Preparation and characterization of soy protein thin films: Processing-properties correlation

Thin films based on soy protein and polyols were prepared by two different processing methods. The effect of preparation process, casting or compression was analyzed in order to explain the differences observed in the functional properties of the films, mainly in optical, barrier, and mechanical properties. These differences were related to the changes in the structure during film forming. Results indicate that casting films show better properties than the films prepared by hot-pressing. Films prepared by casting were flexible and transparent and showed less yellowish color, lower gloss and much higher resistance against water. (C) 2013 Elsevier B.V. All rights reserved.