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15 July 2019, Volume 40 Issue 13
Basic Research
Effect of Cytoskeletal Protein Degradation on Texture of Grass Carp (Ctenopharyngodon idella) during Ice Storage
JIA Shengnan, YANG Fang, ZANG Jinhong, XIA Wenshui, JIANG Qixing, XU Yanshun, YU Peipei
2019, 40(13):  1-7.  doi:10.7506/spkx1002-6630-20180721-270
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The aim of this work was to investigate the changes of cytoskeletal proteins in the dorsal muscle of grass carp (Ctenopharyngodon idella) during ice storage by immunohistochemistry, and to analyze the changes in the microstructure and textural properties by ultrastructural observation and measurement of shear force and drip loss. In addition, this study clarified the relationship between the degradation of cytoskeleton protein and the deterioration of fish texture, which will a provide theoretical foundation for the quality preservation of freshwater fish. The results showed that cytoskeleton proteins significantly degraded during ice storage. Titin, nebulin, and dystrophin degraded by 76.10%, 78.21%, and 71.14%, respectively. The light and dark bands of grass carp muscle fibers were unclear after 14 days of ice storage. The Z-band and M-band were degraded. and the muscle fiber structure severely broke or became loose. Meanwhile, shear force rapidly decreased from 81 N to 32 N within 10 days of storage, while drop loss increased from 1.6% to 7.8%. Correlation analysis indicated a significantly positive correlation between shear force and the integrated option density (IOD) of titin and dystrophin (P < 0.01). In contrast, a significantly negative correlation was observed between drip loss and the IOD of titin and dystrophin (P < 0.01). The above results showed that the degradation of cytoskeletal proteins may be an important cause of the destruction of muscle fiber and textural deterioration of grass carp during ice storage.
Effects of Two Different Feeding Patterns on Umami Substances and Expression of Related Genes in Sunit Sheep Meat
LUO Yulong, LIU Chang, LI Wenbo, WANG Bohui, DOU Lu, ZHAO Lihua, DU Rui, WANG Zhenggang, JIN Ye
2019, 40(13):  8-13.  doi:10.7506/spkx1002-6630-20180629-518
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The objective of this study was to investigate the difference in taste characteristics, umami substances and the expression of umami-related genes in Longissimus dorsi, Biceps femoris and Triceps brachii muscles from Sunit sheep subjected to two different feeding patterns (grazing and stall feeding). Sunit sheep were slaughtered at the age of 12 months for the collection of muscle samples. The results showed that the umami and saltiness of meat from grazed sheep were higher than those of stall-fed sheep, while the bitterness and astringency were lower than those of the latter. The contents of inosine monophosphate (IMP) and inosine (INO) as umami substances in meat from grazed sheep were significantly higher than in meat from stall-fed sheep (P < 0.05). The expression of adenosine monophosphate deaminase 1 (AMPD1) gene in Longissimus dorsi of grazed sheep were significantly higher than that in stall-fed sheep (P < 0.05), and there was also a significant increase in the expression of adenylosuccinate lyase (ADSL) and aminoimidazole carboxamide ribonucleotide transformylase (ATIC) gene in Biceps femoris (P < 0.05). For grazed sheep, a significant positive correlation was found between the expression of AMPD1 and ADSL (P < 0.01). Correlation analysis showed that IMP content was positively correlated with the expression of AMPD1 highly significantly (P < 0.01) in grazed sheep and with the expression of ATIC significantly (P < 0.05) in both grazed and stall-fed sheep. Finally, we concluded that when the expression of umami-related genes was increased, there was a concomitant increase in the content of umami substances.
Effect of Drying Temperature on Fatty Acid Composition in Air-Dried Beef during Chilled Storage
LI Yuhui, WANG Jungang, LIU Chengjiang, GUO Anmin, HAN Dongyin
2019, 40(13):  14-21.  doi:10.7506/spkx1002-6630-20180812-103
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To investigate the effect of drying temperature on lipid oxidation and fatty acid composition in air-dried beef during chilled storage, beef round from Xinjiang brown cattle was marinated and then air-dried at different temperatures (20 ℃ for 48 h, 40 ℃ for 20 h, 50 ℃ for 12 h, or 60 ℃ for 8 h). After being cooled down to room temperature, the meat samples were stored in a refrigerator at 4 ℃. Sampling occurred on days 0, 15, 30 and 60 for analysis of changes in pH, peroxide value (POV), acid value (AV), thiobarbituric acid reaction substrate (TBARS) value, and the lipid content and fatty acid composition of total intramuscular lipids, phospholipids, triglycerides and free fatty acids. The results showed that the pH value of air-dried beef decreased first and then marginally increased with the prolongation of storage time (P > 0.05). Air-drying temperature significantly affected the fat content (P < 0.05), whereas storage time had no significant effect (P > 0.05). The POV, AV and TBARS value of the samples dried at the same temperatures increased with storage time. Drying temperature had no significant effect on intramuscular fatty acid composition or the contents of triglycerides and phospholipids in air-dried beef, but increasing drying temperature led to marked increases in free fatty acid content. Compared with air drying at 20 ℃,the free fatty acid content in the sample dried at 60 ℃ increased by 0.84%, 1.82%, 1.45%, and 1.14% after 0, 15, 30 and 60 days of storage, respectively. For the samples dried at 50 and 60 ℃, a preferential hydrolysis of polyunsaturated fatty acids (PUFA) in phospholipids was observed, as demonstrated by a marked decrease in the percentage of PUFA in phospholipids whereas a significant increase in the percentage of PUFA in free fatty acids existed during storage. Therefore, the results of this study provide insights into why air drying temperature can affect flavor formation during the processing of air-dried beef.
Antimicrobial Activity and Mechanism of Carvacrol against Enterobacter cloacae
ZHOU Qi, YUAN Kang, LIU Fang, DU Lihui
2019, 40(13):  22-27.  doi:10.7506/spkx1002-6630-20180630-540
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Carvacrol has a good bacteriostatic effect and can meet people’s requirements for safe food preservatives without any toxic or side effects. In the present study, the minimum inhibitory concentration (MIC) and bactericidal activity of carvacrol against Gram-negative Enterobacter cloacae (C4) were detected, and the cell membrane potential and extracellular ATP content of E. cloacae treated by carvacrol were measured. A laser scanning confocal microscope was used to detect the cell permeability, and a scanning electron microscope was used to observe the cell morphology. Furthermore, the antibacterial mechanism was discussed. The results showed that the MIC of carvacrol against E. cloacae was 0.5 μL/mL. The permeability of the cytoplasmic membrane was increased when the carvacrol concentration was raised from 0.25 to 2 μL/mL. The membrane potential changed and ATP leaked out from the cells after this treatment. Scanning electron microscope (SEM) images revealed the treated bacterial cells became dry and cracked. Carvacrol concentrations above 1 μL/mL almost solubilized the bacterial cells. Thus, carvacrol may exert its inhibitory effect on E. cloacae mainly by simultaneously changing the cell membrane permeability and the cell membrane potential, thereby resulting in massive leakage of intracellular components, such as ATP.
Impact of CO2 De-astringency on Physicochemical Properties, Phenolic Compounds and Antioxidant Capacities of Persimmon Fruit
CHEN Jiaxin, ZHOU Mo, BI Jinfeng, LI Xuan, GUO Chongting, CHEN Qinqin, XIN Guang
2019, 40(13):  28-35.  doi:10.7506/spkx1002-6630-20181023-265
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In our present experiment, persimmon fruit were treated with CO2 for different periods of time (0, 12, 20, 28, 36 and 44 h) for the removal of astringency, and the physicochemical properties, the contents of sugar, total phenolics, total flavonoids and tannic acid and antioxidant capacity during the de-astringency process were investigated. The results showed that treatment time had no obvious influence on the hardness, water content, water activity, pH or carbohydrate content of persimmon fruit. However, the soluble solid value and total phenolic content exhibited significant downward trends with increasing treatment time. Through gradient ultrafiltration, the phenolic compounds were separated into three fractions according to their weight average molecular mass (MW), including high molecular mass phenols (HPs, MW > 10 kDa), medium molecular mass phenols (MPs, 10 kDa > MW > 3 kDa) and low molecular mass phenols (LPs, MW < 3 kDa). The contents of HPs decreased significantly with treatment time (P < 0.05), MPs were not detected, and the contents of LPs were kept unchanged during the process (P > 0.05). Moreover, the 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical, 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacities and ferric ion reducing antioxidant power of persimmon fruit were decreased by 95%, 96% and 96% after de-astringency treatment, respectively. The results illustrated that the phenolic compounds in persimmon fruit were mainly composed of high molecular mass tannins and low molecular mass polyphenols. High molecular mass tannins were the main contributors to the antioxidant capacities of persimmon fruit, but many of them were lost during the de-astringency process.
Suitability Evaluation of Different Citrus Varieties for Whole Fruit Juice Processing
LI Qili, SUN Junjie, SHAN Yang, FU Fuhua, YANG Ying, LIU Wei
2019, 40(13):  36-44.  doi:10.7506/spkx1002-6630-20180624-453
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In order to evaluate the quality of whole citrus fruit juice, 30 different citrus varieties (including Satsuma mandarin, ponkan, ‘Bingtang’ sweet orange and navel orange) from 7 regions in China were collected and determined for 18 indicators such as physicochemical, nutritional and processing properties. Principal component analysis (PCA) was applied to choose the best varieties suitable for whole citrus fruit juice processing. It was shown that there were significant differences in the number of seeds, and the contents of total flavonoids, limonoid and nomilin among different varieties; however, the differences in juice yield, L value, and b value were small. The results of factor analysis showed that the first six principal component factors including bitterness, processing, color, nutrition, acidity, and sweetness were extracted with eigenvalue over 1 and a cumulative contribution rate of 82.566%. Moreover, Newhall navel orange, ‘Fuben’ navel orange I, ‘Fuben’ navel orange II, ‘Bingtang’ sweet orange, ‘Daozhou’ navel orange, and ‘Langfeng 7904’ navel orange showed the best suitability for whole fruit juice production. The results in the present paper can provide a useful guidance for selecting proper citrus varieties for whole fruit juice processing.
Analysis of Starch Properties and Huangjiu Flavor from Three Sorghum Varieties
WANG Zhiwei, YAN Fengxia, XU Jialiang, LIU Qingshan, REN Qing
2019, 40(13):  45-51.  doi:10.7506/spkx1002-6630-20180528-388
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Huangjiu was made from ‘JZ 22’, ‘JLB 2’ and ‘JLB 3’ sorghum, and the effect of sorghum starch on the flavor quality of Huangjiu was studied. The starch, amylose, protein and fat contents and other physicochemical indexes of the sorghum varieties were detected. The endosperm morphology was analyzed by scanning electron microscopy. Then starch was extracted from each variety and their solubility and swelling power were tested. The gelatinization properties of starch were tested by differential scanning calorimetry. Changes in the kinds and contents of volatile flavor substances during the fermentation process were determined. The results showed that a total of 102, 109 and 110 volatile substances were detected in ‘JZ 22’, ‘JLB 2’ and ‘JLB 3’ wines at concentrations of 392.210, 344.342, and 635.695 mg/L, respectively. Among them, 2-methyl-1-propanol, 3-methyl-1-butanol, phenylethyl alcohol, hexadecanoic acid ethyl ester, 9,12-octadecadienoic acid, ethyl ester and 2-methoxy-4-vinylphenol were the major flavor substances. The amylopectin content of ‘JLB 3’ wine was the highest, and it contained the largest number and amount of flavor substances, indicating that starch had a positive effect on the types and contents of flavor substances in Huangjiu. This study provides a theoretical basis for raw material selection for Huangjiu.
Effect of Mechanical Force during Turning-over on the Formation of Aliphatic Aroma in Oolong Tea
ZHOU Ziwei, YOU Fangning, LIU Binbin, DENG Tingting, LAI Zhongxiong, SUN Yun
2019, 40(13):  52-59.  doi:10.7506/spkx1002-6630-20180528-377
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Turning-over is the core processing stage for the formation of aroma quality of oolong tea. In order to understand the effect of mechanical force during the turning-over process on the formation of aliphatic aroma compounds in oolong tea leaves, fresh tea leaves, turned-over tea leaves and spread tea leaves (collected at the same time point) of the oolong tea cultivar Camellia sinensis cv. Maoxie were used as test materials. We detected the contents of linoleic acid and linolenic acid by ultra-performance liquid chromatography tandem mass spectrometry, which are considered the precursors of fatty acid metabolism. The results showed that mechanical force during turning-over could significantly reduce the contents of linolenic acid and linoleic acid in tea leaves (P < 0.05), while spreading treatment could significantly only reduce the content of linoleic acid in fresh leaves (P < 0.05), although the content of traumatic acid in the spread tea leaves was lower than that of fresh tea leaves, it was still significantly higher than that of the turn-over tea leaves (P < 0.05). Also, we detected the contents of aliphatic aroma compounds in each kind of tea leaves by headspace-gas chromatography-mass spectrometry, and the results displayed that under the mechanical force, the relative content of C6-aldehydes in turned-over tea leaves descended significantly, whereas the contents of C6-alcohols and leaf alcohol ester derivatives increased obviously. The contents of C6-alcohols and leaf alcohol ester derivatives in spread tea leaves were far lower than in turned-over tea leaves. The results of quantitative polymerase chain reaction (qPCR) demonstrated that the LOX1 and ADH genes had a higher relative expression level in turned-over tea leaves, while the LOX2, LOX3 and HPL genes had a higher relative expression level in spread tea leaves. The correlation analysis illustrated that a highly significant negative correlation between the relative expression level of LOX1 and C6-aldehydes content for each kind of tea leaves (P < 0.01), and a significant positive correlation between the relative expression level of LOX1 and C6-alcohols content and leaf alcohol ester derivatives content (P < 0.05). In addition, a highly significant positive correlation between the relative expression level of ADH and leaf alcohol ester derivatives content. On the other hand, there was no significant correlation between the relative expression level of LOX2 and HPL and each aliphatic aroma compound (P > 0.05). To sum up, the LOX1 and ADH genes were up-regulated during turning-over, suggesting a close relationship with the formation of natural floral or fruity aroma of oolong tea.
Identification of Antioxidants Produced by Bacillus subtilis natto in Liquid-State Fermentation of Buckwheat
ZHAO Mouming, ZOU Ying, LIN Lianzhu, WU Jian
2019, 40(13):  60-67.  doi:10.7506/spkx1002-6630-20180610-146
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The composition and structure of phenolics produced during the liquid-state fermentation of buckwheat using Bacillus subtilis natto were identified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). In addition, antioxidant peptides were isolated from the fermentation broth by ultrafiltration, alcohol fractionation, and macroporous resin column chromatography. The peptide profile was identified by UPLC-MS/MS. Eight phenolic compounds including caffeic acid, protocatechuic acid, syringic acid, chlorogenic acid, catechin, rutin, vitexin and hyperin were identified. The elution fraction rich in antioxidant peptides with protein content of 66.51% and oxygen radical absorbance capacity of 1 731.52 μmol/g was obtained by ultrafiltration, ethanol fractionation and chromatography on XAD-16 macroporous resin. Twenty seven peptides were identified from the fermentation products. Twenty three peptides longer than 7 amino acids were obtained through database search against Swissprot using Mascot, which have not been reported in the BIOPEP database. All these peptides contained hydrophobic amino acids and eleven of them contained at least one amino acid with strong antioxidant activity. The IY dipeptide fragment in GDKIYNVF, the LY dipeptide fragment in CRNLLLYPAGA, the PW dipeptide fragment in PWFFTST, and the GPP tripeptide fragment in QGSGGPPIV were reported as antioxidants according to the BIOPEP database. The identified phenolics and peptides contributed largely to the antioxidant activity of the fermentation product.
Synthesis and Antioxidant Activity of Selenium-Containing Konjac Oligo-glucomannan
LIU Qishun, CHEN Wei, GONG Fengqin, TAN Haidong, YIN Heng
2019, 40(13):  68-73.  doi:10.7506/spkx1002-6630-20180704-058
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In order to obtain selenium-enriched oligo-glucomannan, selenium-containing konjac oligo-glucomannan was synthesized from konjac oligo-glucomannan, which was prepared by enzymatic hydrolysis of natural konjac glucomannan. The structure of the synthetic product was determined using infrared spectroscopy and nuclear magnetic resonance spectroscopy. The selenium content was measured using inductively coupled plasma mass spectrometry. Antioxidant activity was characterized in vitro. The results showed that selenium-containing konjac oligo-glucomannan was successfully synthesized, and the selenium content was 5.9 g/kg, which was much higher than that of natural konjac oligo-glucomannan. The product had high scavenging capacity against hydroxyl radicals, and could be used as an antioxidant ingredient in functional foods.
Effect of Annealing Temperature and Time on the Physicochemical Properties of Corn Starches with Different Amylose Contents
WANG Yusheng, SHANG Mengshan, CHEN Haihua
2019, 40(13):  74-80.  doi:10.7506/spkx1002-6630-20180702-011
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In order to provide useful information to explore the mechanism of the effect of annealing treatment on the physicochemical properties of corn starch, we evaluated the pasting properties, thermal properties, swelling power, crystalline structure, birefringence, and morphological structure of corn starches with different amylose contents (normal corn starch (NCS) and waxy corn starch (WCS)) annealed at different temperatures for different periods. The results showed that annealing treatment affected the amorphous zones of NCS and WCS, but exerted no effects on their crystal types. The thermal stabilities and anti-shear abilities were enhanced significantly after annealing. Annealing treatment retarded the retrogradation and gelatinization of the two starches and significantly reduced the peak viscosity and swelling power (P < 0.05). Annealing temperature up to 60 ℃ enhanced the above effects, leading to a significant decrease in the gelatinization enthalpy and the relative crystalline degree and obvious destruction of the morphological structure. However, prolonged annealing time did not significantly retard the retrogradation of NCS and WCS starches while having no significant effect on the gelatinization enthalpy, swelling power, or morphological structure.
Food Engineering
Effect of Electron Beam Irradiation on Biochemical Properties and Structure of Myofibrillar Protein from Lateolabrax japonicus Meat
ZHANG Han, GAO Xing, XUAN Shifen, XU Dalun, ZHANG Jinjie, QIAN Yunxia, YANG Wenge
2019, 40(13):  81-86.  doi:10.7506/spkx1002-6630-20180518-265
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To study the feasibility of electron beam irradiation for application to aquatic products, the effects of different electron beam irradiation doses (1, 3, 5 and 7 kGy) on the biochemical properties and structure of myofibrillar protein from Lateolabrax japonicus meat such as salt-soluble protein content, sulfhydryl content, disulfide bond content, Ca2+-ATPase activity, surface hydrophobicity, carbonyl content and conformation. The results showed that total sulfhydryl content was significantly higher in the 1 kGy group compared to the control group (P < 0.05), while there was no significant change in any other indices (P > 0.05). As the irradiation dose continued to increase, the contents of salt-soluble protein content and reactive sulfhydryl and ATPase activity decreased significantly whereas carbonyl and disulfide bond contents increased; higher irradiation dose resulted in more significant changes. The surface hydrophobicity of myofibrillar protein rose with irradiation dose up to 5 kGy and then decreased at higher doses. Circular dichroism (CD) spectroscopic analysis indicated that the conformation of myofibrillar protein was converted from an α-helix to β-sheet structure as a result of increasing irradiation dose. Higher doses of electron beam irradiation could cause the oxidation of myofibrillar protein. To minimize the effect on myofibrillar protein, L. japonicus meat should be irradiated at low doses before cold storage. These results provide the basis for the application of electron beam irradiation in the preservation of fish meat.
Effect of Molecular Distillation on the Removal of 8 Phthalic Acid Esters and the Quality of Sea Buckthorn (Hippophae rhamnoides L.) Pulp Oil
LIU Yulan, CHEN Li, ZHANG Xiaolong, ZHANG Zhenshan, MA Yuxiang
2019, 40(13):  87-93.  doi:10.7506/spkx1002-6630-20180704-048
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Sea buckthorn (Hippophae rhamnoides L.) pulp oil (SPO) is an expensive edible vegetable oil due to its beneficial bioactive ingredients, but this oil may pose a risk of phthalic acid esters (PAEs) exceeding the legal limits, depending on various factors such as growing environment, picking methods, and storage methods. In the present study, two-stage molecular distillation (MD) was used to remove 8 PAEs from SPO. Fatty acid composition and the contents of VE, phytosterol, and flavonoids in SPO were detected before and after MD to evaluate the effect of MD on the removal of PAEs and the retention of bioactive constituents. The results showed the contents of di-butyl phthalate (DBP) (1.626 mg/kg) and bis(2-ethylhexyl) phthalate (DEHP) (10.933 mg/kg) in raw sea buckthorn pulp oil (R-SPO) greatly exceeded the limits (0.3 and 1.5 mg/kg respectively) specified in China’s national standard for the use of food contact materials and food additives. The content of DBP decreased from 1.626 to 0.071 mg/kg during the first stage of MD, which was far below the legal limit, and the content of DEHP reduced from 10.933 to 0.668 mg/kg during the whole MD process. The removal rates of DBP, DEHP, DINP and the sum of these PAEs and five others were 98%, 94%, 85% and 93%, respectively; after two-stage MD, the retention rates of VE, sterol and flavonoids were 14%, 32%, and 46% respectively. Fatty acid composition of SPO did not change obviously, almost no trans-fatty acids were produced, whereas the proportion of free fatty acids decreased visibly. These results indicated that the two-stage molecular distillation process was an effective method to remove high concentrations of PAEs from edible vegetable oils, but it could result in large losses of nutrients such as VE, sterol and flavonoids. One-stage molecular distillation could reduce the contents of DBP and DEHP in edible vegetable oil to less than the legal limits while avoiding losses of nutrients, increasing the retention rates of VE, sterol and flavonoids up to 35%, 55% and 63%, respectively.
Effects of Different Thawing Methods on Quality of Squid
TAN Mingtang, XIE Jing, WANG Jinfeng
2019, 40(13):  94-101.  doi:10.7506/spkx1002-6630-20181022-246
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Five different thawing methods including natural air thawing, water soaking thawing, ?owing water thawing, microwave thawing and ultrasonic thawing were individually used to thaw frozen squid. The differences in thawing time, and the water-holding capacity, color, pH, malondialdehyde (MDA) content, sufhydryl content and texture properties of thawed squid were analyzed. Meanwhile, low-field nuclear magnetic resonance (LF-NMR) was used to determine the transverse relaxation time T2, and nuclear magnetic resonance imaging (MRI) and optical microstructure observation of thawed squid were conducted. The results indicated that the thawing time of microwave thawing was the shortest, followed by ?owing water thawing. Flowing water-thawed squid had higher water-holding capacity as compared to the other thawing methods, and maintained its compact microstructure with intramuscular membranes remaining intact. With respect to color, pH and the oxidation degree of protein and fat, ?owing water thawing were the best of the five thawing methods. Although ultrasonicthawed squid had the best texture properties, the spacing between muscle fiber bundles was locally enlarged because of the concussion of water during the thawing process. Overall, ?owing water thawing is an ideal thawing method for frozen squid.
Nutrition & Hygiene
Lactobacillus plantarum Alleviates Metabolic Syndrome by Modulating Intestinal Short-Chain Fatty Acid Levels
ZHU Guangsu, WANG Gang, WANG Yuanyuan, MA Fangli, ZHAO Jianxin, ZHANG Hao, CHEN Wei
2019, 40(13):  102-109.  doi:10.7506/spkx1002-6630-20180301-004
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Purpose: To investigate the regulatory effect of Lactobacillus plantarum on metabolic syndrome induced by high-fat-high-sucrose (HFHS) diet in rats and its possible mechanism of action. Methods: Serum metabolic parameters such as lipids and glucose and liver antioxidant status were determined; histopathological analysis was performed for liver, duodenum and pancreatic islet tissues and the levels of short-chain fatty acids (SCFAs) in rat faces were also examined. Results: HFHS-fed rat developed hallmark features of metabolic syndrome, and L. plantarum attenuated the development of metabolic syndrome but the effect varied among strains. Further analysis demonstrated that supplementation with L. plantarum CCFM591 significantly enhanced blood glucose-insulin homeostasis, attenuated the pathological changes in pancreatic islet and small intestinal tissues, and elevated the level of SCFAs in stool. Conclusion: L. plantarum CCFM591 may ameliorate the progression of HFHS diet-induced metabolic syndrome by modulating the levels of intestinal SCFAs.
Tartary Buckwheat Tea Polysaccharide Induces Mitochondria-Mediated Apoptosis in A549 Human Lung Cancer Cells
YANG Erwan, ZHANG Min, YANG Xingbin, YANG Hongyan
2019, 40(13):  110-115.  doi:10.7506/spkx1002-6630-20180707-093
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Objective: To investigate the effect of tartary buckwheat tea polysaccharide (TBTP) on the apoptosis of A549 human lung cancer cells and its underlying mechanisms. Methods: TBTP was obtained by water extraction. 3-(4,5-Dimethyl- 2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to detect the influence of TBTP on the proliferation of A549 cells. Flow cytometry was applied to determine the effect of TBTP on cell apoptosis in A549 cells. The production of reactive oxygen species (ROS) was assessed by DHE and Mito SOX Red staining. The change of mitochondrial membrane potential was assessed by JC-1 staining. Meanwhile, Western blot analysis was used to evaluate the expression of Bcl-2-associated X protein (Bax), Bcl-2, cleaved caspase-3 and cytochrome c. Results: MTT assay showed a significant inhibitory effect of TBTP on A549 cells proliferation in a dose- and time-dependent manner. After 24 hours’ cultivation, TBTP also promoted A549 cells apoptosis in a dose-dependent manner. TBTP treatment promoted mitochondrial ROS production and oxidative stress in A549 cells. The mitochondrial membrane potential of A549 cells also decreased after TBTP administration, accompanied with increased cytochrome c release from mitochondria. Furthermore, TBTP treatment up-regulated the expression of Bax and cleaved caspase-3, and decreased Bcl-2 expression. Conclusion: TBTP exerts a novel anti-proliferative effect through induction of mitochondria-mediated apoptosis in A549 cells.
Effects of Free and Bound Polyphenols from Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chow on Phenotype Transformation of Human Aortic Smooth Muscle Cells
LI Hanqing, LIU Fengming, SHAN Shuhua, LU Yang, ZHANG Xiaoli, LI Zhuoyu
2019, 40(13):  116-122.  doi:10.7506/spkx1002-6630-20180526-364
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The effects of free and bound polyphenols from the fruit flesh, seeds and leaves of Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chow on phenotype transformation of human aortic smooth muscle cells (HASMC) were studied. Each plant material was crushed and extracted sequentially with ethanol followed by digestion with alkali or a mixture of methanol and acid. The content of polyphenols was determined by the Folin-Ciocalteu assay, and the contents of free and bound polyphenols in the three plant materials were compared. The effects of the polyphenols on HASMC phenotype transformation were observed by inverted microscopy and fluorescence staining. The results showed that the yields of free polyphenols and bound polyphenols extracted by acid digestion from leaves were the highest among the three materials. Moreover, the free polyphenols from leaves and the bound polyphenols from seeds obtained by acid digestion could significantly promote the phenotype transformation of HASMCs from the synthetic type (trough-shaped) to the contractile type (shuttle-shaped) in a time- and dose-dependent manner. Therefore, they have potential applications in the prevention and treatment of atherosclerosis.
Modulatory Effect of Set Yogurt with Tartary Buckwheat Juice on Intestinal Flora in Mice
ZHOU Yiming, ZHAO Shen, FENG Fei, LIU Qian, ZHOU Xiaoli, XIAO Ying
2019, 40(13):  123-129.  doi:10.7506/spkx1002-6630-20180511-172
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In this paper, the modulatory effect of set yogurt with tartary buckwheat on the intestinal flora in mice was studied. The quantity and composition of the intestinal flora were detected by quantitative real-time polymerase chain reaction (qPCR) and Illumina high throughput sequencing and the contents of short chain fatty acids (acetic acid, propionic acid, butyric acid, and lactic acid) in mouse feces by gas chromatography-mass spectrometry. Results showed that the yogurt increased the number of Lactobacillus, Bifidobacterium and Clostridium leptum as beneficial bacteria in the gut by 523.81, 911.01 and 12.18 times, and decreased the number of harmful Enterobacter, Enterococcus and Bacteroides by 99.89%, 97.31% and 99.02%, respectively when compared with the control group. In addition, the fecal contents of acetic acid, propionic acid, butyric acid and lactic acid were increased by 36.87%, 75.59%, 56.26% and 92.36% when compared to the control group. This effect was better than that of pure yogurt. The results of high-throughput sequencing showed that the yogurt with tartary buckwheat could significantly increase the diversity of the intestinal flora in mice when compared with the pure yogurt and the control groups. At the level of phylum, the abundance of Firmicutes and Verrucomicrobia were significantly reduced, and the abundance of Bacteroidetes was significantly increased by the yogurt with tartary buckwheat (P < 0.05). At the level of genus, it could significantly increase the abundance of norank_f__Bacteroidales_S24-7_group and Faecalibaculum, and significantly reduce the abundance of Ruminococcaceae_UCG-014, unclassified_f__Lachnospiraceae, and Lachnospiraceae_UCG-006 (P < 0.05). The abundance of the dominant species in the gut was increased by the yogurt with tartary buckwheat. In conclusion, set yogurt with tartary buckwheat could promote the proliferation of beneficial bacteria and inhibit the proliferation of harmful bacteria. Besides, it could promote the production of short chain fatty acids in the gut, increase the diversity of the intestinal flora, and optimize the structure of the intestinal flora.
N-Acetyl-cysteine Attenuates Nonylphenol-Induced Damage in Mouse Sertoli TM4 Cells
LIU Xiaozhen, NIE Shaoping, YU Qiang, HUANG Danfei, XIE Mingyong
2019, 40(13):  130-136.  doi:10.7506/spkx1002-6630-20180614-242
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Objective: The aim of this study was to explore the effect of N-acetyl-cysteine (NAC) on nonylphenol (NP)-induced oxidative stress and cell apoptosis in TM4 mouse Sertoli cells. Methods: The cells were divided into 4 groups: control group, NP group (20 μmol/L NP), NP + NAC group (sequential treatment with 5 mmol/L NAC for 4 h followed by 20 mmol/L NP for 24 h), NAC group (sequential treatment with 5 mmol/L NAC for 4 h followed by normal cell culture medium). Cell survival rate was monitored by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, and reactive oxygen species (ROS) generation and cell apoptosis were analyzed by flow cytometry. Caspase-3 activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, and malondialdehyde (MDA) content were measured by assay kits. The phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was detected by Western blot assay. Results: Compared with the control group, NP decreased cell survival rate significantly (P < 0.05), induced reactive oxygen species (ROS) generation, increased SOD and CAT activities, and decreased MDA content in Sertoli TM4 cells. Additionally, NP induced cell apoptosis, increased caspase-3 activity, and activated the ERK/JNK signaling pathways. Compared with the NP group, NAC pretreatment attenuated ROS production, reduced SOD and CAT activities and increased MDA content. Moreover, NAC blocked cell apoptosis, increased caspase-3 activity, and activated the ERK/JNK signal pathways. Conclusion: NAC attenuated NP-induced damage in mouse Sertoli TM4 cells, which may be related to the ability of NAC to attenuate NP-induced oxidative stress and cell apoptosis and block the activation of the ERK and JNK signaling pathways.
Alleviatory Effect and Underlying Mechanism of Konjac Oligosaccharides on High Glucose Induced-Metabolic Syndrome in Rats
JIAO Dan, LI Haoxia, WU Dandan, ZHOU Zhongkai
2019, 40(13):  137-142.  doi:10.7506/spkx1002-6630-20180612-175
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In this study, SD male rats were employed to establish a diabetic animal model by tail vein injection of streptozotocin in an effort to explore the effect of konjac oligosaccharides (KOS) on blood glucose, serum lipid composition and oxidative stress levels and to clarify the underlying mechanism. The results showed that compared with the diabetic model group, fasting blood glucose, and the serum levels of triglyceride, total cholesterol, and low density lipoprotein were significantly decreased (P < 0.05, P < 0.01), serum high density lipoprotein, total antioxidant capacity and insulin (INS) secretion level were significantly improved in the KOS intervention group (P < 0.05). The analysis of the genes involved in glycolipid metabolism and oxidative stress pathways revealed that the expression levels of glycogen synthesis-related gene glutamine synthetase 2, insulin-induced genes Insig1 and Insig2, oxidative stress-related gene Hmox1 and epidermal growth factor receptor gene were significantly up-regulated (P < 0.05). In contrast, the expression of gluconeogenesis-related gene glucose-6-phosphatase catalytic subunit 1, triglyceride synthesis-related gene, sterol regulatory element binding protein-1, fatty acid synthesis-related genes ACC and FAS, oxidative stress-related genes and insulin-like growth factor binding protein-1 were greatly down-regulated in the KOS intervention group (P < 0.05). We concluded that KOS can regulate blood glucose and glycolipid metabolism, and inhibit oxidative stress induced by diabetes mellitus, and enhance antioxidant capacity in the body.
Cytoprotective Effect and Underlying Mechanism of Pentapeptide Derived from Manchurian Walnut (Juglans mandshurica Maxim) Meal Protein on PC12 Cells against H2O2-Induced Damage
GUO Yong, QIN Hanxiong, WEI Zhen, FANG Li, MIN Weihong
2019, 40(13):  143-149.  doi:10.7506/spkx1002-6630-20180529-414
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The protective effect of the pentapeptide Leu-Pro-Leu-Leu-Arg (LPLLR) from manchurian walnut (Juglans mandshurica Maxim) meal protein on PC12 cells against hydrogen peroxide (H2O2)-induced damage were investigated and the underlying mechanism was elucidated based on the NF-κB/iNOS/NO signaling pathway. The results showed that LPLLR had no cytotoxicity and significantly increased the survival rate of PC12 cells suffering from oxidative stress induced by H2O2. LPLLR could reduce the production of reactive oxygen species (ROS) and malondialdehyde (MDA), and enhance the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) and acetylcholine (ACh) level (P < 0.05, P < 0.001) in H2O2-induced PC12 cells. ELISA and Western blotting results confirmed that LPLLR could up-regulate the expression of SOD2 and down-regulate the expression of nuclear transcription factor-κB (NF-κB) p65 and inducible nitricoxide synthase (iNOS), as well as decrease the secretion of NO (P < 0.05, P < 0.001). Therefore, LPLLR can protect PC12 cells against hydrogen peroxide-induced injury.
Hepatoprotective Effect of Dendrobium candidum Polysaccharides on Alcohol-Induced Acute Liver Injury in Mice
LUO Qun, SHEN Xianrong, HOU Dengyong, HE Ying, JIANG Dingwen, WANG Qingrong, CHEN Wei
2019, 40(13):  150-154.  doi:10.7506/spkx1002-6630-20180325-334
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The hepatoprotective effect of polysaccharides isolated from the dried stems of Dendrobium candidum by hot water extraction was evaluated on alcohol-induced acute liver injury in mice. Mice were intragastrically administrated with 50% alcohol to induce alcohol-induced acute liver injury. Thereafter, the mice were gavaged with the polysaccharides for 14 consecutive days. At the end of the experiment, blood was taken by removing eyeballs, and then the mice were sacrificed with cervical dislocation to harvest their liver tissues. Red blood cell (RBC), haematocrit, mean corpuscular volume, white blood cell (WBC) and hemoglobin were measured using a blood cell counter. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activity and triglyceride (TG) content in liver, as well as alanine transaminase (ALT), aspartate transaminase (AST) and TG levels in serum were measured. Histopathological liver changes were examined. The results showed that RBC and WBC levels, the serum levels of ALT, AST and TG, and SOD, GSH-Px activity and TG content in liver, and liver index significantly differed (P < 0.05 or P < 0.01) between the control and model groups. Dendrobium candidum polysaccharides significantly reduced liver index, RBC, WBC, ALT, AST and TG levels as well as enhanced the activities of SOD and GSH-Px in the liver of mice suffering from alcohol-induced acute liver injury (P < 0.05 or P < 0.01). The polysaccharides promoted recovery from hepatic tissue injury. To conclude, this study suggests that Dendrobium candidum polysaccharides have a significant hepatoprotective effect on alcohol-induced acute liver injury in mice.
In Vivo Hypolipidemic, Hypoglycemic and Antioxidant Properties of Functional Vinegar Powder Made from Minor Grains
CHEN Shujun, ZHANG Junmei, LI Jiayi, ZHENG Jie, XING Huiya, WU Mengyue
2019, 40(13):  155-160.  doi:10.7506/spkx1002-6630-20180610-123
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The chemical composition of a functional vinegar powder made from minor grains was evaluated. Meanwhile, a mouse model of hyperlipidemia was established by feeding a high-fat diet and used to explore the hypolipidemic, hypoglycemic and antioxidant effects of the vinegar powder. The results showed that the functional vinegar powder could significantly reduce the contents of total cholesterol, triglyceride and low density lipoprotein-cholesterol in the serum of hyperlipidemia mice (P < 0.05), increase the serum level of high density lipoprotein-cholesterol (P < 0.01), reduce the malondialdehyde content in the liver, and increase superoxide dismutase, catalase and glutathione peroxidase activity (P < 0.05) and it had a certain hypoglycemic effect, suggesting that vinegar powder can effectively regulate blood lipid and blood glucose levels and increase antioxidant function in a dose-dependent manner.
Protective Effect of Chitooligosaccharides on Acute Alcohol-Induced Liver Injury in Mice
DING Rongrong, JIANG Qixing, WANG Bin, XIA Wenshui, YANG Fang, XU Yanshun
2019, 40(13):  161-165.  doi:10.7506/spkx1002-6630-20180601-006
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In this paper, the protective effect of chitooligosaccharides (COS) on acute alcohol-induced liver injury was studied. A mouse model of acute liver injury was established by administering 50% ethanol at a dose of 12 mL/kg mb to mice after 30 continuous days of oral gavage with COS. The mice were sacrificed for histopathological examination of liver tissue. Besides, the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and total cholesterol (TC) concentration in serum, liver coefficient, and glutathione (GSH) content, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in liver were detected. The results showed that the degree of liver injury in the COS group was mitigated compared with the alcohol model group. The positive control and COS groups exhibited a significant reduction in serum ALT, AST and TC levels and a significant increase in hepatic GSH content and SOD activity as well as a significant decrease in liver index and MDA level (P < 0.05). Therefore, chitooligosaccharides has a significant protective effect on alcohol-induced liver injury in mice.
Effects of Fermented Wheat Bran Polysaccharides on Antioxidant Capacity, Morphological Structure and Tight Junction Protein Expression in Rat Jejunum
WANG Yuan, YANG Kexin, DUAN Yuanxiao, WANG Wenwen, AN Xiaoping, QI Jingwei
2019, 40(13):  166-170.  doi:10.7506/spkx1002-6630-20180524-339
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This study was conducted to investigate the effects of oral supplementation with fermented wheat bran polysaccharides (FWBPs) on antioxidant capacity, morphological structure and tight junction protein expression in the jejunum of weaned rat pups. Forty healthy weaned Wistar rats with similar body mass were randomly assigned to five groups, including control (saline), VC (positive control, 100 mg/kg mb), and low-, medium- and high-dose FWBPs groups (20、40、80 mg/kg mb in a dosage of 0.4 mL). The experimental duration was 21 days. The total antioxidative capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, and glutathione (GSH) and 8-hydroxydeoxyguanosine (8-OHdG) contents in jejunum were measured. Histopathological examination with hematoxylin and eosin (HE) staining was used to analyze villus height and crypt depth, and the ratio of villus height to crypt depth was calculated. The mRNA expression of the tight junction proteins Claudin-1, Occludin and zonula occludens-1 were determined using quantitative real-time polymerase chain reaction (qPCR). The results showed that oral administration of FWBPs at 40 mg/kg mb significantly improved T-AOC, CAT, SOD and GSH-Px activities and GSH content in jejunum (P < 0.05), and significantly decreased the content of 8-OHdG (P < 0.05). FWBPs increased the villus height and decreased crypt depth, thus resulting in increased villus height/crypt depth ratio. The mRNA expression of the tight junction proteins in the jejunum was significantly up-regulated in the FWBPs groups. In summary, fermented wheat bran polysaccharides can improve the antioxidant capacity and jejunal morphology and promote the expression of itght junction proteins, thereby preserving intestinal health in weaned rats.
Molecular Typing of Salmonella Species Isolated from Beef Abattoirs by Pulsed-Field Gel Electrophoresis Analysis
DONG Pengcheng, ZHANG Yimin, MAO Yanwei, LIANG Rongrong, HAN Guangxing, ZHU Lixian, LUO Xin
2019, 40(13):  171-176.  doi:10.7506/spkx1002-6630-20180709-129
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In order to investigate and specify the transmission and cross-contamination of Salmonella during bovine slaughtering, the source of strains isolated from six different processing points (hides, pre-evisceration carcasses, postevisceration, post-washing carcasses, chilled carcasses, meat and feces) was traced at the molecular level by pulsed-field gel electrophoresis (PFGE). The data showed a better insight into the distribution of Salmonella than serotyping. The similarity of 48 PFGE patterns ranged from 48.0% to 100.0% and 22 different profiles were identified from all these isolates at a similarity level of 95.7%. No highly similar pattern was found among different abattoirs. Serious and widespread crosscontamination from live animals’ hides and feces to carcasses was verified. Slaughtering plants should pay more attention to pre-slaughter management strategies to avoid cross-contamination problems and spraying intervention in dehided carcasses should be included as an extra critical control point to reduce the risk of Salmonella infection.
Extraction and Modification of Pectin from Finger Citron Fruit and Its Preventive Effect on Cadmium-Induced Liver and Kidney Injury
WU Shaji, KOU Xingran, DING Yinyi, WANG Hongxin
2019, 40(13):  177-186.  doi:10.7506/spkx1002-6630-20180220-174
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In this paper, the effects of chemical modification on the chemical properties and cadmium adsorption capacity of pectin from the peel of finger citron fruit were studied. The cadmium adsorption capacity and adsorption process were analyzed by kinetic and thermodynamic studies. Furthermore, a 20-day gavage experiment using ICR mice was performed to explore the preventive effect of pectin on cadmium-induced liver and kidney injury. The esterification degree of the modified pectin was significantly lower than that of the unmodified one. The modified pectin had stronger cadmium adsorption capacity than its unmodified counterpart. The adsorption process of cadmium mainly involved ion exchange and physical adsorption. In addition, the pectin significantly alleviated the increased aspartate aminotransferase, alanine aminotransferase, total bilirubin, γ-glutamyl transpeptidase, urea nitrogen, and creatinine in plasma, and urinary albumin level (P < 0.05). Moreover, the activities of superoxide dismutase, catalase and glutathione peroxidase in the liver and kidney of the mice treated with either the unmodified or the modified pectin were significantly higher than those in the cadmium exposure group (P < 0.05). The pectin significantly alleviated cadmium-induced oxidative stress, and mitigated the morphological changes of the liver and kidney. In conclusion, the chemical modification process reduces the esterification degree and enhances the cadmium adsorption capacity of finger citron pectin. The pectin can effectively relieve cadmiuminduced liver and kidney injury.
Soluble Soybean Polysaccharides Ameliorate L-Carnitine-Induced First-Pass Metabolism in the Small Intestine of Mice
LI Wenfeng, TAO Wen, CHEN Luhong, ZHENG Qiaoran, ZHOU Feng, TAN Si, XING Jie
2019, 40(13):  187-194.  doi:10.7506/spkx1002-6630-20180620-388
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Objective: To study the effect of soluble soybean polysaccharides (SSPS) on intestinal metabolism, oxidative stress and inflammation-related proteins in mice fed L-carnitine. Methods: A total of 24 male Kunming mice were randomly divided into three groups: normal group, L-carnitine group and SSPS group. At the end of the 56-day feeding period, all mice were sacrificed to assess the changes in the levels of P-glycoprotein (P-gp), multidrug resistance protein (MRP) 1, MRP3, interleukin (IL)-1, IL-6, tumor necrosis factor-α (TNF-α), uridine diphosphateglucuronosyltransferase (UGT), sulfotransferase (SULT), and malondialdehyde (MDA) in the small intestine. Results: The concentrations of P-gp and MRP3 in the small intestine homogenate supernatant of mice in the L-carnitine group were significantly higher than that of the normal group (P < 0.05). However, SSPS significantly decreased P-gp concentration (P < 0.05), and slightly decreased MRP3 concentration in the small intestine of L-carnitine-fed mice, suggesting that SSPS could inhibit L-carnitine-induced first pass metabolism. Additionally, co-treatment of SSPS and L-carnitine on mice effectively prevented the increase of MDA content, the decrease of superoxide dismutase (SOD) activity, and the weakening of hydroxyl radical-scavenging capacity, indicating that SSPS could inhibit L-carnitine-induced oxidative stress. However, the activities of SULT and UGT, and the concentrations of IL-1, IL-6 and TNF-α in the small intestine did not differ significantly among all groups of mice (P > 0.05), suggesting that excessive L-carnitine and SSPS treatment did not affect the II phase metabolism or lead to inflammation. Furthermore, metabonomic analysis showed that SSPS could inhibit the disorders of energy metabolism and lipid metabolism caused by long-term excessive intake of L-carnitine. Conclusion: The first pass metabolism induced by L-carnitine can be effectively prevented by SSPS via controlling oxidative stress and metabolic disorders.
Analysis of Microbial Community Structure in Poultry Slaughterhouses and Antibiotic Resistance Assessment of Escherichia coli
WANG Peipei, DAI Xianjun, YANG Hua, XIAO Yingping
2019, 40(13):  195-202.  doi:10.7506/spkx1002-6630-20180518-261
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Microorganisms in the environment as well as on the surface of slaughtering equipment play a significant role in microbial cross-contamination during chicken processing in slaughterhouses. The aim of this study was to investigate the microbial community structure and antibiotic resistance genes in the water as well as on the ground and slaughtering equipment of a slaughterhouse. Moreover, Escherichia coli were isolated for drug resistance evaluation and genomic typing by enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR). Water was sampled from the hanging, slaughtering, scalding and dehairng, evisceration, pre-cooling, packaging, refrigeration and viscus storage sections and bacterial samples were collected from the ground of each section and the surface of slaughtering equipment using sterile gauze swab. The microbial community structure was analyzed by high-throughput 16S rRNA V3–V4 gene sequencing on Illumina Hiseq, and the total bacteria and E. coli isolated were evaluated for resistance genes to 9 classes of 24 antiobiotics by PCR. The results showed that Proteobacteria, Firmicutes, and Actinobacteria were the predominant phyla in all the slaughterhouse samples and the dominant genera were spoilage and pathogenic Acinetobacter, Streptococcus, Psychrobacter and Pseudomonas. A total of 21 drug resistance genes were detected in these samples, and the prevalence of sulI, sulII, blaTEM, aadA1, floR, tetA, ereA and qnrS was more than 88.9%, which did not coincide with that in the E. coli isolates. This indicates that there may be some other strains carrying drug resistance genes and the multiple drug resistance of the E. coli isolates is serious. ERIC-PCR genotyping results showed that E. coli can be cloned and propagated along the slaughter production chain. This study will lay the theoretical foundation for exploring the relationship between microorganisms in the slaughterhouse environment and the contaminant microorganisms in chicken.
Postprandial Glycemic Responses of Dried Jujubes and Jujube-Rice Meals
ZHU Ruixin, DONG Yang, FAN Zhihong, YE Ting, WANG Linlin, LIN Jinxuejiao
2019, 40(13):  203-207.  doi:10.7506/spkx1002-6630-20180604-029
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To investigate the postprandial glycemic responses of dried jujubes (DJ) and jujube-rice meals, 7 samples including cooked japonica rice, uncooked DJ, steamed DJ, simmered DJ, rice (R) plus uncooked DJ (R + DJ), cooked rice (CR) with DJ (CR + DJ) and rice congee (RC) with DJ (RC + DJ) were selected for this study. The texture properties of cooked and uncooked DJ samples and the postprandial blood glucose levels of 11 healthy subjects within 240 min were measured and the glycemic index (GI) was calculated. Although all cooking treatments led to significantly lower hardness and firmness when compared with uncooked DJ, simmering treatment exerted the greatest impact on the texture parameters. The GIs of uncooked DJ, steamed DJ and simmered DJ were 56, 65 and 56, respectively, and simmered DJ showed the greatest mean amplitudes of glycemic excursion and largest negative area under curve. The GIs of rice, R + DJ, CR + DJ and RC + DJ turned out to be 78, 75, 82 and 85, respectively. It was suggested that uncooked DJ but not cooked dried jujube could be integrated into glycemic management diets in place of high GI carbohydrate meal. The results indicated that the postprandial glycemic response of a meal needed to be actually tested but not calculated by simple summation of the GI of each food ingredient.
Effect of Blueberry Anthocyanin Extract on Proliferation, Differentiation, and Lipid Accumulation in Human Adipose-Derived Stem Cells
CHEN Xiaotong, MA Sisi, ZHENG Tingting, CHEN Jie, LI Yali, DENG Yuanle, HE Fang, YIN Wenya
2019, 40(13):  208-215.  doi:10.7506/spkx1002-6630-20180328-374
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Objective: This study was conducted to investigate the potential of blueberry extract to alter the growth, differentiation, and function of human adipose-derived stem cells (hADSCs) and to evaluate its ability of reducing adipose tissue formation and the possible underlying mechanisms. Methods: Human adipose-derived mesenchymal stem cells were isolated and primarily cultured to establish a model cell differentiation in vitro. Blueberry anthocyanin extract at different concentrations was used to intervene in different growth phase of adipocytes. The 3-(4,5-dimethyl-2-thiazolyl)- 2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and the lactate dehydrogenase assay were measured to observe hADSC proliferation in different phases. Oil Red O staining and the AdipoRed assay were used to investigate lipid accumulation in hADCSs during the course of differentiation. The glucose uptake assay was used to investigate glucose uptake in fully differentiated mature human adipocytes. Enzyme-linked immunosorbent assay and real-time polymerase chain reaction were used to measure the expression of adipogenesis-related genes and the secretion of adipocytokines. Results: 1) Treatment with blueberry anthocyanins extract (25–175 μg/mL) for 48 h dose-dependently inhibited hADSCs proliferation in the logarithmic and confluent phases of growth (P < 0.05). It also inhibited hADSCs proliferation in the differentiation phase (P < 0.05), and lipid accumulation in mature adipocytes (P < 0.01). 2) The blueberry extract increased glucose uptake in mature adipocytes in both the absence and presence of 1 μmol/L insulin, and significantly up-regulated the expression of adiponectin (P < 0.05). 3) Peroxisome proliferator-activated receptor γ (PPARγ) expression in differentiating adipocytes was down-regulated by the blueberry extract during differentiation, while it was up-regulated in mature adipocytes (P < 0.05). These results suggest that the blueberry extract can reduce the proliferation and inhibit the differentiation of hADSCs to generate fewer mature adipocytes and less lipid accumulation. Furthermore, the blueberry extract also can maintain or enhance the function of human mature adipocytes by increasing glucose uptake and upregulating the expression of adiponectin and PPARγ. Conclusion: Blueberry anthocyanin extract may have the potential to inhibit obesity.
Packaging & Storage
Preservative Effect of Modified Atmosphere Packaging with Different Oxygen Concentrations on Prepared Duck Meat
DANG Yali, XU Siyu, CAO Jinxuan, SUN Yangying, PAN Daodong
2019, 40(13):  216-221.  doi:10.7506/spkx1002-6630-20180730-362
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Modified atmosphere packaging (MAP) was used to prolong the shelf life of prepared duck meat. Modified atmospheres with different oxygen concentrations: MAP1 (20% CO2 + 80% N2), MAP2 (20% CO2 + 40% O2 + 40% N2) and MAP3 (20% CO2 + 80% O2) were evaluated in comparison with tray packaging as control. All the packaged samples were stored in a refrigerator at 0-4 ℃. Microbiological and physicochemical qualities were measured during storage. The results showed that compared with the control group, each of the MAPs could effectively inhibit the growth of microorganisms and reduce the production of total volatile basic nitrogen (TVB-N) in prepared duck meat. The preservative effect of the O2-containing modified atmospheres (MAP2 and MPA3), both giving a shelf life of 12 days, was significantly better than that of MAP1 and the control group (P < 0.05). After storage for 12 days, the thiobarbituric acid reactive substances (TBARS) value and Enterobacteriaceae number in the MAP2 group were significantly lower than those in the MAP3 group (P < 0.05) while the reverse was true for the total colony number. Nevertheless, no significant differences in TVB-N content or L* values was found between MAP2 and MAP3 (P > 0.05). Collectively, MAP2 has the best preservative effect on prepared duck products.
Effect of Soy Protein Isolate on Storage Quality of Fresh-Cut Peaches
SHI Keke, ZHU Shuhua
2019, 40(13):  222-229.  doi:10.7506/spkx1002-6630-20180709-116
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To investigate the preservative effect of soy protein isolate (SPI) on fresh-cut peaches, fresh-cut peaches were immersed respectively in 0 (double distilled water, control), 10, 20, and 40 g/L SPI solutions before being stored at 4 ℃ for 10 days. The physiological and biochemical indicators associated with the quality and browning of fresh-cut peaches were determined during the storage period. The results showed that the quality of fresh-cut peaches was best maintained by treatment with 20 g/L SPI, which inhibited ethylene release rate, respiratory intensity and bacterial growth. At the end of the storage period, the sample showed increases in the color parameter L* value, firmness and soluble solids content (SSC), lower mass loss rate and decay incidence, and a decrease of 24%, 20% and 17% in the accumulation of reactive oxygen species (ROS), malondialdehyde (MDA) and total phenols, respectively, compared with the control group. Simultaneously, the activities of polyphenol oxidase (PPO), peroxidase (POD) and catalase (CAT) were reduced respectively by 45.5%, 22%, and 44%. These results indicate that the application of 20 g/L SPI can improve the storage quality, enhance the antioxidant capacity, inhibit browning and prolong the storage period of fresh-cut peaches.
Controlling Effect and Mechanism of Trichothecium roseum Hyphal Cell Wall Extract on Apple Blue Mold
ZHANG Yandong, HU Wenjin, LI Yongcai, BI Yang, ZHANG Tingting, HU Peifang
2019, 40(13):  230-236.  doi:10.7506/spkx1002-6630-20180620-387
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Fuji apple fruit were artificially wounded and inoculated with Penicillium expansum (blue mold) at 24 h after being treated with a hyphal cell wall extract from Trichothecium roseum so as to evaluate the control of the extract on apple blue mold and to partially elucidate the underlying biochemical mechanism. The results showed that the treatment of the cell wall extract could effectively inhibit the development of inoculated P. expansum in apple wounds, and the best effect was observed at a concentration of 150 mg/mL, resulting in a reduction in disease severity of 29.5% after 5 d storage when compared with the control group. Further studies showed that the activity of polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), 4-coumaryl coenzyme A ligase (4CL), cinnamic acid-4-hydroxylase (C4H) and cinnamyl alcohol dehydrogenase (CAD) was significantly increased by the treatment of the extract at 150 mg/mL (P < 0.05). At the same time, the contents of total phenols, flavonoids and lignin in fruit tissues were also increased. These findings suggested that the hyphal cell wall extract from T. roseum might enhance disease resistance by promoting the metabolism of phenylpropane, and increasing the activity of resistance-related enzyme activities and the accumulation of antifungal compounds.
Effect of Steam Cooking Combined with Water Extract from Perilla Leaves on the Quality of Prepared Crisp Grass Carp (Ctenopharyngodon idellus C. et V) Fillets during Frozen Storage
LIN Wanling, DING Mo, YANG Xianqing, WANG Jinxu, LI Laihao, ZHAI Honglei, WU Yanyan, MA Xuejun
2019, 40(13):  237-244.  doi:10.7506/spkx1002-6630-20180706-086
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In order to explore the effect of steam cooking and water extract from Perilla leaves on the quality of frozen crisp grass carp (CGC) fillets, the texture, water-holding capacity (WHC), salt-soluble protein (S-SP) content, Ca2+-ATPase activity, total volatile base-nitrogen (TVB-N) content, thiobarbituric acid (TBA) value and sensory evaluation of raw fish fillets with soaking in the extract (raw group), steam cooked fish fillets with soaking in the extract (cooked group) and raw fish fillets with soaking in distilled water (control group) were investigated during frozen storage. Results indicated that the time of passing through maximum ice crystal formation zone for cooked and raw fillets were longer than that for the control group. Compared with the control and raw groups, the cooking group had higher hardness, springiness, chewiness and lower WHC, S-SP content and TVB-N content during frozen storage. The textural characteristics, WHC, S-SP content, and Ca2+-ATPase activity of the raw group were superior, whereas the TBA value and TVB-N content were inferior compared with the control group. After frozen storage for 300 d, the TBA value of the raw group was 3.85 times higher compared with the initial value and the TVB-N content was lower than 20 mg/100 g. Furthermore, the sensory evaluation showed that the sensory quality of all three groups continuously declined. The sensory scores for texture, taste, and broth turbidity of the three groups followed the decreasing order of cooked fillets, raw fillets, and control. Overall, steam cooking combined with water extract from Perilla leaves maintained better quality of CGC during frozen storage.
Effects of Different Concentrations of Apple Polyphenols on Quality of Fresh-Cut Taro (Colocasia esculenta (L.) Schott)
WU Songxia, GAO Haiyan, LIU Ruiling, Han Yanchao, WU Weijie, CHEN Hangjun
2019, 40(13):  245-251.  doi:10.7506/spkx1002-6630-20190225-176
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In order to control browning and prolong the shelf life, the effects of dipping fresh-cut taro in distilled water (CK) versus different concentrations (0.3%, 0.5% and 0.7%) of apple polyphenols (APP) on its color, hardness, carbohydrate content, total phenol and malondialdehyde (MDA) contents and browning-related enzyme activities during storage at (10.0 ± 0.5) ℃ were studied. The results showed that the browning process of taro slices was postponed by APP treatment and the best effect was observed with an APP concentration of 0.5%. Compared with the control group, 0.5% APP treatment maintained better color and hardness of taro slices, delayed the increase of phenylalanine ammonialyase activity and the total phenol content, and inhibited the increase of peroxidase, polyphenol oxidase and lipoxidase activities and malondialdehyde content, thereby delaying browning and keeping better storage quality of fresh-cut taro slices.
Effect of Low-Voltage Electrostatic Field Combined with Modified Atmosphere Packaging on the Quality of Litopenaeus vannamei during Controlled Freezing-Point Storage
DUAN Weiwen, QUAN Qinguo, GAO Jing, MAO Weijie, HAO Jiming, LIU Shucheng, JI Hongwu
2019, 40(13):  252-259.  doi:10.7506/spkx1002-6630-20180805-041
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In order to extend the shelf life of Litopenaeus vannamei and improve the quality during controlled freezing-point storage ((?1 ± 1) ℃), the effects of different storage conditions including (I) controlled freezing-point storage (CFPS), (II) low-voltage electrostatic field (LVEF) combined with CFPS (LVEF-CFPS), (III) modified atmosphere packaging (MAP) combined with CFPS (MAP-CFPS), and (IV) LVEF combined with MAP and CFPS (LVEF-MAP-CFPS) on the quality of L. vannamei were investigated. Changes in total bacterial count, total volatile basic nitrogen (TVB-N) content, pH, K value, drip loss, whiteness, and sensory and rheology properties were monitored and compared between the four groups. The results showed that the LVEF-MAP-CFPS had the best preservative effect among these storage conditions, and it could significantly inhibit spoilage and deterioration caused by microorganisms, maintain the sensory quality, and delay the degradation of nucleotides to some extent, thus extending the shelf life up to 14 days, 8 days longer than the blank group (air-packaged and stored at low temperature). The color a nd sensory score were good, drip loss rate was less than 3%, and softening was delayed during the late period of storage. Low-voltage electrostatic field can be useful to extend the shelf life of L. vannamei.
Improved Postharvest Quality of Apricot (Prunus armeniaca L. cv. Diaogan) during Storage at Near-Freezing Temperature
BAI Guorong, GUO Minrui, LU Di, CHEN Guogang, NAN Lijun
2019, 40(13):  260-266.  doi:10.7506/spkx1002-6630-20180619-370
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The purpose of this work was to investigate the effects of near freezing temperature storage versus storage at 0–1 ℃ and 15 ℃ on the postharvest physiology and storage quality of Xinjiang-grown Diaogan apricot fruit. The results showed that the freezing point of Diaogan apricots was determined to be ?3.1 ℃. Compared with two other storage temperatures, storage at near-freezing temperature (?1.5 to ?2.0 ℃) could effectively inhibit respiration rate and reduce decay incidence in apricots by suppressing membrane permeability and the accumulation of malondialdehyde (MDA). In addition, near-freezing temperature storage could increase the activity of peroxidase (POD) and inhibit the activity of polyphenol oxidase (PPO) as well as maintain higher fruit firmness and higher contents of soluble solids, titratable acid and VC. The quality of Diaogan apricots was still good after 70 days of storage at near-freezing temperature. Overall, near-freezing temperature storage could be an appropriate method to maintain the quality of Diaogan apricots.
Development and Application of Intelligent Indicator Films Using Blended Film-Forming Solutions Combined with Purple Sweet Potato Anthocyanins
JIANG Guangyang, XIAO Liyuan, WANG Zhangying, CHEN Anjun, WU Hejun, ZHANG Zhiqing
2019, 40(13):  267-273.  doi:10.7506/spkx1002-6630-20180706-083
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Intelligent indicator films were prepared by using binary combinations of starch (S), carboxymethyl cellulose (CMC), and konjac glucomannan (KGM) as film-forming agents and anthocyanins from purple sweet potato (P) as a freshness indicator. The mechanical properties, moisture content, aqueous solubility, microstructure, compatibility, and stability of the intelligent indicator films were determined and compared, and their application for detecting fish freshness was assessed. The results showed that the starch/CMC composite film had the highest tensile strength (15.39 ± 1.15) MPa, the lowest water content (24.17 ± 1.21)%, and the best stability of color. The KGM/CMC film had the best elongation (44.79 ± 1.43)%. Scanning electron microscopic examination showed that the microstructure of these films varied greatly, and the cross section of the starch/CMC composite film was smooth and tight. Furthermore, the starch/CMC film was used to identify the freshness of fish stored at 25 ℃. The total volatile basic nitrogen (TVB-N) content was 15.2 mg/100 g after 24 h, indicating the occurrence of fish spoilage. At the same time, the color of the intelligent indicator film was light red and eventually changed into light blue after 48 h. These results indicate that the starch/CMC film is more suitable for freshness detection, and purple sweet potato anthocyanins show promise for developing stable indicator films.
Effect of Polylactic Acid/Poly(butylene succinate-co-adipate) Biodegradable Film Containing Different Essential Oils in Preserving Quality and Extending Shelf-life of Fresh-Cut Broccoli
JIANG Jinyong, TANG Haibing, LUAN Donglei, LI Li
2019, 40(13):  274-280.  doi:10.7506/spkx1002-6630-20180615-317
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Using 3% ginger essential oil (GEO) or 3% tea tree essential oil (TTO) as the antioxidant and antibacterial ingredient and polylactic acid/poly(butylene succinate-co-adipate) (PLA/PBSA) as the membrane material, respectively, PLA/PBSA, GEO-PLA/PBSA, and TTO-PLA/PBSA films were prepared by blending modification and extrusion casting. The performance of the biodegradable films was tested and their efficiency in preserving the quality of fresh-cut broccoli at (24 ± 1) ℃ was evaluated. A preliminary study was also conducted to investigate the changes of oxygen and carbon dioxide concentrations induced by post-harvest respiration in the microenvironment and the self-regulation mechanism was dissected. The results showed that all three kinds of packaging films could effectively maintain the sensory quality of fresh-cut broccoli, inhibit the increase in MDA content, and delay the decline in the contents of chlorophyll, VC, soluble solids during its storage. The GEO-PLA/PBSA film showed the best permeability for oxygen and carbon dioxide and antioxidant activity. Consequently, it reduced the post-harvest respiration rate of broccoli, and had the best preservative efficiency, which could effectively extend the shelf life of broccoli by 2–3 days.
Reviews
Recent Progress in Food-Derived Natural Polysaccharide Intervention in Inflammatory Bowel Disease
CHEN Guowei, QIU Chunhong, TIAN Lingmin, BAI Weibin
2019, 40(13):  281-287.  doi:10.7506/spkx1002-6630-20180619-371
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Polysaccharides are biologically active macromolecules present in many plants. Inflammatory bowel disease causes extensive damage to the colon and disrupts immune system homeostasis. Although drugs can alleviate inflammatory bowel disease to some extent, many of them can cause adverse reactions in clinical practice. Polysaccharides have been shown to prevent or mitigate colon damage and immune system disorders caused by inflammatory bowel disease. In this article, recent advances in understanding the protective effects and molecular mechanisms of food-derived natural polysaccharides against inflammatory bowel disease are reviewed, which will hopefully provide a theoretical rationale for the prevention of inflammatory bowel disease and the mechanistic exploration of nutrition intervention strategies.
Recent Progress in Applications of Mass Spectrometry Imaging in Food Science
TANG Xuemei, XIE Shuyue, HUANG Yufen, WAN Kai, WANG Fuhua
2019, 40(13):  288-295.  doi:10.7506/spkx1002-6630-20180528-391
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Mass spectrometry imaging is an untargeted and label-free chemical imaging technique that allows for the analysis of hundreds to thousands of molecules in a single experiment. As an emerging “molecular microscope”, chemical imaging based on mass spectrometry has become common in the fields of biomedicine, pharmaceutical, and botanical research, and it is an emerging technology that has opened up opportunities for fundamental research in food science. This review briefly describes the development of mass spectrometry imaging and ionization techniques for it, and systematically summarizes the recent applications of mass spectrometry imaging in the field of food science.
Effect of Strain Heterogeneity of Food-Borne Pathogens on Microbiological Risk Assessment: A Review
YU Wenying, ZHANG Zhaohuan, LIU Haiquan, Pradeep Kumar MALAKAR, PAN Yingjie, ZHAO Yong
2019, 40(13):  296-303.  doi:10.7506/spkx1002-6630-20180628-509
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Microbial risk assessment is one of the most important scientific tools to ensure food safety. It is crucial for the development of food safety policies, regulations and standards. Strain heterogeneity is the inherent characteristic of microorganisms, and is prevalent in various pathogens, affecting the accuracy and uncertainty of microbiological risk assessment. This review summarizes the current studies on strain heterogeneity. Meanwhile, the conception of strain heterogeneity is proposed and its main types are also elaborated, including growth and death heterogeneity, biofilm heterogeneity, virulence heterogeneity and antibiotic resistance heterogeneity. Furthermore, the manifestation of heterogeneity is analyzed and the influence of heterogeneity of microorganisms on microbiological risk assessment is discussed. This review proposes four solutions to decrease the impacts of strain heterogeneity and puts forward the concept of meta-model, which will hopefully help improve the accuracy and reliability of microbiological risk assessment.
Recent Progress in Mechanism of Action and Application of Methyl Jasmonate in Postharvest Quality Regulation of Fruits and Vegetables
CUI Xixi, LI Fujun, ZHANG Xinhua, GUO Yanyin, LI Xiao’an
2019, 40(13):  304-311.  doi:10.7506/spkx1002-6630-20180805-036
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Methyl jasmonate (MeJA) is a growth regulator ubiquitously found in plants, which has a wide range of physiological functions. MeJA can significantly induce disease resistance, improve chilling tolerance, maintain the postharvest quality and prolong the storage period of fruits and vegetables. The mechanism of action of MeJA in improving the postharvest quality of fruits and vegetables mainly include inducing gene expression, increasing the antioxidant and disease resistance-related enzyme activities, promoting the accumulation of disease resistant-related substances, and improving energy metabolism. In this article, the structure and physicochemical properties of MeJA are described and the current status of the application of MeJA to postharvest fruits and vegetables as well as its mechanism of action and application modes (alone or in combination with other treatments) is reviewed. In addition, future research and application prospects are also discussed. We expect that this review can provide valuable information for further studies on the application of MeJA in postharvest fruits and vegetables.
Mechanisms through Which High-Pressure Treatment Reduces the Use of Salt in Low-Salt Meat Products and Its Application in Quality Improvement: A Review
HAN Ge, QIN Zeyu, ZHANG Huan, KONG Baohua
2019, 40(13):  312-319.  doi:10.7506/spkx1002-6630-20180521-303
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Salt reduction in meat products is a general trend of the current development of meat products, but it may cause quality deterioration of meat products. Ultra high-pressure technology, a new non-thermal processing technology, can reduce the amount of salt used in meat products while improving the functional properties of muscle proteins, and consequently enhancing the quality of low-salt meat products. This article discusses recent progress in the application of high-pressure treatment in the quality improvement of reduced-salt meat products with respect to water retention, cooking loss, salty taste, color and microbiological safety, and summarizes the mechanisms by which high pressure treatment reduces the use of salt in low-salt meat products. This paper also discusses the limitations and future prospects for the application of ultra-high pressure technology to low-salt meat products. Overall, this review provides a theoretical basis for promoting the applications of ultra-high pressure technology to low-salt meat products.
A Review of the Application of Machine Vision Technique in Sensory Testing of Aquatic Foods
JIA Zhixin, FU Linglin, YANG Xinting, SHI Ce, WANG Haiyan, ZHOU Jinru, WANG Yanbo
2019, 40(13):  320-325.  doi:10.7506/spkx1002-6630-20180730-364
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Machine vision technique is a non-destructive, fast and economical inspection technology. Based on a review of the current status of research on machine vision technique, the advantages of a machine vision system and the ways in which it is used to detect color, shape and size are presented in the present paper. On this basis, the application of machine vision technique is discussed and analyzed carefully in aquatic products such as fish, shrimp, scallops and oysters. In addition, the limitations of machine vision technique in the sensory detection of aquatic foods are pointed out and future development prospects in deep learning are discussed. The purpose of this paper is to provide technical support for sensory testing of aquatic foods to ensure consumer safety.
Recent Progress in the Application of Heat Treatment in Wheat Storage and Processing
LIU Yuanxiao, LI Mengmeng, BIAN Ke, GUAN Erqi, LIU Yuanfang
2019, 40(13):  326-333.  doi:10.7506/spkx1002-6630-20180623-444
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Heat treatment is commonly used in wheat storage and processing. Proper heat treatments are beneficial to improve the storage stability, and processing, nutritional and eating quality of wheat and flour, which is of great significance for ensuring food safety and improving wheat quality. However, wheat quality may be influenced adversely by improper heat treatment. The heat treatment methods commonly used in wheat processing are summarized in this paper and their applications in killing of insect pests, sterilization, detoxification, enzymatic inactivation and quality improvement are reviewed. Meanwhile, the negative effects of heat treatment on wheat quality and some countermeasures are proposed. Therefore, it is necessary to comprehensively understand the changes in wheat and flour quality during heat treatment and to study the effects of heat treatment on the final product quality. Moreover, the mechanism underlying these changes should be explored in order to improve the heat treatment process in a targeted manner and to develop heat treatment equipment for industrial applications to reduce the cost of heat treatment. It is desired that this review will promote the continuous development of heat treatment technology for applications in wheat storage and processing.
Recent Progress in Rapid Screening Methods for Antibacterial Peptides
XUE Hui, TU Yonggang, XIONG Chunhong, LI Jianke, LUO Wenxiang, ZHAO Yan
2019, 40(13):  334-339.  doi:10.7506/spkx1002-6630-20180615-331
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Antimicrobial peptides are a class of special bioactive peptides with broad-spectrum antibacterial activities, and are extensively applied in medicine, food, agriculture and other fields. This paper summarizes the applicability and characteristics of various pretreatment methods for detection of antibacterial peptides in crude samples. Emphasis is placed on the rapid screening methods for antimicrobial peptides, including bacterial adsorption method, cell membrane affinity chromatography, simulated cell membrane affinity chromatography, capillary electrophoresis, thin layer chromatography autoradiography and high throughput sequencing. This review will provide useful information for discovering new antimicrobial peptides and enriching the existing bank of antimicrobial peptides.
Recent Advances in the Application of Stable Isotope and Mineral Element Analysis in Tracing the Geographical Origin of Cereal Grains
LIU Wenwen, CHEN Yan, YANG Hui, GENG Anjing, WANG Fuhua
2019, 40(13):  340-348.  doi:10.7506/spkx1002-6630-20180813-125
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Tracing the geographical origin of cereal grains is an important part of identifying their authenticity. Stable isotope and mineral element analysis have the advantages of high sensitivity and reliability, and the association of the information obtained with growing environmental conditions and planting methods followed by chemometric classification, discrimination and modelling allows to trace the geographical origin of cereal grains. In this article, we provide a systematic review of the recent advances over the past more than one decade in the application of stable isotope and mineral element analysis in tracing the geographical origin of cereal grains. Meanwhile, we discuss the problems existing in tracing the geographical origin of cereal grains, and propose the future prospects and research priorities for the application of stable isotope and mineral element analysis in this field.