Microencapsulation of Citrus latifolia peel essential oil by spray-drying using maltodextrin: Characterization, antimicrobial activities, and release profile

The present study aimed to encapsulate Citrus latifolia peel essential oil (LEO) by using spray-drying technique. The effects of operation parameters including maltodextrin concentration (200-350 mg/g mixture), LEO concentration (10-25 mg/g mixture), homogenization time (10-25 min), inlet temperature (120-180 degrees C), and feed flow rates (120-300 ml/h) on the encapsulation indexes, physiochemical properties and antibacterial activities of LEO microcapsules were investigated. With maltodextrin concentration of 300 mg/g, LEO concentration of 15 mg/g, homogenization time of 20 min, inlet temperature of 140 degrees C, feed flow rates of 120 ml/h, the microencapsulation yield (MEY), microencapsulation efficiency (MEE), surface oil (SO) were 89.59%, 92.60%, 7.40%, respectively. Additionally, the LEO microcapsules had an average diameter from 0.75 to 3.50 mu m, with spherical structures and trapped-LEO in the core capsules. TGA and DSC analysis displayed a good thermal stability in the structure of microcapsules. Noticeably, the antibacterial activity of LEO increased after encapsulation. Furthermore, results from drug kinetic study have shown that the Peppas model was the primary mechanism governing the release of LEO in the food medias. The chemical compositions of LEO before and after encapsulation remained well preserved. The utilization of maltodextrin as a potential wall material has shown a clear improvement regarding active substances' properties.