Biocompatible κ-Carrageenan Gel Films with Clove Essential Oil Nanoemulsion: Optimization, Properties, and Strawberry Preservation Efficacy

Emulsion-filled hydrogels have attracted considerable attention due to their potential for inhibiting foodborne pathogens. However, development of packaging films based on essential oil nanoemulsion-filled hydrogels and their efficacy in food preservation remains relatively limited. This study engineered a biocompatible κ-carrageenan (KC)-based gel film loaded with clove essential oil nanoemulsion (CEON), exhibiting excellent dual-function antibacterial and antioxidant properties for preserving strawberries.The results revealed that incorporating CEON dramatically boosted the film's ultraviolet (UV) barrier properties (reducing UV transmittance to 0.02%), antimicrobial activity (producing an inhibition zone diameter of 6.5 cm), and antioxidant activity (demonstrating DPPH/ABTS radical scavenging rates exceeding 90%). Concurrently, the film exhibited remarkable flexibility, with its elongation at break increasing from 4.8% to 35%. The thus-formed unique porous network, characterized by a “hydrophobic surface yet moisture-permeable matrix”, effectively modulated the internal microenvironment. The CEON-loaded KC gel film not only effectively inhibited the growth of spoilage microorganisms on strawberries, extending their refrigerated shelf life to 10 days, but also demonstrated excellent biocompatibility as confirmed by seed germination and cytotoxicity assays. This study provides novel insights for developing high-performance and environmentally friendly food preservation materials.