Biological Systems Engineering


Date of this Version



Published in Cereal Chemistry Vol. 74, No. 4, 1997. Copyright © 1997 by the American Association of Cereal Chemists, Inc. Used by permission.


There has been increased interest in development of biopolymer films and coatings from protein, polysaccharide, and lipid materials in recent years. The qualities of renewability, degradability, compostability, and edibility make such films particularly appealing for food and nonfood packaging applications. Moreover, wide commercialization of biopolymer films will provide a value-added innovative use for traditional agricultural commodities as sources of film-forming materials. Research findings on production, properties, and potential applications of edible films have been reviewed (Krochta 1992, Conca and Yang 1993, Gontard and Guilbert 1994). Protein films in particular have been discussed in detail by Gennadios et al (1994a) and by Torres (1994). Zein, the prolamin fraction of corn proteins, is used in formulations of protective coatings for confectionery items, shelled nuts, and pharmaceutical tablets (Gennadios et al 1994a). Several recent studies have focused on development and property evaluation of zein-based films (Aydt et al 1991; Gennadios et al 1993a,b; Park et al 1994b; Park and Chinnan 1995; Yamada et al 1995), zein-paper laminates (Trezza and Vergano 1994), and methylcellulose and zein-fatty acid laminates (Park et al 1994c, 1996). Functionality of zein in barrier packaging for popcorn (Wu and Schwartzberg 1992), tomatoes (Park et al 1994a), cooked turkey (Herald et al 1996), and shell eggs (Wong et al 1996) has been evaluated.