Project Summary​

To date food packaging amounts as the most consuming application for plastics. Bioplastics are envisaged as a more environmentally sustainable source of plastic materials than currently used petroleum-based plastics. However, bioplastics remain problematic in that they are currently more expensive, can compete with feed and have shortages in performance, specially barrier properties, to guarantee food quality and safety aspects of added-value foods. The MultiBioPack project aims to develop an innovative bio-based multilayer concept for food packaging, largely derived from by-products, with active and bioactive properties which would provide a solution to the above limitations. This packaging structure will consist on four main layers: One structural outerlayer made of blends of commercial PHA with PHA produced from mixed bacterial cultures fed with cheese whey and reinforced with cellulose obtained from by-products. This layer will provide the package with low cost, mechanical performance, thermoformability and water resistance. A second interlayer made of two electrospun sub-layers: The first one will provide the package with gases and vapours barrier and the second one will have an active role by means of incorporating antimicrobials with controlled release properties. A third layer made of commercial food contact permitted PHA which will serve as functional barrier to avoid undesired migration and to provide additional control over the antimicrobials release. It is an additional objective of the project to laminate the three previous layers together to undergo (low) thermoforming to develop a novel tray concept. Finally, a bioactive spray coating inner layer will be applied on the multilayer with the ability to release in a controlled way bioactive compounds into model food products. As a proof of concept of this bioactive coating, two different extracts obtained from food by-products containing polyphenols and carotenoids, respectively, will be encapsulated using various food hydrocolloids, dispersed in a food-contact acrylic resin and applied through spraying coating onto the food contact PHA layer. The stability and bioaccessibility of the bioactive compounds within the model food products will be evaluated during storage and simulated in-vitro digestion, respectively. The project will also characterize the mechanical, thermal, barrier and antimicrobial properties of the concept. Overall and specific migration studies will be performed to asses the food safety of the concepts. Finally, the biodegradability of the full packaging prototype will be assessed in composting assays.