Modulation of Pectin Film Properties via Various Solid Lipid Nanoparticles Formulations: Water Barrier and Mechanical Insights

Despite pectin-based films have been intensively studied as an alternative to plastic, their poor moisture barrier and mechanical properties remain challenging for researchers and industry. This study investigated the influence of four various solid lipid nanoparticles (SLN) formulations on pectin films. Their physical, mechanical, thermal, and morphological properties were tested to determine the functionality as active food packaging. Unloaded and rosemary oil-loaded pectin-stabilized SLN and Tween 20-stabilized SLN were characterized by size (between 140 and 436 nm), zeta potential (between −50 and −28 mV), and encapsulation efficiency (93.6% and 82.6%). SEM results exhibited the compatibility between pectin and SLN. The addition of SLN decreased the water vapor permeability (up to 92%), water uptake at 0.84 aw (up to 37%), moisture content (up to 20%), and tensile strength (up to 74%) of pectin films. No significant change for the elongation at break was observed, compared to Control, in all developed pectin-based films (p > 0.05). Dynamic mechanical analysis showed a more elastic than viscous behavior of films between 30°C and 90°C. In vitro antimicrobial assay of pectin/rosemary oil-loaded SLN showed limited effect under Escherichia coli, Salmonella enterica, and Staphylococcus aureus. Pectin/SLN films immediately disintegrated in water. In conclusion, the present study indicates that the developed pectin/SLN films represent a promising preliminary approach as innovative and sustainable packaging materials intended for dried foods, while further studies are required to validate their suitability as a food-contact packaging system.