Physicochemical, Antioxidant and Antimicrobial Properties of Electrospun Poly(ε-caprolactone) Films Containing a Solid Dispersion of Sage (Salvia officinalis L.) Extract

In this study, novel active films made of poly(ε-caprolactone) (PCL) containing a solid dispersion of sage extract (SE) were developed by means of the electrospinning technique and subsequent annealing treatment. Initially, the antioxidant and antimicrobial potential of SE was confirmed. Thereafter, the effect of SE incorporation at different loading contents (5%, 10%, and 20%) on the physicochemical and functional properties of the films was evaluated. The films were characterized in terms of morphology, transparency, water contact angle, thermal stability, tensile properties, water vapor, and aroma barrier performances, as well as antioxidant and antimicrobial activities. Thin, hydrophobic films with good contact transparency were produced by annealing of the ultrathin electrospun fibers. Interestingly, the effect of SE addition on tensile properties and thermal stability of the films was negligible. In general, the water vapor and aroma permeability of the PCL-based films increased by adding SE to the polymer. Nevertheless, a strong 2,2-diphenyl-1-picrylhydrazyl (DPPH(·)) free radical scavenging ability, and a strong activity against foodborne pathogens Staphylococcus aureus and Escherichia coli were achieved by SE incorporation into PCL matrix. Overall, the obtained results suggest great potential of the here-developed PCL-based films containing SE in active food packaging applications with the role of preventing oxidation processes and microbial growth.