Relationship between structure and properties of modified potato starch biodegradable films

Potato starch was gelatinized in the presence of water and varying amounts of glycerol at 90 degrees C. Starch/glycerol films were prepared by casting with water. The addition of glycerol produces a decrease in the crystallinity of the starch in the films. Starch was acetylated (with acetic acid and anhydride) and maleated (with maleic anhydride). Differential scanning calorimetric analysis revealed decrease in the glass transition temperature (T-g) with the chemical modification. The starch modification on the equilibrium moisture content was determined at 25 degrees C. The esterifications produce a decrease in the maximum moisture sorption. (c) 2006 Wiley Periodicals, Inc.