A Comprehensive Study on Gelatin- and Whey Protein Isolate-based Edible Films as Carriers of Fireweed (Epilobium angustifolium L.) Extract

Abstract

The properties of gelatin (GEL) and whey protein isolate (WPI) edible films incorporated with fireweed extract (FE, 0-0.05%) were compared. The GEL films had more crystalline structure, thus were mechanically stronger and less permeable to water vapor than the WPI films. Furthermore, GEL offered more transparent, less yellow, and more stretchable films. In turn, the WPI films had superior UV-protective potential. An increase in the FE concentration yielded films with improved UV-blocking ability. The WPI films incorporated with higher levels of FE (0.025–0.05%) exhibited better antiradical potential in comparison to the GEL films. This result indirectly indicates that the WPI-based films, being more soluble and less swellable, ensured faster release of FE than the GEL films. The slower building up of the antiradical activity of the FE-supplemented GEL films suggests that GEL could be more useful in the development of slow/less migratory active packaging systems for high moisture food.