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.

Effect of Vacuum Packaging on Storage Quality of Peanut

The purpose of the study is to investigate the effect of vacuum packaging on storage quality of peanut. The acid value,peroxide value,relative conductivity,mildew rate and germination rate of peanut were examined in both vacuum-packed bags and control packaging bags.The results showed that the acid value,peroxide value,relative conductivity and mildew rate of peanut were maintained at a lower level and germination rate was maintained at a higher level in vacuum-packed bags than in control packaging bags. The storage quality of peanut in vacuum-packed bags was better than in control packaging bags. The order of different vacuum degree of vacuum-packed bags from good to bad according to storage quality of peanut was- 0. 06 MPa >- 0. 09 MPa >- 0. 03 MPa,and- 0. 06 MPa was the most beneficial vacuum degree for the peanut storage.

Effect of Modified Atmosphere Packaging (MAP) on the Stability of Anthocyanins and Degradation of Phenolic Compounds during Postharvest Storage of Pomegranate Fruit

Effects of storage temperature, packaging material, elevated CO2 and reduced O2 contents in the package headspace, and their interaction effects on the total content of anthocyanins and degradation of phenolic compounds during long storage of “Malase Torsh Saveh” pomegranate were studied. The study findings showed that only storage temperature and its duration had significant effects on the degradation of phenolic compounds. The content of anthocyanins was affected by the single effect of storage time and its 3-way interaction effect with the storage temperature and the fruit’s surrounding gas composition. Higher contents of both total anthocyanins and browning pigments were recorded at 2°C storage temperature. The Browning Index (BI) of the pomegranate extracts showed to change quadratically with the variations in the total anthocyanins content but linearly with the variations in the content of browning compounds. Thermal dipping treatment and its interaction with the storage time also had significant effect on the BI values of the extracts obtained from modified atmosphere packaged pomegranates stored at 6 °C.

Effect of Freshness Protection Package on Storage and Preservation of Chinese Cabbage

The effect of freshness protection package on Chinese cabbage placed in the self-made shelf in ventilated storage was investigated, and the physiological-qual-ity indexes change were determined during the storage period. The results showed that the losses of weight and vitamin C were significantly reduced. The accumula-tion of crude fiber was effectively inhibited. But protein content was maintained at a low level and the rotting more serious of Chinese cabbage at the end of the stor-age packaged with the fresh keeping bags.

Model of gas exchange dynamics for modified-atmosphere packages containing fresh produce

A model for modified-atmosphere packaging （MAP） systems containing fruits and vegetables was developed.The computer simulation was performed to predict the gas mass concentrations inside the packages and was successfully verified by experiments with yellow peaches at 5,15 and 25 ℃ using two types of packaging films.A Michaelis-Menten type respiration model with noncompetitive inhibition mechanism due to CO2 was adopted while the respiration rates were measured with an improved permeable system method suitable for either steady or unsteady state.The applicability of the model in the design of MAP systems was demonstrated with a calculation to evaluate film specification and equilibrium concentrations of O2 and CO2 in the package containing yellow peaches.

The Use of Chloride, Citric and Ascorbic Acid Dip and Packaged Film to Extend the Shelf Life of Pejerrey (<i>Odonthested bonaerensis</i>) during Storage at Different Temperatures

The objective of this study was to analyze the effect of chloride, citric and ascorbic acid dip treatments in conjunction with two types of packaging films (with high and low gas permeability) on microbial growth in samples of pejerrey fillets (Odonthestes bonaerensis) at three storage temperatures (4&#176;C, 0&#176;C and -1.5&#176;C). Colour, pH, texture modification and chemical changes were also studied. Psychrotrophic microorganisms, sp. were modelled by the Gompertz’ equation. Lag phase duration, specific growth rate and maximum population density were calculated. The activation energy (E&#181;) was calculated reaching values of 147 and 177 kJ/mol when the low permeability packaging films were employed. We used psychrotrophic microorganisms, sp., as a predictor of the shelf life of product. The application of treatment with chloride, citric and ascorbic acids, extended 1 - 2 days the storage life of the product (time to reach 106 CFU/g) when the packaging material used was polyethylene. The use of chloride, citric and ascorbic acids and vacuum packaging produced shelf life values of 7.7, >25 and >25 days at 4&#176;C, 0&#176;C and -1.5&#176;C respectively. The products had very good organoleptic characteristics, maintained their colour and texture appropriate, and absence of pathogenic microorganisms. These values indicated that the growth models were acceptable for expressing the growth of microorganisms on pejerrey fillets, which can be applied to ensure the safety of fish and to establish standards for avoiding microbial contamination.

Study on Vigor of Kenaf Seeds Stored with Different Packaging Methods for 31 Years

This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and comprehensively estimate changes in seed vigor of seeds stored with different packaging materials. Hibiscus cannabinus L. seeds were stored in aluminium box, seed box, glass bottle, POlyethylene film bag, sack and kraft paper bag as packaging materials in a, long-term bank and tested for their seeds germinability, electrical conductivity and field seedling rate after 31 years. The results showed that the kenaf seeds with an initial germination rate of 88% exhibited the germination rates over 79.7% after being stored in the 6 packaging materials for 31 years, the germination rates of seeds packaged with paper bag and sack and of those sealed in film bag and aluminium box showed significantly decreased germination rates, while the seeds sealed in seed boxes and glass bottles exhibited non-significant decreases in seed germination rate, and their germination rates were still above 85%. Seed box and glass bottle were the packaging materials most suitable for long-term safe storage of kenaf seeds with a safe storage period long than 31 years.

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).

Influence of cutting size and packaging materials on the quality of fresh-cut winter squash (var. Ajijimang)

Winter squash (var. Ajijimang) washed in 100 mg.L-1 chlorine water and cut into 4 and 8 parts was packed in different packaging materials, 35 μm micro-perforated P-Plus (MPP), 50 μm polyethylene (PE), 80 μm nylon/PE (Ny/PE), and 90 μm PE films separately. Fresh-cut samples were then stored at 10℃ for up to 17 days. The 35 μm MPP having a high oxygen transmission rate (OTR) has the most stable gas exchange ratio while the 80 μm Ny/PE was the most unstable. Firmness of the mesocarp remained acceptable until the end of storage regardless of the cutting size. Soluble solids content (SSC) remained stable and even slightly increased to a certain extent within 6 days. An increase in pH after 10-day storage suggested the activity of microorganisms within the packaging films. Strong off-odor was detected in samples packaged in 80 μm Ny/PE film after 13 days of storage. Mold was observed in all 1/4 cut samples on day 13 except the sample packaged with 80 μm Ny/PE film. However, no mold was found in all 1/8 cut samples except 35 μm MPP film on day 13. Severe mold invasion was apparent on the onset of the 17-day storage in 35 μm MPP film and 50 μm PE film. Samples cut into 8 parts and packed in 80 μm Ny/PE and 90 μm PE films had less mold incidence compared with other two packaging films. Fresh-cut winter squash packaged in 90 μm PE film maintained quality with shelf-life of 10 days at 10℃. Winter squash as fresh-cut commodity, with the right packaging material has the potential for longer period of storage in retail stores.

超声波处理结合微孔气调包装对鲜切菠萝蜜冷藏品质的影响

为了明确超声波(US)处理结合微孔气调包装(MMAP)对鲜切菠萝蜜微生物总数和冷藏品质的影响,并确定最佳保鲜手段,采用对照(蒸馏水,10 min)、US(300 W,10 min)、MMAP(蒸馏水,10 min,5%O2、6%CO_(2),15个打孔数)以及US+MMAP四种方式处理鲜切菠萝蜜,样品在10±1℃下储存8 d,每2 d一次测定微生物及理化指标。结果表明,与对照相比,三种处理均可显著抑制鲜切菠萝蜜冷藏期间菌落总数、霉菌和酵母菌数生长繁殖(P<0.05),有效地延缓了由微生物引起的腐败变质,维持了鲜切菠萝蜜较高的组织硬度、可溶性固形物、可滴定酸,VC和总酚含量等,同时降低了丙二醛含量、多酚氧化酶和过氧化物酶活性,抑制了果实褐变,且US+MMAP联合处理显著优于单一处理。因此,超声波处理结合微孔膜气调包装(US+MMAP)能有效延长鲜切菠萝蜜的保鲜期。

五种鲜切蔬菜冷藏过程中的微生物多样性

微生物腐败是影响鲜切蔬菜货架期的重要因素之一,研究其腐败过程中的微生物多样性和主要腐败菌,可针对性地开发有效的抑菌技术,延长货架期。该研究探究了真空包装和普通包装对菠菜、上海青、芹菜、西兰花和细香葱这5种蔬菜4℃冷藏过程中菌落总数和微生物多样性的影响,并对主要腐败菌进行分离、鉴定。结果表明,真空包装可以有效抑制菌落总数的增长,贮藏8~15 d后,2种包装蔬菜的细菌多样性均增加。5种普通包装蔬菜中优势细菌为假单胞菌属、黄杆菌属、黄假单胞菌属和杜擀氏菌属;在5种真空包装蔬菜中优势细菌存在较大差异,但乳球菌属、拉恩氏属和魏斯氏属均存在。不同品种蔬菜携带的主要真菌丰度差异较大,其中,链格孢霉属和线黑粉酵母属等是导致腐烂变质的常见微生物。5种普通包装蔬菜的主要腐败细菌均为革兰氏阴性菌,而真空包装中主要为拉乌尔菌属、假单胞菌属和芽孢杆菌属,且主要腐败细菌大多并非腐败蔬菜中的优势菌。研究结果初步明确了5种蔬菜冷藏期间的微生物菌群结构和主要腐败菌,为鲜切蔬菜保鲜技术的开发提供参考。

新型液态金属电池材料体系及其相关技术的研究与进展

作为一种新型储能技术,液态金属电池以独特的结构赋予了自身低成本、高倍率、长寿命、易于制造和放大等特性,被认为是固定式储能极有前途的解决方案之一。自2006年Sadoway教授提出液态金属电池概念以来,不同的电池材料体系得到广泛的研究。本文在详细介绍液态金属电池工作原理和电池材料选择标准后,按照工作温度分级介绍了高温液态金属电池(>300℃)、中温液态金属电池(100~300℃)以及室温液态金属电池(<40℃)的材料体系。并在此基础上按不同温区系统综述了液态金属电池近年来研究进展,而后讨论了液态电池封装技术的抗腐蚀问题,最后指出了未来液态金属电池可能的发展趋势。

Preparation,Characterization and Hot Storage Stability of Asphalt Modified by Waste Polyethylene Packaging

Waste polyethylene packaging （WPE） was used to modify asphalt, and hot storage stability of the modified asphalt was studied in this paper. The morphological change and component loss of WPE modified asphalt were characterized by fluorescence microscopy, Fourier transform infrared spectroscopy （FT-IR）, differential scanning calorimetry （DSC）, thermogravimetry （TG） and isolation testing. In addition, the mechanism of the hot storage stability of WPE modified asphalt was discussed. The results showed that the modification of asphalt with WPE was a physical process. It was found that the filament or partly network-like structure formed in the modified asphalt system was beneficial to improving the hot storage stability. Moreover, the addition of WPE resulted in a decrease in both the light components volatilization and the macromolecules decomposition of asphalt. It was demonstrated that when the content of WPE in matrix asphalt was less than 10 wt%, the service performances of modified asphalt could be better.

Effects of Different Storage Methods on the Fruit Quality and Physiological Changes in Yihong Honey Peach

Taking Yihong,the main cultivar of mid-ripening honey peaches(Prunus persica)in Hunan,as material,this study explored the effects of different storage methods on the fruit quality and physiological changes in Yihong honey peach by the combination of polyethylene film packaging with low-temperature storage.The results showed that the weight loss rate of packaged storage at normal temperature(T1)was significantly lower than that of unpackaged storage at normal temperature(CK),but there was no significant difference in other indicators.In the middle of storage,the respiration rate and ethylene release of packaged storage at 0℃(T3)were extremely significantly lower or significantly lower than those of unpackaged storage at 0℃(T2),packaged storage at 0℃after cold adapting at 8℃for 5 d(T4),and packaged storage in a fluctuating temperature range of 0~3.5℃(T5).After storage,the structure of the middle lamella in the cell wall of T3 was compact and uniform,and the mitochondrial structure was complete,while the cell walls and mitochondria of T4 and T5 were severely deformed and disintegrated.The activities of antioxidant enzymes peroxidase(POD)and superoxide dismutase(SOD)of T3 was significantly higher than those of T4 and T5,and the content of malondialdehyde(MDA)and polyphenol oxidase(PPO)of T3 was also the lowest.Therefore,0°C packaged storage can effectively delay the senescence of Yihong honey peach and prolong its freshness period.

Effect of grinding methods and packaging materials on fenugreek and black pepper powder quality and quantity under normal storage conditions

The effects of different grinding methods and packaging materials on qualities of fenugreek and black pepper powders were evaluated.Various parameters and their evaluation methods are as follows:change in colour determined using Chroma meter calorimeter,aroma and odour measured by sensory evaluation,and change in moisture measured using oven drying method.Packaging materials such as glass jar,steel jar,plastic jar,aluminum bag and poly bags were used for keeping ambient and cryogenically ground fenugreek and black pepper powders.Packed powders were stored in dry and cool places under ambient condition.Sensory evaluation revealed quality reduction in terms of colour,odour,flavour,aroma and acceptability for fenugreek and black pepper powder stored for a long term(6 months).However,glass jar and steel jar were found to be better containers for storing powders for longer storage period than other options.For practical applications,the present investigation on the deterioration behaviour of fenugreek and black pepper powder contributes to the design of a suitable grinder out of ball,hammer,rotor,and pin mill for spice grinding.The study also helps select a suitable packaging material or container to store spice powders.A method to assess the quality of stored powder and its deterioration with the storage time is provided.

不同浓度1-甲基环丙烯处理对蓝莓贮藏品质的影响

为探究不同浓度1-甲基环丙烯(1-MCP)结合自发气调包装(MAP)对蓝莓冷藏期间保鲜效果的影响,以‘莱克西’蓝莓为试材,采后2 h内入预冷库,装入气调箱并对其进行0.5、1.0、1.5μL/L 1-MCP处理,冷链车运输96 h后入冰温库((-0.5±0.3)℃)贮藏,每10 d测定蓝莓的品质指标、生理指标和挥发性成分。结果表明:MAP结合3种浓度1-MCP处理均能延缓蓝莓果实硬度的下降,保持相对较高的花色苷、VC、可溶性固形物、可滴定酸含量,抑制呼吸峰值和乙烯生成速率。利用SPSS主成分分析得出各处理的保鲜效果排序为:MAP+1.0μL/L 1-MCP>MAP+1.5μL/L 1-MCP>MAP+0.5μL/L 1-MCP>MAP。在蓝莓贮藏过程中醛类(52.34%~86.13%)和萜类(7.26%~32.44%)是其主要挥发性成分,MAP+1.0μL/L 1-MCP处理的蓝莓果实能保持较高的醛类物质和萜类物质相对含量。综上,MAP结合1.0μL/L 1-MCP处理对蓝莓的保鲜效果最佳。

肉桂精油处理结合真空包装对冷鲜牛肉的保鲜作用

为探究肉桂精油对冷鲜牛肉的保鲜效果,用不同浓度的肉桂精油溶液浸泡牛肉并真空包装后于4℃下贮藏20 d,以菌落总数、挥发性盐基氮值、硫代巴比妥酸值、pH值以及感官评分为指标,测定肉桂精油对冷鲜牛肉的保鲜效果,同时考察牛肉中肉桂醛含量变化和精油对牛肉适口性的影响。结果表明,肉桂精油处理结合真空包装对冷鲜牛肉有显著保鲜作用,且浓度越大保鲜效果越好,1.2%肉桂精油处理后的牛肉在第20天各项指标仍在标准范围内。牛肉的菌落总数、挥发性盐基氮值和pH值的增长速度均得到控制,脂质过氧化程度得到延缓。肉桂醛含量对冷鲜牛肉适口性影响结果表明,经过1.2%肉桂精油保鲜的牛肉中,肉桂醛含量仅为0.09 mL/kg,并不影响牛肉的口感。因此,肉桂精油结合真空包装对鲜牛肉具有很好的保鲜效果,且不会影响牛肉的适口性。

俄罗斯液体潜射弹道导弹长期贮存材料工艺技术

对液体潜射弹道导弹长期加注贮存技术的发展进程、最新进展及研究现状进行概述。重点介绍俄罗斯液体潜射弹道导弹的结构设计、材料选取和制造工艺以及出厂加注封装和密封性检测方法,最后指出实现长期加注贮存的技术路径。

保鲜剂结合不同硅窗面积气调包装对西兰花贮藏品质的影响

为进一步检验前期西兰花硅窗气调关键参数筛选研究结果,并期望得到相较于单一硅窗气调贮藏效果更好的保鲜剂结合硅窗气调包装的西兰花的贮藏方法。以甘肃特色高原蔬菜耐寒优秀西兰花为材料,采用60 mg/L的二氧化氯保鲜剂溶液、蒸馏水浸泡清洗处理,以无处理为对照,再结合2℃下硅窗面积分别为6、8 cm^(2)的硅窗保鲜袋包装,通过叶绿素、抗坏血酸(Vc)、总酚、总花色苷和硫代葡萄糖苷含量等营养指标的测定,考察各处理方法对西兰花25 d贮藏期内品质的影响。结果表明,相较于单一的硅窗气调袋包装保鲜,保鲜剂或蒸馏水清洗处理结合硅窗气调保鲜有更好的保鲜效果,其中60 mg/L的二氧化氯保鲜剂溶液清洗处理效果更优。2℃贮藏温度下,同样处理方式的西兰花,硅窗面积为8 cm^(2)的硅窗袋气调袋包装的保鲜效果要优于硅窗面积为6 cm^(2)的硅窗气调袋包装;60 mg/L的二氧化氯保鲜剂溶液浸泡清洗,结合硅窗面积8 cm^(2)的硅窗气调袋包装的西兰花的贮藏品质最好,在25 d贮藏期内各营养指标总体高于其他处理。

相变混凝土抗压强度与储热能力试验及分析

为研究硅藻土相变混凝土在建筑围护结构中的应用,进行了相变储能骨料的封装方式试验和相变混凝土的抗压强度、保温性能试验,得到不同封装方式下相变储能骨料的质量损失率、不同相变储能骨料掺量下相变混凝土的抗压强度和储热能力的变化规律。结果表明:用水泥净浆封装相变储能骨料,操作简便且封装效果好,相变储能骨料在50次高低温循环后,质量损失率仅为1.97%;当相变储能骨料的掺量为20%时,抗压强度和保温性能综合效果最优,抗压强度达到31.48 MPa,温度阻尼率达到0.538 5。