Porous Calcium Carbonate-Encapsulated Oregano Essential Oil-Reinforced Poly(vinyl alcohol) Film for Active Strawberry Packaging

Abstract

In this work, the composite antibacterial film (PVA-OEO@CaCO3) was developed by combining porous calcium carbonate@oregano essential oil microspheres with poly(vinyl alcohol). The thickness, mechanical properties, light transmittance, and water vapor permeability were characterized. The film exhibited a smooth, uniform surface; increasing OEO@CaCO3 content raised thickness but reduced mechanical properties. Water vapor permeability dramatically decreased from 6.85 ± 0.26 to 5.15 ± 0.22 (×10–13·g·cm·cm–2·s–1·Pa–1), enhancing moisture retention. The film also blocked UV light effectively. Antibacterial tests showed sustained activity for 7 days, with slower reduction of inhibition zones compared to the control. Strawberry preservation trials demonstrated extended shelf life up to 7 days at room temperature.