Effects of α1/α2 ratios and drying temperatures on the properties of gelatin films prepared from tilapia (Tilapia zillii) skins

Effects of alpha(1)/alpha(2) ratios and drying temperatures on the properties of tilapia skin gelatin films were investigated. Tensile strength (TS) of alpha(1)-subunit based films and alpha(2)-subunit based films were 30.4 MPa and 12.8 MPa, respectively. When films were prepared from alpha-subunits at alpha(1)/alpha(2) ratio of 2/1, both TS and elongation at break (EAB) of films were the highest. The color of alpha-subunit based composite films was similar to that of alpha(2)-subunit based films. However, no obvious changes in the SDS-PAGE patterns were observed between film-forming solutions and films. On the other hand, the TS and EAB of alpha-subunit based composite films prepared at 10 degrees C or 15 degrees C were much higher than those of films prepared at 20 degrees C or 25 degrees C. Circular dichroism analysis revealed that triple helical structure was formed in the films containing alpha(1)-subunit dried at 15 degrees C or below, thus forming strong strength films. (C) 2015 Elsevier Ltd. All rights reserved.