Effect of cross-linking in surface properties and antioxidant activity of gelatin films incorporated with a curcumin derivative

Gelatin was chemically cross-linked with lactose in order to analyze the effect of this reaction in the antioxidant capacity of gelatin films. Since phenolic compounds are formed during cross-linking, the antioxidant activity of gelatin films was assessed. Although these cross-linking films showed certain antioxidant capacity, the incorporation of tetrahydrocurcumin (THC) into the films forming solutions greatly increased the antioxidant capacity of gelatin films. Total phenolic content, expressed as mg gallic acid equivalent(GAE), increased from 14 to 43 mg GAE/L. Furthermore, free radical scavenging capacity showed a three-fold increase, as shown by inhibition values'. The changes observed were related to the differences found in the film surface, such as lower gloss and higher roughness. (C) 2016 Elsevier Ltd. All rights reserved.