The effect of oxidized ferulic acid on physicochemical properties of bitter vetch (Vicia ervilia) protein-based films

The aim of the present study was to investigate the effect of oxidized ferulic acid on some physicochemical features of bitter vetch protein concentrate-based films. Our results indicate that moisture content, total soluble matter, water vapor permeability, and mechanical resistance values of the films prepared in the presence of oxidized ferulic acid were significantly modified in comparison with the ones detected with films obtained in its absence. In fact, film moisture content, total soluble matter, and water vapor permeability significantly decreased when oxidized ferulic acid was added to the film forming solutions, whereas both film tensile strength and elongation at break resulted markedly higher. Moreover, atomic force and scanning electron microscopy analyses showed that film morphology was also markedly affected by the presence of oxidized ferulic acid, film surface roughness, and compactness resulting higher than the ones observed in control samples. Therefore, these findings show a marked improvement in obtaining edible films derived from cheap starting biopolymers, such as bitter vetch proteins, potentially useful for different food and pharmaceutical applications. (C) 2015 Wiley Periodicals, Inc.