Investigation of physicochemical and antibacterial properties of dill (Anethum graveolens L.) microencapsulated...

The present study delves into the encapsulation of dill essential oil utilizing the fluidized bed coating methodology. The investigation focused on the impact of essential oil concentration and the application of maltodextrin and arabic gum as the primary and secondary coating agents. The dominant compounds in the dill essential oil were identified as limonene (32.32%), carvone (35.43%), and cis-dihydrocarvone (5.43%). The antimicrobial potency of the dill essential oil was evaluated, demonstrating notable inhibition against Streptococcus mutans with inhibition zone diameters ranging from 5.4 mm to 16 mm for concentrations between 250 μg/mL and 2000 μg/mL. For Streptococcus sobrinus, the inhibition zones measured from 6.6 mm to 18 mm across the same concentration gradient. An increase in maltodextrin concentration was associated with a decrease in moisture content, bulk density, and tapped density, while it improved microencapsulation efficiency and loading capacity. In contrast, a higher concentration of arabic gum increased moisture content, loading capacity, and encapsulation efficiency, but reduced bulk density and tapped density. Elevating the essential oil concentration increased all physicochemical properties of the microcapsules, except for tapped density. The optimal conditions for microencapsulation involve using a 2000 ppm concentration of dill essential oil with 75% maltodextrin and 0.1% arabic gum as carrier agents. Scanning electron microscopy images indicated that the microcapsule particles were nearly spherical with a smooth, intact surface. The release rate of phenolic compounds in a simulated saliva environment reached its maximum at 98.32% after 20 min, showcasing an efficient release profile.