Analysis of Safety and Testing Methods of Food Plastic Packaging Materials
- Categories:Company News
- Time of issue:2020-07-15
Analysis of Safety and Testing Methods of Food Plastic Packaging Materials
The continuous development of modern economy and technology and the continuous improvement of people’s living standards have also promoted the development of the modern food plastic packaging industry. The types of modern plastic food packaging materials are gradually increasing, and the food safety factors affecting plastic packaging are also emerging in endlessly, not only raw materials and Corresponding to the influence of processing methods or auxiliary agents, there are also some product quality and the lack of strict laws and regulations are also important factors affecting food safety. This article analyzes the types of harmful substances in food plastic packaging materials, and improves the safety of food plastic packaging materials and reduces the content of harmful substances in plastic packaging materials by studying the detection methods of the content of harmful substances and the amount of migration of harmful substances.
Keywords: plastic packaging, material, safety, analysis
The global retail market is booming day by day in different innovative ways. Plastic has almost replaced metal, wood, glass and paper in the packaging industry, making plastic packaging have a tremendous development in the food packaging field. Since food needs to be protected from various environmental factors from production to consumption. Therefore, packaging is needed to protect food, and the shelf life of packaged food may vary from a few days to more than a year. Therefore, the performance of the packaging material must have sufficient durability to ensure that the shelf life is not affected. However, a wide variety of additives are used in the production and processing of plastic packaging materials to modify pure polymer materials to obtain required physical properties. These plastic materials themselves and additives will have a migration effect when they are in contact with food, which will affect the safety of food to a certain extent, thereby posing a threat to human health.
One: Types and characteristics of plastic packaging materials
1. Polystyrene (PS)
Polystyrene has the characteristics of good transparency, excellent rigidity and good hygiene.
Food packaging has broad application prospects, such as bottle caps, instant noodle boxes, fast food boxes and other disposable containers.
2. Polyethylene (PE)
Polyethylene resin is the most commonly used raw material in plastic packaging products for food at this stage. It has the characteristics of good crystallinity, high transparency, good barrier properties, mechanical properties, and chemical stability. Among them, linear low-density polyethylene can be made into film materials and is widely used in the fields of plastic bags, cling film and inner plastic packaging film.
3. Polycarbonate (PC)
Polycarbonate has good transparency, heat resistance and impact resistance, and is usually used for food packaging such as baby bottles and water bottles. PC is synthesized from bisphenol A and diphenyl carbonate through transesterification reaction or the reaction of bisphenol A and phosgene. Before 2009, the sanitary standards of food utensils, containers and packaging were not revised, and the inspection of PC products met the general requirements of plastics. Bisphenol A is a raw material for the manufacture of PC, but due to the properties of estrogen, it is called an endocrine inhibitor, which may affect the reproduction and neurodevelopment of fetuses and babies. At present, PC products have been banned from being used in baby products such as baby bottles.
2: Detection method of hazardous substance content
1. Liquid chromatography-tandem mass spectrometry
Liquid chromatography-tandem mass spectrometry is a method of dissolving a mixture in an organic solution and using the spectral change characteristics of the compound to determine the substance content in the mixture. The specific steps of the method are as follows: first, weigh the mixture, and dissolve the weighed mixture in the organic solution; second, consistent with gas chromatography-mass spectrometry, use technical means to remove the organic ions in the mixed solution For separation, in the classification process, different colored spectral bands will be generated in the solution, combined with the spectral residence time of various types of additives, to determine the content and properties of the compounds in the mixture.
2. Headspace-gas chromatography
Headspace-gas chromatography is a detection method that extracts the mixture under specific conditions and uses related equipment for desorption injection, so that it can form different types of chromatographic bands. The specific steps of the method are as follows: first, place the mixture in a closed space, and after a period of time, collect the air in a specific environment; secondly, extract the collected volatile substances into solution Different color spectrum bands can be formed; finally, the components of the spectrum band are analyzed to determine the material properties and specific content of the mixture. This method has high detection sensitivity and is suitable for the determination of the residual amount of alcohol esters, benzene and volatile organics.
3. Gas chromatography-mass spectrometry method
It has an important application in the detection of plasticizer content in plastic materials. Yan Ming studied the method of gas chromatography-mass spectrometry to detect the content of dibutyl phthalate in different batches of samples. In the second samples, only 13 batches of samples containing dibutyl phthalate were detected, indicating that dibutyl phthalate is rarely used as an additive in food packaging materials. In addition, Guo Chunhai et al. studied the use of gas chromatography-mass spectrometry to analyze the content of plasticizer 46 in polyvinyl chloride films.
Three: Improve the safety of plastic food packaging
1. Improve corresponding laws and regulations
In recent years, China has promulgated a series of laws and regulations on plastic packaging for food. The most recent one was the "Food Safety Law of the People's Republic of China" revised by the State Council in 2015. However, there is still a lack of complete laws and regulations for plastic food packaging.
2. Use modern technology to ensure safety performance
If you want to really improve the material safety of plastic food, you can use modern technology. (1) Use plastic packaging materials with very high safety and hygienic indicators, such as higher purity resins, and do not use discarded and recycled old plastics as actual materials. (2) Continue to study modern, hygienic and non-toxic processing auxiliary materials, and gradually improve modern plastic blending technology to ensure that plastics are environmentally friendly, hygienic and non-toxic during food packaging, and improve the actual performance of plastic food packaging materials. 3) With the support of modern technology, continue to research and develop modern new processing technologies, and use supercritical modern technology to reduce harmful substances produced in the processing of raw materials. (4) Actively develop modern intelligent means for actual food packaging, strict progressive scientific design, specific protection of food packaging under reasonable design and packaging, and use of the edibility and water solubility of certain materials to add Great green guarantees the intensity of testing to avoid uncertain pollution caused by human operations. (5) Gradually increase the actual supervision and inspection of related plastic products, focusing on testing a series of substances such as antioxidants and plasticizers in plastics and additives or heavy metals to ensure the actual supervision of food packaging.
3. Popularize food safety knowledge
Relevant law enforcement officers should actively explore the hazards of plastic food safety, and strengthen consumers' safety awareness through media propaganda. For example, do not use plastic packaging to hold high-temperature food; when heating in a microwave oven, use the corresponding porcelain as a container for heating, instead of using plastic products.