Influence of binder type and concentration on physical properties of agglomerated, spray-dried, and high oil loaded microcapsules

Abstract

This study aimed to investigate the effects of the type of binder and binder concentration on physical properties of agglomerated, spray-dried, and high oil loaded microcapsules. Spray drying was used to microencapsulate soybean oil (500 g kg -1 of dry matter) which served as a model core material in a wall system consisting of soy protein isolate (SPI) and maltodextrin (MD) (1:3 w/w ratio). Spray drying of the core-in-wall emulsions led to small particles (~20 μm) having poor handling and reconstitution properties. Fluidized bed agglomeration of the spray-dried microcapsules using MD with varying dextrose equivalent (DE) values (10-18) as an aqueous binder solution improved the handling and reconstitution properties of the powders. The system containing MD with the DE value of 14 (MD14) presented the highest dispersibility and was chosen to determine the effect of binder concentrations (0-200 g L -1 ). The optimum binder concentration was 150 g L -1 MD with a DE value of 14 which resulted in the largest particle size of the agglomerate (657 μm) having a very good flowability and low cohesiveness. The wettability (wetting time = 3 s) and dispersibility (98%) of this agglomerate were very good.