Activating Paper Applying Gelatin, Starch and Chitosan Coatings Loaded With O/W Emulsions Encapsulating Rutin, Carvacrol and α‐Tocopherol

This study investigated the functional properties of monolucid and kraft papers coated with gelatin, starch or chitosan containing conventional, nano or Pickering emulsions encapsulating rutin, carvacrol or α‐tocopherol, aiming at their future use as active food packaging. Scanning electron microscopy and atomic force microscopy revealed that control and nanoemulsion films of all biopolymers developed smoother and more homogeneous surfaces than those containing conventional or Pickering emulsions, indicating a strong effect of emulsion type on film microstructure. However, emulsion incorporation enhanced the ultraviolet–visible light barrier of the films, which may be associated with structural discontinuities and changes in light scattering due to oil droplets into film matrix. Incorporation of conventional emulsions into gelatin and chitosan films improved tensile strength and reduced water vapour permeability, whereas all emulsified films exhibited pronounced antioxidant activity due to the encapsulated hydrophobic bioactives. When applied as paper coatings, coated kraft paper showed superior mechanical reinforcement compared with monolucid paper, particularly for gelatin formulations with conventional or Pickering emulsions, which markedly increased tensile strength required in cellulosic packaging applications.