Iron-loaded microcapsules produced by complex coacervation: A promising strategy for food fortification

Iron deficiency anemia remains one of the main nutritional challenges in childhood, especially in socioeconomically vulnerable regions. This study proposes an innovative solution through the microencapsulation of ferrous sulfate (Fe 2+ ) using whey protein isolate (WPI) and gum arabic (GA) as wall materials, aiming to overcome the technical challenges of conventional fortification. The results demonstrated the formation of microparticles with an average size between 0.5-5.1 μm and encapsulation efficiency of 44.6-61.1%. Physicochemical analyses confirmed the stability of the system, with emphasis on thermal resistance up to 331.6°C. The practical application in dairy beverages showed promising results: after 21 days of storage, the formulations with microencapsulated iron had concentrations 17 times higher than those of free iron (2.47 mg/100mL vs. 0.14 mg/100mL), sufficient to supply 22% of the recommended daily intake for children. This approach has significant advantages over conventional methods, including greater protection of the nutrient against degradation and potential for large-scale application. The findings suggest that microencapsulation by complex coacervation with WPI-GA may represent a technically feasible and economically accessible alternative for nutritionally vulnerable populations. • A novel iron microencapsulation system via WPI–gum arabic coacervation achieved 61.1% efficiency. • Microencapsulated iron demonstrated unprecedented retention in dairy matrices, maintaining 17 times higher concentration (2.47 vs. 0.14 mg/100 mL) than free iron after 21 days of storage. • High thermal stability (up to 331.6 °C) ensures compatibility with industrial food processing without nutrient loss. • A single serving provides 22% of the daily iron requirement for children, offering a scalable strategy to address iron deficiency in vulnerable populations.