Application of the hottest soft plastic packaging

Application of soft plastic packaging in meat processing

I. meat production

meat consumption is an important symbol to measure the living standard of a country's people. Since the reform and opening up, the adjustment of policies has led to the rapid development of agricultural economy. For 25 consecutive years, China's meat production has continued to grow. According to the data of China Meat Association, the total output of meat in China reached 77.43 million tons in 2005. Including 50.1 million tons of pork, 7.11 million tons of beef, 4.35 million tons of mutton and 14.64 million tons of poultry

II. Current situation of meat industry

meat processing is not only an ancient industry, but also an emerging industry. After years of development and construction, China's meat food industry has gradually formed a complete industrial system integrating livestock and poultry breeding (base), slaughtering and segmentation, meat products processing, cold storage and transportation, logistics and distribution, wholesale and retail and related supporting industries. It plays an important role in the national economy and the people's livelihood, and plays an important role in promoting production, developing the economy, improving people's lives and stabilizing the market

meat processing includes raw and fresh meat segmentation and processing and the production of cooked meat products. There are thousands of commodities. Raw meat products mainly include hot meat, frozen meat and cooled meat. The hot fresh meat is slaughtered and eaten now, and its taste is hard, and it is easy to decay after a long time; Frozen meat often has ice crystals piercing the cell membrane when frozen, and the juice loses and tastes bad when thawed; The carcass temperature of chilled meat should be continuously reduced to 0 ~ 4 ℃. After segmentation and packaging, it is always controlled at this temperature from production to sales. Therefore, microbial growth and enzyme activity are inhibited, maintaining and improving the quality and taste of meat

cooked meat products mainly include: Western low-temperature products (sausage, ham, barbecue), high-temperature products (ham sausage), fermented products (Parma ham, salami sausage) and Chinese traditional products (pickled, cured, sauce, stewed, roasted, smoked, dried, etc.). Western style low-temperature products have low heating and ripening temperature, high yield, fresh and tender taste, and the flavor mainly comes from foreign additives; The heating and ripening temperature of Chinese traditional products are high, the time is long, the yield is low, the color is deep, and the flavor mainly comes from Maillard reaction; After high temperature and high pressure treatment, the protein denaturation of high-temperature products is complete, and it can be preserved at room temperature for a long time. The additional tariff is 25%; The protein of fermented products is denatured and matured under the action of microorganisms and enzymes, and has a unique flavor. The combination of different processes and formulas can produce a variety of different products

since the reform and opening up, the material has been enriched, and the people's living standards have been continuously improved, providing a broad space from raw materials to the market, which has led to the rapid development of China's meat processing industry

however, the urbanization rate of China is still about 40%. Due to many reasons such as living habits, living standards and cold chain conditions, the variety and quality of meat products are quite different from the international level. The proportion of meat deep-processing products in developed countries in the world generally reaches about 50% of the total output, and some countries even reach as high as 70%, while China only accounts for about 10%

at present, fresh meat on the market is still dominated by white bars, and the proportion of split meat and small packaged meat is less than 10%. Even in big cities such as Beijing and Shanghai, the small packaged chilled meat in the retail market only accounts for less than 20% of the market volume. The total output of cooked meat products increased from 150000 tons in 1980 to 2.3 million tons in 2001. Due to the increase in the output of Western-style products and the "return" of traditional Chinese products to the market, cooked meat products exceeded 4million tons in 2005, and the varieties supplied on the market were enriched. All meat enterprises carry out technological innovation, adjust product structure, and constantly improve product quality

Third, soft plastic packaging in meat production

the primary purpose of food packaging is to ensure food safety and hygiene. Packaging materials of different properties meet the requirements of packaging, processing, storage and transportation of various meat products

(I) packaging of frozen cut meat

frozen cut meat is the cut meat that needs to be stored for a long time, exported and sold for a long time. After reshaping and packaging, it is packed (plate) and frozen at a low temperature (25 ℃). Low temperature storage can inhibit the life activities of microorganisms, delay the effects of tissue enzymes, oxygen, light and heat, and maintain the quality of meat for a long time. The shelf life can reach more than 4 months. Sealable composite materials such as pet (polyester film)/pe (polyethylene)/al (aluminum foil) and other vacuum packaging or inflatable packaging materials can be used, but most manufacturers often only use single-layer polyethylene film for economic reasons

(II) packaging of chilled cut meat

bacteria grow very fast in exposed or simply packaged fresh meat. At 4 ℃, bacteria multiply twice a day, 15 times at 16 ℃, 700 times at 21 ℃ and 3000 times at 27 ℃. Therefore, the shelf life of meat at room temperature is only half a day, and cold storage is only 2-3 days. The cooling and segmentation of meat is to pack the meat after segmentation and processing by cooling the body temperature to about 4~c after about 20 hours, so as to strictly control the reproduction of microorganisms. After packaging, they are transported by refrigerated vehicles to food supermarkets without refrigerated display containers for sale. The packaging generally adopts non-toxic, cold resistant, flexible and transparent plastic film, so that consumers can see the true color of raw meat

the gases used in inflatable packaging are mainly nitrogen and carbon dioxide. It can keep the color of oxygenated myoglobin of meat bright red. Pa/evoh/pe can be thermoformed, with good stiffness and high barrier property. It is suitable for air withering packaging. Pa/evoh/pe has high barrier property and is suitable for vacuum packaging. The shelf life of modified atmosphere packaging pork is about 14 days. The shelf life of vacuum packed pork is about 30 days and that of beef is about 80 days

(III). Vacuum (body fitted) shrink packaging for fresh meat preservation

vacuum (body fitted) shrink packaging bags have good moisture resistance, compared with non shrink products, can__ l_?? Improve the appearance of packaged products, strengthen the protection of products, reduce blood exudation and extend the shelf life of products. The vacuum shrink bag of Hyatt company of the United States can shrink by 30% to 50% in hot water at 85 'C. It can shrink evenly, and has high oxygen barrier ability, which will be further enhanced after shrinkage

(IV) packaging of Western-style low-temperature meat products

western style low-temperature products are often sliced in a sterile room and vacuum packaged, so that the food in the packaging bag is isolated from the outside world. Vacuumizing can create an anoxic environment, proliferate lactic acid bacteria and anaerobic bacteria, reduce pH, inhibit enzyme activity and the growth of spoilage microorganisms, slow down the oxidation rate of fat in meat, and extend the storage life of products

for vacuum packaging materials, they are required to have good gas barrier, water vapor barrier, fragrance barrier and blackout. Most of them are made of more than three layers of materials. For example, the composite packaging bag pet/evoh/pe has high barrier property and is suitable for vacuum packaging of ham; Opa/alu/pe bags are suitable for pasteurization; Pet/alu/pet/pe bags are suitable for the disinfection of cooked ham. Why do we need electronic universal testing machine to stop testing all kinds of data

(V). Packaging of traditional Chinese meat products

in order to prolong the shelf life of traditional Chinese meat products, soft cans and cooking bags are often used for packaging and sterilization. Soft can materials are mainly made of pet/al/cpf three-layer composite, and transparent cooking bags are mainly made of pet/cpp or pa/cpp. Because the soft can made of aluminum foil has good barrier and light proof performance, the vacuum can be stored at room temperature for 9-12 months after high temperature sterilization if the change-over switch is turned to the "fast back" position. Compared with glass and metal cans, soft cans are easy to carry and open. The products include Chinese traditional meat and poultry products such as sauce elbow, roast chicken, sauce duck, etc. However, due to high-temperature sterilization treatment, the deterioration of product flavor, crisp and rotten, and heavy can flavor are common problems in cooking bags and soft can packaging. Now, cooking at 121 ℃ for a few minutes, immediately reducing to 90 ℃ and heating for dozens of minutes, basically overcoming the shortcomings such as flavor deterioration. The transparent cooking bag composed of pet/cpp or pa/cpp two-layer materials has a short shelf life because the barrier property is not high and the packaged meat products are easy to oxidize and deteriorate. At present, the development of transparent and high barrier packaging materials is the focus of international research

(VI). Packaging materials for high-temperature products (sausage)

high temperature sausage has been concerned by meat processing plants and small town consumers because its shelf life can reach 6 months at room temperature. At present, there are no less than 900 high-temperature sausage production lines in China, and the total output of high-temperature sausage is about 2million tons, accounting for about half of cooked meat products. The packaging material (casing) used is biaxially stretched polyvinylidene chloride (PVDC) film, which is an intermediate layer composite film. It is sealed and welded into a cylinder by high-frequency heat sealing. After filling the material, both ends punch, and then after 121 ℃ high-temperature cooking, through high-temperature sterilization, the meat products have reached a commercial bacteria free state, and there are few bacteria left in the products, which will not cause the deterioration of the products. Because PVDC film has strong barrier to gas and moisture, it has transparency, can be used for high-temperature sterilization, and the price is cheap. Henan Shuanghui, Luoyang Chundu and Guangdong Foshan all produce ham sausage packed with PVDC film, which has become the leading product in high-temperature meat products

(VII). The other three kinds of artificial casings are nylon casings, cellulose casings and collagen casings, which are widely used in the production of low-temperature intestinal products. Nylon casing has good oxygen resistance and shrinkage. It can be cooked at 120 ℃ for two hours. It is adopted by large, medium and small manufacturers. Cellulose casing has good air permeability, and the product can be smoked with small caliber（ φ 17～ φ 50) for the production of skinned sausage, large caliber（ φ 85～ φ 150) is used to produce Western-style ham. China's cellulose casings are mainly imported, and the annual consumption is about 3million meters. Collagen casings are edible casings produced from collagen fibers extracted from bovine dermis. Their ingredients are the same as those of natural pig and sheep casings, and their homogeneity is good. They can adapt to sausage machines with a high degree of automation. They are used by most large and medium-sized meat manufacturers. Collagen the market of plastic machinery enterprises in China will be more open up. The casings are mainly umbrella 13 No.1 middle school 30. Now the annual consumption in China is about 400million meters. The domestic manufacturers include Guangxi Wuzhou casings factory, with an annual output of more than 250million meters. The rest depends on imports. It is estimated that the demand for collagen casings in China will reach about 800million meters by 2010

IV. the development of food packaging technology will drive the development of meat industry.

cooked meat products are rich in protein, microorganisms are easy to reproduce, and the fat in meat products is easy to oxidize and deteriorate during storage. The key of packaging technology is to extend the shelf life of products and ensure food safety, quality and original flavor

at present, the world has accelerated the basic research of plastic packaging with high health requirements. We have increased the development and promotion of new non-toxic plasticizers for soft plastic materials, and new packaging materials have been introduced. We should pay attention to the research and development of safe high-performance materials. It should be noted that compared with developed countries, the proportion of our meat deep-processing products is still very low, and there is still much room for development. With the further improvement of living standards and the change of people's consumption concept, the demand for meat products is developing towards hygiene, nutrition, flavor, convenience and high-grade. These are inseparable from the progress of food packaging technology. From the perspective of market changes, expanding consumption, promoting production through sales, high quality and good price, the production of meat will be more and more stable and standardized, and the sales volume of packaging products will be further expanded in domestic cities

reprinted from: plastic packaging