Films are thin coatings of materials that protect the product against mechanical and corruption factors. The use of edible films and coatingsis developed these days because they can retain the quality, flavor and moisture content of the product and also are degradable and easy to use. Proteins are an apt choice for such film’s base material as their suitable barrier property against oxygen, CO2 and fat especially in low relative humidity. Collagen is a protein biopolymer used specially for meat products and has good mechanical properties although its permeability to O2 increases with RH degrees. Higher water solubility and lower resistance of collagen to moisture has to be eliminated by increasing cross-link density with polysaccharide derivatives. Another way is blending of hydrophilic synthetic polymers with collagen that represents better mechanical properties. The best method for its extraction is acid hydrolysis which is a mediocre one.
