Glass transition temperatures and some physical and sensory changes in stored spray-dried encapsulated flavors

Commercial spray-dried powder flavors (strawberry and orange) encapsulated in different amorphous matrices (maltodextrin and maltodextrin-sucrose) were stored for 20 days under constant relative humidities of 32%, 43%, 58% and 75%. Glass transition temperatures (T-g) of the different powders and maltodextrin DE 12 were measured using differential scanning calorimetry (DSC). Caking/collapse visual observations and aroma strength (measured by a trained sensory panel) were recorded and correlated with the glass transition temperature of the different spary-dried flavors. Glass transition data explained collapse occurrence and loss of aroma strength in encapsulated strawberry and orange flavors after storage at various relative humidities. The presence of sucrose in the carrier formulation negatively affects storage stability of the encapsulated flavor. (c) 2006 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.