In recent years, the meat processing industry of various countries in the world has achieved rapid development, and various meat products have made important contributions to enriching and facilitating people's lives. In this important development process, new types of meat packaging such as multi-layer co-extrusion high barrier packaging, with its advantages of high barrier, high and low temperature resistance, no pollution, and strong puncture resistance, will play a role in the quality of meat products and food safety. The role of escort.
my country's total meat production ranks first in the world, but the proportion, variety and quality of deep-processed meat products are far from developed countries in the world, including meat food packaging technology, especially flexible packaging technology. For example, composite plastic packaging currently occupies a considerable market in meat product packaging. Composite packaging is a composite package of biaxially oriented polypropylene and polyethylene, or a composite package of polyester and polyethylene. They are composed of two materials combined with an adhesive, which not only has poor barrier properties, but also Adhesives contain benzene, esters, ketones and other harmful substances and peculiar smells, which are easy to migrate and penetrate and pollute food. The country has repeatedly inspected the quality of foods and showed that some foods are unqualified due to harmful substances leaking out of composite packaging bags (films). of.
The implementation of the "Food Safety Law" has raised the safety of meat food to a new level, an important aspect of the packaging quality of meat products. Food packaging materials cannot be turned into "invisible additives", resulting in unsafe meat products. It is the duty and responsibility of food companies and packaging companies to provide consumers with fresh, nutritious and safe meat products.
According to engineer John Zhang, the seven-layer and nine-layer co-extrusion high-barrier packaging is an internationally advanced packaging for meat products. This technologically innovative packaging will play an important role in improving the modernization of the domestic meat industry and ensuring food safety.
The packaging of meat products must meet the quality requirements of different meat products: the first is oxygen barrier. During the processing of meat products, due to the role of oxygen, the meat pigment is turned into methemoglobin, which causes the product to fade, promotes fat oxidation and the proliferation of aerobic microorganisms, so preventing the product from contact with oxygen is important for maintaining product quality , Improving preservation is extremely important. The second is moisture resistance. If product moisture penetrates from the inside of the packaging film in the form of water vapor, the flavor and internal quality of the product will also change. The third is impact resistance (puncture resistance). Since meat products collide and squeeze in the logistics process and their own hardness, packaging materials are required to have impact resistance. The fourth is cold resistance. Especially for frozen meat products, packaging materials are required to maintain their strength and impact resistance even at a low temperature of -45°C. The fifth is heat resistance. That is to say, the softening point is high. Some meat products require high-temperature cooking and multiple sterilization, and the packaging materials are required to not deform or expand after heating. The sixth is oil resistance. It is necessary to prevent the free fat precipitated from the product from penetrating to the outside of the film, but also to avoid the dissolution and penetration of the film at the sealing opening to ensure the quality of the product.
The national "Standard for Dry Compounding and Extrusion Compounding of Plastic Composite Film Bags for Packaging" (GB/10004-2008) stipulates that the residual solvent content in food packaging is controlled to not more than 0.5 ㎎/㎡, and benzene solvents are not detected. At present, although a small number of packaging manufacturers switch to water-based adhesives, problems such as high cost, unstable quality, packaging bag delamination, and vacuum leakage have emerged one after another. The damage rate of packaging bags and the loss rate of products have greatly increased, seriously affecting The economic benefits of users. In this regard, Wen Xiusong, secretary-general of the Composite Film Products Professional Committee of the China Plastics Processing Industry Association, believes that the contamination of food with harmful substances such as benzene in composite packaging has become a more common problem. This is because the composite materials must be glued together, and the fragrant and aliphatic glues contain harmful substances, which easily penetrate into the food.
In response to the special requirements of meat products for packaging, the new multi-layer co-extrusion high barrier packaging is developed and produced. It does not use any adhesives, but uses physical methods by using more than three extruders to combine different functional resin materials such as PA, PE, PP, EVA, EVOH, etc., are melted and extruded separately to join together, and then subjected to inflation molding, cooling and compounding together. It is suitable for the packaging of meat products including freezing, pasteurization, high-temperature cooking, and stretch film. Among them, the frozen packaging is suitable for pork, beef and mutton, chicken, duck, goose, fish and shrimp and all kinds of seafood, frozen and fresh packaging at -18℃ to -45℃; pasteurized packaging is suitable for various cooked meat products, such as Ham and sausage products that require vacuum pasteurization; high-temperature cooking packaging, suitable for all kinds of cooked meat (chicken, duck, goose, pig's trotters) and other products that require 120 high-temperature sterilization; stretch film packaging Suitable for foods with long shelf life such as ham.
Seven-layer and nine-layer co-extrusion high-barrier packaging has the characteristics of no pollution, high barrier, strong function, low cost, high strength, and flexible structure. Compared with dry composite packaging materials, seven-layer co-extruded high-barrier packaging materials Adhesives are not used, thus preventing the contamination of food by harmful substances such as esters and benzene, ensuring food safety and basically air-tight. The vacuum degree of seven-layer co-extrusion can reach 100%, while that of dry composite materials is generally 90%. The seven-layer co-extrusion consists of more than two layers of nylon, which greatly improves the tensile and tear strength of the packaging, is not easy to be damaged, is resistant to storage and transportation, and is easy to keep. It can effectively avoid the oxidative deterioration of food and inhibit the reproduction of microorganisms, thereby extending the shelf life of meat products to more than 6 months. The use of multi-layer co-extruded high-barrier packaging is the most economical and effective way to maintain the food brand image and expand the market.