Protein-based resins for food packaging

Uncorrected proofCurrently, mainly non-biodegradable petroleum-based synthetic polymers are used as packaging materials for foods, because of their availability, low cost and functionality. However, biodegradable/edible films can be made from polysaccharides, proteins and lipids without the environmental issues of petroleum-based polymers and with the additional advantage of being available from renewable sources or as by-products or waste-products from the food and agriculture industries. Although these sources are not enough, by far, to replace the synthetic polymers/films, they can help in reducing packaging wastes and can replace them in specific applications. Proteins have the extra advantage of allowing a wider range of functional properties than polysaccharides and lipids. This is conferred by their composition based on combinations of 20 different amino acids, which usually allows high intermolecular binding. This chapter starts by describing the main protein sources used in packaging materials, followed by a section dealing with materials processing and characterization. The chapter ends with an overview of current and foreseen applications. Nanotechnology applications through the utilization of materials at the nano-scale size in protein-based films are a valuable alterative for the improvement of the properties of packaging materials (water vapour transmission, mechanical, thermal). In particular, nanofilms and multi-nanolayer films constitute promising solutions for food applications using protein-based materials