A new biodegradable material for food storage
The dried food market is growing rapidly due to advantages over fresh produce such as cheaper transportation costs and longer storage life. This increased demand has resulted in high volumes of food packaging waste, 80 % of which is currently non-recyclable. Dried food is usually packaged using modified atmosphere packaging (MAP), where carbon dioxide and oxygen levels are adjusted to reduce bacterial growth and thus preserve the food. Such packaging usually consists of multilayer plastic materials that are not fully recyclable. The EU-funded project BIOACTIVELAYER (Active and biodegradable multilayer structure for dehydrated or dried food packaging applications) worked to develop biodegradable dried food packaging. The aim was to substitute MAP with a multilayer biodegradable structure based on paper, particularly for the dried baby food market. Researchers started off by enhancing the external paper layer's moisture barrier by coating it with a blend of waxes and resins. For the main moisture-barrier layer, they used a composite containing polyhydroxyalkanoate, which is a biodegradable plastic naturally produced by bacterial fermentation. The researchers selected materials with low permeability to oxygen, carbon dioxide and water vapour to create an oxygen-barrier layer to prevent food spoilage by oxidation. They also added oxygen-scavenging molecules, which 'absorb' oxygen, to reduce its levels inside the packaging. BIOACTIVELAYER developed a multilayer material that fulfils the mechanical requirements for the design of a dried food pouch. The new biodegradable material is resistant to fats and its opacity prevents light-induced food spoilage. If just 5 % of currently used MAP is substituted with BIOACTIVELAYER's product, this will eliminate over 300 000 tonnes of non-renewable plastic packaging waste.
