Analysis of the most popular new flexible packagin

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Analysis of new flexible packaging materials to ensure food safety

with the continuous improvement of material quality and processing technology, flexible packaging is playing a more and more important role in the field of food industry. In 2002, the sales of flexible packaging in the food industry exceeded that of hard packaging, accounting for 56% of the total sales. Flexible packaging is also popular in foreign markets. Because of its safety, hygiene and convenience, soft packaged food is very popular in Japan. In 2002, the production of flexible packaging food in Japan exceeded 280000 tons, with a total output of 6 Yield point: the tensile time field of the material reaches 19.9 billion yen. Among coffee products, flexible packaging products are far more than canned food, accounting for 93%; Sauces increased to 51%; The soup is 44%

food flexible packaging materials have attracted much attention in many aspects. Air permeability and airtightness of flexible packaging materials are important factors affecting the shelf life of food. If the sealing property is damaged, the food will be contaminated and deteriorated. Cap (clean air packaging) and map (modified atmosphere fresh-keeping packaging) are applied to some foods, which requires that the packaging should have good sealing to prevent gas leakage. However, foods that are prone to moisture change, such as dry powder, milk powder and sugar, need to have good sealing to prevent moisture from entering. Cooked food should have a high degree of sealing, so as to prevent microbial invasion

I. paper packaging materials

pure paper is non-toxic and harmless. However, due to the pollution of raw materials or processing, there are usually some impurities, bacteria and some chemical residues in paper and paperboard, such as detergent, paint, modifier, etc., which affect the safety of packaged food

at present, the safety problems of food packaging paper mainly include: the raw materials of paper are not clean, so that the finished products are infected with a large number of molds; Treated with fluorescent brightener, the paper contains fluorescent chemical pollutants; The packaging paper is coated with wax to make it contain too much polycyclic aromatic compounds; Pollution caused by color pigments and food contact; Improper recycling or treatment of packaging materials may cause food pollution during reuse

1. anticorrosive paper

the anticorrosive paper for food packaging produced by Japanese company is prepared by soaking the base paper in an ethanol solution containing 20% sodium succinate and 0.07% sorbic acid, and then drying it. The food packed with brine can be stored at 38 ℃ for three weeks without deterioration. A new type of packaging paper produced by another Japanese company can prevent the food from mildew and deterioration for a long time without damaging the food flavor. The paper is made by fusing special monoglyceride with its compounds, dissolving it in water and ethanol as an effective component, and then spraying or soaking it on the paper and drying it. It can be used to package all kinds of food

Tofu paper

tofu paper is made of tofu residue into water-soluble paper. It has a wide range of applications, including the packaging of instant noodles, condiments, barbecue, cakes and fruits. The preparation method is to add fatty acid and protease into the bean curd residue, decompose it, wash it with warm water, dry it into food fiber, and then add sticky substances such as yam, taro, dextrin, oligosaccharide and polypropylene glycol. This kind of paper is easy to decompose after use, can be used as compost, and can also be recycled for papermaking. It has low environmental pollution and can be used for food packaging

3. deodorizing paper

more than 40 kinds of deodorizing packaging paper materials have been studied, mainly divided into three types: Class A belongs to chemical deodorizing type. It can remove the odor or peculiar smell of nitrogen compounds and sulfur compounds plus ammonia, dimethylamine, trimethylamine, hydrogen sulfide, etc. Class B belongs to physical type. It is mainly used to remove odor or peculiar smell such as hydrogen sulfide and carboxylic acid. It is characterized by good deodorization effect for high concentration hydrogen sulfide. Class C materials are mixed deodorization type. It is mainly made of activated carbon deodorant, which has good deodorizing power at low concentration, so it is characterized by solid particles in macro view. Deodorizing wrapping paper film used in food packaging can have the effect of deodorizing and keeping fresh. General deodorization packaging is mainly used for the packaging of food with special smell or peculiar smell, agricultural products and aquatic products

4. fruit dregs paper

a kind of fruit dregs paper produced abroad is produced from apple dregs discarded in the food industry. The preparation method is to remove the seeds in the fruit residue, tamp it into pulp, and add an appropriate amount of wood fiber. This kind of paper is easy to decompose after use. It can be used as compost or recycled for papermaking. It has low environmental pollution and can be used for food packaging

5. paper based composite packaging

this is a kind of composite flexible packaging, mainly including film type, bag lining type, embedded type, liquid type, etc. The main problem of paper-based composite packaging is to solve the problem of anti-seepage, because the oil molecules are very small. For example, Japan has developed a composite paper box containing edible oil, which is very successful. The structure of the composite paper is PE/paper/PE/Al/PET/PE. The composite paper is made of 6 layers of aluminum and plastic with paper as the base material. Because the composite layer has aluminum foil, its performance is better than that of glass bottle and plastic bottle. It is safe, light, and beautifully printed, which improves the added value and competitiveness of goods

a kind of super strength composite paper has been developed abroad. The paper is as white as snow, as thin as cicada wings, and as soft as brocade. It is still intact after repeated folding. It is also called soft glass, and the price is low. This kind of "paper" is made of basalt pulled into fibers at a high temperature of 2000 ℃, impregnated with phenolic resin and infiltrated into clay powder. As the main material is rock, it will not become brittle, moldy or moth eaten after long-term storage, and can dye and print colors. It is widely used

II. Plastic bag packaging materials

plastic packaging materials have the advantages of light weight, convenient transportation and sales, good chemical stability, easy processing and good decorative effect, and have a good protective effect on food. However, there are still some health and safety problems. For example, the surface pollutants of plastic packaging cause the micro dust and impurities on the packaging surface to pollute the food. Toxic monomer residues and toxic additive residues of plastic packaging materials. In addition, improper recycling or treatment of packaging materials will also cause food pollution during reuse. Plastic bag packaging materials are developing towards non pollution and safety

1. antibacterial film

microorganism breeding on the surface of food is the main cause of deterioration. Adding anti microbial enzymes or other substances to packaging materials can greatly improve the storage life of food. Antibacterial film is a typical representative of this kind of material. For example, biological enzymes can be added to packaging paper and packaging film, which can make them have the functions of anti-oxidation, sterilization and delaying the reaction speed of enzymes in food; In addition, biological enzymes can also be made into preservatives, which can be used alone or mixed into food containers to prolong the shelf life of food. Glucose oxidase and lysozyme are commonly used in food packaging. The former has the greatest function in food preservation and packaging, which is to remove oxygen and prolong the shelf life of food; The latter is mainly used as a preservative to inhibit bacteria. Antibacterial substances such as silver and copper ions, quaternary ammonium salts, nisin and chamaecolol can also be added to the packaging materials. For example, Japan has successfully developed a series of antibacterial packaging materials with silver zeolite antibacterial film as raw material, which has antibacterial effect on a variety of pathogenic bacteria. The main characteristics of the packaging material are as follows: the antibacterial effect lasts for a long time. Because the antibacterial agent is vapor phase, it has no adverse effect on the inner package and has good stability; In the process of packaging and processing, it has high thermal stability, stable concentration and no adverse impact on the working environment. At present, the widely used antibacterial packaging material is antibacterial packaging film, which is made by adding antibacterial agent into polyolefin film. It has antibacterial effect on most common microorganisms such as coliform, Staphylococcus aureus, Bacillus perforans, Aspergillus niger, etc

the Russian Institute of practical material technology has recently developed a food packaging bag that can absorb water, sterilize and be used for many times, so that foods that are easy to deteriorate, such as cheese sausage, can be preserved for a long time. Russian experts added dehydrated mineral salts, enzymes and other substances to food packaging polymers. The inner surface of the packaging bag rich in these substances can absorb excess water and kill bacteria, thus improving the internal environment of the packaging bag. In addition, the enzyme in the additive can regulate the smell of food

recently, a special film that can detect bacteria has been developed abroad, that is, a special coating is coated on the surface of ordinary food packaging film to make it have the special function of detecting bacteria. A kind of bacteria detecting film used for raw and cooked meat packaging. If the packaged meat food is no longer fresh and the content of harmful bacteria exceeds the food hygiene standard, packaging with this film will change the original transparent and colorless packaging film into a warning color, so that customers immediately know that it is no longer edible

2. high barrier film

high barrier film is a film with multi-layer structure, which is extruded from a material with strong gas barrier and a polyolefin with strong thermal suture and water barrier. The use of high barrier film can prevent microbial reproduction caused by the penetration of oxygen and other gases; Prevent oxidation of contents due to oxygen penetration; Prevent the outflow of fragrance, solvent, etc., and improve the storage of contents. It is mainly used for packaging meat processing products (ham, sausage, fresh fish jelly, clam slices), raw meat, cheese, salad dressing, sauces, agricultural products and seafood processing products

3. composite plastic materials

American researchers have developed a corn plastic packaging material that is easy to decompose. It extracts three genes that can produce plastics from bacteria that produce biopolymers, and then transfers them to rape plants. After a period of time, a plastic polymer liquid is produced, and a rape plastic can be obtained after refining and processing. The food packaging materials made of this kind of plastic can be used by the safety belt impact tester after being discarded, which meets the following specifications: decomposition, no pollution residue

and wheat plastic. This is the use of wheat flour, glycerin, glycol, silicone oil, etc. mixed and dried, and then hot pressed into a translucent thermoplastic film. The advantage of plastic packaging food with wheat is that it can be decomposed by microorganisms

British researchers have recently developed a PHB bacterial plastic. It uses sugar to cultivate a kind of bacteria, and then it is processed into a material similar to polypropylene. This kind of material is non-toxic and easy to biodegrade. It is an ideal material for processing food packaging bags. At the same time, there is no pollution to the environment

in a word, the development trend of newly developed food flexible packaging materials at home and abroad is towards high-performance, non-toxic and harmless, green environmental protection, convenient use and safety. At the same time, the new packaging materials are introduced, and their recycling technology is also introduced to minimize the damage of packaging to the ecological environment. □ (references omitted)

(about the author: pengshanshan, female, Professor of Food Engineering Department of Guangdong Shaoguan University.)

source: Guangdong packaging

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