Active gelatin films incorporated with eugenol nanoemulsions: effect of emulsifier type on films properties

The objective of this work was to study the impacts of the addition of eugenol nanoemulsions (NE) stabilised with two natural emulsifiers, soy lecithin (SL) or sodium caseinate (NaCas), on the properties of gelatin films for active packaging. All the films added with NE displayed higher tensile strength and elongation at break than control films. Films added with NaCas-stabilised NE were more resistant to tension compared to films added with SL-stabilised NE. Gelatin films added with both NE, showed significant differences in surface roughness compared to control film. Fourier-transform infrared spectra showed that both NE achieved complete miscibility within the films. Differential scanning calorimetry analyses suggested compatibility among both NE embedded into the films. These films indicated great antioxidant activities monitored via ABTS radical scavenging activities. These findings are essential to better design active films incorporated with nanoemulsions, in order to optimise film formulation rationally towards their eventual application as food packaging.