Biodegradable Protein-based Films from Plant Resources: A Review

This review provides an overview of studies on the film-forming properties of soy protein, wheat gluten and corn zein. Biodegradable films from these proteins have been investigated extensively. Casting is the most often used film-forming method. Glycerol is added as plasticizer in many studies. The proteins are normally dissolved or dispersed in suitable solvents with plasticizers. The resulting solutions or dispersions form free standing films on a plate by casting the mixture and subsequent drying. Posttreatments such as coating, beating, and radiation are also employed to improve film properties. These protein films in general are water sensitive and lack mechanical strength but are good oxygen barriers. Further studies to improve the properties of the films for food packaging materials are also discussed. (C) 2010 American Institute of Chemical Engineers Environ Prog, 29: 203-220, 2010