Microencapsulation of Citronella Essential Oil (Cymbopogon winterianus) with Different Wall Materials Using Spray Drying

Essential oils have flavoring and biological properties such as insect repellency, pesticide properties, antifungal, and bactericidal action. A limiting factor in the application of essential oils in industrialized products is the volatility and thermosensitivity of their components. Microencapsulation is an alternative for using these compounds on a large scale, a technique widely used to protect bioactive compounds against environmental damage. Thus, the objective of the study was to encapsulate the essential oil of Citronella (Cymbopogon winterianus) in different wall materials through the spray drying technique. Three formulations of wall materials were evaluated using: Gum arabic (GA) and maltodextrin (MD), gum arabic (GA) and whey protein concentrate (WPC) powder with 60% protein and maltodextrin (MD), and concentrate whey protein (WPC) powder with 60% protein. The amount of oil in the emulsion was set at 10% (w/v) and the wall materials at 40% (w/v) in a 1:1 ratio. The emulsions were subjected to spray drying using inlet and outlet air temperatures of 120°C and 65-70°C, respectively. The highest microencapsulation efficiency was observed for microcapsules formed by gum arabic (GA) and maltodextrin (MD), which also showed good thermal properties, low humidity, and water activity, important parameters to maintain product stability.