Release kinetics modeling and fungal control potential of encapsulated thyme (Thymus vulgaris) essential oil

Abstract

The essential oils have antifungal properties and their volatilization can be controlled through encapsulation. The work aimed at controlling the release kinetics of thyme (Thymus vulgaris) essential oil through ionic gelation encapsulation to assess the potential of inhibiting the development of Penicillium spp. Thyme essential oil was encapsulated with sodium alginate (NaAlg; 0.5 and 1.0%), calcium chloride (CaCl₂; 0.8 and 2.5%), and different residence times in the calcium solution (10, 20, 40, and 60 min). Batches of capsules were placed in closed containers and volatilization was monitored. Release kinetics were evaluated through transient regime mass balances. Capsules had diameter and thickness between 2.16-2.81 and 0.20-0.46 mm, respectively. The best systems used AlgNa/CaCl₂-1.0/0.8%, with residence in the calcium solution of 10 and 20 min, obtaining encapsulation efficiencies of 94.0 and 90.1%, respectively. Penicillium digitatum was inhibited through the controlled release of the essential oil.