The Technological Institute of Plastics (AIMPLAS) has coordinated the European research project PLA4FOOD, which has made it possible to develop a new generation of food packaging materials that combine biodegradable and active properties, as well as natural extracts such as encapsulated garlic molecules that release their antioxidant, antimicrobial and antifungal properties in a controlled manner when in contact with food items.
Three layers with three properties
The packaging obtained with this project can be rigid (trays) or flexible (film for bags), and in both cases they present three layers. The active natural additives are only in the inner layer; the one in contact with food.
In the case of iceberg lettuce, for example, it has been observed that oxidation in the cut area takes around 15% more time to appear than with regular packaging. In all cases, once the products' shelf life expired, these were still firm and suitable for consumption, while vegetables in regular packaging were wet and soft, with moulds appearing on tomatoes and microorganisms on all food items.
The outer layer incorporates moisture absorbers, which are of paramount importance in the case of salads, as the product will retain its best appearance as long as it remains dry. Lastly, every layer contains plasticiser additives that are also biodegradable and which improve the material's properties for their industrial processing. To be precise, they have increased the flexibility of conventional polylactic acid by around 30%.
In addition to all this, the multi-layer structure makes it possible to use additives only in the layer where they are needed, which entails several additional advantages, such as the production of thinner and lighter packaging materials.
AIMPLAS is the Technological Institute of Plastics, based in the Spanish city of Valencia. It is a member of the Spanish Federation of Technological Centres (FEDIT) and the Technological Institutes' Network of the Region of Valencia (REDIT).
AIMPLAS is a non-profit organisation established with the goal of acting as technological associate of companies linked to the plastic sector, offering them comprehensive and personalised solutions through the coordination of Research and Development projects and technological services.