Modeling of Release Mechanism of Sage (Salvia fruticosa Miller) Phenolics Encapsulated in Alginate Capsule: Physicochemical Properties

Abstract

Alginate capsules are promising delivery systems for encapsulation and release of phenolics since they can be fabricated from food-grade biopolymers using mild processes. On the other hand, knowing the release kinetic of the phenolic in the capsules is critical for capsule fabrication and product quality improvement This study is aimed at mathematically modeling the transfer of encapsulated sage (Salvia fruticosa Miller) phenolics in alginate particles to water and to determine some physicochemical properties of capsules containing different concentrations of phenolics. The water activity values (aw) of the capsule varied between 0.9976 and 0.9990. Sphericity factors of 1 (37.5 ppm), 2 (75 ppm), 3 (150 ppm), 4 (300 ppm), and control (0 ppm) samples were determined as 0.042, 0.044, 0.043, 0.273, and 0.039, respectively. The yellowness (+b ^∗) value of the samples increased significantly as the added sage extract concentration increased. While the phenolic content of the samples was determined between 0.174 and 1.1831 mg/kg GAE, the antioxidant activity values were determined between 0.9602 and 6.6930. To understand the mechanism of phenolic release from the capsules, six different mathematical models were used (First Order, Higuchi, Korsmeyer-Peppas, Hixson and Crowell, The Peppas-Sahlin, and Gompertz). The highest R² (0.9952-0.9979) and the lowest RMSE (1.0171-1.7032) values were calculated in The Peppas-Sahlin among the six models. The Peppas-Sahlin model kinetic parameters indicated the dominance of Fickian diffusion and the minor effect of relaxation process in the mechanism of phenolic release.