Synergistic stabilization of carvacrol emulsions using alginate, caseinate, and montmorillonite: enhancing encapsulation efficiency and controlled release

Encapsulating carvacrol offers a promising approach to improving its stability, delaying oxidation, and enhancing its biological activity. This study explores the combined effects of alginate, caseinate, and montmorillonite on carvacrol emulsion stability to maximize encapsulation efficiency (EE). Box-Behnken experimental design was used to optimize the formulation, varying the concentrations of alginate (2-4 % w/w), caseinate (0-2 % w/w), and montmorillonite (0-2 % w/w). Emulsion stability was assessed based on droplet size, zeta potential, and yield stress, EE and microcapsule loading capacity. The results demonstrated that alginate and caseinate contribute to emulsion stability, while montmorillonite further reinforces the system by acting as a mechanical barrier, improving encapsulation and controlled release. The optimal formulation was 3.37 % w/w alginate, 2 % w/w caseinate, and 1 % w/w montmorillonite, which yielded an EE of 98.61 % and enhanced emulsion stability. The stabilizing mechanism involves increased steric repulsion between droplets and a gel-like network that resists coalescence and phase separation. Additionally, in vitro, release kinetics, and antimicrobial assays in food-simulating media confirmed the improved performance of the optimized formulation. These findings highlight the potential of combining clay minerals with biopolymer emulsifiers to create stable and efficient essential oil encapsulation systems, paving the way for more effective applications in the food industry.