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Table of Content

15 August 2021, Volume 42 Issue 15
Invited Papers
Development Status and Strategic Thinking of Cultivated Meat
WANG Shouwei, SUN Baoguo, LI Shilei, LI Yushuang, SUN Jinyuan, LI Yingying
2021, 42(15):  1-9.  doi:10.7506/spkx1002-6630-20210625-297
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With the rapid development of cultivated meat and related industries around the globe, comprehensively analyzing the existing problems and bottlenecks in this field and drawing on the experience of developed European countries and the United States are of great significance for future food development in China. This paper highlights the necessity of developing cultured meat in China in order to alleviate the stress of breeding industries, ensure the safety of meat supply and improve the development level of food science and technology. The current status of the development of cultured meat in developed European countries, the United States and Japan is reviewed with respect to capital investment, regulation and technological development, and the experience that these counties provide to China is summarized. Furthermore, the problems facing the development of this area in our country such as imperfect integration of disciplines, industrial environment, supervisory laws and regulations and key technologies are discussed, and countermeasures and suggestions are proposed for development planning of cultured meat, seeking breakthrough in key technologies, cultivating superior enterprises, and establishing a supervision system.
Basic Research
Effect of Corn Fiber Gum-Whey Protein Isolate Maillard Conjugates on the Stability and in Vitro Digestibility of Curcumin-Loaded Emulsions
ZHU Qiaomei, YU Xiaowen, CHEN Haitao, YIN Lijun
2021, 42(15):  10-18.  doi:10.7506/spkx1002-6630-20200705-058
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In the present study, Maillard conjugates were prepared by reacting corn fiber gum (CFG) with whey protein isolate (WPI), and the effects of CFG-WPI conjugates obtained at different thermal treatment times on the stability of oil-in-water (O/W) emulsions were investigated. O/W emulsions encapsulating curcumin were prepared using different emulsifiers and evaluated for in vitro digestibility. The obtained results indicated that the optimum conditions to prepare CFG-WPI conjugates were as follows: heating temperature 60 ℃, humidity 79% and reaction time 96 h. Compared with CFG, WPI, CFG-WPI physical mixture, CFG-WPI conjugates resulted in smaller particle size and lower clarification index of emulsion systems. In addition, CFG-WPI conjugates increased the resistance of emulsions to external environmental factors such as pH and calcium concentrations, thus significantly improving the stability of emulsions. The in vitro digestion profile of curcumin-loaded emulsions suggested that the presence of CFG retarded the hydrolysis of lipids in emulsions. Compared with WPI, CFG and CFG-WPI mixtures and conjugates improved the bioavailability of curcumin. The particle size of urcumin-loaded emulsions stabilized by CFG-WPI conjugates was an important factor affecting its in vitro digestibility and bioavailability. This study may provide a basis for understanding the formation mechanism and digestion properties of CFG-WPI conjugates-stabilized emulsions, and simultaneously open up a new way to achieve the value-added utilization of CFG.
Quality Change of Tilapia Fillets during Freeze-Thaw Cycles Characterized Based on Fractal Dimension of Microstructure
FU Renhao, WANG Chunling, CHEN Zheng, LIN Xiangdong, FENG Aiguo
2021, 42(15):  19-26.  doi:10.7506/spkx1002-6630-20200722-302
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In order to explore the pattern of changes in the quality of tilapia fillets during freeze-thaw cycles and to elucidate the underlying mechanism, fresh fillet samples weighing approximately (130 ± 10) g were repeatedly frozen at ?4, ?18 or ?30 ℃ and thawed for up to four times and analyzed at each cycle. The correlation between quality parameters and the fractal dimension of the microstructure was analyzed. The porous microstructure formed by ice crystals in frozen fillets was characterized based on the fractal dimension and the quality parameters were measured. The results showed that the fractal dimension decreased with increaing number of freeze-thaw cycles. After four freeze-thaw cycles at ?4, ?18 and ?30 ℃, the fractal dimension decreased from an initial value of 1.925 to 1.815, 1.843 and 1.853, respectively, accompanied by a decrease in the elasticity and hardness as well as total peak area and an increase in the conductivity, total volatile basic nitrogen (TVB-N) content and total color difference ΔE. Overall, these parameters showed less changes with the decrease in freezing temperature. In addition, significant correlations were found between the fractal dimension and these quality indicators (P < 0.05, P < 0.01). Therefore, the fractal dimension has proved to be a novel and feasible method for evaluating the quality of tilapia fillets during freeze-thaw cycles.
Effect of Acid Stress on Acid Resistance, Cell Membrane and Membrane Protein of Salmonella typhimurium
LI Linqiong, HONG Jing, ZHANG Lijun, GAO Yulong
2021, 42(15):  27-36.  doi:10.7506/spkx1002-6630-20201223-261
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Objective: To investigate the effect of repeated citric acid treatment on the acid resistance, cell membrane and membrane protein of Salmonella typhimurium CGMCC 1.1190. Methods: Three acid-resistant strains were obtained after CGMCC 1.1190 was subjected to acid stress in trypticase soy broth (TSB) adjusted to pH 3.0, 2.7 or 2.5 with citric acid, then transferred and incubated repeatedly for 12 times. The D-values, colony morphology, cellular morphology, membrane permeability, membrane fluidity and membrane protein of these acid-resistant strains were determined and compared with each other. Results: The D-values of the acid-resistant strains were increased with increasing number of acid stress treatments. The lower the pH, the larger the D-values and the more significant the differences in the morphology of colonies and individual cells among the three strains. Compared with the original strain, the acid-resistant strains showed a significant decrease in the percentage of dead cells stained by propidium iodide (PI) at pH 2.0 (P < 0.05). It was indicated that acid stress at lower pH led to lower cell membrane permeability to H+ together with an increase in the phase transition temperature (Tm) of cell membrane phospholipids in the acid-resistant strains, suggesting decreased cell membrane fluidity. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated increased expression of cell membrane proteins with molecular mass of 35 to 180 kDa in the acid-resistant strains accompanied by the appearance of new bands with molecular mass of 135 and 180 kDa. Conclusion: Acid stress at lower pH increased the acid resistance of CGMCC 1.1190, made the colonies smaller and the individual cells longer, reduced the cell membrane permeability and fluidity, and increased the expression of some cell membrane proteins and the types of expressed proteins. These changes could be beneficial for the growth of this strain under acid stress, improving its survival.
Physicochemical Properties, Structural Characterization and Hypoglycemic Activity in Vitro of Degraded Polysaccharides from Blackcurrants
XU Yaqin, YANG Haihong, LI Dalong, CHEN Zhe, WANG Libo, YANG Yu
2021, 42(15):  37-43.  doi:10.7506/spkx1002-6630-20200725-344
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The polysaccharide from blackcurrant fruit obtained by microwave-assisted solvent extraction was degraded by the Fe2+-VC-H2O2 method under ultrasonic assistance, and purified by Sepharose 6B column chromatography inton two fractions (DP-1 and DP-2). The results of liquid chromatography showed that the molecular masses of DP-1 and DP-2 were 1.29 × 106 and 1.07 × 106 Da, respectively. Gas chromatography indicated that both polysaccharides were composed of six monosaccharides but with different molar ratios. Fourier transform infrared (FTIR) spectroscopy, periodate oxidation and nuclear magnetic resonance (NMR) spectroscopy proved the existence of α- and β-pyranose rings in the chains of both polysaccharides and that each was mainly composed of six sugar residues. The functional characterization showed that DP-1 and DP-2 had definite moisture absorption and retention abilities and thermal stability. The two polysaccharides had significant inhibitory activity on α-glucosidase and α-amylase with maximum inhibition percentages of (67.45 ± 3.45)% and (73.22 ± 0.48)% for α-glucosidase, and (64.74 ± 2.08)% and (73.28 ± 2.52)% for α-amylase being observed at a concentration of 2.0 mg/mL respectively. Besides, the inhibitory effects of the two polysaccharides on α-amylase were reversible and competitive. Therefore, this study may provide a theoretical basis for further utilization of polysaccharides from blackcurrant fruit.
Purification and Thermal Stability of Geraniin from Rambutan (Nephelium lappaceum) Peels
LI Yujing, SUN Liping, ZHUANG Yongliang
2021, 42(15):  44-49.  doi:10.7506/spkx1002-6630-20200703-036
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Geraniin is a naturally occurring hydrolysable ellagitannin with significant biological activity. Earlier, we have demonstrated that rambutan peel is rich in geraniin. In this study, the rapid separation and purification of geraniin from rambutan peel polyphenols (RPP) extract was carried out by medium-pressure liquid chromatography (MPLC) with a reversed-phase C18 column system and preparative high-performance liquid chromatography (HPLC). The identification of geraniin and its thermal degradation products was conducted by ultra-performance liquid chromatography-quadrupole-orbitirp-mass spectrometry (UPLC-Q-Orbitrap-MS). The results showed that the content of geraniin in freeze-dried rambutan peel was 12.67 g/100 g (on a dry matter basis). Geraniin with a purity of 95.63% and a yield of 6.00% (on the basis of the dry mass of rambutan peel) was obtained. The purified geraniin showed instability to heating. The percentage of degradation loss was 17.13% after treatment at 60 ℃ for 10 hours, and was 73.97% after treatment at 100 ℃ for 2 hours. In the degradation products of geraniin, gallic acid, corilagin, hexahydroxybiphthalic acid, brevifolin carboxylic acid, galloyl-bis-HHDP-glucose, ellagic acid, and brevifolin were detected as phenols with lower molecular mass. The results of the study can provide a discussion on the controlled degradation and bioavailability of geraniin.
Inhibitory Effect of Natural Antioxidants on the Formation of Thermal Processing Hazards in Red Braised Pork
LIU Lichun, JIANG Yujie, SHEN Mingyue, XIE Mingyong, NIE Shaoping
2021, 42(15):  50-57.  doi:10.7506/spkx1002-6630-20200704-045
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This study aimed to explore the inhibitory effects of three natural antioxidants (bamboo leaf antioxidant, tea polyphenols, and rosemary acid) applied at different concentrations (0, 0.1, 0.15, 0.2 and 0.5 g/L) on the formation of thermal processing hazards (acrylamide, trans fatty acids and furan) in red braised pork as a typical Chinese dish. The results showed that the three antioxidants had significantly different effects on the formation of various thermal processing hazards. The inhibition rate of 0.2 g/L bamboo leaf antioxidant on furan formation in red braised pork was 72.7%, and the inhibition rates of 0.15 g/L tea polyphenols on the formation of acrylamide and trans fatty acid were 47.8% and 19.1%, respectively, while rosmarinic acid at 0.5 g/L was able to effectively inhibit all three hazards. The results from this study can provide a technical reference for inhibiting the formation of harmful substances in Chinese dishes.
Effects of Cooking Methods on Flavor Characteristics of Pacific Cod Head Soup
WANG Yuanyuan, LI Xuepeng, WANG Jinxiang, LI Jianrong, LI Tingting, GUO Xiaohua
2021, 42(15):  58-65.  doi:10.7506/spkx1002-6630-20200721-289
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Pacific cod head soups were prepared by various cooking methods, namely atmospheric pressure cooking (AP), high pressure cooking (HP), atmospheric pressure and high pressure cooking (AP-HP), and high pressure and atmospheric pressure cooking (HP-AP) and were evaluated for total solids content, color, sensory score, amino acid nitrogen content, protein content, nucleotide content, organic acid content, flavor characteristics (determined by electronic nose), taste characteristics (determined by electronic tongue) and volatile substances (determined by gas chromatography-mass spectrometry, GC-MS). Our aim was to investigate the effects of these four cooking methods on the flavor characteristics of cod head soup. The results showed that the total solids content and nucleotide content of cod head soup prepared by HP were significantly higher compared with those prepared by the other three cooking methods (P < 0.05), and the whiteness, amino acid nitrogen content, and protein content were also higher. The sensory score and organic acid content of cod head soup prepared by AP-HP was significantly higher than those of the other three groups (P < 0.05). The electronic tongue results showed that the AP group had a weaker umami taste than the other groups, whereas there was no significant difference in the other taste attributes evaluated. The electronic nose results showed that the odor characteristics of the HP and AP-HP groups were similar, but were significantly different from those of the HP-AP and AP groups, which may be due to significant differences in odor components including aromatic compounds, nitrogen oxides, ammonia, alkanes, methane, ethanol, etc.. In total 27, 25, 28 and 40 volatile compounds were identified in AP, HP, AP-HP and HP-AP soup samples. Collectively, these results indicated that high pressure cooking may be a more suitable method for processing cod head soup.
Effects of Ginseng Extracts on Eating Quality of Roast Chicken
ZHOU Yajun, WANG Xuesong, CHEN Yan, WANG Shujie
2021, 42(15):  66-73.  doi:10.7506/spkx1002-6630-20210131-366
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In order to develop high-quality roast chicken marinated with ginseng extracts with good nutritional and health properties, this study explored the inhibitory effects of ginseng extracts on fat and protein oxidation in roast chicken marinated with ginseng extracts and the influence on its eating quality. Roast chicken was prepared by injection of different amounts of hot aqueous extracts of red ginseng (steamed and dried root of Panax sp.), while ginseng (dried root of Panax sp.) and ginseng cultivated under forest, separately and was evaluated for meat shear force, pH, cooking yield, color, texture, protein carbonyl content, protein sulfhydryl content, thiobarbituric acid reaction substances (TBARS) value, and sensory scores. The results showed that the content of total saponins in red ginseng extract was the highest, and the scavenging capacity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonicacid (ABTS) cation radical were the strongest; the contents of polyphenols and flavonoids in understory ginseng extract were the highest. With the increase in ginseng extract dosage, the hardness and chewiness of roast chicken were enhanced, the color parameters L*, a* and b* and protein sulfhydryl content were increased strikingly, and the TBARS value and protein carbonyl content were significantly decreased (P < 0.05). At the same dosage, red ginseng extract had the most significant effect on the contents of protein carbonyl and sulfhydryl groups (P < 0.05), while white ginseng extract resulted in the highest TBARS value. With the increase in ginseng extract dosage, the sensory score of roast chicken increased significantly at first and then decreased significantly (P < 0.05), reaching the highest value at a dosage of 1.0%. Therefore, proper addition of ginseng extracts can improve the color, improve the eating quality of roast chicken, and inhibit the oxidation of fat and protein, with red ginseng being the most effective among the ginseng extracts studied.
Food Engineering
Effects of Low Temperature Plasma Treatment on Flavor Characteristics of Raw and Cooked Brown Rice
ZHANG Peiyin, MENG Ning, LIU Ming, LIU Yanxiang, ZAN Xuemei, TAN Bin, SUN Ying, ZHAI Xiaotong
2021, 42(15):  74-80.  doi:10.7506/spkx1002-6630-20200729-380
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In order to study the effect of low temperature plasma treatment on the flavor characteristics of raw and cooked brown rice, gas chromatography-ion mobility spectrometry (GC-IMS) was used to measure and analyze the characteristic flavor compounds of raw and cooked brown rice before and after low temperature plasma treatment. The differences in the fingerprints of volatile organic compounds in the samples were characterized by data visualization, and the plug-in Matching matrix in the LAV software was used to analyze the similarity among the samples. The results showed that the similarity of the volatile substances between low temperature plasma-treated brown rice (LTP-BR) and brown rice (BR) was 83.25%. The relative concentrations of alcohols, ketones and terpenes in raw BR such as 2,3-butanedione, acetone, eucalyptus monomer, eucalyptus dimer, n-hexanol monomer, n-hexanol dimer, diallyl disulfide, pinene and limonene increased and new compounds responsible for floral, pine-like and other refreshing odors were detected after LTP treatment. The similarity between cooked brown rice (C-BR) and cooked, low temperature plasma-treated brown rice (C-(LTP-BR)) was 89.5%, and the relative concentrations of aldehydes and terpenes in C-(LTP-BR) samples increased. Therefore, LTP treatment had a positive effect on the overall flavor of cooked brown rice, enriching the flavor without producing off-flavor substances. This study provides a theoretical basis and data support for applying low-temperature plasma to improve brown rice flavor.
Quality Evaluation of Instant Potato Congee Treated by Air Puffing Based on Variation Coefficients
BAI Jie, JIANG Huabin, ZHANG Xiaofei, LI Yumei, LI Jingwei, YUAN Nuo, ZHANG Sai, PENG Yijiao
2021, 42(15):  81-88.  doi:10.7506/spkx1002-6630-20200901-005
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In order to explore optimal air puffing conditions for instant potato congee, the effects of different air puffing treatments on the nutritional components, color difference, texture characteristics, rehydration characteristics and volatile aroma components of instant potato congee were studied by combining physicochemical analysis techniques with colorimeter, texture analyzer and gas chromatography-mass spectrometry (GC-MS). Furthermore, a comprehensive quality evaluation was carried out. The results showed that suitable air puffing treatment could reduce moisture content and well preserve the color, total dietary fiber and soluble dietary fiber of potato congee. It also could shorten the rehydration time, improve the rehydration ratio and impart roast nut-like aroma, burnt aroma and the unique aroma of edible tubers to instant potato congee. Based on variation coefficients, water content, volatile aroma components (heterocyclic compounds, aldehydes, hydrocarbons) contents, chewiness, hardness, and rehydration time accounted for a larger proportion of the overall evaluation. The results of the comprehensive evaluation showed that the quality of the potato congee treated at 130 ℃ for 50 s was the best. Scanning electron microscopy (SEM) results showed that potato congee exhibited a porous network structure after air puffing treatment, and the internal structure became swollen and loose. The infrared spectroscopic result showed that the molecular configuration of protein and starch was affected by air puffing treatment. It is concluded that appropriate air puffing treatment could improve the quality of potato porridge and shorten the rehydration time.
Effect of Extrusion Treatment on the Rheological and Film Formation Properties of Corn Flour
FAN Hongxiu, LI Yanxia, LIU Tingting, LIU Hongcheng, WANG Dawei, ZHANG Yanrong
2021, 42(15):  89-98.  doi:10.7506/spkx1002-6630-20210112-121
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The high-temperature and high-pressure extrusion modification technology was used to improve the texture and stability of corn flour. The effects of corn flour particle size, extrusion temperature and water content on the rheological and film-forming properties of corn flour were studied to determine the optimal extrusion conditions. The film-forming mechanism of corn flour was explored by studying the intermolecular interaction and crystal structure of corn flour membrane. Results showed that after high-temperature and high-pressure extrusion the structure of corn flour film became more compact, and the surface became flatter and smoother with significantly fewer holes in it. When the corn flour particle size, extrusion temperature and water content were 120 mesh, 165 ℃ and 34%, respectively, we successfully prepared a corn flour film with high mechanical properties and water resistance as well as low solubility. The extruded corn flour paste had high viscoelasticity and large thixotropic loop area and the molecular interactions of the system were strong. In addition, the extrusion process changed the crystal structure of corn flour from type A to type V, decreased the crystallinity, and partially degraded amylopectin into amylose and low-molecular-mass amylopectin, which easily form a highly ordered molecular chain arrangement to improve the retrogradation and film-forming properties of color flour starch. The interactions among biomacromolecules in the extruded corn flour such as starch, protein and fiber were enhanced, which was accompanied by the formation of strong and stable hydrogen bonds, contributing to the formation of a more compact structure network.
Effect of Ultrafine Grinding on the Quality of Tartary Buckwheat Noodles
CHENG Jiayu, GAO Li, TANG Xiaozhi
2021, 42(15):  99-105.  doi:10.7506/spkx1002-6630-20200924-293
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In order to improve the utilization value of tartary buckwheat and the eating quality of tartary buckwheat noodles, ultrafine grinding technology was used to prepare ultrafine tartary buckwheat flour in this study. The effects of ultrafine grinding and the particle size of ultrafine powder on the farinographic properties of tartary buckwheat dough and the quality characteristics of tartary buckwheat noodles were investigated. It was found that the damaged starch content of tartary buckwheat flour increased significantly with the decrease of particle size (P < 0.05), and the L* value rose from 72.20 to 77.48. Meanwhile, the peak viscosity, trough viscosity and final viscosity significantly increased (P < 0.05). Overall, the application of ultrafine grinding technology improved the gelatinization characteristics of tartary buckwheat flour, thus accelerating dough formation, prolonging dough stability time, increasing dough viscoelasticity, and making the internal network structure of dough more uniform and compact. The breaking rate of noodles made from ultrafine tartary buckwheat flour decreased (P < 0.05) compared with that of noodles made from common tartary buckwheat flour, the optimal cooking time and cooking loss decreased by up to 50% approximately, and the texture characteristics improved significantly.
Effects of Heat Processing Methods on Nutritional Properties and Antioxidant Activity of Lentinus edodes
ZHOU Haoyu, YU Mingjun, NIE Yuanyang, ZHANG Penghui, YANG Wei, LI Bo
2021, 42(15):  106-114.  doi:10.7506/spkx1002-6630-20200724-335
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In order to explore a scientific and reasonable heat treatment method for cooking and processing Lentinus edodes, five processing methods including boiling, microwave, steaming, high temperature and high pressure (HTHP), and deep-fat frying were applied on L. edodes, and the effects of these heat processing methods on the nutritional composition, nutrient bioavailability, and antioxidant activity of L. edodes were studied. The results showed that the contents of polysaccharide, dietary fiber, protein and total phenol, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, and reducing power in L. edodes were significantly reduced by boiling, deep-fat frying and microwave treatment (P < 0.05), while steaming and HTHP treatment did not affect or slightly increased these parameters. The content of ergosterol was increased by 30.22% by boiling and decreased by 24.00% by deep-fat frying, while it was not affected by microwave, steaming and HTHP treatment. The bioavailability of polysaccharides, proteins, and total phenols in L. edodes could be significantly improved by the five heat processing methods (P < 0.05), and the protein content of thermally processed L. edodes had an extremely significantly negative correlation with its bioavailability (P < 0.01), while the contents of polysaccharides and total phenols had no significant correlation with their respective bioavailability (P > 0.05). The antioxidant activity of thermally processed L. edodes was significantly positively correlated with the contents of polysaccharides, total dietary fiber and total phenols (P < 0.05 or 0.01). In general, steaming and HTHP treatment were beneficial to retain the nutrient composition and improve the antioxidant activity of L. edodes. This study provides a useful reference for scientific and reasonable processing, cooking, and consumption of L. edodes and other edible mushroom.
Process Optimization and Kinetic Analysis of Pd/Carbon Nanotubes Catalyzed Transfer Hydrogenation of Soybean Oil
DU Jing, ZHANG Chenchen, WANG Ying, GAO Jiajia, ZHU Xiuqing, YU Dianyu, WANG Liqi, LUO Shunian, SHI Yongge
2021, 42(15):  115-120.  doi:10.7506/spkx1002-6630-20200721-273
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In order to reduce the production of trans-fatty acids during oil hydrogenation, Pd/carbon nanotubes (Pd/CNTs) were used as a catalyst for the transfer hydrogenation of soybean oil. Response surface methodology was used to optimize the reaction conditions based on the iodine value of soybean oil, and the kinetics of the hydrogenation reaction was analyzed. The results showed that the optimum reaction conditions were as follows: hydrogenation temperature 84 ℃, catalyst dosage 0.2%, ammonium formate donor concentration 0.33 mol/50 mL, and hydrogenation time 90 min. The reaction rate constants for trienoic acid, dienoic acid and monoenoic acid were 4.9 × 10-2, 8.7 × 10-3 and 8.31 × 10-4, respectively. The selectivity for hydriding linoleic acid and linoleic acid was as high as 5.63 and 10.47. The iodine value of hydrogenated soybean oil, containing only 10.2% trans-fatty acids, was 95.3 g/100 g. Catalytic transfer hydrogenation has great prospects for application in the preparation of low-trans-fatty-acid hydrogenated oils and can provide a theoretical basis for the development of the oil hydrogenated oil industry.
Nutrition & Hygiene
Effect of Food-Grade κ-Carrageenan on Risk of Colitis and Accumulation of Body Fat in Obese Mice
ZHANG Hui, YANG Ruili, LIU Fang, ZHOU Sainan, LU Na, TANG Qingjuan
2021, 42(15):  121-128.  doi:10.7506/spkx1002-6630-20200729-365
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Objective: To explore the effect of various dosage of food-grade κ-carrageenan on the risk of colitis and the accumulation of body fat in obese mice. Methods: After feeding C57BL/6Cnc male mice with a low-fat or high-fat diet for 5 weeks, the mice fed with the high-fat diet was 22% heavier than those fed with the low-fat diet, indicating that an animal of obesity model was successfully constructed. The mice were divided into seven groups, including normal control (NC), high-fat diet (HFD) model and HFD + 0.05% (H0.05%), 0.5% (H0.5%), 1% (H1%), 2.5% (H2.5%) or 5% (H5%) carrageenan groups. After feeding for 6 weeks, the mice were sacrificed to examine indicators related to colon inflammation and body fat accumulation. Results: Disease activity index (DAI), myeloperoxidase activity and the relative mRNA expression of inflammatory factors in the colon, and colonic physiological structure were not significantly different among all groups (P > 0.05). The secretion of prostaglandin E2 in the colon of mice in the H1% and H2.5% groups decreased by 13.94% and 20.75%, respectively compared to the HFD group (P < 0.05). The body mass, body fat percentage and epididymal adipocyte size of mice in the H5% group decreased by 10.51%, 37.67% and 31.59%, respectively compared with the HFD group (P < 0.05). Conclusion: Dietary addition of 0.05%–5% food-grade κ-carrageenan had no risk of inducing colitis in obese mice, and 5% carrageenan inhibited the accumulation of body fat.
Regulatory Effect of Soluble and Insoluble Dietary Fiber from Tartary Buckwheat on Glucose and Lipid Metabolism in Diabetic Mice
QIU Ju, ZHU Hong, WU Weijing
2021, 42(15):  129-135.  doi:10.7506/spkx1002-6630-20200507-062
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The present study examined the contents and glucose lowering capacities of soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) from tartary buckwheat bran, and it comparatively evaluated the effect of supplementation with the two types of dietary fiber on glucose and lipid metabolism in high-fat diet/streptozotocin-induced diabetic mice. The content of IDF in tartary buckwheat bran was (19.52 ± 0.21)%, approximately 5 times as high as that of SDF ((4.02 ± 0.19)%). SDF was more effective than IDF in lowering blood glucose at the same dose. However, when administered at a dose five times higher than SDF dose, IDF was more effective in lowering serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) than SDF; and promoted insulin secretion, improved glucose tolerance, lowered hepatic total cholesterol (TC) and stimulated the production of short-chain fatty acids (SCFAs) as effectively as did SDF. Therefore, both SDF and IDF could improve glucose tolerance and lower lipid accumulation in serum and liver, which were closely associated with the increase in the production of SCFAs in the cecum content. The results from this study may provide a scientific basis for understanding the regulatory effect of different types of dietary fiber from cereals on glucose and lipid metabolism.
Curcumin Attenuated Hypoxia/Reoxygenation-Induced Injury in LLC-PK1 Cells via Na/K-ATPase/Src Signaling Pathway
ZHAI Bingzhong, ZHANG Lijing, LIU Zhen, CHEN Jianguo, HU Zhihang, MEI Song, HU Wenli, LOU Minhan, WANG Yin, QU Xuefeng
2021, 42(15):  136-142.  doi:10.7506/spkx1002-6630-20200918-237
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Objective: This study aimed to elucidate the role of curcumin as an incomplete promoter of Na/K-ATPase (NKA) in protecting cells from hypoxia/reoxygenation (H/R)-induced injury by inducing the activation of the NKA/steroid receptor coactivator (Src) receptor complex. Methods: The effects of curcumin on the activity and conformation of NKA were determined by NKA screening test. An H/R model was used to simulate oxidative damage in cells. After LLC-PK1 cells were pre-protected with curcumin for 1 h and then treated with hypoxia for 1 h followed by reoxygenation for 3 h, the activity of extracellular lactate dehydrogenase (LDH), cell viability, and the expression levels of Src, phosphorylated steroid receptor coactivator (p-Src), extracellular signal-regulated protein kinases (Erk) and phosphorylated extracellular signal-regulated protein kinases (p-Erk) were examined. Results: Curcumin could inhibit the activity of NKA, change its conformation and activate the NKA/Src signaling pathway through increasing the phosphorylation levels of Src and Erk1/2. However, the co-existence of curcumin and ouabain could increase the activity of NKA and inhibit the over-activation of the NKA/Src signaling pathway. Curcumin attenuated oxidative stress-induced injury in LLC-PK1 cells, decreased the level of LDH activity, increased cell viability, and effectively lowered the expression levels of p-Src and p-Erk. Conclusion: Curcumin has a bi-directional regulatory effect on the NKA/Src signaling pathway. It could protect cells from H/R by inducing the activation of the NKA/Src receptor complex.
Preparation and Evaluation of Carboxymethyl Pullulan-Calcium Complex in Vivo
LI Haiying, YANG Xianghe, WEI Zhenzhen, JIA Bei, YANG Wenzhi
2021, 42(15):  143-149.  doi:10.7506/spkx1002-6630-20200724-330
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Carboxymethyl pullulan-calcium chelate [CMP-Ca (II)] was synthesized by the reaction between water-soluble carboxymethyl pullulan (CMP), prepared from pullulan, and Ca2+ and was structurally characterized by ultraviolet (UV) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Based on the calcium content in CMP-Ca (II) determined by titration, one-factor-at-a-time method and response surface methodology with Box-Behnken Design were used jointly to determine the optimal preparation conditions for CMP-Ca (II). Finally, a Balb/C mouse model of osteoporosis was created to evaluate the efficacy of CMP-Ca (II) as a calcium supplement by measuring bone mass, mineral density and hardness. The results of UV and FTIR showed that carboxyl and hydroxyl groups in CMP chelated with calcium ions. The optimal conditions for preparing CMP-Ca (II) were as follows: Ca2+/CMP mass ratio 2:1, pH 10 and 50 ℃, and the calcium content of CMP-Ca (II) prepared under the optimized conditions was 10.3%. The animal experiment results showed that CMP-Ca (II) was able to improve the bone mass, mineral density and hardness of mice suffering from osteoporosis and reduce serum alkaline phosphatase (ALP) activity, indicating that CMP-Ca (II) could regulate calcium absorption in mice with osteoporosis, relieve osteoporosis and improve bone status. The method for preparing CMP-Ca (II) presented in this study proved to be simple and convenient and could provide a strategy for the development of a new calcium supplement.
The Freshener Inosine 5’-Monophosphate Disodium Aggravates Lipid Metabolic Disorder in Elderly db/db Mice
JIANG Yunjia, LIU Jinyan, XU Saijun, WANG Yang, ZHANG Bin, CHENG Zhong, XU Yang, XIE Yong
2021, 42(15):  150-158.  doi:10.7506/spkx1002-6630-20201009-045
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The freshener inosine 5’-monophosphate (IMP) is a structural analogue of adenosine 5’-monophosphate (AMP), which may activate AMP-activated protein kinase (AMPK) to enhance glucose and lipid metabolism, thus alleviating the symptoms of diabetes and hyperlipidemia. However, no studies have been published to determine whether IMP and its disodium salt (IMP-Na2), a commonly used freshener in our daily life, can regulate glucose and lipid metabolism. In this study, C57/KsJ-db/db (db/db) mice at the age of six months were administered intragastrically with IMP at a dose of 50 mg/(kg mb) daily for 8 weeks. Afterwards, physiological indicators of the mice were measured. C57/BL/6j mice were allocated to a normal control group. Results showed that no significant changes in mouse body mass were observed during the administration period. Blood glucose concentration in db/db mice was lowered, but it was still remarkably higher than that in normal animals. The serum levels of triglyceride, total cholesterol, high-density lipoprotein, low-density lipoprotein, alkaline phosphatase, aspartate aminotransferase, alanine aminotr ansferase, lactate dehydrogenase were increased in the IMP administered group compared to the model group, suggesting that IMP could aggravate hyperlipidemia and liver damage in mice. Molecular interaction analysis revealed that IMP and AMPKγ subunits formed a complex that could activate AMPK to promote the oxidation and decomposition of fatty acids in vivo. In vitro experiments revealed that the lipid-lowering activity of IMP was significantly higher than that of lovastatin. It not only caused fatty acid hyperoxidation in mice to increase reactive oxygen species concentration and consequently cause liver damage, but also caused the accumulation of acetyl-CoA to aggravate lipid metabolism disorders. In conclusion, IMP may cause damage to the liver of elderly people with metabolic syndrome disorders and exacerbate lipid metabolic disorders. Accordingly, new food safety standards for IMP should be established as soon as possible.
Synthesis of Eriocitrin and Its Protective Effect on in Hydrogen Peroxide-Induced Oxidative Damage in Human Umbilical Vein Endothelial Cells
LIANG Zeng’enni, WANG Qiuan, ZHANG Juhua, SU Donglin, FU Fuhua, LI Gaoyang, LIU Wei, SHAN Yang
2021, 42(15):  159-166.  doi:10.7506/spkx1002-6630-20200914-171
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Eriocitrin was successfully synthesized by aluminum trichloride-pyridine demethylation reaction from hesperidin, as confirmed by 1H and 13C nuclear magnetic resonance (NMR), to explore its protective effect and mechanism on human umbilical vein endothelial cells (HUVEC) from hydrogen peroxide (H2O2)-induced oxidative damage. The results showed that eriocitrin had no toxic effect on cells HUVEC, and even significantly promoted the survival of HUVEC cells suffering from oxidative stress though without clear dose dependence (P < 0.05). Eriocitrin significantly reduced the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) content (P < 0.05), increased antioxidant enzyme activities (superoxide dismutase, glutathion peroxidase and catalase) (P < 0.05), up-regulated Bcl-2/Bax protein ratio (P < 0.05) and down-regulated p53 protein expression (P < 0.05). It is suggested that eriocitrin can effectively prevent H2O2-caused damage to HUVEC cells, which is related to its antioxidant activity and inhibition on cell death.
Lactic Acid Bacteria-Fermented Huyou (Citrus paradisi cv. Changshanhuyou) Juice Regulates Diet-Induced Obesity in Mice
YAN Xu, WANG Fangjie, WU Zufang, WENG Peifang
2021, 42(15):  167-173.  doi:10.7506/spkx1002-6630-20200723-317
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In this experiment, we investigated the regulatory effect of Huyou juice co-fermented by Lactobacillus plantarum L1 and Lactobacillus fermentum L2 on high-fat-diet-induced obesity in mice. Mice were adaptively fed with high-fat diet for one week before dividing them into a low-fat diet group, a high-fat diet group, a high-fat diet + fermented Huyou juice group and a high-fat diet + nonfermented Huyou juice group. A high-fat diet induced obese mouse model was successfully established. After eight weeks of oral administration of fermented Huyou juice (FHJ) and non-fermented Huyou juice (NFHJ), serum biochemical indexes and liver antioxidant indexes of mice were analyzed, and liver tissue sections were observed. Compared with the high-fat diet group, the body mass of mice in the high-fat diet + FHJ and high-fat diet + NFHJ groups was reduced significantly, serum total cholesterol, triglyceride and low-density lipoprotein cholesterol concentrations were decreased significantly (P < 0.05), and high-density lipoprotein cholesterol concentration was increased significantly (P < 0.05), indicating that blood lipid levels tended to return to normal. The accumulation of fat in liver tissue was decreased, liver antioxidant capacity was increased, and the activity levels of aspartate amino-transferase and alanine transaminase were lowered, demonstrating that both FHJ and NFHJ alleviated liver injury in obese mice, FHJ being more effective. FHJ showed good probiotic properties in the regulation of obesity in mice and thus could be used as a functional food to reduce body fat and lose body mass. This study may provide a theoretical basis for the deep processing of Huyou resources and the development of health functional products.
Physicochemical Properties of Insoluble Dietary Fiber from Defatted Rice Bran and Its Effect on Intestinal Microbiota of High-Fat Diet Fed Rats
LIU Qian, FAN Yuchuan, LIU Sushi, ZHAO Jieyu, WEI Tao
2021, 42(15):  174-179.  doi:10.7506/spkx1002-6630-20200730-395
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Defatted rice bran is rich in dietary fiber and can be considered a good source of dietary fiber. In this study, rice bran insoluble dietary fiber (RBIDF) was obtained from defatted rice bran by sequential enzymatic treatment and evaluated for surface structure, composition and physicochemical properties. In addition, the effects of intervention with RBIDF on the intestinal microbiota of high-fat diet fed rats were investigated in detail. The composition analysis showed that the content of insoluble diet fiber in RBIDF was approximately 64%, and its surface structure was more loose and porous than that of defatted rice bran. RBIDF possessed improved water/oil-holding capacity and good adsorption capacity for glucose and cholesterol, reaching up to approximately 6.4 and 12.8?mg/g, respectively. RBIDF also exhibited excellent antioxidant properties by scavenging hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Intragastric administration of RBIDF could improve changes in the population and composition of gut microbiota caused by high-fat diet, regulating the intestinal microbiota balance. The results suggested that the RBIDF from defatted rice bran presented excellent bioactivity both in vitro and in vivo. This study could provide a theoretical basis for the development and utilization of RBIDF .
Packaging & Storage
Occurrence Patterns of Alternaria Toxins in Tomatoes Inoculated with Alternaria spp.
QU Jingyao, LIN Yucheng, MAO Xin, LU Guozhu, YUAN Zhipeng, ZHANG Yaoyao, YOU Yanli, LI Yanshen
2021, 42(15):  180-186.  doi:10.7506/spkx1002-6630-20200809-120
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In order to investigate the occurrence patterns of Alternaria toxins in tomato fruit infected with Alternaria, fresh tomatoes were artificially injured, inoculated with a spore suspension of Alternaria spp. tomato and stored at 4 or 25 ℃ for 15 days. Samples were taken at three intervals for analysis by high resolution mass spectrometry (HRMS), and the obtained data were analyzed using MZmine and Xcalibur software. The original mass spectral dataset was processed by MZmine and imported into the global natural products social molecular networking platform to establish a molecular network for visual analysis of the metabolic pathways of Alternaria toxins using feature-based molecular networking (FBMN). The results showed that no toxins occurred in inoculated tomato after storage at 4 ℃. Alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA) and tentoxin (TEN) were all detected after 5, 10 and 15 days of storage at 25 ℃, and altenuene (ALT) was detected only on day 15, with TeA being detected at the highest level in all three samples. The presence of hidden toxins combined with AOH and AME sulfate was confirmed by using the Diagnostic Fragmentation Filtering (DFF) function in MZmine and through exact mass measurement with Xcalibur software. The metabolic pathway diagram established based on FBMN showed that AOH, AME and TeA had more relational networks, and TEN and ALT molecular nodes existed in isolation. This research may provide theoretical support for controlling the occurrence of Alternaria oxins in tomatoes and its preservation.
Effect of Postharvest Melatonin Treatment on Quality and Reactive Oxygen Species Metabolism in Strawberry
HUANG Honghui, GU Lijuan, LI Meilin, ZHENG Yonghua, JIN Peng
2021, 42(15):  187-193.  doi:10.7506/spkx1002-6630-20200819-254
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To evaluate the effect of exogenous melatonin on the quality preservation of strawberry during storage, this work studied the influence of melatonin at different concentrations (100, 300 and 500 μmol/L) on the decay and nutritional quality of strawberry during postharvest storage at 20 ℃. The results showed that melatonin at all concentrations could inhibit fruit decay, delay the decrease of firmness and total soluble solids, and maintain ascorbic acid (ASA) with 300 μmol/L being the most effective concentration. In addition, 300 μmol/L melatonin had a significantly positive effect on the antioxidant capacity of strawberry during storage for up to 12 days at low temperature (4 ℃). It could also slow down the accumulation of malondialdehyde (MDA) and hydrogen peroxide, inhibit superoxide anion radical production, and maintain glutathione (GSH), ascorbic acid content and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX). Moreover, the scavenging capacities of strawberry on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical and hydroxyl radicals were significantly increased after treatment with melatonin. Therefore, melatonin treatment proved to be effective in extending the storage life and maintaining the quality of strawberry.
Comparison of Reactive Oxygen Species (ROS) Metabolism between ‘Golden Delicious’ and ‘Fuji’ Apple Fruit after Harvest
LÜ Jingyi, DING Siyang, ZHANG Junhu, XU Dongle, SUN Mingyu, ZHANG Yingzhi, GE Yonghong, LI Jianrong
2021, 42(15):  194-199.  doi:10.7506/spkx1002-6630-20200801-005
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Changes in reactive oxygen species (ROS) metabolism-related physiological indexes were studied during the postripeness and senescence of ‘Golden Delicious’ and ‘Fuji’ apples stored at (23 ± 2) ℃. The results showed that the firmness of ‘Golden Delicious’ apples decreased faster than that of ‘Fuji’ apples and the respiration and ethylene peaks occurred 49 days earlier in ‘Golden Delicious’ apples than in ‘Fuji’ apples. The rate of superoxide anion radical (O2-·) production and the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) in ‘Golden Delicious’ apples were higher than those in ‘Fuji’ apples during storage. The activities of peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) in ‘Fuji’ apples were lower than those in ‘Golden Delicious’ apples during the whole storage period (P < 0.05, P < 0.01), and their peak activities occurred 63, 56 and 49 days later than in ‘Golden Delicious’ apples, respectively. Although glutathione reductase (GR) activity reached its peak in ‘Fuji’ apples 49 days later than in ‘Golden Delicious’ apples, its peak value was 2.11 times higher than that in ‘Golden Delicious’. Moreover, compared with ‘Golden Delicious’ apples, ‘Fuji’ apples maintained higher ascorbic acid (AsA) content and lower ascorbate peroxidase (APX) activity during postharvest ripening. In conclusion, the ROS level and ROS metabolism-related enzyme activities in ‘Golden Delicious’ apples were higher than those in ‘Fuji’ apples, and the ripening and senescence rate was faster than that in ‘Fuji’ apples after harvest. Thus, the storage life of ‘Golden Delicious’ apples was shorter than that of ‘Fuji’ apples. These data indicate that the storability of different apple cultivars may be closely related to ROS level, but considering the complex ROS production and scavenging system, its relationship with ROS metabolic capacity still needs to be further elucidated.
Preservation Effect of Ozone Treatment Combined with Modified Atmosphere Packaging on Moso Bamboo Shoots
CHEN Lei, HUANG Jie, YANG Rui, ZHOU Zhongyu, BI Xiufang, LIU Xiaocui
2021, 42(15):  200-205.  doi:10.7506/spkx1002-6630-20200709-135
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Moso bamboo shoots were pretreated with ozone water (OW) or ozone gas (OG) and then stored under modified atmosphere packaging (MAP) in order to investigate the effect of the combination of ozone water/gas and MAP (OW + MAP and OG + MAP) on the preservation of bamboo shoots. Changes in decay incidence, crude fiber content, hardness, polyphenol oxidase (PPO) activity and peroxidase (POD) activity during storage at 4 ℃ were monitored. The results showed that the decay incidence, crude fiber content, and hardness of the untreated bamboo shoots increased significantly during storage. After 28 days storage, the decay incidence was 60%, and the crude fiber content and hardness increased by 116.87% and 118.82%, respectively. Compared with the untreated control group, MAP, OW + MAP and OG + MAP could effectively delay the decay and hardening of bamboo shoots, and inhibit PPO and POD activities. Treatment with 9 μL/L OG for 40 min) combined with MAP had the best preservation effect on bamboo shoots; the lowest decay incidence of 15% was observed on day 28, accompanied by an increase in crude fiber content of only 22.69%. It was found that the ozone pretreatment showed a good effect on the preservation of bamboo shoots, with OG being more effective better than OW. Therefore, pretreatment with OG could effectively extend the storage period of bamboo shoots.
Effect of Chitosan Treatment on Disease Index, Disease Resistant-Related Enzyme Activities and Disease Resistance-Related Substance Contents in Passiflora caerulea L. Fruit during Storage
GUO Xin, LIN Yuzhao, LIN Hetong, LI Qian, DUAN Ruiqi, ZHU Wenjing
2021, 42(15):  206-212.  doi:10.7506/spkx1002-6630-20200723-315
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In order to understand the e?ect of chitosan treatment on the postharvest disease development of Passiflora caerulea L. and the underlying mechanisms, freshly harvested fruit (cv. Fujian Baixiangguo 1) were soaked in distilled water (control) and a 1:200 dilution of Kadozan (a novel chitosan formulation) for 5 min, separately, and then stored at (28 ± 1) ℃. Disease index, disease resistance-related enzyme activities and disease resistance-related substance contents were measured every three days. The results indicated that chitosan treatment could significantly reduce disease index of Passiflora caerulea L. fruit during postharvest storage (P < 0.05, P < 0.01); on day 15, the disease index of the treated fruit was 2.21, which was only 55.39% of that (3.99) of the control fruit. In addition, compared with the control fruit, chitosan treated-fruit maintained higher contents of total phenols and lignin, and higher activities of phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumarate CoA ligase (4CL), cinnamyl alcohol dehydrogenase (CAD), polyphenol oxidase (PPO), peroxidase (POD), chitinase (CHI), and β-1,3-glucanase (GLU) in the pericarp. These findings suggested that chitosan treatment could enhance disease resistance of harvested Passiflora caerulea L. fruit, consequently suppress the development of postharvest diseases and prolong the storage life by promoting the generation and accumulation of disease resistance-related substances and increase the activities of disease defense-related enzymes in the pericarp.
Effect of Methyl Jasmonate Treatment on Chilling Injury-Related Physiological Factors and Nutritional Quality of Postharvest Green Bell Peppers
FU Anzhen, ZUO Jinhua, WANG Qing, GAO Lipu, MA Lili, BAI Chunmei, YAN Zhicheng, MU Jianlou
2021, 42(15):  213-219.  doi:10.7506/spkx1002-6630-20210127-302
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In order to explore the effects of methyl jasmonate (MeJA) treatment on the chilling injury-related physiological factors and nutritional quality of postharvest green bell peppers, freshly harvested bell peppers (cv. ‘Jingtian 3’) were dipped in 30 μmol/L MeJA solution or distilled water as control for 10 min and stored at 4 ℃ after shade drying. During storage, the chilling injury index, mass loss percentage, hardness, soluble solid content, total chlorophyll content, the contents of antioxidant substances such as VC, total phenols and flavonoids and malondialdehyde content of green bell peppers were determined as well as the activities of polyphenol oxidase (PPO), peroxidase (POD), ascorbate peroxidase (APX) and catalase (CAT). The results showed that MeJA treatment significantly inhibited chilling injury of green bell peppers, slowed down the reduction of VC, total phenols and flavonoids, and significantly increased the activities of antioxidant enzymes such as PPO, POD, APX and CAT (P < 0.05, P < 0.01), thus enhancing the antioxidant capacity and slowing down the deterioration of green bell pepper quality. In conclusion, MeJA can reduce chilling injury of green bell peppers, and maintain the physiological quality during cold storage, thereby prolonging the storage life.
Reviews
Recent Progress on Nutritional Regulation of Metabolic Reprogramming in Immune Cells
PAN Xiaohua, PAN Lilong, SUN Jia
2021, 42(15):  220-230.  doi:10.7506/spkx1002-6630-20201218-214
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Nutrients, including glucose, lipids and amino acids, fuel metabolic reprogramming of immune cells, and are closely linked to the proliferation, differentiation and function of diverse immune subsets. In this article, we provide a general framework for understanding the metabolic reprogramming and nutritional requirement of immune cells, competition for nutrients between different immune cells, and among immune cells, tumors, and pathogens. In addition, the impact of insufficient nutrients (glucose, lipids and amino acids) on the activation and function of immune cells are also illustrated. The information gathered in this review can be helpful to deeply understand the importance of nutrient availability in regulating immune responses, and potentially guide the prevention and treatment of immune-related diseases.
Progress in Applications of Electrospinning/Electrospraying Based on Electrohydrodynamics in the Food Field
FENG Kun, WEI Yunshan, WU Hong
2021, 42(15):  231-241.  doi:10.7506/spkx1002-6630-20200618-248
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Recently, functional micro/nanomaterials have played an important role in the field of food safety and nutrition. Particularly, the electrospinning/electrospraying based on electrohydrodynamics has been favored by researchers due to its simple equipment requirement, convenient operation, mild conditions and availability to produce micro/nanomaterials with high encapsulation efficiency and good controlled release properties. While its application in the food field is currently still in its early stage, this technology exhibits great potential. Therefore, this review briefly summarizes the definition and classification of electrospinning and electrospraying, focusing on recent progress in their applications in the food field. Also, this review points out their application limitations, which is expected to provide a reference and inspiration for the application of electrohydrodynamic technology in the food field.
Effect of Flavor Substances in Alcoholic Beverages on Ethanol Metabolism in Human Body: A Review
JIANG Yang, ZHANG Cuiying, LI Yu, XIAO Dongguang
2021, 42(15):  242-250.  doi:10.7506/spkx1002-6630-20200525-295
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Flavor compounds in alcoholic beverages (ABs) refer to trace organic components, mainly including alcohols, aldehydes, acids, esters, aromatics and terpenes. Flavor compounds account for approximately 2% of the total volume of ABs, while they play a vital role in the quality, style and typicality of ABs. It has been gradually accepted that flavor substances in ABs affect both their quality and human health, and therefore have drawn increasing research interest.?The metabolism of flavor compounds from ABs (especially flavor skeleton compounds that account for more than 90% of the total amount) in the body can influence the oxidation and decomposition rate of ethanol. This article provides an overview of skeleton flavor components in ABs, and the metabolic mechanisms of ethanol in vivo. In addition, this article reviews the current studies on the effects of flavor compounds in ABs on ethanol metabolism in the body, and gives an outlook on future research directions. It is expected to provide a theoretical basis and guidance for the development of ABs with health benefits.
Recent Advances in Big Defensins of Marine Invertebrates
XU Yanhong, MIN Jun, ZHOU Honglei, ZHANG Yi, LIU Wei, HU Xiaoke
2021, 42(15):  251-260.  doi:10.7506/spkx1002-6630-20200904-053
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Big defensins are cysteine-rich cationic antimicrobial peptides (AMPs) formed by serially connecting the N-terminal hydrophobic domain with the C-terminal β-defensin-like domain. These domains have different antibacterial activities. Moreover, big defensins have conserved salt-stable antimicrobial activity and the N-terminal domain can drive the self-assembly of big defensins into nanonetworks that entrap and kill bacteria. So far, big defensins have been mainly found in the innate immune system of invertebrate animals and amphioxus that is a primitive chordate holding a key phylogenetic position bridging from invertebrates to vertebrates. Moreover, the C-terminal domain of big defensins has similar structure and bioactivity to the β-defensin of vertebrates, which has aroused interest in investigating the biological evolution and function of defensins and the evolution of the immune system in species related to defensins. Based on the progress that has been made in the identification and characterization of big defensins in recent years, herein we present an integrated review of the molecular structures and evolution of big defensins, together with their antibacterial mechanism and expression regulation as well as their application prospects in the fields of aquaculture and aquatic product safety and in the development of new antimicrobial drugs. This review will provide a reference in the application of big defensins.
Recent Progress on Shelf-Life Prediction of Aquatic Products during Storage and Transportation
WANG Hongli, WANG Xichang, SHI Wenzheng, ZHOU Fen, WANG Yueke
2021, 42(15):  261-268.  doi:10.7506/spkx1002-6630-20200603-038
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Aquatic products are prone to physicochemical, microbial and sensory changes during postmortem storage and transportation because of their high water and highly unsaturated fatty acid contents and high endogenous protease activity as well as the combined action of exogenous microorganisms and endogenous enzymes, resulting in quality deterioration. Modeling the shelf-life of aquatic products based on changes in sensitive indexes is of great significance to the rapid prediction and evaluation of the quality of aquatic products. This paper summarizes the connotation of and the methods (isothermal method and accelerated shelf-life testing method) used for the shelf-life prediction of aquatic products during storage and transportation and the classification of shelf-life prediction models established, and it reviews the recent progress in this research area, with the aim of providing a new idea for modeling for the shelf-life prediction of aquatic products.
Progress in Detection Techniques for Biogenic Amines in Aquatic Products
LIU Yanan, LI Huan, CHEN Jian, SU Laijin, FU Linglin, WANG Yanbo
2021, 42(15):  269-277.  doi:10.7506/spkx1002-6630-20210221-229
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Aquatic products are rich in protein and other nutrients, which are easily contaminated by microorganisms during processing or storage, leading to spoilage. Previous studies have found that this process is often accompanied by the production of a large number of biogenic amines. Further studies have shown that excessive intake of biogenic amines will cause food poisoning. Therefore, effective methods for detecting the contents of biogenic amines in aquatic products are of great significance for ensuring the safety of aquatic products. In view of this, this paper summarizes the formation mechanism and toxicity of biogenic amines and the maximum residue limits for them adopted by different countries, and discusses in depth the indirect and direct methods commonly used to detect biogenic amines, with a view to providing support for more accurate and efficient detection, prevention and control of biogenic amines.
Advances in Technologies for Identification of Geographical Characteristics of Baijiu
LU Xiangkai, YANG Biao, FAN Baomin, SUN Hui, ZHANG Huijuan, SUN Xiaotao
2021, 42(15):  278-284.  doi:10.7506/spkx1002-6630-20201010-069
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Due to the differences in raw materials and microbial communities during the fermentation process, Baijiu possesses unique geographical characteristics in terms of trace elements, isotopes, and flavors, which can be identified through instrumental analysis combined with chemometrics. Based on the origins of the geographical characteristics of Baijiu, the instrumental methods for the identification of raw materials and microbial fermentation products such as inductively coupled plasma mass spectrometry (ICP-MS), isotope ratio mass spectrometry (IRMS), chromatography, spectrometry, and biomimetic sensors are reviewed. The application fields and defects of these methods are proposed and the crucial issues and future trends in the identification of the geographical characteristics of Baijiu are discussed. We believe that this review will provide a reference for the analysis and identification of Baijiu.
Progress in Preparation and Application of Zein-Based Nanoparticles
GE Sitong, JIA Rui, LIU Huimin, ZHENG Mingzhu, CAI Dan, LIU Jingsheng
2021, 42(15):  285-292.  doi:10.7506/spkx1002-6630-20210127-297
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Zein is the major storage protein of corn, and a natural amphiphilic polymer material. Based on the fact that zein can self-assemble and has different dissolution characteristics in different solvents, it can be used to prepare various types of nanoparticles to encapsulate bioactive compounds or stabilize emulsions. Recently, increasing studies focus on zein-based nanoparticles in the field of food and nutrient delivery, which suggest that zein-based nanoparticles with improved stability, higher encapsulation efficiency and loading capacity for bioactive compounds can be prepared by complexing zein with proteins, polysaccharides, polyphenols, surfactants or other substances. Herein, we summarize the preparation methods and applications of zein-based nanoparticles and discuss existing problems in order to provide a theoretical reference for the application of zein in the food field.
Progress in Quality Changes and Control Technologies of Frozen Aquatic Products during Cold Chain Circulation
HAN Xinyuan, FAN Zhenyu, CONG Jiaojiao, JIANG Qingqing, WANG Xichang
2021, 42(15):  293-299.  doi:10.7506/spkx1002-6630-20200721-281
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Aquatic products are popular among consumers due to their rich nutrients and unique flavor. However, temperature fluctuations during cold chain circulation will lead to a decrease in the nutritional value and deterioration of the eating quality of frozen aquatic products. The influence of temperature fluctuations on the quality properties of frozen aquatic products and its underlying mechanism are reviewed in this article, and the emerging technologies to improve the quality of frozen aquatic products are also summarized from multiple perspectives. We believe that this review which will provide a theoretical basis and technical guidance for the quality maintenance and control of frozen aquatic products during cold chain circulation.
A Review on Thickening, Gelling and Emulsifying Properties of Polysaccharides
LI Xiuxiu, SHANG Jing, YANG Xi, XUE Jia, GUO Yurong
2021, 42(15):  300-308.  doi:10.7506/spkx1002-6630-20200617-239
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Polysaccharides are renewable natural macromolecules, which possess remarkable rheological properties and can function as a thickening, gelling, and emulsifying agent. Therefore, polysaccharides are commonly used as additives in the food industry. However, polysaccharides are complex with diverse structures and rheological properties. A limited number of studies regarding the rheological properties of food polysaccharides have been reported in China. Beginning with an overview of the nature of polysaccharides as water-soluble macromolecules, this paper summarizes the basic principle for the use of polysaccharides as a thickening, gelling and emulsifying agent and the factors affecting the gelation of food polysaccharides. Besides, the mechanism of intermolecular aggregation of non-gelable polysaccharides and amphiphilic polysaccharides is discussed. This review is expected to provide theoretical references for further applications of polysaccharides in the food industry.
Beneficial Effects of Yeasts and Applications in Foods
MU Zhiyong, YANG Yijin, WANG Guangqiang, XIONG Zhiqiang, SONG Xin, LI Guohui, AI Lianzhong, XIA Yongjun
2021, 42(15):  309-318.  doi:10.7506/spkx1002-6630-20200609-123
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Yeast is closely related to our daily life and is widely used in the food, beverage, feed and industrial alcohol fields. Apart from functioning as a fermentation starter, yeast shows important probiotic properties. Compared with traditional probiotics, yeast is more effective in the treatment of diarrhea, immunity improvement and nutritional enhancement. In addition, yeast produces metabolites (carbon dioxide and ethanol) that contributes positively to the varieties and flavor of foods. While numerous studies about the application of yeast have been reported, its probiotic function has been rarely concerned. In this paper, we review recent applications of yeast in antibacterial treatment, lowering cholesterol levels and diarrhea treatment, as well as in the production of alcohol, dairy products and enzymes. Besides, the safety, application limitations and prospects of yeast are also discussed.
Progress in Common Food Allergens and Technologies for Their Detection
NING Yawei, YANG Zheng, MA Mengge, LIU Zhuo, CHEN Yi, ZHAO Zhongqing, LI Qiang, ZHANG Yan
2021, 42(15):  319-328.  doi:10.7506/spkx1002-6630-20200614-191
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In recent years, the incidence of food allergy is increasing, so that food safety issues caused by food allergic reactions have gained extensive attention. Although at present, there is yet no effective treatment for allergic diseases, to avoid foods containing allergens is the most effective method for preventing allergic reactions. Therefore, allergen detection and labeling are of important warning significance for allergic people. This article introduces readers to the structures and characteristics of eight common food allergens, and summarizes the three major detection methods for allergens, namely protein-based immunological assays, gene-based molecular biological technology and mass spectrometry with a focus on their advantages and limitations. Furthermore, potential future directions in this area are discussed.
Progress in Understanding the Effect of Enzymatic Modification on Gel Properties of Soy Protein Isolate
WANG Jiarong, DING Yangyue, JIANG Yunqing, DONG Heliang, WANG Qiuye, CHENG Jianjun
2021, 42(15):  329-336.  doi:10.7506/spkx1002-6630-20200602-023
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Soybean protein isolate (SPI) has high nutritional value and good functional properties. The alkali dissolution and acid precipitation method is conventionally used to prepare SPI, which, however, is prone to cause partial protein denaturation, thus yielding thermodynamically stable water-insoluble large aggregates and/or precipitates. This phenomenon has an unfavorable impact on the gel properties of SPI. In practice, SPI can be modified physically, chemically or enzymatically to improve its gel properties. It is difficult to control the degree of denaturation of physically or chemically modified SPI due to low specificity. In contrast, enzymatic treatment has received extensive attention due to its mild reaction conditions, high product yield, and safety in the production process. This article reviews the effects of different enzymatic modification methods on the formation and performance of SPI gel, and describes the formation mechanism of SPI hot gel and cold gel. Meanwhile, an overview of the effects of limited enzymatic hydrolysis, enzyme-induced side chain grafting reaction and enzyme-induced cross-linking reaction on the formation of SPI gel is presented, and future prospects for the development and application of enzymatically modified SPI gel are discussed.
Progress in Understanding the Stress Response Mechanisms and Functions of Aroma Compounds in Tea
YAN Zhen, WANG Dengliang
2021, 42(15):  337-345.  doi:10.7506/spkx1002-6630-20200910-117
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Tea aroma is an important part in the sensory evaluation and commercial description of tea. During preharvest growth and postharvest processing, tea synthesizes, accumulates and releases aroma compounds in response to various stress factors. The accumulation of aroma compounds is beneficial to improve tea aroma quality and to develop the stress defense mechanism. This paper reviews recent progress in understanding the mechanism of the regulation of aroma compounds metabolism in tea in response to biological stress factors such as leaf-eating pests and pathogen infection, as well as abiotic stress factors such as environmental factors and processing and evaluates its application value in practice. We believe that this review provides a theoretical basis for improving tea aroma quality and preventing tea plant diseases and insect pests.
Progress in Bioactive Selenium-Containing Peptides
JIA Lei, XIANG Jiqian, YIN Hongqing, HE Hui, HOU Tao
2021, 42(15):  346-355.  doi:10.7506/spkx1002-6630-20200428-368
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Selenium is an essential trace element for human growth and metabolism, and bioactive selenium-containing peptides are an important organic source of selenium. Besides the nutritional value of selenium and its derivatives, various potential health benefits of selenium-containing peptides have been gradually discovered. While selenium-containing peptides are mostly isolated from selenium-enriched plants, selenium resources are unevenly distributed and the existing production technologies have some limitations, making it impossible to meet the industrial production requirements. Moreover, the structure of selenium-containing peptides has not yet been systematically explored so that there is no sufficient evidence to support the structure-activity relationship of selenium-containing peptides. The development of proteomics and peptidomics helps researchers better understand selenium-containing peptides. Based on recent studies in China and abroad, this article summarizes the biological functions of selenium and its metabolic pathways, as well as the sources, preparation methods, biological activities and structural characteristics of bioactive Se-containing peptides. A comparison of the biological activities of Se-containing peptides and their selenium-free counterparts is presented as well. We expect that this review will theoretically guide further research and development of bioactive Se-containing peptides.
Progress in Analytical Methods for the Determination of Deoxynivalenol and Its Derivatives
LIU Hui, WU Ying, HUANG Hua
2021, 42(15):  356-365.  doi:10.7506/spkx1002-6630-20200529-360
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Deoxynivalenol (DON), a type B trichothecene mycotoxin mainly produced by Fusarium graminearum infecting cereal crops such as wheat. DON is currently the most common mycotoxin found in cereal and cereal products, which has obvious toxicity and can cause acute or chronic toxic effects on both animals and humans through consumption of contaminated feeds and foods. Therefore, in order to protect consumers’ health and minimize economic loss, it is urgent to establish efficient, simple, and rapid analytical techniques to detect DON and its derivatives in agricultural products. In this review, the common analytical methods for detecting DON and its derivatives qualitatively and quantitatively are summarized. The highlights of newly emerging technologies and their potential applications are also discussed. The information provided in this review will be used for the scientific selection of an appropriate method for detecting DON and its derivatives.