Standard Article

Edible Films and Coatings from Soybean and Other Protein Sources

  1. Navam S. Hettiarachchy,
  2. S. Eswaranandam

Published Online: 15 JUL 2005

DOI: 10.1002/047167849X.bio084

Bailey's Industrial Oil and Fat Products

Bailey's Industrial Oil and Fat Products

How to Cite

Hettiarachchy, N. S. and Eswaranandam, S. 2005. Edible Films and Coatings from Soybean and Other Protein Sources. Bailey's Industrial Oil and Fat Products. 6:11.

Author Information

  1. University of Arkansas, Fayetteville, Arkansas

Publication History

  1. Published Online: 15 JUL 2005


Biobased materials, which are diverse in nature, chemistry, and properties, expand the possibilities to tailor-made edible films for food industries. Film formation is a result of polymerization of unfolded proteins by disulfide and hydrogen bonds and hydrophobic interactions. Plasticizers can increase chain mobility and are necessary to produce protein or polysaccharide-based films to have flexibility and mechanical strength for handling. Low-molecular-weight organic acids with one or more OH group also have a plasticizing effect on films. Edible films are produced by dry processing by extrusion and by wet processing by casting film-forming solution. Homogenous thin films with uniform thickness can be cast with a Drawdown instrument. Viscosity can be used to optimize the film-forming solution. Color characteristics of the film can be affected by addition of chemicals, heat curing, and ultraviolet (UV) treatment. Mechanical strength of the film can be improved by cross-linking of the polymers by means of UV/γ radiation. Edible films should have adequate mechanical strength and extensibility to maintain integrity and withstand physical stress. Protein films are excellent gas barriers but poor moisture barriers because of their hydrophilic nature. Edible film can be tailored to incorporate antimicrobials, antioxidants, phytonutrients, nutraceuticals, nutrients, flavors, colors, and food additives. These areas need extensive research.


  • edible film;
  • drawdown instrument;
  • UV irradiation;
  • soy protein;
  • plasticizer;
  • viscosity;
  • color;
  • tensile strength;
  • water vapor permeability