Microencapsulation of okara protein hydrolysate by spray drying: physicochemical and nutritive properties, sorption isotherm, and glass transition temperature

Abstract

The objective of this work was to evaluate the physicochemical and nutritive properties, sorption isotherm, and glass transition temperature (Tg) of okara protein hydrolysate microencapsulated with maltodextrin or modified starch by spray drying. Freeze-dried hydrolysate without a wall material was obtained as a non-encapsulated sample. The type of wall material had no significant influence on the powder properties. There were differences between encapsulated and non-encapsulated samples, mainly in the sugar profile, mean particle size (∼13 and 208 µm, respectively), and anhydrous powder Tg (∼100 and 55 °C, respectively). Microencapsulation improved the critical relative humidity of storage from 25% to ∼55%.