wen WANG Ting YUAN Ding ZHANG Chang-cheng ZHAO Hai-xia HE Yu-min LIU Chao-qi ZHOU Zhi-yong
    2020, 36(1):8-15. DOI: 10.13982/j.mfst.1673-9078.2020.1.002
    [Abstract](416) [HTML](280) [PDF 1.29 M](657)
    Abstract:
    The purpose of this study was to investigate the regulation of saponins from Panax japonicus (SPJ) on endoplasmic reticulum stress-related proteins in natural aging rats and the intervention on neuronal apoptosis. Male SD rats were randomly divided into four groups: 6-month old group, 24-month old group and SPJ-treated groups with the doses of 10 mg/kg and 30 mg/kg. Western blot was used to detect the expression of endoplasmic reticulum stress-related proteins (GRP78, p-PERK, p-EIF2α, ATF4, ATF6, XBP1) and apoptosis-related proteins (p-JNK, CHOP, Bcl-2, Bax) in cerebral cortex and hippocampus of SD rats. The results showed that ,compared with the 6-month old group, the protein expression levels of GRP78, p-PERK, p-EIF2α, ATF4, ATF6, p-IRE1, XBP1and Bcl-2/Bax were noticeably reduced by 80% or 59%, 82% or 78%, 79% or 77%, 94% or 74%, 72% or 66%, 78% or 81%, 82% or 71%, 90% or 92% in the cerebral cortex or hippocampus of 24-month old group rats, respectively. And, p-JNK/JNK and CHOP increased by 1 or 1.72,3.33 or 1.33 times, respectively. In addition, these changes were reversed after different dozes of SPJ treatment. In summary,SPJ treatment can maintain endoplasmic reticulum homeostasis in brain tissue by up-regulating the levels of endoplasmic reticulum stress-related proteins and anti-apoptosis proteins, and down-regulating levels of pro-apoptosis-related proteins, hence to reduce neuronal apoptosis of aging rats.
    3  Rapid Antidepressant Effects of β-asarone on Depressive Model Mice
    HUANG Meng-jiao QIAO Wang WANG Ying-jiao YANG Hao ZHANG Ying-ying HUANG Xin-wu
    2020, 36(1):16-21. DOI: 10.13982/j.mfst.1673-9078.2020.1.003
    [Abstract](401) [HTML](362) [PDF 666.96 K](749)
    Abstract:
    The potential rapid antidepressant effect of β-asarone was investigated in this work. The effect of different administration methods of β-asarone on rapid antidepressant action and their biological mechanism were further evaluated. The 70 male KM mice were randomly divided to model group (n=60) and normal group (n=10). The model group was given chronic unpredictable stimulation, while the normal group was fed normally. After twenty-one days of feed, sucrose preference test was conducted on the model group to select 40 mice, which were successfully depression modeled. These 40 mice randomly were divided into five groups: β-asarone nasal cavity administration, β-asarone intragastric administration, Yueju pill nasal cavity administration, Yueju pill intragastric administration and model control group. Eight mice in the normal group were selected as normal control group. After 30 min of a single drug administration, open field experiment, tail suspension experiment and forced swimming experiment were conducted. Western blot was used to detect the expression of brain derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) in hippocampus of KM mice at 45 min post the single administration. The open-field test scores of the β-asarone group were higher than those of the model control group (p<0.05), forced swimming test and tail suspension test (p<0.05). Compared with the model control group, the expression of BDNF and TrkB in hippocampus of mice in the β-asarone group increased significantly after 45 minutes of administration (p<0.05). β-asarone exhibits a rapid antidepressant-like potential effect, and the potential rapid antidepressant effects might be associated with the up-regulation of BDNF and its receptor TrkB.
    4  Anti-inflammatory Effects of an Extract from Platycodon grandiflorum on Rats with Rheumatoid Arthritis
    YANG Xin WANG Le
    2020, 36(1):22-27. DOI: 10.13982/j.mfst.1673-9078.2020.1.004
    [Abstract](355) [HTML](232) [PDF 718.28 K](740)
    Abstract:
    To explore the intervention and anti-inflammatory effects of an extract from Platycodon grandiflorum on joint swelling in rats with rheumatoid arthritis, fifty-five SD rats were selected, with five as the normal group, and the remaining 50 rats established as rheumatoid arthritis models (which were divided into the model group, drug control group, and low, medium and high concentration groups, respectively). The paw volume, arthritis index, and the levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), interleukin-8 (IL-8), C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α) were measured. The results showed that: On the 1st, 7th, 14th and 20th day after modeling, the paw volume of the rats in the high concentration group was 2.12 mL, 2.60 mL, 2.93 mL and 2.49 mL, respectively, and the arthritis index was 2.03, 2.86, 5.25 and 4.37, respectively, which were lower than those of the other four groups (p < 0.05); the levels of MDA, IL-8, CRP and TNF-α in the high concentration group were 21.46 μmol/L, 101.33 pg/mL, 4.34 mg/L and 4.8 mg/L, respectively, and the levels of SOD and GSH-Px were 86.11 nU/mL and 85.37 U/L, respectively, which were higher than those of the other four groups (p<0.05). The extract from Platycodon grandiflorum could reduce the degree of joint swelling in rats with rheumatoid arthritis, improve antioxidant capacity while inhibiting inflammation.
    5  Improvement of Folic Acid on the Toxicity of TAR DNA-binding Protein 43 (TDP-43) in Amyotrophic Lateral Sclerosis Caenorhabditis elegans
    YANG Liu CHENG Man WANG Meng-ying LIANG Xiao-shan ZHANG Xu-mei
    2020, 36(1):28-34. DOI: 10.13982/j.mfst.1673-9078.2020.1.005
    [Abstract](407) [HTML](240) [PDF 899.28 K](573)
    Abstract:
    To investigate the effect of folic acid supplementation on amyotrophic lateral sclerosis (ALS) caused by the toxicity of TAR DNA-binding protein 43 (TDP-43), the transgenic Caenorhabditis elegans (C. elegans) transformed into human TDP-43 was selected as a model organism. The lifespan, reproductive capacity, paralysis rate, head thrash frequency, feeding ability and learning and memory capacity of nematodes were evaluated after exposure to different concentrations of folic acid (0.01 mmol/L, 0.025 mmol/L, 0.05 mmol/L). The results showed that, compared with the control group, the lifespan of the nematodes in the 0.025 mmol/L group and the 0.05 mmol/L group increased by 22.48% and 11.92%, respectively. The reproductive capacity of the 0.025 mmol/L group increased by 25.26%. The paralysis rate of nematodes in 0.01 mmol/L group and 0.025 mmol/L group decreased by 20.19% and 37.62%, respectively. The frequency of head thrash in the 0.025 mmol/L group increased by 17.14%, 32.88% and 39.18% on the 2nd, 4th and 6th day after folic acid intervention, respectively. The feeding ability of the three intervention groups increased by 24.58%, 60.30% and 15.85%, respectively, and the learning and memory ability also increased by 36.84%, 57.89% and 31.58%, respectively. The above data were statistically significant (p<0.05). Compared with the 0.01 mmol/L group and the 0.05 mmol/L group, the paralysis rate of the 0.025 mmol/L group decreased significantly (p<0.05), and other indexes increased significantly (p<0.05). The results showed that folic acid supplementation could improve the toxic effects caused by hTDP-43 protein in ALS nematodes, and folic acid at the concentration of 0.025 mmol/L might be the optimal intervention dose for ALS nematodes.
    6  Semicarbazide Exposure Induces Histological Damage and Enzymatic Reactions in Apostichopus japonicas
    TIAN Xiu-hui XU Ying-jiang ZHENG Wei-yun CUI Yan-mei JIANG Fang GONG Xiang-hong
    2020, 36(1):35-42. DOI: 10.13982/j.mfst.1673-9078.2020.1.006
    [Abstract](382) [HTML](199) [PDF 1.60 M](814)
    Abstract:
    According to the acute toxicity test, the median lethal concentration (LC50 ) of semicarbazide at 96 h was 3.72 g/L in Apostichopus japonicas (calculated as semicarbazide hydrochloride), with the 95% confidence interval as 3.43 g/L~4.02 g/L. Semicarbazide had an effect on the structure of the respiratory tree, intestines and muscles of Apostichopus japonicas. In the 1/5 LC50 group, respiratory tract lesions were severe and intestinal tissue was disintegrated with disordered smooth muscle lesions. In the 1/25 LC50 and 1/50 LC50 groups, pathological changes in respiratory, intestinal, and muscle tissues were slow but progressive and cumulative. Apostichopus japonicas was excitotoxicitory upon the exposure to the toxicity of semicarbazide, and the activities of antioxidant enzymes and key enzymes associated with neurotransmission increased first and then decreased, that is, induced first and then inhibited, with the 1/5 LC50 group exhibiting the most obvious symptom of poisoning. The 1/25 LC50 group had the highest activities of superoxide dismutase (SOD), catalase (CAT) and acetylcholinesterase (AChE), followed by the 1/5 LC50 group and 1/50 LC50 group. At the medium concentration, the maximum SOD activities of respiratory tree, intestinal and muscle for the 1/25 LC50 group were 1.78 times, 1.67 times and 2.50 times of those for the control group, respectively. The maximum CAT activities of respiratory tree, intestinal and muscle for the 1/25 LC50 group were 1.87 times, 1.96 times and 2.04 times of those for the control group, respectively. The maximum AChE activities of respiratory tree, intestinal and muscle for the 1/25 LC50 group were 7.86 times, 6.24 times and 2.86 times of those for the control group, respectively. In the end, all the enzymatic activities tended to reach the levels similar to those of the control group, which might be related to the immunity and fatigue of Apostichopus japonicas.
    7  Mechanisms Underlying Off-flavor Production in UHT-enabled Wall-breaking Pine Pollen during Storage
    ZHAO Qiao-li LIU Qi-song SHI Li-hua SHAN Yue LI Jin-wei LIU Yuan-fa
    2020, 36(1):43-51. DOI: 10.13982/j.mfst.1673-9078.2020.1.007
    [Abstract](532) [HTML](322) [PDF 1.21 M](754)
    Abstract:
    The changes in the essential nutrients, common oxidation indices and volatile constituents, along with the causes of odor generation and the main off-flavor components, were investigated during the storage of ultra-high temperature instantaneous sterilization (UHT)-enabled wall-breaking pine pollen. The results showed that after a 30-day storage, the contents of crude fat and unsaturated fatty acids decreased by 31.37% and 14.03%, respectively, and the relative contents of free fatty acids and saturated fatty acids increased by 38.78% and 32.34%, respectively, with the contents of crude proteins, total sugars and amino acids remaining unchanged. In the early stage of storage, the content of free fatty acids in the UHT-enabled wall-breaking pine pollen was lower, but increased sharply after 8 days and reached 9.53 mg/kg at the 30th day. The peroxide value and thiobarbituric acid value increased first and then decreased with the prolongation of storage, and reached the maximum, 6.09 meq/kg and 34.52 mg/kg, respectively, at the 3rd day and 5th day. In addition, the main volatile components of the UHT-enabled wall-breaking pine pollen increased steadily during storage, with the changes of hexanal and hexanoic acid being the most significant (reaching 12.69 μg/g and 10.51 μg/g, respectively after 5 days). These results indicated that the off-flavor of UHT-enabled wall-breaking pine pollen was produced mainly via lipid oxidation during storage, and the oxidation was more severe in the early stage of storage. Hexanal and caproic acid, the secondary oxidation products of oil oxidation, were the main volatile components of the wall-breaking pine pollen during storage, which also accounted for odor generation.
    8  Protective Effects of Lentinan on Bone Metabolism in Vitamin D Deficient Rats via Vitamin D-fibroblast Growth Factor-23-Klotho Axis
    CHEN Qiu LI Jia-xin
    2020, 36(1):52-57. DOI: 10.13982/j.mfst.1673-9078.2020.1.008
    [Abstract](313) [HTML](332) [PDF 812.25 K](800)
    Abstract:
    To investigate the effect of Lentinan on bone metabolism in vitamin D deficient rats via vitamin D-fibroblast growth factor-23-Klotho axis, fifty SD healthy rats were selected, with 10 as control group, and the remaining 40 as the vitamin D deficient models (which were divided into the model group, vitamin D3 group (1000 U/kg), low-dose lentinan group (150 mg/kg) and high-dose lentinan group (450 mg/kg), with 10 rats per each group). The levels of serum calcium, phosphorus, alkaline phosphatase, vitamin D-fibroblast growth factor (FGF)-23-Klotho axis factors and bone metabolism indices were measured. The results showed that the serum levels of 25 (OH) VD3, 1,25 (OH) VD3, FGF-23 and Klotho in the control group were 75.58 ng/mL, 4.98 ng/mL, 468.25 pg/L, 62.58 pg/mL, respectively, while for the model group, the 25(OH)VD3, 1,25(OH)VD3 and Klotho decreased to 34.35 ng/mL, 3.52 ng/mL and 40.12 pg/mL, respectively, and the FGF-23 level increased to 896.35 pg/L. The differences between the data of these two groups of rats were statistically significant (p<0.05). The levels of 25 (OH) VD3, 1, 25 (OH) VD3 and Klotho in the high dose lentinan group increased to 71.24 ng/mL, 4.85 ng/mL and 58.68 pg/mL, respectively, which were statistically higher than those in the vitamin D3 group and the low dose lentinan group. Whereas, the level of FGF-23 of the high dose lentinan group decreased to 552.23 pg/L, which was statistically lower than those in the vitamin D3 group and the low dose lentinan group (p<0.05). Lentinan polysaccharides acts on the vitamin D-FGF-23-Klotho axis, regulates the axis factors, and increases the vitamin D content to improve osteogenesis and protect the bones of the vitamin D deficient rats.
    9  A Comparative Study on Quality Characteristics of Toona sinensis Sprouts by Different Sterilization Methods
    CHENG Jing-jing WANG Zhao-gai SHI Guan-ying ZHANG Le WANG Xiao-min JIANG Peng-fei ZHAO Li-li WANG Xu-zeng
    2020, 36(1):58-68. DOI: 10.13982/j.mfst.1673-9078.2020.1.009
    [Abstract](571) [HTML](265) [PDF 1.24 M](840)
    Abstract:
    To explore the effects of different sterilization methods on quality characteristics of Toona sinensis sprouts, Toona sinensis sprouts were treated by Ultra High Pressure (UHP) technology, Microwave-Ultraviolet (MW-UV) technology and traditional thermal sterilization technology. The sterilization effects of different methods were compared by sensory evaluation and total plate counts (TPC). Then the effects of different sterilization methods on the quality of Toona sinensis sprouts were evaluated comprehensively by determining the contents of nitrite and bioactive substances, color, volatile components and their relative contents. The results showed that UHP had the best germicidal efficacy (TPC were 0.92 cfu/g), followed by MW-UV (1.28 cfu/g), and Pasteurization was the worst (6.80 cfu/g). After UHP treatment, the index values were better than those of other methods, but the effect of UHP treatment on terpenes in the main aroma components of Toona sinensis sprouts was significant, and the relative content decreased by 28.16%. After MW-UV treatment, the color deterioration of Toona sinensis sprouts was more serious, but the aroma components were closest to those of the control group. Pasteurization could preserve the original color and volatile components of Toona sinensis, but the losses of the bioactive components were higher (the loss rates of polyphenols, flavones and alkaloids were 6.94%, 18.39%, 3.61% respectively). The indicator values of Toona sinensis sprouts treated by High-Pressure Steam Sterilization (HPSS) were inferior to those of other samples. Collectively, UHP and MW-UV technologies are superior to the traditional pasteurization and HPSS methods, which can better maintain the qualities of Toona sinensis sprouts.
    10  Analysis and Evaluation of the Nutritional Components in Fish Skin and Fish Meat of Four Species of Puffer Fish
    CHEN Xiao-ting WU Jing-na XU Min LIU Shu-ji SU Yong-chang QIAO Kun LIU Zhi-yu
    2020, 36(1):69-77. DOI: 10.13982/j.mfst.1673-9078.2020.1.010
    [Abstract](696) [HTML](256) [PDF 818.82 K](808)
    Abstract:
    Nutritional components of fish skin and fish meat of puffer fish, including Fugu. flavidus, Fugu. bimaculatus, Fugu. rubripes, Fugu. obscurus, were analyzed and evaluated. Four species of puffer fish had higher protein content and lower fat content, better protein quality of fish meat, but higher trace elements and more fresh and sweet flavor were found in fish skin. The crude protein content of fish skin (20.17%~37.61%) was higher than that of fish meat (18.13%~23.27%). The highest protein content was 37.61% in flavidus, Fugu. The ∑ EAA/∑TAA (39.01%~43.11%), ∑EAA/∑NEAA (65.26%~71.57%) and EAAI values (0.75~1.00) of fish meat were higher than those in fish skin (16.61%~20.49%, 19.78%~25.70%, 0.25~0.51, respectively). They were accorded with FAO/WHO standard and the highest content was Fugu. bimaculatus. The crude fat content of fish skin (0.20%~0.40%) and meat (0.21%~0.4%) was low. The ∑FA (0.28%~0.39%), w-3 PUFA (0.05%~0.15%) and w-6 PUFA (0.01%~0.09%) contents of fish meat were higher than those of fish skin (0.15%~0.24%, 0.02%~0.03%, 0.01%~0.04%, respectively). The highest content of w-3 PUFA was found in Fugu. rubripes. The fish skin of Fugu. flavidus contained higher Ca2+ content (1737.47 mg/100 g), the fish meat of Fugu. bimaculatus contained higher K+ content (439.00 mg/100 g), and the Fugu. rubripes contained the highest Zn2+ content (0.90 mg/100 g, 8.93 mg/100 g, respectively). The results showed that the four species of puffer are all high protein and low fat economic fishes, with rich and balanced proportion of amino acids, fatty acids and mineral elements and high nutritional value.
    11  Effects of in Vitro Digestion on Phenolic Acid Content and Antioxidant Activity of Artemisia selengensis Turcz Leaves
    XIONG Wen WU Ting CAO Wei-wei PAN Si-yi XU Xiao-yun
    2020, 36(1):78-83. DOI: 10.13982/j.mfst.1673-9078.2020.1.011
    [Abstract](561) [HTML](179) [PDF 1017.85 K](945)
    Abstract:
    The changes of phenolic acids content, antioxidant activity and tyrosinase inhibitory activity of Artemisia selengensis Turcz leaves extract in vitro digestion were studied. The results showed that content of chlorogenic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid and 1,5-dicaffeoylquinic acid decreased significantly after simulated digestion. Total phenolic acid content and antioxidant activities including DPPH, FRAP and ABTS increased significantly after in vitro simulated digestion. The contents of total phenolic acid in crude extract and purified sample were increased by 73.57%, 23.79%, respectively. The antioxidant capacity of DPPH, FRAP and free radical scavenging capacity of ABTS in crude extract and purified sample increased by 36.17% and 53.29%, 28.71% and 15.45%, 163.67% and 49.50%, respectively. In addition, the inhibitory rate of Artemisia selengensis Turcz leaves extract on tyrosinase activity increased significantly after in vitro digestion, the inhibition rate of crude extract could reach 49.88%, respectively, which could effectively inhibit melanin production and benefit for whitening. Therefore, Artemisia selengensis Turcz leaves extract exhibits good antioxidant activity and tyrosinase inhibitory activity after in vitro digestion, which has the potential to develop the whitening products. Results in this work provided a reference for the development of Artemisia selengensis Turcz leaves, a by-product of Artemisia selengensis Turcz stem processing.
    12  Comparison of Nutrient Composition and Texture Properties Between Soy Protein Ball and Three Meatballs
    CHEN Yu-ling YANG Mei NIU Yue-ting CAI Hui-zhen
    2020, 36(1):84-90. DOI: 10.13982/j.mfst.1673-9078.2020.1.012
    [Abstract](625) [HTML](481) [PDF 765.52 K](694)
    Abstract:
    Nutrient composition and texture properties were detected in three meatballs and DSP (drawing soy protein) ball fried in palm oil to evaluate its application value. National standard methods were used to analyze nutrient composition. Texture of four types of balls were analyzed by a food texture analyzer. The protein content was as follow: DSP ball 39.06 mg N/g > pork meatball 30.11 mg N/g > beef meatball 19.9 mg N/g > fish meatball 12.79 mg N/g. The cholesterol content was as follow: beef meatball 28.71 mg/100 g > pork meatball 25.27 mg/100 g > fish meatball 14.83 mg/100 g > DSP balll 1.21 mg/100 g. The fat content of pork meatball was significantly higher than the other three samples (p<0.05). The maximum of total amino acid, essential amino acid and umami amino acid content were found in the DSP ball and were 15.44±0.59, 5.33±0.20, 8.89±0.34 (g/100 g), respectively. The four types of meatballs had a high proportion of unsaturated fatty acids, accounting for 59% to 73% of their total fat content. The maximum of springiness and resilience were obtained in DSP ball , which were 96.84%±1.43% and 52.77%±0.56%, respectively. Results showed that DSP ball had high protein content, low cholesterol, rich unsaturated fatty acids, high nutritional value and good taste. It can be used as a substitute for traditional meatballs.
    13  Improvement of Polyhydroxy Saccharides on Recrystallization of Water in Litopenaeus vannamei during Frozen Storage
    QI Xue-er YAO Hui QI He MAO Jun-long HAO Gui-juan ZHANG Bin
    2020, 36(1):91-97. DOI: 10.13982/j.mfst.1673-9078.2020.1.013
    [Abstract](518) [HTML](281) [PDF 1.04 M](809)
    Abstract:
    The aim of this study was to explore the cryoprotective effects of different saccharides on whiteleg shrimp (Litopenaeus vannamei) muscle during frozen storage with temperature fluctuations. The effects of xylooligosaccharide, carrageenan oligosaccharide, trehalose, and algae oligosaccharide on quality characteristics of shrimp muscle were evaluated upon exposure to temperature fluctuations between -55 ℃ and -24 ℃, with sodium pyrophosphate and distilled water treatments as the positive and negative controls, respectively. The results showed that xylooligosaccharide, carrageenan oligosaccharide, trehalose, and alginic oligosaccharide significantly reduced the thawing loss of frozen shrimp, compared with the distilled water treated group (the lowest value was 8.58% in carrageenan oligosaccharide group) during 144 days of frozen storage with temperature fluctuations. These saccharides effectively maintained the texture properties of shrimp muscle, the optimum elasticity and chewiness were 1.42 mm and 6.80 mJ, respectively. Meanwhile, these saccharides soaking treatments also slowed the degradation of myofibrillar proteins (106.10 mg/g~111.67 mg/g), decreased Ca2+-ATPase activity (0.124 U/mg~0.136 U/mg) and total sulfhydryl content (7.6 mmol/L~8.1 mmol/L) in the shrimp muscle. Microstructure results showed that compared with distilled water group, the muscle connective structure of shrimp tissues treated with saccharides was more complete, the gap among muscle bundles was smaller, and there was no large area of distortion and rupture observed, which showed good maintenance effects on the microstructure of frozen shrimp tissues. These results suggest that the xylooligosaccharides, carrageenan oligosaccharides, trehalose, and alginate oligosaccharides can be developed and utilized as the antifreeze and water-retaining agents for frozen shrimps.
    14  The Preservative Effect of Tea Polyphenols/ε-Polylysine Hydrochloride Composite Microcapsules on Sciaennops ocellatus Fillets
    YANG Hua YANG Li-li WANG Ming WEI Xu-qing SUN Tong ZHOU Bin LI Jian-rong
    2020, 36(1):98-105. DOI: 10.13982/j.mfst.1673-9078.2020.1.014
    [Abstract](509) [HTML](224) [PDF 1.16 M](800)
    Abstract:
    In this study, microcapsules with sustained release properties were prepared by spray drying using polylactic acid (PLA) and ethyl cellulose (EC) as the wall materials, and tea polyphenols (TP), ε-polylysine hydrochloride (ε-PL) or TP/ε-PL mixture as the core substance(s). Using Sciaennops ocellatus fillets as the preservation objects, the preservation performance of the preservatives and their derived microcapsules were studied. The results showed that after the treatment with the preservatives and microcapsules, the growth of microorganisms in the fish fillets was inhibited, with the changing rate of pH being slowed down, the rates of fat oxidation and protein decomposition decreasing, and the decreasing rates of sensory score and texture index ranking for the fish fillets being reduced. From the 11th day, the total number of colonies of the fish fillets treated with microencapsulated preservatives was lower than that for those treated with unencapsulated preservatives in the same period (by 0.20 to 0.37 lg(cfu/g). The treatment with the TP/ε-PL composite preservative and its derived microcapsules led to a decrease of 0.17~1.09 lg(cfu/g) in the total number of colonies of the fish fillets, compared with the treatment with a single preservative and its derived microcapsules in the same period. Therefore, the microencapsulation of preservatives had a long-lasting antibacterial activity, and the combination of TP and ε-PL exhibited a synergistic effect and led to a greater preservative effect (which extended the shelf life of fish fillets by 3~5 days).
    15  Development and Characterization of Antibacterial Chitosan Composite Films Incorporated with Gliadin-coated AgNPs
    YAN Li GU Li-rong LAI Fu-rao YIN Shou-wei
    2020, 36(1):106-112. DOI: 10.13982/j.mfst.1673-9078.2020.1.015
    [Abstract](433) [HTML](327) [PDF 1.06 M](821)
    Abstract:
    In this work, the Ag nanoparticles / gliadin / chitosan composite antimicrobial films were successfully constructed using the cast method to achieve the stabilization and synergistic effect of Ag nanoparticles (AgNPs). Self-assembled gliadin colloidal particles acted as both chelator and stabilizer of AgNPs, effectively inhibited the aggregation of AgNPs. As compared with other films, gliadin /AgNPs composite films possessed excellent transparency. SEM and EDS confirmed that AgNPs were evenly distributed on the composite film. Moreover, gliadin /AgNPs composite films had excellent sustained-release properties. Human skin fibroblast evaluation results showed that the composite films have better biocompatibility. More important, confocal laser scanning microscope (CLSM) revealed that the gliadin /AgNPs composite films possessed stronger antibacterial effect on E. coli and S. aureus. These films are of great value in the development of antibacterial food packaging materials, wound dressings and implants.
    16  Effects of Salicylic Acid Spray Fumigation on Postharvest Quality of Xinjiang Xiaobai Apricot
    WEI Zheng ZHANG Zheng WEI Jia WU Bin CHEN Li-na LI Chen-hao ZHANG Jian
    2020, 36(1):113-119. DOI: 10.13982/j.mfst.1673-9078.2020.1.016
    [Abstract](497) [HTML](243) [PDF 1.12 M](682)
    Abstract:
    The Xinjiang Xiaobai apricot was taken as the tested material, which was fumigated by salicylic acid (SA) with different concentrations (10, 30 and 50 mmol/L) and distilled water (as control), then stored at room temperature (25±1℃). The effect of SA on the quality of apricot during postharvest storage was investigated. The results showed that compared with the control, the SA treatment can maintain the quality of Xiaobai apricot in different degrees. SA treatment significantly reduced the rate of weight loss, the contents of soluble solids (TSS), titratable acid (TA) and ascorbic acid (Vc), and cell membrane permeability. On the 6th day of storage, the firmness, weight loss rate, the contents of TSS, TA, Vc and cell membrane permeability were 9 N, 10.20%, 14.6%, 0.73%, 7.14 mg/100 g, and 49.90% in apricot group treated with 30 mmol/L SA treatment, respectively. The quality and nutritional components of apricot during storage were well maintained by SA fumigation treatment. The decay rate of apricot by 30 mmol/L of SA treatment was significantly reduced, which was only 1.66% on the 6th day. The respiration rate and ethylene production of the SA treated apricot were decreased as well. The peaks of respiratory and ethylene were delayed 1 day and reduced by 16.23% and 20.01% respectively, which were significantly different from the control group. In conclusion, the fumigation technology as a new treatment could significantly improve the storage quality of Xinjiang Xiaobai apricot.
    17  Degradation Kinetics of Vitamin C in Strawberry Juice during Storage
    ZHANG Yuan-yuan ZHANG Ying-tong HU Hua-li ZHANG Lei-gang ZHOU Hong-sheng LUO Shu-fen LI Peng-xia
    2020, 36(1):120-126. DOI: 10.13982/j.mfst.1673-9078.2020.1.017
    [Abstract](482) [HTML](447) [PDF 1015.31 K](796)
    Abstract:
    The effects of different storage conditions on the degradation of vitamin C in strawberry juice was investigated, the contents of vitamin C in strawberry juice which was stored in glass or PET bottles at 4 ℃, 20 ℃ and 37 ℃ were analyzed during the whole storage period. Corresponding kinetic models were also established. The results showed that the degradation rate of vitamin C in strawberry juice increased with the increase of storage temperature and the half-life period declined accordingly. At the same storage temperature, the degradation rate of vitamin C in PET bottles was higher than that in glass bottles. The degradation kinetics of vitamin C in strawberry juice from glass and PET bottles followed by first-order kinetic model, with the reaction activation energies of 32.04 kJ/mol and 28.26 kJ/mol, respectively. The correlation coefficient between the verified values of prediction models and the measured values was R2 > 0.99, indicating the validity of the model. It means the equation could be used for estimating the first-order losses of vitamin C in the stored strawberry juice, at any specific temperature and degradation ratio. The thermodynamic functions of activation (ΔG≠, ΔH≠, ΔS≠, and K≠) were determined and can provide valuable information for degradation mechanism of vitamin C.
    18  A Predictive Shelf-life Model for Pork Patties Affected by Specific Spoilage Bacteria
    YAN Yu-wen CUI Yue-hui ZHU Ying-chun
    2020, 36(1):127-135. DOI: 10.13982/j.mfst.1673-9078.2020.1.018
    [Abstract](396) [HTML](342) [PDF 993.15 K](651)
    Abstract:
    The predictive shelf life model for pork patties affected by specific spoilage bacteria (SSB) was established. The SSB were inoculated into the ozone-treated pork patties, vacuum packaged and stored at -1, 4, 10, 15 and 22 ℃ (temperature fluctuation ±1 ℃). The total volatile base nitrogen (TVB-N), pH and thiobarbituric acid resctive subastances (TBARS) values, the total viable count (TVC), and the sensory scores of the patties were determined during the storage period (0~11 d). Using the modified Gompertz equation and square root model (Bĕlehrádek), a microbial shelf life model of the patties with SSB as the key quality factors was established. The results showed that the modified Gompertz equation seemed to fit better the growth curves of SSB under different storage temperatures, while the square root model (Bĕlehrádek) described the effects of temperature on the maximum specific growth rate (μmax) and the lag phase (Lag). Both of which showed good linearity (R2 as 0.98 and 0.83, respectively). The average logarithmic value of minimum SSB for the pork patties stored at -1, 4, 10, 15 or 22 ℃ was (6.94±0.21) lg (cfu/g), and the average value of lgNmax was (8.65±0.16) lg(cfu/g). Accordingly, the model for patties stored at -1 ℃~22 ℃ was established. The prediction model was validated based on the measured shelf life at 10℃ and 15℃, and the relative error was less than 10%, indicating that the model based on the square root equation was effective for predicting the shelf-life of SSB in pork patties stored at -1 ℃~22 ℃.
    19  Effects of Antiseptic Co-UV Sterilization on the Bactericidal Effect and Quality of Youtazi
    SHEN A-qian CHEN Shu-chang FENG Zuo-shan BAI Yu-jia WANG Ya-ru ZHANG Qian-ting HUANG Wen-shu
    2020, 36(1):136-142. DOI: 10.13982/j.mfst.1673-9078.2020.1.019
    [Abstract](339) [HTML](216) [PDF 936.00 K](651)
    Abstract:
    In order to explore the effects of different treatments (different antiseptics, UV sterilization time, UV sterilization distance) on the quality of Youtazi (aerobic bacteria, moulds/yeasts, Escherichia coli count, color difference and sensory evaluation), single factor and orthogonal experiments were employed to determine the optimal parameters. The results showed that the optimum sterilization conditions were Nisin addition 0.012%, sterilization time 45 min and sterilization distance 10 cm. At -4 ℃, the amount of mold/yeast bacteria reached 2.85 log (cfu/g) after 19 days of storage in the experimental groups, which exceeded the national standard limit of 2.18 log (cfu/g), while the amount of mold/yeast bacteria reached 2.28 log (cfu/g) only after 9 days in the control group; in ambient temperature, the amount of mold/yeast bacteria exceeded the standard limit on the 5th days in the experimental groups, while in the control group the amount of mold/yeast bacteria was 2.43 log (cfu/g) on the 3rd day, which exceeded the national standard already. The storage of Youtazi in ambient temperature and -4 ℃ were prolonged to 4 days and 17 days, respectively. This research could provide theoretical basis for the industrialization of Youtazi.
    20  Enzyme Activity Production by Pure and Mixed Cultures of Torulaspora delbrueckii and Saccharomyces cerevisiae during Cider Fermentation
    ZENG Chao-zhen KANG San-jiang ZHANG Ji-hong ZHANG Fang ZHANG Hai-yan YUAN Jing SONG Juan
    2020, 36(1):143-149. DOI: 10.13982/j.mfst.1673-9078.2020.1.020
    [Abstract](423) [HTML](306) [PDF 951.97 K](865)
    Abstract:
    In this paper, Fuji apple was used as raw material and the changes of β-glucosidase, pectinase, protease and amylase activities in pure and mixed cultures (MST1: 105 cfu/mL Saccharomyces cerevisiae/106 cfu/mL Torulaspora delbrueckii; MST2: 104 cfu/mL Saccharomyces cerevisiae/106 cfu/mL Torulaspora delbrueckii) during apple juice fermentation were studied. The results showed that in pure culture, except for α-amylase and pectinase, the maximum enzyme activities of β-glucosidase and acid protease produced by S. cerevisiae 32168 were higher than those of T. delbrueckii 1004, the maximum activity level were 2.03 nmol/(min·mL) and 43.93 nmol/(min·mL), respectively; the areas under the enzyme curve were 10.65 and 223.73, respectively. The area under the pectinase curve was higher in T. delbrueckii 1004, reaching 14.17, while there was no significant difference in α-amylase. In the mixed culture, except for acid protease and α-amylase, the maximum enzyme activity values of β-glucosidase and pectinase were higher than those of the pure culture and the maximum enzyme activity value was up to 2.37 nmol/(min·mL) and 4.56mg/h·mL, respectively; the areas under the enzyme curve were up to 15.11 and 19.71, respectively. A lot of enzymes were produced by pure and mixed of T. delbrueckii and S. cerevisiae throughout the fermentation process. These enzymes help to catalyze the hydrolysis of natural precursor polymers in apple juice and improve the quality of cider. The mixed inoculation can be used as another different fermentation method from the pure fermentation of Saccharomyces cerevisiae.
    21  Pichia pastoris Whole Cell-Catalyzed Synthesis of a Novel High-intensity Sweetener Rebaudioside A
    TANG Xiao-yan CHEN Mei-qi LIN Ying LIANG Shu-li
    2020, 36(1):150-155. DOI: 10.13982/j.mfst.1673-9078.2020.1.021
    [Abstract](488) [HTML](278) [PDF 699.47 K](858)
    Abstract:
    In this study, we constructed a codon-optimized UDP-glycosyltransferase UGT76G1 and a sucrose synthase AtSUS gene recombinant Pichia pastoris strain, GS115/pPIC9K-UGT/pPICZA-AtSUS, to achieve intracellular co-expression of the two enzymes in Pichia pastoris. The co-expressed strain was used as a whole-cell catalyst for the in vitro catalytic reaction, to successfully convert ST into RA. On this basis, optimization was performed on reaction temperature, reaction pH, substrate UDP concentration and substrate sucrose concentration. After the recombinant strain was induced with methanol, the catalytic capacity of the cells at different fermentation times was investigated. The catalytic capacity of the cells was the greatest after fermentation for 120 h, with the RA yield as 0.58 mg/mL. After the optimization of the catalytic conditions for the whole cells in the catalytic system of co-expressed, the optimized catalytic conditions were: reaction pH 7.0, UDP concentration 1 mM, sucrose concentration 70 mM, MgCl2 concentration 3 mM, ST concentration 10 mg/mL, with the recombinant bacteria capable of converting 10 mg/mL ST to 7.46 mg/mL RA (if the cells with an OD600 value of 30 were mixed with the above systems and allowed a reaction for 15 h at 200 rpm and an optimum temperature of 45 ℃). This research provides technical support for the RA enzymatic biosynthesis and its industrialization.
    22  Functional and Structural Analysis of Carbohydrate-binding Module of Eukaryotic α-L-rhamnosidase
    CAI Yu-chen CAO Bo-han GONG Jian-ye LI Li-jun NI Hui
    2020, 36(1):156-162. DOI: 10.13982/j.mfst.1673-9078.2020.1.022
    [Abstract](295) [HTML](188) [PDF 1.50 M](903)
    Abstract:
    The analyses of the physicochemical properties and the construction of the phylogenetic tree for the eukaryotic α-L-rhamnosidase CBM were performed using ExPASy website and MEGA 6.0 software, in order to analyze the function of CBM in the CBM67 family of eukaryotic α-L-rhamnosidase located in the CAZy database. It was found that the eukaryotic α-L-rhamnosidase CBM can be divided into three major classes, and most are hydrophobic proteins, with the number of amino acids in the range of 239~377, molecular weight (Mr) in the range of 24540.58~40740.16 u, isoelectric point (pI) in the range of 3.93~8.74, total number of negatively charged residues in the range of 20~29, total number of positively charged residues in the range of 6~33, total number of atoms in the range of 3415~5712, and average hydrophilicity coefficient in the range of -0.077~0.377. The amino acid region of the eukaryotic α-L-rhamnosidase CBM in the CBM67 family was determined by sequence alignment analysis using the ClustalX 2.0 program and the Espript website. Using the Discovery Studio 2019 software for homology modeling and molecular docking, the three-dimensional structure of α-L-rhamnosidase CBM consisting of 12 β-sheets was constructed. The molecular docking with L-rhamnose revealed that CBM could recognize substrates through producing strong hydrogen bonds and van der Waals forces with L-rhamnose, to promote the occurrence of enzymatic hydrolysis. These results will help us understand better the structural basis and common approaches for CBM to recognize and bind to the substrate, thus, provide theoretical guidance for improving the binding of CBM.
    23  Effects of Different Culture Media and Food Additives on Staphylococcal Enterotoxin Type P
    LI Xiang-xiang DU Xuan ZHAO Yan-ying TANG Jun-ni
    2020, 36(1):163-168. DOI: 10.13982/j.mfst.1673-9078.2020.1.023
    [Abstract](270) [HTML](232) [PDF 640.93 K](695)
    Abstract:
    In this study, the food-source Staphylococcus aureus SA-106 strain, which produces new staphylococcal enterotoxin P, was used as a research object. The growth of strain in LB medium, skim milk and sterile cooked pork was studied by plate counting, and the secretion of staphylococcal enterotoxin P was determined by enzyme-linked immunosorbent assay. At the same time, the effects of food additives (tea polyphenols and Nisin) on the secretion of SEP protein were also explored. The results showed that when SA-106 was grown in LB medium and skim milk, the bacteria could enter the growth stationary period at about 12 h; and the secretion of enterotoxin SEP protein continued to increase during the growth, reaching 10.28 μg/mL and 6.59 μg/mL at 120 h, respectively. While when grown in pork, the strain entered the growth stationary period at about 24 h, and the SEP secretion was 9.12 μg/g at 48 h. By comparison, the secretion of SEP protein of strain S-106 was higher in cooked pork and LB medium, and the secretion of SEP protein in skim milk was slightly lower, indicating that different culture medium had an effect on the secretion of enterotoxin protein P. Further, the addition of tea polyphenols and Nisin has a certain inhibitory effect on the growth of bacteria and the production of enterotoxin SEP. This study has a certain reference value for the production and control of staphylococcal enterotoxin P.
    24  Development of A Walnut Smear Cheese
    TIAN Yang ZHOU Yan ZHAO Cun-chao SHI Chong-ying TAO Liang
    2020, 36(1):169-177. DOI: 10.13982/j.mfst.1673-9078.2020.1.024
    [Abstract](497) [HTML](274) [PDF 971.17 K](731)
    Abstract:
    In this work, peeled walnut kernel was used as raw material to study the cheese processing technology and develop a new vegetable-based cheese. Using sensory evaluation and free amino acid content as reference indexes, the optimum enzymatic hydrolysis conditions were selected. The effects of fermentation time and the addition of cream, whey protein and sucrose on curd milk were studied by single factor experiment combined with response surface optimization. The fermentation technology of walnut cheese was further studied. The results showed that: lipase Palatase 20000 L addition, flavor protease complex enzymatic hydrolysis (addition ratio was 1:2, addition amount was 0.2%), walnut milk had the best enzymatic hydrolysis effect and the highest sensory score. The content of free amino acid of the hydrolysate was (764±44) mg/100 g. Response surface optimization results showed that the sensory score of walnut was the highest (90.5) when the amount of whey protein, cream, sucrose and fermentation time were 1.56%, 0.81%, 6.37%, 24 hours, respectively. The content of free amino acids and free fatty acids in walnut cheese increased significantly after fermentation. The total content of free amino acids increased from 279.97 mg/kg to 1262.02 mg/kg, which played an important role in the formation of unique flavor of walnut cheese. The walnut cheese prepared by this technology had full flavor, high nutritional value and good sensory quality, which can provide reference for the comprehensive development of walnut industry.
    25  Effect of pH on the Lycopene Stability and Its Degradation Kinetics
    ZHAO Wen-hong YAN Ting-ting YIN Wen-ting XIE Yan-li
    2020, 36(1):178-183. DOI: 10.13982/j.mfst.1673-9078.2020.1.025
    [Abstract](642) [HTML](602) [PDF 992.48 K](1079)
    Abstract:
    Lycopene is susceptible to degradation affected by light, oxygen, heat, solvents and its environment. In order to investigate the effect of solution environment on lycopene stability, the UV-vis spectroscopy character of lycopene with different solvents and its degradation kinetics were analyzed in thiswork. The solvents were including dimethyl sulfoxide (DMSO), tetrahydrofuran (THF) and acetone. The results showed that the characteristic wavelength of lycopene in different solvents appeared the redshift distribution from acetone of 505 nm to DMSO of 511 nm and THF of 523 nm in UV-vis spectroscopy. Lycopene represented as H-type aggregation and observed the blue shift of the maximum of UV absorption peak in water-organic solvent. The experimental results of degradation kinetics showed that the degradation of lycopene in different solvents conformed to first-order reaction law, and it was stable in acetone solvent with a half-life of 25.48 h. The lycopene were stable in acidic and alkane media, but limitedly resistant to strong acid and alkali solution and strong solvent. These results indicated that lycopene was suitable for keeping stability under weak acid and alkane media of acetone and THF aqueous solutions. This study provided a theoretical basis for processing, packaging, and storage of tomato products.
    26  Optimization of Green Wheat Berry Meal Replacement Powder Formula
    ZHANG Kang-yi HE Meng-ying KANG Zhi-min GAO Ling-ling SUN Fan-shu
    2020, 36(1):184-191. DOI: 10.13982/j.mfst.1673-9078.2020.1.026
    [Abstract](620) [HTML](208) [PDF 789.66 K](936)
    Abstract:
    To optimize the formula of green wheat berry meal replacement powder, single factor experiment and uniform design methods combined with multiple regression analysis were used to process data. The single factor experiment results illustrated that the additions of green wheat berry powder, xylitol, CMC-Na and sodium citrate and particle size of green wheat berry powder were the factors with a great influences on dissolving quality of meal replacement powder. Uniform design and principal component analysis showed that the factors influencing sensory evaluation were ordered as: sodium citrate addition>particle size of green wheat berry powder; and the factors influencing wettability were ordered as: CMC-Na additions>particle size of green wheat berry powder. Solubility, dispersibility and hydratability were followed by the quadratic polynomial regression models. The four principal components extracted accounted for 92.72 % of the total variation, thus achieving dimensional reduction; Through ridge regression analysis, a regression model for comprehensive score was established with a good degree of fitting. Partial least squares regression analysis predicted the best formula: green wheat berry powder (61%), millet flour (18%), oat powder (12%), xylitol (8%), CMC-Na (0.85%), sodium citrate (0.28%) and green wheat berry powder (125 mesh), under which the comprehensive score was 1.13. The solubility of the product was good. This study laid the foundation for promoting green wheat berry meal replacement powder.
    27  Effect of Edible Coatings on Oil Content and Permeation of Chinese Deep-fried Dough Cake and Elucidation of the Underlying Mechanism
    HE Ye LIU Guo-qin
    2020, 36(1):192-197. DOI: 10.13982/j.mfst.1673-9078.2020.1.027
    [Abstract](474) [HTML](192) [PDF 1.00 M](730)
    Abstract:
    Reducing oil content is a guarantee of the healthy development of fried food. This study investigated the effects of two different types of coating materials, methylcellulose (MC) and soybean protein isolate (SPI), on the oil content and inhibition of oil absorption in Chinese deep-fried dough cake (CFDC). Scanning electron microscopy (SEM) and optical microscopy (OM) with Sudan red staining were used to examine the effects of different MC coating on oil penetration elucidate the underlying mechanism of reducing oil content by MC coating. The influence of coating on the sensory quality of CFDC was studied by colorimeter and TPA. The results showed that compared with the control, the two coatings could significantly reduce the oil content of CFDC (p<0.05), with MC performing better in inhibition of oil absorption than SPI. When the MC concentration was 1%, the inhibition of oil absorption was the greatest, with the inhibition rate being 53.77%, and the contents of the surface oil and internal oil decreasing by 58.66% and 45.43%, respectively. Microstructural analysis showed that edible coating could make the surface of CFDC smoother with fewer holes, and while significantly reducing oil penetration depth; All these results indicated that the coating can effectively reduce the oil content of CFDC, make the surface structure denser, and inhibit oil penetration and migration. This study also showed that MC coating had little influence on the color and texture of CFDC, which provides theoretical foundation and technical guidance for further production of CFDC with a low oil content but high quality.
    28  Preparation Study of Chicken Jerky Reconstituted by Flammulina velutipes Polysaccharide Complex
    LI Deng-long WU Bin WANG Yu-tao LIU Xue-ming ZHANG Ye-hui ZHANG You-sheng ZHU Ming-jun CHENG Jing-rong
    2020, 36(1):198-205. DOI: 10.13982/j.mfst.1673-9078.2020.1.028
    [Abstract](344) [HTML](259) [PDF 1005.94 K](569)
    Abstract:
    In this study, Flammulina velutipes polysaccharide was added into chicken jerky, and its overall quality resulted from the addition of Flammulina velutipes polysaccharide, fat and white granulated sugar was studied. Single factor and response surface methodology were combined to explore its optimal formulation and the texture, color, oxidation characteristics and antioxidant activity of the developed products were investigated. The results showed that the optimal formula of the chicken jerky enriched with Flammulina velutipes polysaccharide was 850.00 g/kg chicken breast, 20.00 g/kg salt, 3.00 g/kg compound phosphate, 5.00 mL/kg papain, 3.00 g/kg Flammulina velutipes polysaccharide, 100.95 g/kg fat and 107.59 g/kg sugar. After the addition of Flammulina velutipes polysaccharide, the hardness (13367.92 N), chewability (11048.72N·cm), brightness (L*: 36.10) and yellowness (b*:18.03) of preserved meat were remarkably decreased. Besides, the oxidation degree of product was effectively controlled since the carbonyl and TBARS value of the products were 0.50 nmol Trolox/mg pro and 0.33 MDA mg/100 g, respectively, which were 35.90% and 82.20% lower than those of the control. Meanwhile, the product also showed good antioxidant activity (ABTS scavenging ability: 48.61 nmol Trolox/mg pro; DPPH scavenging ability: 62.85%; FRAP value: 45.17 nmolTrolox/mg pro, respectively). The present study is helpful to improve the added value of traditional chicken jerky and provide theoretical basis for the development of functional meat products.
    29  Preparation and Characteristics of High-oil-load Antarctic Krill Oil Powder Stabilized by Natural Quillaja Saponin
    LI Jin-yu CHEN Xiao-wei YANG Xiao-quan
    2020, 36(1):206-213. DOI: 10.13982/j.mfst.1673-9078.2020.1.029
    [Abstract](354) [HTML](397) [PDF 1.29 M](1024)
    Abstract:
    Antarctic krill oil has attracted much attention as a novel marine functional oil with a very high market value. However, their susceptibility to oxidation and unpleasant flavour has greatly limited their applications in food, medicine and other industries. In this study, antarctic krill microcapsule oil powder was prepared by spray-drying and using natural saponins (QS) as the emulsifier, and its flavour and antioxidant properties were improved through oil phase structuring. Compared with the commercial krill oil powder, QS could stabilize the feed to enable the production of high-oil-load (75%) powder with the encapsulation rate up to 90.01%. Compared with the commercial krill oil powder, the use of QS could effectively mask its fishy smell. Its flavor could still be improved after the addition of a structurant, with phytosterol and oryzanol being the most effective. Moreover, the oxidation stability of the oil powder prepared using QS was higher than that of the commercial krill oil powder. Adding the antioxidant improved oxidation stability, with the addition of ascorbyl palmitate leading to the highest oxidation stability. The product obtained in this study possesses good thermal stability (120 ℃, 30 min), salt ion stability (500 mM) and pH stability (pH 3~11). The addition of food grade SiO2 could further improve fluidity and fast-dissolving properties.
    30  Effect of Drying Method on Drying Rate, Physical and Chemical Properties of Brown Sugar
    DU Xi-shang LIU Jie ZHOU Feng TUO Chao-yue LIU Ming-han XIE Cai-feng
    2020, 36(1):214-219. DOI: 10.13982/j.mfst.1673-9078.2020.1.030
    [Abstract](410) [HTML](226) [PDF 784.43 K](972)
    Abstract:
    In this work, the drying rate, solubility, total phenol content, color value and sugar content of brown sugar were used as indicators to evaluate the effects of hot air drying and vacuum drying at different drying temperatures (45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃) on drying rate and physical and chemical properties of brown sugarby. Results indicated that the two drying methods had significant effects on the drying rate, solubility and total phenol content of the brown sugar (p<0.05), but the color value, fructose content, glucose content and sucrose content were not significantly different (p>0.05). In vacuum drying at 70 ℃, the drying rate was 1.36±0.03 mg water/min, brown sugar had the fastest dissolution time of only 317±6 s, total phenol content was 5.60±0.04 mg GAE/g, retention rate was 94.92%, brown sugar color value was 19900±100 IU, the increase rate was only 10.56%. In conclusion, different methods and different temperatures had a greater influence on the drying rate and physical and chemical properties of brown sugar. The optimal condition of the drying treatment of brown sugar was vacuum drying, and the drying temperature was 70 ℃.
    31  Optimization for Esterification Liquid Preparation of Liquor Yellow Water Esterified with Lipase
    YAN Chen-lin LI Zhan-sheng ZHANG Jia-hui LI Bing-qian LIN Ying
    2020, 36(1):220-226. DOI: 10.13982/j.mfst.1673-9078.2020.1.031
    [Abstract](319) [HTML](348) [PDF 874.20 K](1023)
    Abstract:
    In this study, yellow water, a by-product of Luzhou-flavor liquor, was used as the research material to investigate the influence of processing conditions including the amount of edible alcohol (95%, V/V) for addition, reaction temperature and the amount of Candida antarctica Lipase B (CALB) on the esterification of yellow water. The product refining process was also discussed. The results of single factor experiment and response surface optimization showed that the increases in ester content and aroma were the greatest under the optimum conditions (amount of edible alcohol, 52.5% (V/V); amount of CALB enzyme, 5.32% (W/V); 31.5 ℃ for 48 h), with the contents of ethyl acetate, ethyl lactate, ethyl hexanoate and total ester being 1.81 g/L, 6.09 g/L, 14.49 g/L and 22.39 g/L, respectively, and the concentration of liquor flavor increased by 31.9 times. The conversion rate of the CALB enzyme remained unchanged after it was used repeatedly (10 times). A mixture of liquor aroma-active substances were obtained after distillation and extraction of the esterification reaction product of yellow water, with the total ester recovery rate being 76.56%. This study has shown that yellow water can be used to produce functional esterification liquids such as natural equivalent flavors and liquor-blending liquid. The optimized process required mild conditions and a short reaction cycle and is industrial scalable, leading to a significantly increased ester content. This study is of great significance for the recycling of liquor yellow water resources.
    32  Study on Extraction and Functional Properties of Different Casein in Yak Milk
    WANG Gao ZHOU Wei ZHAO Cun-chao WEI Guang-qiang HUANG Ai-xiang
    2020, 36(1):227-234. DOI: 10.13982/j.mfst.1673-9078.2020.1.032
    [Abstract](400) [HTML](824) [PDF 1.12 M](832)
    Abstract:
    In this work, fresh yak milk was used as a raw material to separate and extract the different casein by adding calcium salt and employing its isoelectric point. Single factor experiments screened the extraction and separation parameters of α-, β-, κ-casein in yak milk. SDS-PAGE was applied to analyze the purity of different casein in yak milk. At the same time, the solubility, emulsification, and foamability of α-, β-, κ-casein in yak milk were analyzed and compared. The results showed that the optimum concentration of Ca2+ and the optimum temperature for casein components separation in yak milk were 0.08 mol/L and 2 ℃, respectively. At this point, the separation effect of α- and β-casein in yak milk was better compared to the other. When different casein in yak milk was close to isoelectric point (pI), the solubility, emulsification, and foaming ability were at the lowest. On the contrary, the foam stability was at its best. The solubility of the casein component which was close to the isoelectric point was the lowest, the solubility of α-, β-casein was at its highest at 2.1 (60%, 80%, respectively), while the κ-casein was at its highest at pH 6.22 (43%). In the range between 40 and 80 ℃, the solubility of κ-casein was significantly affected by temperature. In pH 2.1, the emulsification ability and foaming ability of α-, β-, κ-casein were at the largest, and the emulsion stability was gradually increased from the isoelectric point. This study aimed to provide ideas for the utilization and advanced processing of yak milk casein, as well as providing a scientific basis for the development and utilization of Yunnan’s unique dairy products.
    33  Optimization of the Processing Technology of Guizhou Ciba Chili
    WU Zhao-qing HUANG Qiu-hong YANG Xin LIU Qiu-jiang HU Ping CHENG Hua
    2020, 36(1):235-241. DOI: 10.13982/j.mfst.1673-9078.2020.1.033
    [Abstract](419) [HTML](291) [PDF 979.14 K](2057)
    Abstract:
    In this work, Huaxi pepper, Zunyi Chaotian pepper and Guizhou Lantern pepper were used as the main raw materials, and the salt, ginger, garlic, cooking wine and pepper seeds were used as supplementary materials to prepare Guizhou Ciba chili based on the traditional method. The Box-Behnken response surface method was used to optimize the processing of Ciba Chili and determine the optimum proportion based on the single factor experiment. The results showed that the ratio of Guizhou Huaxi pepper, Zunyi Chaotian pepper and Guizhou Lantern pepper was 3:2:3 (2.60 g:1.70 g:2.60 g). The ratio of ginger to garlic was 1:1 (2.14 g:2.14 g). The frying time of pepper seeds was 30 s (0.83 g). The salt content was 1.50 g. Liquor content was 0.50 mL and cooking for 6 minutes. The sensory score of the Ciba chili production reached 93.87+1.60 with bright color, aromatic flavor, moderate spicy feeling, uniform texture and unique flavor. All physical and chemical indexes and microbial indexes of the Ciba chili met the local safety standard of Guizhou Ciba chili, which had good product quality characteristics. It provided a theoretical basis for the industrial development and promotion of Ciba chili.
    34  Comparative Analysis of Volatiles of Flowery Black Teas and Dancong Teas from Guangdong Province
    MEI Shuang CHEN Wei MA Cheng-ying CHEN Dong QIAO Xiao-yan
    2020, 36(1):242-252. DOI: 10.13982/j.mfst.1673-9078.2020.1.034
    [Abstract](352) [HTML](264) [PDF 927.46 K](599)
    Abstract:
    To provide reference for further understanding the characteristics of tea varieties, black teas and dancing teas processed by tea varieties with different genetic backgrounds as experimental materials, the volatiles were analyzed by gas chromatography and mass spectrometry (GC-MS), extracted by headspace solid phase microextraction (HS-SPME). The characteristic volatiles of black teas from different tea varieties were identified. The results showed that terpene alcohols were the most abundant volatiles in black teas made by tea plants of Hongyan 12 (HY12), Daye qilan 10(QL10), and dancing teas made by Lingtou dancong (LT) and Wuye dancong (WY). Terpene alcohols and aromatic aldehydes were the main volatiles of HY12 and QL10. Terpenes, hydrocarbons, terpene ketones, and fatty ketones were the important volatiles of LT and WY. And indoles may distinguished the flavors between LT and WY. Partial least squares discriminant analysis further confirmed that the aromas had slightly differences between WY and LT, due to similar genetic background and t identical processing technique. The aroma profiles were different between, in term of different genetic background. Therefore, the principal volatiles of all teas were the same through identical processing technique, QL10 and HY12 but the genetic background determines the aroma profile of tea varieties.
    35  Study on the Flavor Improvement of Cooking Liquid and Enzymatic Hydrolysate of Aloididae aloidi
    BU Ying ZHU Lun-wei HE Wei ZHU Wen-hui LI Xue-peng LI Jian-rong LIU He YU Zhi-guo
    2020, 36(1):253-261. DOI: 10.13982/j.mfst.1673-9078.2020.1.035
    [Abstract](486) [HTML](201) [PDF 1013.69 K](797)
    Abstract:
    In this work, the flavor characteristics of free amino acids in the cooking liquid and enzymatic hydrolysate of Aloididae aloidi were studied, and the improvement effect of clam sauce on their flavor was evaluated. The results showed that the total free amino acid in enzymatic hydrolysate of Aloididae aloidi was significantly higher than that of cooking liquid (11685 mg/100 mL vs 2498 mg/100 mL). Moreover, the umami amino acid in enzymatic hydrolysate of Aloididae aloidi and the cooking liquid was 1650 mg/ 100 mL and 696 mg/ 100 mL, respectively. Thus, the flavor contribution of delicious amino acids in enzymatic hydrolysate was greater than that of cooking liquid. The electronic nose sensor had the difference response to each sample, among them, the sensor W5S (sensitive to nitrogen and oxygen compounds) had the largest response value, and the linear discriminant analysis could be used to distinguish each sample completely. The results of gas chromatography-mass spectrometry showed that 47 kinds (mainly aldehydes and alcohols) of volatile flavor substances were identified in 3 clam sauce groups. The relative contents of aldehyde compounds in the cooking liquid group (CG), enzymatic hydrolysate group (HG) and blank group (BG) were 31.73%, 32.39% and 18.48%, espectively. The relative contents of alcohols were 12.90%, 15.43% and 11.16%, respectively. In conclusion, the enzymatic hydrolysate of Aloididae aloidi can effectively enrich and promote the flavor of food, and have the potential to be a new type of natural seasoning.
    36  Comparison and Analysis of Chemical Components and Their Antimicrobial Activity of Essential Oils from Three Artemisia Plants
    GAO Hai-rong WANG Ya-xin XIE Chen LUO Qing LIU Xin-yu WANG Yan QIAN Duo-duo
    2020, 36(1):262-268. DOI: 10.13982/j.mfst.1673-9078.2020.1.036
    [Abstract](424) [HTML](356) [PDF 995.69 K](920)
    Abstract:
    To find effective and green antibacterial preservatives for food, the essential oils of Artemisia argyi, Herba Artimisiae sieversianae and Artemisia japonica from Henan were extracted by steam distillation method, their chemical components were detected and identified by GC-MS analysis. The results showed that the main components of essential oil of Artemisia argyi were Neointermedeol (16.82%), Caryophyllene oxide (10.51%), β-Caryophyllene (6.45%), Terpinen-4-ol (5.22%), endo-Borneol (4.60%), Eucalyptol(4.55%). The main components of essential oil of Herba Artimisiae sieversianae were Caryophyllene oxide (15.24%), Falcarinol (14.34%), Spathulenol (6.61%), 4(15),5,10(14)-Germacratrien-1-ol (6.27%), n-Hexadecanoic acid (5.72%), α-Cadinol (5.19%) . The main components of essential oil of Artemisia japonica sieversianae were Cyclohexanone (30.14%), Caryophyllene oxide (9.74%), 1,2-xylene(4.72%),2-Propenoic acid (4.38%), (3Z,6E)-a-Farnesene (3.88%), (E)-alpha-famesene (3.80%), β-Caryophyllene (3.31%). The three essential oils all contained Caryophyllene, Caryophyllene Oxide, Neointermedeol, (-)-Spathulenol and Terpinen-4-ol with high content. The antimicrobial activity of essential oil of three Artemisia plants was determined by filter paper disk disffusion. Results showed that the three kinds of essential oils had good antimicrobial effects on three tested microbes: Escherichia coli, Micrococcus tetragenus and Bacillus cereus. The antibacterial activity of the essential oil of Artemisia argyi and Herba Artimisiae sieversianae was stronger than that of Artemisia japonica. Therefore, the essential oil of Artemisia plants is expected to be a potential natural antibacterial agent and food preservative.
    37  Effects of Nano-composite Packaging on Volatile Flavor Compounds of Zhuyeqing Liquor
    CHEN Kai-ke
    2020, 36(1):269-274. DOI: 10.13982/j.mfst.1673-9078.2020.1.037
    [Abstract](374) [HTML](233) [PDF 664.63 K](678)
    Abstract:
    The effects of nano-composite packaging on volatile flavor compounds of Zhuyeqing liquor were studied in the research by preparing five types of food grade nano-composite packaging. Three volatile flavor compounds in Zhuyeqing Liquor were determined by high performance liquid chromatography before and after packaging of nano-composites. The similarity of chromatograms before and after packaging was calculated, and the effect of nano-composite packaging on its volatile flavors was analyzed after 200 days of storage. The results showed that the plastic particles and the nano-masterbatch were packaged in a nano-composite with a mass ratio of 75:5, that is, the Model 2 package had the best effect in suppressing the volatilization of flavor substances. The model “2” had the highest similarity with the chromatograms before packaging, which were 95.68%, 96.14% and 97.47% respectively. Compared to liquor without nano-composite packaging, nano-composite packaging model 5 showed the lowest similarity of chromatograms of esters, alcohols and aldehydes, which was only 79.87%, 87.92% and 72.37%. The nano-composite effectively maintained the volatile flavor compounds of Zhuyeqing liquor during storage, and maintained a low membrane permeability by delaying the qualitative change of Zhuyeqing liquor. The research provides a theoretical basis for controlling the quality of Zhuyeqing liquor.
    38  Monitoring Analysis in Four Varieties of Vegetables from Zhanjiang and Their Effects of Washing Methods on the Content of Pesticide Residues
    LIU Shu-min TANG Lan-lan CHEN Zhi-ling JIANG Min
    2020, 36(1):275-280. DOI: 10.13982/j.mfst.1673-9078.2020.1.038
    [Abstract](483) [HTML](306) [PDF 711.99 K](711)
    Abstract:
    In this work, organophosphorus and carbamates pesticide residues of 80 samples obtained from four breeds of vegetables including Chinese cabbage (Brassica campestris L.), lettuce (Lactuca sativa L. var. ramosa Hort.), flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee) and Romaine lettuce (Lactuca sativa var longifoliaf. L.) from local markets in Zhanjiang were detected by enzyme inhibition method according to national standard GB/T 5009.199-2003. Effects of different washing methods (washing with water, salt, rice washing water and edible baking soda respectively) on the pesticide residues in flowering Chinese cabbage and Romaine lettuce were studied. The results showed that the pesticide was found in all samples and the detection rate was 100%.Three samples, which were all Chinese cabbage, were proved to exceed the national standard, and the over standard pesticide residues rate was 0.094%. Four kinds of washing methods all affected the pesticide residues removement from vegetables, and the removement rates were from 9.91% to 96.26%. Compared to the other three methods, the salt water washing had the best effect on wiping out pesticide from the vegetables. The optimal washing effect for flowering Chinese cabbage and Romaine lettuce was soaked in 10‰ of salt water for 20 min.
    39  Degradation of Veterinary Drug Residues by Electrolysis
    CHENG Yong-you LIU Hong-bin MA Feng-wei SUN Yi-peng
    2020, 36(1):281-287. DOI: 10.13982/j.mfst.1673-9078.2020.1.039
    [Abstract](306) [HTML](179) [PDF 745.41 K](576)
    Abstract:
    This study used two commercially available electrolytic cleaners as experimental objects to examine their abilities to degrade veterinary drug residues. The degradation efficiency and influencing factors for the two cleaners to degrade substances like penicillins, sulfonamides, fluoroquinolones, tetracyclines, and β-agonists were investigated by the enzyme-linked immunosorbent assay kit and colloidal gold test strips. The effects of the electrolytic cleaner on the residual veterinary drug in actual pork and pig liver samples were studied by HPLC. The results show that the electrolytic cleaners could effectively degrade penicillins, sulfonamides and β-agonists in aqueous solutions, but exhibited low degradation efficiency towards other compounds such as enrofloxacin, ciprofloxacin and ofloxacin. For the malachite green solution at 50 mg/L, the cleaner 1 (power: DC24V/2.5A) took 6 min for complete degradation, whilst the cleaner 2 (power: DC24V/5A) only required 2 min. For the malachite green solution at100 mg/L, the degradation was completed in 2 min in the presence of NaCl at 100 mg/L and in 4 min with 50 mg/L NaCl, but not completed with 25 mg/L NaCl even up to 10 min. The addition of 0.5% serum to the malachite green solution could not enable the cleaner to complete the degradation within 10 min. The residual amount of salbutamol, enrofloxacin, ciprofloxacin, sulfamethoxazole and sulfamethoxazole pyrimidine remained over 80%, after the pork and pig liver samples were subjected to the cleaner. The experimental results showed that the performance of the electrolytic cleaner was greatly affected by the power of the equipment, type and concentration of electrolyte, presence of serum and state of the samples. The degradation of residual compounds in meat products by using electrolytic cleaners is affected by many influencing factor, thus, this approach cannot ensure the effective removal of veterinary drug residues in meat products.
    40  Early Warning Analysis of Glyphosate Residues Dynamics on Tea Safety Risk
    HUANG Ming PEI Shao-fen SHAO Zeng-lang WANG Xiao-xia TANG Xing-yan HUANG Ye-fei
    2020, 36(1):288-295. DOI: 10.13982/j.mfst.1673-9078.2020.1.040
    [Abstract](367) [HTML](287) [PDF 907.71 K](817)
    Abstract:
    Rapid detection of glyphosate (GLY) and aminomethyl phosphonic acid (AMPA) in different parts of tea trees (roots, stems, leaves) and soils was established by using high liquid chromatography tandem mass spectrometry. The tea tree was extracted with ultrapure water and the soils was extracted with KOH solution. Then, the extracts were purified by C18 solid phase extraction cartridge, before derivatization with 9-fluorenylmethoxycarbonyl (FMOC-Cl) in a sodium borate buffer. The derivatized sample was separated on an Agilent poroshell C18 column using a gradient elution with the mobile phase composed of 5 mmol/L ammonium acetate and acetonitrile containing 0.1% formic acid. Electrospray ionization in positive ion mode, multiple reaction monitoring, isotopic internal standard method were used to study systematically the effects of extraction conditions on GLY detection. The results showed a good linearity between GLY and aminomethylphosphonic acid in the range of 2.5~80 ng/mL, with the correlation coefficient (r2) higher than 0.999 and the limit of quantification as 0.50 mg/kg. For the blank tea tree and soil samples at three spiked levels (0.05, 0.40, 1.60 mg/kg), the average recoveries of GLY and AMPA were 76.95%~112.57% with the relative standard deviations (RSD) as 2.01%~6.83% (n=4). The established method was rapid, sensitive and stable, thus suitable for the determination of GLY in different parts of tea trees and soils. The dynamic analysis of residual GLY showed that the amount of the GLY accumulated in tea leaves was the highest when the dosage applied was 0.3 g/m2. Over time, the amounts of residual GLY in different parts of tea trees and soils gradually decreased with with the degradation rate of GLY in soil being the highest. This research can provide technical support for the subsequent studies on the uptake, translocation and metabolism of GLY in non-target tea trees.
    41  Research Progress on the Effects of Ultrasonic Technology on the Quality of Beef and Its Derived Products
    ZHOU Jian-wei MENG Qian GAO De LIU Dong-hong DING Tian
    2020, 36(1):296-302. DOI: 10.13982/j.mfst.1673-9078.2020.1.041
    [Abstract](728) [HTML](240) [PDF 653.50 K](1034)
    Abstract:
    Ultrasound is an emerging energy-efficient food processing technology that can be used alone or in combination with other processing methods to improve the quality of beef and its derived products. In this paper, the research progress of ultrasonic processing technology applied to beef worldwide was elaborated in terms of sensory quality, protein properties, nutrition and safety. The effects of ultrasonic technology on the tenderness of fresh beef, physicochemical and functional properties of beef protein, as well as the fatty acid profile, amine generation, sterilization, flavor substances of beef products were summarized. Furthermore, this paper discusses the mechanisms of ultrasonic technology to improve the quality of beef as well as the sensory quality, physicochemical properties, nutrition and safety of its derived products, provides prospect on the application of ultrasonic processing technology in beef industry and indicates further research directions associated with this technology.

    Editor in chief:李琳

    Inauguration:现代食品科技

    International standard number:ISSN 1673-9078

    Unified domestic issue:CN 44-1620/TS

    Domestic postal code:46-349

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