Encapsulation of citral in formulations containing sucrose or trehalose: emulsions properties and stability

Abstract

The performance of formulations for citral encapsulation by spray drying was assessed. Focus was put on the emulsions properties and stability. Formulations contained sucrose or trehalose with or without maltodextrin and a modified starch as emulsifier. Viscosity, molecular mobility, microstructure, droplet size distribution, and stability were analyzed before and after spray-drying. Instability processes operated in the emulsions bulk, being flocculation the main one. Droplet size and viscosity influenced the emulsions stability. An increase in viscosity attained by the addition of MD delayed the global destabilization processes. Emulsion properties and stability were similar between the formulations containing sucrose or trehalose. Also, there were no differences regarding aroma retention or sensorial perception of citral. The mixture of maltodextrin and trehalose presented higher Tg values allowing to maintain the glassy state of the powder in broader temperature and relative humidity conditions. Trehalose presented a promising performance as an ingredient in the carrier formulation to encapsulate citric flavors.