Development and characterization of maltodextrin microparticles to encapsulate heme and non-heme iron

Selection of an appropriate encapsulating material and its properties are critical issues to optimize iron encapsulation systems. Therefore, the aim of this work was to develop and characterize different types of heme and non-heme iron-maltodextrin microparticles. Different concentrations of bovine erythrocytes (BE) and ferrous sulfate (FS) were encapsulated using an optimal maltodextrin concentration of 40% w/v by spray-drying. The microparticles were characterized by iron content, yield, Z potential, size, color, SEM, FTIR and iron release under simulated gastrointestinal conditions. Results indicate that FS microparticles exhibited a higher iron content (54-90 mg/g) than BE microparticles (0.28-0.77 mg/g), Z Potential for all microparticles was negative and FS microparticles had a smaller size (918-981 nm) than BE microparticles (10,390-16,643 nm). FS microparticles had an irregular spherical shape and a shriveled surface, while BE microparticles exhibited a spherical shape and a smooth surface. The main interactions of FS microparticles were O-H bridges and C-O bonds, whereas for BE microparticles these were O-H, C-O and N-H bonds. Iron was released from both types of microparticles: high amounts under gastric conditions, and quickly under intestinal conditions.