Characterization of encapsulated rosemary phenolic extract using different coating materials and methods and its performance in heating process as oil natural antioxidant.

This study investigates the microencapsulation of rosemary extract using inulin (In), arabic gum (AG), and their combination as wall materials (Mx), employing freeze drying (FD) and spray drying (SD) techniques. The encapsulated powders were directly incorporated into frying oil and heated at 180 °C. The release of phenolic compounds and oxidative stability of the oil were evaluated after 0, 2, 4, and 6 h of thermal treatment. Comparative analysis showed that while SD powders containing AG exhibited favorable initial characteristics in some physicochemical tests, FD-Mx powders demonstrated superior retention of phenolic compounds and antioxidant activity during prolonged heating. After 6 h of thermal exposure, the released phenolic content reached 37.96 mg/g, and the oil induction time was 1.19 h. Overall, the results indicate that the drying method and wall material composition influence the thermal behavior and functional performance of encapsulated plant extracts, as natural antioxidant, during a heating process.