Biodegradable and active zein-gelatin-based electrospun mats and solvent-cast films incorporating sage extract: Formulation and comparative characterization

This study aimed to develop active, biodegradable materials for food packaging by incorporating sage extract (SE) within a zein-gelatin blend by electrospinning and solvent casting. The fabrication techniques, SE incorporation, and its content (5, 10% w/w) determined the materials' properties. Electrospinning produced 0.36-0.53 mm thick, non-transparent fibrous mats (mean fiber diameter 1.12-1.36 mu m). Solvent casting generated 0.34-0.41 mm thick, transparent continuous films. The analysis indicated the constituents' compatibility, homogenous dispersion, and efficient SE incorporation without strong chemical interactions and phase separation. The solvent-cast films presented more ordered structures, higher mechanical resistance, elongation, and water vapor barrier performance than the electrospun mats. The SE-incorporating formulations showed phenolics' delivery ability to food simulants influenced by structure, SE content, and media polarity. The electrospun mats expressed higher DPPH center dot radicals' inhibition, while the solvent-cast films showed stronger Staphylococcus aureus and Escherichia coli growth inhibition, increased by SE incorporation. All formulations showed rapid complete bio-disintegration in compost (18-25 days).