Microstructure of microcapsules consisting of whey proteins and carbohydrates

Microstructure was studied on spray-dried microcapsules with wall systems consisting of mixtures of whey protein isolate (WPI) and maltodextrins (DE 5, 10, 15) or corn syrup solids (DE 24). Structure of microcapsules was appreciably affected by type of carbohydrate and by the WPI-to-carbohydrate ratio. The extent of surface indentation was inversely related to the proportion of WPI in the wall system. Ratio of low-to-high molecular weight solutes in the wall system affected structure. At a WPI-to-carbohydrate ratio of 1:1 or higher, whey proteins improved the surface-smoothness and decrease surface indentation of maltodextrin-based microcapsules. Combinations of WPI with high-DE value carbohydrates were more effective than those with carbohydrates of low DE value in limiting surface-dents formation.