Effect of surfactants on the functional properties of gelatin-based edible films

The aim of this research was to evaluate the plasticizing effect of natural surfactants lecithin or yucca extract from Yucca schidigera on gelatin-based films. Films containing yucca extract showed higher tensile strength values (∼90–40 MPa) and moisture contents (∼15%) and less elongation (∼5%) and water vapor permeability values (∼0.22–0.09 g mm m−2 h−1 kPa−1) compared to films containing lecithin. Soluble films (∼20–50%) were obtained when yucca extract was used while lecithin produced low soluble films (<10%). The opacity of the films (∼14.5–16.2%) was similar for both surfactants and the film surface morphologies were continuous and homogeneous. X-ray diffraction indicated that the addition of surfactants produced amorphous films compared to gelatin-based films and FT-Infrared spectroscopy showed no evidence of association between the surfactants and the gelatin. The plasticizing effect was not obtained after surfactants addition and casting technique.