Analysis of quality-related proteins in golden pompano(Trachinotus ovatus)fillets with modified atmosphere packaging under superchilling storage

Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.

Effects of Carbon Dioxide Treatment and Modified Atmosphere Packaging on the Quality of Long Distance Transporting “Maehyang” Strawberry

This study was conducted to investigate the effects of carbon dioxide (CO2) and modified atmosphere (MA) packaging on the quality of strawberry during long distance transportation. “Maehyang” strawberries (Fragaria x ananassa Duch.) with red color on 70% of the fruit surface were harvested in Gyeongnam province, Korea. The samples were placed in gas-tight chamber with 30% CO2 concentration for 3 hours at 3°C. Strawberry samples were then packaged with modified atmosphere-modified humidity (MA/MH) packaging film. Samples treated with CO2 alone and combined CO2 with MA packaging were stored for one day at 1°C, transported for 10 days at 1°C, and distributed for 3 days at 4°C. Carbon dioxide alone or combination with MA packaging was effective in maintaining quality of “Maehyang” strawberries. Carbon dioxide treatment significantly increased firmness and reduced softening index and decay rate during 14 day transportation and distribution. Samples treated with CO2 + MA had higher overall score with low softening index and weight loss after 14 days of transportation and low temperature distribution compared to CO2 treatment only. The results indicated that a short term application of CO2 or combination treatment of CO2 and MA could be good postharvest handling for maintaining freshness of “Maehyang” strawberries during long distance vessel export.

Effects of Active Modified Atmosphere Packaging on Postharvest Quality of Shiitake Mushrooms (Lentinula edodes) Stored at Cold Storage

The effects of active modified atmosphere packaging （MAP） on the postharvest quality of shiitake mushrooms stored at cold temperature （4°C） were investigated.The gas components were 2% O2 ＋7% CO2 （MAP1）,2% O2 ＋10% CO2 （MAP2） and 2% O2 ＋13% CO2 （MAP3）,respectively.The results showed that active MAP could extend the shelf-life of shiitake mushrooms to 17 d and the concentration of carbon dioxide could influence the postharvest quality of shiitake mushrooms.MAP2 treatment inhibited the increase in respiration rate and malondinaldehyde （MDA） contents,delayed the decrease in firmness,soluble sugar and vitamin C,and obviously reduced the activity of polyphenol oxidase （PPO） and the degree of browning,therefore maintaining better quality.

Effects of 1-methylcyclopropene and modified atmosphere packaging on fruit quality and superficial scald in Yali pears during storage

The Yali pear（Pyrus bretschneideri Rehd.） is susceptible to superficial scald during prolonged cold storage and at shelf life. This study investigated the effects of 1-methylcyclopropene（1-MCP） and modified atmosphere packaging（MAP） on changes of fruit quality and superficial scald during cold storage and at shelf life in Yali pear. Compared with MAP, the combination of MAP and 1-MCP（MAP＋1-MCP） treatment reduced the carbon dioxide and ethylene content inside the packaging bag. The 1-MCP, MAP, and MAP＋1-MCP treatments reduced the superficial scald index, malondialdehyde content, O2^-· production rate and relative conductivity and inhibited the accumulation of α-farnesene and conjugated trienes in the peel. 1-MCP and MAP＋1-MCP treatments maintained a higher phenolic content and enhanced the catalase and superoxide dismutase activities in the fruit, while reduced activities of lipoxygenase and polyphenol oxidase in the peel preceding the onset of superficial scald. Comprehensive analysis indicated that the MAP＋1-MCP treatment is the most effective method tested for improving the quality of Yali pears during cold storage and at shelf life.

Using a Modified Soil-Plant-Atmosphere Scheme(MSPAS)to Simulate the Interaction between Land Surface Processes and Atmospheric Boundary Layer in Semi-Arid Regions

This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary layer processes and land surface processes. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feasibility of the model is well proved in this paper. The numerical simulation results from MSPAS show good agreement with reality. The scheme is used to obtain reasonable simulations for diurnal variations of heat balance, potential temperature of boundary layer, and wind field, and spatial distributions of temperature, specific humidity, vertical velocity, turbulence kinetic energy, and turbulence exchange coefficient over desert and oasis. In addition, MSPAS is used to simulate the interaction between desert and oasis at night, and again it obtains reasonable results. This indicates that MSPAS can be used to study the interaction between land surface processes and the atmospheric boundary layer over various underlying surfaces and can be extended for regional climate and numerical weather prediction study.

Monitoring and identification of spoilage-related microorganisms in braised chicken with modified atmosphere packaging during refrigerated storage

This study mainly monitored the dominant bacterial populations and identified the spoilage-related microorganisms of braised chicken meat stored under different CO_(2)-modified atmosphere packaging(MAP)during refrigerated storage using a culture-dependent method and 16S rDNA identification.The quality changes and shelf life of the meat were also measured.The growth rate of total viable count(TVC)in braised chicken was slower with an increase of CO_(2) content in MAP,which also occurred in the remaining bacterial species monitored(lactic acid bacteria,Pseudomonas spp.,Brochothrix thermosphacta).The MAP exerted beneficial effects on the quality of braised chicken,as demonstrated by retarding the production of total volatile basic nitrogen(TVB-N)and delaying lipid oxidation(TBARS test).A total of 14 isolates were identified from braised chickens with different packaging at the end of storage,these included P.fragi(6 isolates),P.psychrophila(2 isolates),Enterococcus faecalis(3 isolates),B.thermosphacta(2 isolates),Staphylococcus equorum(1 isolate).

Using a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to Study the Sensitivity of Land Surface and Boundary Layer Processes to Soil and Vegetation Conditions

A series of sensitivity tests are performed to test the stability and sensibility of the Modified Soil-Plant-Atmosphere Scheme (MSPAS), which was wholly introduced in a previous paper. The numerical simulation results from the experiments show good agreement with physical reality. Besides, some of the results are illuminating. Together with the first paper, it is concluded that MSPAS is a simple but effective model, and it is practically valuable in the research work of desertification control and reforestation in China.

Prolonging the Shelf Life of Ready-to-Serve Pizza through Modified Atmosphere Packaging: Effect on Textural and Sensory Quality

The effects of different modified atmospheres (air: atm1;100% CO2: atm2;100% N2: atm3;50% CO2/50% N2: atm4) on the textural and sensory characteristics of the ready-to-serve pizza at 7℃ ± 1℃ were investigated. The values of hardness, gumminess and chewiness were found to be increased during the storage period while cohesiveness and springiness exhibited a decreasing trend. Overall, the 100% CO2 product yielded the best textural and sensorial characteristics followed by 50%CO2/50% N2 and 100% N2 when compared to conventional packed pizza at 7℃ ± 1℃. Carbon dioxide caused microbial inhibition as well. The shelf life of ready-to-serve pizza significantly increased upto 45 days (a 300% increase) for the samples packaged under 100% CO2 (atm2), 50% CO2/50% N2 (atm4) and 100% N2 (atm3), compared to conventional air pack (15 days).

Effects of Lactoperoxidase System Activation-Oregano Essential Oilor Chlorine on the Quality of Modified Atmosphere Packaged Fresh-Cut Iceberg Lettuce

The present work focused on the effects of the Modified Atmosphere Packaging (MAP) 1 (5% O2 and 10% CO2) or 2 (2% O2 and 5% CO2) and the previous addition of Lactoperoxidase System (LPS) and Oregano essential oil or chlorine washing on the quality of fresh-cut lettuce during refrigerated storage at +4?C. Our results showed the significant effect of this combined treatment on quality improvement during storage. Thus, mesophilic bacteria was reduced in treated samples compared to those untreated with number which not exceeded the critical of 5 × 107 UFC?g-1 (p 2 and CO2 levels created by both atmosphere were not significantly different between the two treatments (p > 0.05). Brightness of lettuce samples was significantly reduced during storage. Thereafter, the PCA data showed the effect of combined treatment on the preservation of hygienic, physico-chemical and sensory quality up to the 7th day of refrigerated storage of these treated samples. The results obtained draw attention to modified atmosphere packaging lettuce and the addition of bio-preservatives which could be an alternative of choice to replace chlorine to preserve the sanitary quality of green products.

Effect of Modified Atmosphere Packaging on Postharvest Quality of Rambutan cv. Binjai

An experiment on retail film packaging system was conducted to compare the atmospheric composition within sealed packs containing rambutan fruits. This research was done in order to study the effect of packaging films with different permeability on the some of physicochemical properties of rambutan during storage at 10℃. The films used were 0.090 mm low density polyethylene （LDPE）, 0.040 mm polyprophylene and 0.057 mm LDPE compared unwrapped fruits. Fruits were evaluated every 5 days for changes in moisture content, total sugars, vitamin C, hardness and color. Unwrapped rambutan had severe browning after 10 days. Sealed packages especially the LDPE had delayed the development of the browning for 20 days of storage and had the lowest weight loss.

Microbial Aspects in Comparing Modified Atmosphere Packaging and Vacuum Packaging on Shelf Life of Fresh Bull Meat

The importance of meat preservation and various reports on different types of packaging, and to compare the effects of modified atmosphere packaging （MAP） and vacuum packaging （VP） on shelf life of flesh bull meat, and microbiological tests on meat together with some chemical and sensory tests was on tight observation. It was an experimental study, 96 samples were randomly packaged in two groups of MAP and VP equally. The package consists of five layers which are Polyvinylidin Chloride （PVDC）, Ethyl Vinyl Alcohol （EVOH）, Poly Ethylene （PE）, Linear Low Density Poly Ethylene （LLDPE）, and poly Amid （PA）, respectively. MAP meat with 700 mL of CO2 per kg of meat. The packaging were made in at-ameh-pars factory and transported in chilled condition to a well prepared refrigerator in National Research Institute of Food Science （NRIFS） of Shahidbeheshti University of Medical Sciences. These samples tested weekly, since first day after packaging, and week 2, 3, 4, 5, 6, 7, and 8. Microbial tests include Total Microbial, Coliform, Lactic Acid Bacteria, Pseudomonas Counts, and Clostridium. Chemical and sensory tests also carried out. Total volatile bases （TVN）, TBA, and pH as chemical analyses and color, odor, and weep as sensory analyses are also added. Results revealed that total microbial count was in standard range within the 6 weeks for VP, and 5 weeks for MAP technique. Other microbial factors including coliforms, lactic acid bacteria are less and somehow in chemical and sensory tests emphasized the microbial figures. recommended for meat packaging. similar pattern to total count, and no clostridia were found. By the way, The results showed that according to our existing facilities, VP is

Effect of Modified Atmosphere Packaging on Postharvest Quality of Barangan Banana

An experiment retail film packaging system was used to compare the atmospheric composition within sealed packs containing barangan banana fruits. This research was done in order to study the effect of packaging films with different permeability properties on the physicochemicalproperties of barangan banana during storage at room temperature （28 ± 2 °C） and at 15 °C. The films used were 0.09 mm low density polyethylene （LDPE）, 0.04 mm polypropylene and 0.057 mm LDPE compared with unwrapped fruits as control. Barangan bananas were evaluated each 5 days intervals for changes in moisture content, total sugars, vitamin C, hardness and color. Unwrapped barangan bananas were overripe and soft after 15 days at both temperature conditions. Sealed packages especially using LDPE at 15 °C delayed the development of the yellow color of banana until 20 days of storage and had the lowest weight loss.

Statistical Investigation and Mapping of Monthly Modified Refractivity Gradient over Pakistan at the 700 Hectopascal Level

This study is an effort to investigate the spatial-temporal variability of the modified refractivity gradient at the 700 hPa pressure level over Pakistan and its neighbouring regions of Afghanistan, India, Iran and the Arabian Sea using the remote sensing data of the AQUA (AIRX3STM) satellite from 2008 to 2012. Trapping conditions only found in December were spread over Khyber Pakhtunkhwa (Gilgit-Baltistan, Pakistan) with an average value of -182.042 M/Km and showing Leptokurtic distributions. The lowest monthly average value super-refractive conditions existed in the autumn season with a strong monthly correlation (>0.91 M/Km). A very high monthly correlation (0.9 M/Km) was found for the super-refractive conditions over the whole time period. The largest spatial and temporal normal conditions appeared in January with the average value for normal conditions being 132.72 M/Km (found over Zabul, Afghanistan) with Leptokurtic distributions. During May normal conditions were the smallest in spatial extent over Pakistan, India and Afghanistan, showing Platykurtic distributions. Sub-refractive conditions mostly prevailed at all times. The probability for extreme sub-refractive conditions was very high in 2008-2012. The highest average sub-refractive conditions appeared in the winter and autumn seasons (spread around Quetta and Kalam, Pakistan). The highest monthly average sub-refractive conditions with a value of 1,265,188 M/Km were found in January and spread around the Sarbaz River Iran. Correlations for the existence of sub-refractive conditions varied from 0.8 M/Km (moderate strong) to 0.4 M/Km during the autumn to winter season. Permanent super-refractive conditions existed over Baluchistan from February to September.

Prediction of specific spoilage organisms in smoked chicken legs with modified atmosphere packaging at 4℃ using multivariate statistical analysis

The present study monitored bacterial succession,physicochemical properties,and volatile organic compounds(VOCs)changes in smoked chicken legs with modified atmosphere packaging(MAP,60% CO_(2) and 40%N_(2))during a 25-day storage period at 4℃.After 15 days of storage,S erratia proteamaculans and Pseudomonas fragi became the predominant bacteria.Furthermore,physicochemical properties changed significantly,as evidenced by an increase in thiobarbituric acid reactive substances and b*(yellowness)value,and a decrease in hardness.A total of 65 VOCs were identified during storage.Correlation between bacterial succession and quality indicators(including VOCs and physicochemical properties)allowed the identification of 26 core dominant bacteria,including S.proteamaculans,Psychrobacter alimentarius,Pseudomonas putida,and Pseudomonas poae,which were positively related to spoilage VOCs(e.g.,1-octen-3-ol,1-pentanol,and 3-methyl-1-butanol)and could be defined as specific spoilage organisms(SSOs).The results of this study provide a systematic approach to predict SSOs in smoked chicken legs during storage,which can also provide a basis for product safety.

STUDY ON THE MODIFICATION OF POLY (METHYL METHACRYLATE) TRANSPARENT MATERIAL

A kind of transparent plastic material has been prepared with bulk copolymer of MMA-MA containing MA 20 vol% as matrix modified by introducing EtOH during bulk copolymerization to increase the transparency and by copolymerizing together with metallic salts of MA forming ionomer polymer to improve the heat-tolerance and hardness. The effect of the contents of the additives on the heat stability, hardness and transparency of the copolymer has been studied. The optical homogeneity of the copolymer material has also been examined. It has been found that the specific property of transparent material of this kind may be obtained by controlling the amounts of EtOH and metallic salt of MA.

不同包装材料和气体比例对冷鲜乌鸡肉品质的影响

为了探究不同包装材料及气调条件对普安盘江乌鸡冷藏过程中肉质的影响,选用4种包装膜(包装膜0(PP),包装膜1(PE/EVOH/PA),包装膜2(PE/TIE/PA/EVOH/TIE/PE/TIE/PA),包装膜3(NY/EVA))对新鲜普安盘江乌鸡肉进行充空气包装,并在不同储藏时间段对鸡肉品质指标进行测定,筛选出保鲜效果最好的包装膜,然后采用保鲜效果最优包装膜结合4种不同气调包装(A组(空气),B组(30%CO_(2)+70%N_(2)),C组(5%O_(2)+40%CO_(2)+55%N_(2)),D组(15%O_(2)+30%CO_(2)+55%N_(2)))进行包装,研究其对普安盘江乌鸡肉品质的影响,确定最优气调包装组合。结果表明,在储藏过程中,4种不同包装膜中,包装膜2的保鲜效果良好,该处理鸡肉的菌落总数和挥发性盐基氮(TVB-N)值相比其他膜相对较低,保鲜效果最佳。气调包装中,D组(15%O_(2)+30%CO_(2)+55%N_(2))的菌落总数和TVB-N值相比其他气调包装组相对较低,能将普安盘江乌鸡保鲜至18 d。综合菌落总数及其他指标,优化的包装材料和气调包装乌鸡肉的货架期相比聚丙烯膜空气包装延长了10 d以上。

气调包装(MAP)对草莓保鲜的影响

研究了气调包装技术对草莓贮藏保鲜的效果。结果表明,草莓最佳气调贮藏的条件为2.5%O2+16%CO2,它能够把草莓的货架寿命延长4～6d;利用LDPE和PVC复合膜明显优于LDPE膜和PVC膜。气调贮藏效果表明,MAP能明显抑制草莓的呼吸作用和水分的蒸腾作用,抑制糖、酸和花色苷等物质的降解。最后研究了包装内气体组分的动态变化。

施加外源乙烯时机对MA贮藏桃果实品质的影响

为了改善桃果实低温贮藏期间品质降低情况,探讨了大久保桃果实在低温条件下自发气调(MA)贮藏期间,不同时间(0、15和30d)加入外源乙烯处理(50～80μL/L)的效果,测定在贮藏期间及20℃下回温3d后果实的硬度、可溶性固形物含量(SSC)、腐烂指数、可滴定酸(TA)、总糖、维生素C(Vc)的含量。结果表明,在0℃下MA贮藏15、30d加入外源乙烯处理能较好地保持果实的质地、可溶性固形物含量,降低桃果实的腐烂率。同时15d时加入外源乙烯处理还能较好地保持总糖和Vc含量,但对可滴定酸的影响与其他MA处理差异不显著。研究表明,MA贮藏大久保桃果实在第15天进行外源乙烯处理效果最好。

MA包装对鲜食核桃冷藏期货架品质及内源激素的影响

以"辽核2号"鲜食核桃为试材,采用Thn-PE11(11μm)、PE30(30μm)、PE50(50μm)和Thk-PE90(90μm)4种MA包装后于(0±0.5)℃下贮藏,定期转入7℃货架期贮藏7d,以6μm的普通薄膜包装为CK,监测各包装袋内气体成分、核仁品质及内源激素含量的变化。结果表明:各MA包装处理均具有提高CO2浓度和降低O2浓度的气调能力;4种包装下鲜核仁的酸价、过氧化值和羰基价均极显著低于CK,其中以PE30和PE50包装最低;PE30和PE50包装核桃的粗蛋白和脂肪含量较高;同时,4种MA包装降低了鲜食核桃脱落酸(abscisic acid,ABA)的含量,显著维持了其贮藏后期较高的赤霉酸(gibberellic acid,GA)与玉米素核苷(zeatin riboside,ZR)的含量。综合考虑各指标变化及成本因素,确定PE30为脱青皮鲜食核桃适宜的MA包装。

黄金梨CA和MAP贮藏保鲜试验

研究了黄金梨不同浓度1-MCP处理后,CA和MAP贮藏条件对果实的防褐保鲜效果。结果表明,3.0%O2+0.5%CO2组合贮藏黄金梨防褐保鲜效果较好,可保持果实较高硬度,完全抑制黑皮,明显降低果心褐变指数;在CA贮藏条件下使用1.0μL/L 1-MCP易对果实产生CO2伤害。挽口和薄袋扎口贮藏结合0.5μL/L 1-MCP处理能获得良好的防褐保鲜效果;在无1-MCP处理条件下,厚袋扎口处理能起到良好的自发气调作用,而1-MCP处理的果实则产生不同程度的CO2伤害。