Spray-drying encapsulation of citral in sucrose or trehalose matrices: physicochemical and sensory characteristics

The potential of the disaccharide trehalose as carrier for producing spray-dried citral was examined. Some physical and sensory characteristics of citral encapsulated in matrices containing either trehalose or sucrose and maltodextrin (MD) were analysed. They included water sorption, glass transition temperatures (T-g), nuclear magnetic resonance (NMR) relaxation and citral retention during spray-drying. The glassy state at room temperature (25 degrees C) was maintained as far as 33% relative humidities (RH) for the spray-dried trehalose formulation and 43% RH for trehalose-MD; however, for sucrose-MD and for sucrose formulations, the glassy state was limited to RHs lower than 33% and 22%, respectively. Sensory evaluation and gas chromatographic analysis indicated that citral retention after spray-drying was similar for matrices containing either trehalose or sucrose. However, trehalose formulations had improved physical stability as compared to sucrose.