Effect of the microstructure on the stability of red onion microcapsules

ABSTRACTThe effect of microstructure on the stability of red onion encapsulated by two processes: (a) spray drying and (b) spray freezing into liquid cryogenic, was evaluated in this work. Water sorption isotherms and glass transition temperature of microcapsules conditioned at various water activities were determined and coupled to evaluate conditions of storage stability. The stability of red onion microcapsules was influenced not only by water activity increase but also by microstructural differences between the two types of microcapsules. Critical water content was a useful tool to establish adequate storage conditions for red onion microcapsules.