Functions of the most popular food active packagin

The function of food active packaging materials

the concept of "active packaging" comes from the opposite of the "inert" packaging materials usually selected by law or custom, especially the packaging materials with "shielding" function applied to food packaging and recognized by the current European regulations. In other words, this kind of packaging product can maintain the characteristics of the packaging content, so that it will not be changed by environmental factors. In addition, it also contains some functional packaging materials that can break through the relevant European laws and regulations and improve the characteristics of the packaging content

at present, in the food packaging industry, the definition of active packaging is mainly based on the system proposed by the European special research center that can improve the conditions of packaging (by releasing substances, eliminating or inhibiting), which can prolong the service life of packaging; Improve health safety; To improve the odor and taste characteristics, the extruder requires the screw speed from start to the required working speed, while ensuring its quality unchanged. The specific overview is as follows:

oxygen inhibitor

although the technology of using plastics with high barrier to oxygen and its application in packaging has been very mature, which can minimize the oxygen content (such as vacuum or modified gas packaging), the requirement for reducing the oxygen content in packaging is still very strong. In fact, oxygen is absorbed by food, which dilutes the concentration in the package. In addition, high barrier plastic products are expensive and usually difficult to process. The application of medium barrier composite plastics in packaging has a much better effect on inhibiting oxygen concentration in a variety of application fields than the glass and metal packaging used at present

another popular development project is beer bottle caps coated with oxygen suppressants. With this oxygen inhibitor, PET bottles can be used instead of glass bottles to fill beer, and the original flavor and taste of beer will remain unchanged for about 9 months after bottling. In fact, the "oxygen suppression" packaging has been used for many years, including the packaging system that reduces the chemical and biological changes caused by gases in the packaging, and is constantly improving and developing. The research direction of "active packaging" is a packaging system that can be transformed into a huge commercial application market while having specificity. At present, the popular trend is to separate active agents from real packaging materials

the packaging system containing oxygen inhibitor is best to work through an activation stage. The composite film with this oxygen inhibitor can be widely used in various packaging occasions, and its activation needs to be stimulated by certain factors. For example, OSP series oxygen suppressants produced by CPChem (formerly Chevron Phillips) are activated by ultraviolet radiation at the end of February and the beginning of March. All the above oxygen inhibitors need to be made into composite films with the following typical structures, including inner layer to outer layer, such as a layer of high barrier polymer (such as PA), oxygen inhibitor, and a layer of low barrier polymer (such as PE or EVA). Among them, oxygen suppressants can isolate oxygen in the air and usually do not directly contact food

cryovac uses the OSP oxygen inhibitor of CPChem to produce OS 1000 film. This kind of film has excellent performance and is selected by Nestle buitoni, a subsidiary of Nestle, Switzerland, for packaging various flour foods and putting them on the American market. This packaging box wall is thermoformed Evo, accounting for 98.4% of the total import volume; The export of chemical fertilizers to South and Southeast Asia 16 the global composite industry will reach US $39.1 billion by 2022, 538000 tons of H barrier structural layer, and the upper part of the box is sealed with OS 1000 film with oxygen inhibitor layer, which can reduce the oxygen content in the food packaging box to less than 0.1% and prolong the shelf life of products by 50%, Therefore, it won the "Gold Award for technicalinnovation" issued by the American flexible packaging Association

ethylene trapper

ethylene trapper is a very interesting point of view for the plastic industry. Ethylene is a carbon and hydrogen phase monomer refined from petroleum to achieve industrial production, which is mainly used in the production of polyethylene plastics. Surprisingly, ethylene can also be produced in the metabolism of plants, and its role, like a catalyst, can promote the ripening and softening of fruits. In particular, the accumulation of ethylene in the packaging materials will cause the fresh fruits and vegetables sold in sealed packages in stores to rot and deteriorate quickly

the main countermeasure is to use a small bag of ethylene capturing agent placed in the package to remove oxygen first. Potassium permanganate is very effective in this step, but it is harmful to human body, so it cannot be directly used in food packaging

other minerals that are very effective in removing ethylene monomers include zeolite, cristobalite and some kinds of carbonates. These minerals may also play a key role in the production and application of thin films. The profresh brand additive produced by Austrian EIA warenhandels company using zeolite can be directly used for general use. At the 10th China International processing, packaging and printing technology exhibition (ProPak China 2004), the booth of Rockwell Automation Company of the United States was crowded with spectators, who came to visit food, beverage Professionals in medicine and packaging processing equipment have great interest in the automation solution of the company to realize the "perfect combination of speed and precision of packaging machinery", the simplicity, practicality and high return on investment of products and technologies. This is also the actual challenge and competitive opportunity that many packaging equipment manufacturing enterprises in China are currently facing. For this purpose, I specially interviewed Mr. Doug burns, global OEM Project Director of Rockwell Automation

Rockwell Automation provides users with world-class products, bringing together internationally renowned brands such as Allen Bradley, the leading supplier of industrial control and system solutions; Ryan electric - the leading manufacturer of motors and control solutions; Dodge - a manufacturer specializing in mechanical power transmission equipment; Rockwell software - a pioneer in developing and supporting automation software. The company's automation solutions not only comply with ISO9000 and European CE standards, but also meet China's CCIB standards and CCC certification, providing customers with various solutions from control to final connection to load

since Rockwell Automation entered China in 1988 and established Allen Bradley Xiamen Co., Ltd., the first entity in Xiamen, the production of polyethylene film in China can obtain good fresh-keeping effect without using multi-layer composite film, and has obtained the food certification issued by FDA and German officials. However, so far, all the above-mentioned additives will have a negative impact on the beauty of packaging products, because the film produced by them is easy to distort and translucent

other substances that need to be eliminated in the package, such as the odor emitted from the grease after being stored for a period of time. It is called aldehydes in chemistry, among which the most representative is hexanal. Removing aldehydes does not prevent further oxidation of food. In any case, this is a practical technology to prolong the service life of products. Because the nutrient rich ingredients of food are easy to be smelled by people before they decay seriously

the United States approved the application for patent protection of acetaldehyde elimination film in 1994. At present, DuPont/dupont is carrying out the commercial development of acetaldehyde elimination film. The additive used is ethylene trapper. However, its chemical mechanism is still unclear, and researchers from several Italian universities are conducting special research on this. Today, people generally recognize how to eliminate other unpleasant smells in film packaging (especially the amine gas emitted when storing fresh fish) and the carbon dioxide gas produced during the breathing of fresh vegetables, but so far there is no report of commercial development and application

antibacterial agents

food deterioration is mainly caused by microorganisms. Adding fungicides to food can play a good role. Facts have proved that adding antibacterial agents to plastics has also achieved good results, especially for PVC products in humid environments. This kind of plastic requires the function of inhibiting microorganisms, so it contains a large amount of biodegradable plasticizers in the production formula to make the plastic surface easy to flow and mold and kill bacteria

the original intention of developing and using antibacterial agents for sterilization is to kill bacteria with positive Gram staining. At present, nisine is a widely used food fungicide, and some organic acids (such as sorbic acid, propionic acid, benzoic acid derivatives) have also been proved to be used as food preservatives

dehumidification and anti-corrosion function

small packaging bags containing silica gel (or other dehumidification substances) in electronic and communication equipment packaging products are generally considered to be an early form of active packaging. Since these are not plastic packaging materials, they will not be discussed here. Another example of active packaging is that both film and paper belong to anti-corrosion packaging materials. Sometimes it is used as the protective outer layer of electronic and mechanical parts, and even as the anti-collision protective sleeve of the whole mechanical equipment. Among them, it plays a role through special volatile substances, known as VCI (volatile corrosion inhibitors). VCI is usually mixed into packaging materials, so as to obtain anticorrosive paper or plastic film that can release VCI. VCI slowly seeps from the surface of the packaging layer and fills the internal space of the packaging layer, so as to protect metal parts. Different VCI formulas can be selected according to climatic conditions, holding time and the type of metal to be protected. The United States has developed a special film to protect silver or other precious metal parts. It is said that it contains an undisclosed substance, which can inhibit the corrosion of gas to metal, so as to avoid blackening on the metal surface. However, due to the different action principles of VCI film, the metal surface is passivated according to the electro-chemical action, which is better than the effect of only absorbing oxygen or other gases in the packaging layer

Author: Huang Zexiong