Development of polyion-complex hydrogels as an alternative approach for the production of bio-based polymers for food packaging applications: a review

Development of packaging materials from renewable resources has for a long time been desirable for sustainability reasons, but with recent explosion in prices of petroleum products, this now becomes also more economically viable. This paper shows how fundamental chemistry underlying three forms of hydrogels—physical hydrogels, chemical hydrogels, and interpenetrating polymer networks (IPN)—can be integrated to produce a new family of food packaging materials from biopolymers, illustrated here using gelatin and low-methoxyl pectin as examples. Application of this technique to create hydrogels from bio-based materials offers the potential for developing novel, biodegradable packaging applications, particularly for foods, that meet the ever-increasing demands for natural and environmentally compatible materials.