Fabrication and characterization of laurel (laurus nobilis) essential oil nanoemulsion stabilized by sodium caseinate/modified α-cyclodextrin.

Abstract

The direct application of essential oils in food systems faces challenges due to their volatility, strong odor, and instability. This study developed nanoemulsions encapsulating laurel (Laurus nobilis) essential oil (LEO) using sodium caseinate (SC) and octenyl succinic anhydride (OSA) modified α-cyclodextrin (α-CD) as composite stabilizers, aiming to enhance emulsion stability and bioactive efficacy. The results demonstrated that a 1:1 SC/OSA-α-CD ratio formed a dense reticular structure with minimal turbidity. NE-S1O1-8 M displayed uniform droplets, the smallest particle size (317.23 nm), and an 86° contact angle. Furthermore, under storage, centrifugation, or heating, NE-S1O1 showed superior stability with negligible changes in particle size or appearance. The encapsulation efficiency, antibacterial and antioxidant activities primarily depended on LEO concentration. The NE-S1O1-8 M emulsion exhibited optimal integrated bioactivity, demonstrating inhibition zones of 18.9 mm against S. putrefaciens and 17.1 mm against S. aureus, along with DPPH and ABTS radical scavenging rates of 79.2 % and 82.8 %, respectively. Although the encapsulation efficiency under this condition was slightly lower than that at 4 × MBC, it remained at a high level above 80 %. This study provides a novel approach for stabilizing active compound-loaded nanoemulsions suitable for food preservation applications.