Investigation of migration potential in food contact PET packagings

As the last link in the food safety chain, ensuring the safety of materials in contact with food, determination the effect on food quality/safety and identification of the health risks from these materials is necessary for the protection of consumer rights. Some substances located in the structure and/or added during the production of these materials can migrate to food and reach detrimental amounts for human health. This substance transition to food is defined as 'migration' or 'release' and it's tried to be set the limitations with total and specific values internationally for each material group. Plastic materials are widely used in the food industry due to their technological advantages such as flexibility, durability, lightness, stability, impermeability and easy sterilization. Because of the wide variety of additives used in the production of these materials and their ability to be reused with the recycling process, this can lead to the transition of some unwanted residues in food. Polyethylene terephthalate (PET) polymer is widely used for the packaging of plastic materials, especially liquid foodstuffs. According to the Plastic Packaging Industry Report 2017 in Turkey, the share of PET packaging is approximately 23% on the production of plastic packaging. In addition to being lightweight, rigid and resistant to impact, PET packages, which is a good gas and moisture barrier, is widely used, especially for beverages. The most important advantage is that it can be fully recycled. The polycondensation reaction of terephthalic acid and ethylene glycol in the presence of antimony(~90%), germanium or titanium based catalyst is the most common process for PET production. The acetaldehyde, a volatile degradation product that occurs during the PET's melting process, can be adhered to the side walls of the molded product. Acetaldehyde in packaging material may go into food which will be put into food to create an undesirable bad taste in some foods and beverages. Phthalate esters are frequently used in the polymer industry for their advantages such as plasticizer effect, heat transfer fluid and high boiling point and low melting point as carriers. Since phthalate esters are not chemically bonded to plastic matrix, they can easily pass through especially oils or oil-rich foods during production and storage. Phthalate esters pose risks for human health because of their endocrine disrupting and toxic effects. In the national regulations accordance with the European Union, for some phthalate esters specific migration limits have been defined. In our country, only the PET food packaging was allowed to be recycled in 2014 with the regulation in Codex Alimentarius – The Regulation on the Substances and Materials to Contact with Foodstuff. This situation provides added value to the industry as well as brings with the risks arising from the use of recycled materials. In this study, it was aimed to determine the risks arising from the production and recycling of PET packages used in the packaging of many liquid foods such as aqueous, acidic, alcoholic and fatty. For this purpose, specific migration analyses (metals, phthalate esters, acetaldehyde) and polymeric structure determination were performed and the results were evaluated in PET packages collected from the market.