日本欧美一级二级三级不卡,一级无遮挡理论片,久久精品视频5,久久久久久久久久久观看,99视频免费在线观看,欧美日本高清视频在线观看,国产伦久视频免费观看视频

Packaging materials occupy a very important position in the material industry. The value of packaging industry in developed countries now accounts for more than 2% of GDP. Now our country also needs to consume a lot of product packaging every year. In recent years, with the progress of people's living standards, especially people's environmental protection is getting more and more attention, so there are higher requirements for packaging, and the voice of green packaging is getting higher and higher. Therefore, it promotes the rapid development of material science with packaging materials as the direction. As the fundamental industry of packaging work, it also drives the development of packaging work.

According to the traditional material classification method, packaging materials can be divided into: paper materials, polymer materials, metal materials, glass and ceramic materials, composite materials, fiber materials, wood, other materials. However, with the development of material science, especially the continuous emergence of new materials, the materials of packaging work present the concept of functional materials. According to the concept of functional packaging materials, functional packaging materials include edible packaging materials and differentiated packaging materials Materials, fresh-keeping packaging materials, selection of absorbent packaging materials, insulation packaging materials, heat-resistant packaging materials, conductive packaging materials and packaging materials.

With the continuous application of high technology in the field of food packaging, a variety of edible packaging materials have come out one after another. These edible packaging materials are generally made of natural edible substances that the human body can absorb and digest, such as protein and starch, Polysaccharide plant fiber and other natural materials are the root materials. Through the interaction between different molecules, the packaging film with porous network structure is made, which does not affect the food flavor. Edible film is rich in materials, can be used, harmless to human body, with certain strength, and other characteristics, as a functional material of packaging work, has made rapid development in recent years, widely used in food, medicine packaging.

As a packaging film, edible packaging film has the following characteristics: water resistance, can delay the removal of food water and oil and other components of nuclear diffusion; optional air permeability and anti permeability ability, block the flavor of food It can be used as the carrier of food color, aroma, taste, nutrition strengthening and antioxidant substances; it can be used as a carrier for food color, aroma, taste, nutrition strengthening and antioxidant substances; it can be used for food, and has good physical and mechanical functions, good appearance and mechanical strength, and is easy to process and shape And so on.

Now, edible packaging materials from the material point of view, the first is protein, starch, chitin and other natural materials.

Edible packaging materials made of protein are divided into animal protein and plant protein. Animal protein is obtained from animal skin, bone, cartilage tissue and so on. This kind of material has good strength property, water resistance and oxygen permeability, which is suitable for meat packaging. For example, the edible packaging film made of an animal protein glue material has high strength, water resistance, and the function of isolating water vapor. Frozen cooking will take the initiative to melt, and can be used to package oil food without changing the flavor of food.

The edible packaging film made of plant protein has good ability to resist moisture and has certain function. Suitable for the packaging of fatty food, it can keep moisture and ensure the original taste of food. Now the most important is edible packaging film of soybean protein, protein, fatty acid, starch edible packaging film, water-resistant protein film, zein edible packaging film, protein coated packaging paper and so on. In addition, there are some alternative edible packaging films, such as milk protein, casein, etc.

The protein extracted from soybean can be used as edible packaging material to replace the plastic made of petroleum. This technology is to soak the soybean, then separate out the protein from the ink, dry the protein simply, remove the moisture, and then mix the protein powder with other ingredients and additives to make edible packaging film or coating, which can be used for packaging food, with some strength, elasticity and moisture-proof function.

Source: Jiangmen packaging materials http://m.lnsyms.com/