Qiaolei see the world Cai Shen Kun, also known as modified atmosphere packaging replacement gas, internationally how to cool a room with a fan known as MAP packaging (ie ModifiedAtmospherePackag how to cool a room with a fan ing), is packaged in a vacuum packaging and nitrogen how to cool a room with a fan on the basis of the development of an improved obtained fresh packaging, mainly for food preservation. The principle is the use of modified atmosphere packaging preservative gas (2 to 4 gas mixing ratio on food characteristics), for packing boxes or bags of air replacement, change the cartridge (bags) of food within the external environment, inhibit bacterial how to cool a room with a fan (microbial) the growth and reproduction, how to cool a room with a fan slowing the rate of metabolism of fresh fruits and vegetables, thus extending shelf life of food or shelf life. With fresh fruits and vegetables as an example: even after picking fresh fruits how to cool a room with a fan and vegetables for respiration, O2 consumption produces CO2, increasing CO2 content in the environment and to reduce the concentration how to cool a room with a fan of O2, using high-permeability plastic film with atmospheric gas exchange, supplement the O2 consumption and exhaust CO2. When the gas permeability of the film speed and vegetable respiration rate are equal, the gas inside the bag reaches a certain equilibrium concentration that can make fruits how to cool a room with a fan and vegetables to maintain a faint breathing rate without causing anaerobic respiration, thus delaying maturation and get fresh fruits and vegetables. how to cool a room with a fan MAP can be achieved without using using preservatives, additives, how to cool a room with a fan under the premise of ensuring the taste of food, nutrients how to cool a room with a fan and freshness. Preservative gas generally consists of carbon dioxide (CO2), nitrogen (N2), oxygen (O2) and a few specialty gases (NO2, SO2, Ar, etc.) components. The role of various gases are as follows: CO2 gas can inhibit the growth of most spoilage bacteria and fungi multiply the effect that the fresh gas in the main antibacterial agent; how to cool a room with a fan O2 most anaerobic bacteria inhibit the growth and reproduction, to keep raw meat color, and to maintain the state of fresh fruits and vegetables fresh breath metabolism; N2 is an inert gas, generally do not react with food effect, nor is absorbed by food, the MAP is used as filling gas to prevent gases such as CO2 escaping how to cool a room with a fan from the package leaving the packing collapse. For different food fruits and vegetables, fresh gas composition and proportion is not the same, for the crop MAP key is to keep the oxygen permeability of packaging materials and products to match the speed of breathing. MAP on the application how to cool a room with a fan of a number of products are already quite mature, such as small food packaging, coffee packaging, processed meat, and now it is also more and more applications in refrigeration, pretreatment of convenience foods, especially in fresh Slice of agricultural products, specialty cheeses and pre-packaged sandwiches and other products packaging widely adopted. The gas permeability of the material how to cool a room with a fan of different MAP system design should take into account various factors, the most important factor is the packaging of the relative content of CO2 and O2, mainly by the gas concentration in the package and packing material determines the permeability how to cool a room with a fan , that is, the proportion of preservative gas control accuracy and packaging materials, gas exchange rate. Vacuum packaging or nitrogen-filled packaging is mostly low MAP material barrier material, with a larger gas permeability. Breathable material differences between the aggregation state of the polymer and materials (crystalline), the polymer structure of the gas diffusion and solubility, using the additive effects how to cool a room with a fan and other factors. However, different kinds of materials, the gas permeability of the same is not the same, the same kind of materials, the transmission is generally the least N2, O2 slightly larger, CO2 has the biggest size of the gas molecules (kinetic diameter , see Table 1) and the shape of the gas molecules. The smaller molecular kinetic diameters, the easier diffusion of the polymer, the diffusion coefficient is. However, the diameter of the gas molecules how to cool a room with a fan is not the only factor that determines the permeability, since the gas permeability is also the solubility of the polymer in the. Another shape of the molecule can also affect the permeability, studies have shown that long strip of molecular diffusion and penetration of the strongest, but small changes in molecular shape will cause large variations in permeability. How to choose the right materials MAP Undoubtedly, modified atmosphere packaging to the product, it must be based on the characteristics of the product packaging material permeability reasonable how to cool a room with a fan choice. MAP gases are generally used for O2, CO2, N2 mixed gas, or O2, CO2 mixed gas, so the choice of materials must be modified atmosphere O2 permeability of the material, CO2 permeability, how to cool a room with a fan N2 accurate permeability test must not favoritism for the detection of various gases, or simply press the test material, O2 permeability ratio conversion experience, you must conduct a comprehensive inspection. Imagine, if the targets detected by mistake or without comprehensive testing which led beneath MAP material selection, not only give companies causing huge economic losses, but also cause serious waste of resources. Currently, the world's widely used method gas permeability test pressure method and equal pressure method two categories. Overall, the test object such pressure method is very simple, can only test the O2 permeability (eg LabthinkTOY-C1 oxygen permeability tester) or CO2 permeability, the company has yet to provide how to cool a room with a fan transparency how to cool a room with a fan for detecting N2 transient devices how to cool a room with a fan such as pressure method. For differential pressure how to cool a room with a fan method is completely different devices, how to cool a room with a fan because this method itself is not selective on test gas can be carried O2, N2, CO2 and other conventional gas tests on low cost, but also to achieve how to cool a room with a fan self-test environment temperature ( If LabthinkVAC-V1 Gas Permeability Tester). In addition, as support for the theory of membrane technology, using vacuum pressure method how to cool a room with a fan is not only able to detect a variety of common equipment gas permeability of the sample, but also on the sample and gives the test gas diffusion how to cool a room with a fan coefficient and solubility coefficient. Equipment with respect to equal pressure method, differential pressure method gas permeability testing equipment more suitable MAP materials research institutions and manufacturers use to conduct a comprehensive how to cool a room with a fan inspection how to cool a room with a fan of materials and conduct a comprehensive analysis. The actual how to cool a room with a fan use of modified atmosphere packaging materials as well as nitrogen in vacuum-packed package developed and improved on the basis of the obtained a fresh packaging, modified atmosphere packaging is mainly used for food preservation. Using modified atmosphere packaging, and sometimes can not only save the environment, reduce the requirements, but also can improve how to cool a room with a fan the shelf life of food. For example, cold meat packaging, there is a vacuum packaging, packaging and composite nitrogen how to cool a room with a fan atmosphere packaging in several forms, but packaged in vacuum packaging and nitrogen packed dark color of cold meat, fresh meat loses original fresh color, it is generally made of composite modified atmosphere packaging, the use of mixed fresh gas from the O2, CO2 composition, can be kept fresh meat color and flavor. Where the O2 concentration ratio is higher, due to higher concentrations of O2 can keep fresh meat, chilled meat bright red color; moderate concentrations of CO2 can hinder inhibit bacterial and microbial growth and reproduction. This will not only extend the shelf life of cold meat and cold meat is also more attractive appearance and color, to attract consumers. Mixed fresh fish fresh gas from the CO2, O2, N2 components. Modified atmosphere packaging for fish, of which CO2 gas concentration higher than 50% required to inhibit aerobic bacteria, mold growth and reproduction; O2 concentration of 10% -15% to inhibit anaerobic bacteria breeding. With the popularity of supermarkets, baked goods, food products, fruits and vegetables, fresh-cut vegetables has also become part of the product shelf sales, because how to cool a room with a fan these types of products, fresh particularity of modified atmosphere packaging to become their first choice. Baked goods is the main component of starch, by bacteria, fungi and other changes caused by rot, fat rancidity deterioration caused by oxidation, aging hard change the molecular structure of starch caused food spoilage. Used in baked foods modified atmosphere packaging of gas from the CO2 and N2 components. For cream cake without using this modified atmosphere how to cool a room with a fan at room temperature for more than 20 days preservation. Microwave dishes, soy and poultry cooked meat packaging, if we adopt to CO2 and N2 as the main gas can effectively restrain the coliform MAP breeding, not only under normal temperature preservation effect, high temperature how to cool a room with a fan sterilization or chilled preservation can get a good shelf life. Clean vegetables, also known as cutting fruits and vegetables, processed fruit and vegetable processing half, in order to meet emerging food processing products workers have safe, fresh, nutritious, convenient features, but after cutting and easy browning. Reduced oxygen content using modified atmosphere packaging to extend the shelf life to maximize how to cool a room with a fan the use of appropriate fresh gas can also prevent browning. Modified atmosphere packaging also applies to peeled and sliced apples, potatoes, leafy vegetables and other fresh fruits and vegetables.
Zhoushan mother Seafood Fish official Taobao http://133012359.taobao.com/ temperature low temperature refrigeration is a common way to preserve, but temperature changes can significantly affect the permeability of the material tested, so the plastic wrap at room temperature detection barrier of the data in the storage how to cool a room with a fan environment, it can not represent the barrier properties. Although some barrier property testing equipment use temperature limit can reach 0 or so, but the state of the sample and the device will be much affected how to cool a room with a fan by low temperatures, and testing personnel can not be tested in a low-temperature environment. So, how accurately informed cling film at low temperature storage environment barrier research data for fresh fruits and vegetables is a need to be resolved in terms of difficulty. Now, to get the low temperature barrier data can be LabthinkVAC-V1 data fitting functions easily. Data fitting is not a simple mathematical estimation, how to cool a room with a fan but the temperature test conditions have experimental data obtained by fitting algorithm specific temperature barrier parameter mathematical calculation. The advantage of this approach is that it need not be tested at low temperatures, how to cool a room with a fan all the data can be used to fit in the general obtained under test conditions, but the material is not selective fitting how to cool a room with a fan function. For example, under normal test conditions: how to cool a room with a fan 30 , 35 , 40 (VAC-V1 self-temperature control function can achieve these temperatures how to cool a room with a fan remain stable), how to cool a room with a fan use of equipment how to cool a room with a fan LabthinkVAC-V1 Gas Permeability Tester detects 125μm thick PC film oxygen permeability test, the test data in Table 2. From the above data fitting 0 , O2 permeability coefficient is 5.62 10-11cm3 cm/cm2 s cmHg, O2 permeation amount is 295.441cm3/m2 24h 0.1MPa. PC with 30 , compared with oxygen barrier film, 0 when the barrier increased approximately 2-fold. The fitting of -20 ~ 50 (253K ~ 323K) PC film oxygen permeation how to cool a room with a fan amount of data into Excel and plotted in Figure 1 can be obtained. From the trend of the curve in Figure 1, we can see that as the temperature decreases membrane permeability increase PC speed gradually accelerated. As the temperature decreases, the barrier properties of the film are generally increasing trend, but the growth rate is not the same, and some grow faster, and some very smooth, so just get the plastic wrap at room temperature barrier data overall guiding significance for fresh fruits and vegetables is very limited. MAP MAP technology research fruits and vegetables how to cool a room with a fan (Modified Atmosphere Packaging), referred to MAP, defined as "to prevent the gas in and out of the material in a gaseous environment regulating food technology." An important feature of the MAP is stored initial adjustment of gas composition inside the package, in order to achieve inhibition of food spoilage and deterioration, maintain the normal shelf life of perishable food quality or extend their shelf life purposes. Therefore, it is called active MAP MAP (Active Atmosphere Packaging). Fresh fruits and vegetables is that people how to cool a room with a fan get vitamin how to cool a room with a fan and dietary fiber main source. After picking their storage how to cool a room with a fan period still has life activity, including the role of respiration and transpiration. Respiration and transpiration and heat released substance a great impact on the quality of fruits and vegetables, causing fruit weight, loss of nutrition, appearance and color damage, eventually leading to rot, loss of food value, how to cool a room with a fan causing huge economic losses. Fruits and vegetables in refrigerated MAP is based on the environment by the packaging temperature, humidity, gas concentration and other factors regulating control action to suppress the respiration and reduce the moisture evaporation rate, so as to achieve the purpose of extending its shelf life. Modified atmosphere packaging for its fruits and vegetables are safe, effective and easy to operate features and abroad in recent how to cool a room with a fan years has become a focus of the study. First, the history and current situation of MAP MAP origins can be traced back to the 1830s, when the fresh beef and mutton packed in large plastic storage bag, and in the aquatic application began in 1930. But the technology in large-scale commercial application is started from 1970. 1979 British Mark & Spencer has launched MAP meat, two years later applied how to cool a room with a fan to the fish, ham and other aspects. As for modified atmosphere packaging of fruits how to cool a room with a fan and vegetables, how to cool a room with a fan as early as 1955, the U.S. National Research Center Gerhard Plant Physiology Laboratory Maersailan, began to study a variety of PE film storage of apples and pears, and storage environment how to cool a room with a fan of oxygen (O2) and Carbon dioxide (CO2) changes made systematic research, and in 1960 published a research report, and called physiological Packaging Storage. Fruit breathing creatures according modulus formula to determine the plastic film, the thickness, size, at a specific temperature conditions, with the PE film with dual effect of O2 and CO2, the gas component to maintain the bag. Our MAP started in the 1990s, the state agricultural preservation Engineering Technology Center in 1988, has developed a special PVC cling film 24 fruit and vegetable recipes, which screened 32 varieties, 47 kinds of specifications for cucumbers, celery, grapes, apples bags and other plastic wrap and pear practical application. MAP parties in recent years has become a hot research. Second, the composition of modified atmosphere packaging of fruits and vegetables during storage system has two main factors, namely aerobic and oxidation reactions, both of which require O2. Therefore, to extend how to cool a room with a fan the shelf-life or to maintain the quality of fruits and vegetables, you need to reduce the environmental O2 content. Tests show that when the package is the O2 content <1%, the growth of various bacteria on the rapid decline, when reduced to <0.5%, the growth inhibition and stops reproduction. However, in practice it is difficult to separate the effective use of vacuum packaging, and the product is inevitably wrinkled
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