Background: Iron deficiency is the most widespread nutritional problem in the world which causes several dysfunctions. The direct addition of iron in food products leads to many physiological and industrial difficulties. Therefore, recent years have seen renewed interest in iron entrapment within the food-grade delivery vehicles. Scope and approach: This review set out to gain further understanding of the physicochemical aspects of foodderived iron carriers (protein-based, carbohydrate-based, lipid-based, and composite systems) in order to boost the stability and triggered release. The review also illustrates several novel topics for research. Key findings and conclusions: Protein carriers increase bioavailability and reduce pro-oxidant role of iron. Protein gels were more successful than protein ligands. The major iron-binding site corresponds to the carboxyl groups located on the side chain of Glu and Asp. The guanidine nitrogen of arginine, the ε-amino nitrogen of lysine, and the imidazole nitrogen of histidine participate in iron–peptide bonding. Glycine, proline, and cysteine may also participate in iron-binding. Carbohydrates regarding the mucoadhesive properties cause slow release. Their gels mostly need calcium ion which is an iron inhibitor. Their acetyl group reduction resulted in intestinal iron release with bypassing it through gastric medium. Iron-loaded lipid-based vehicles were faced with oxidation and iron leakage which decreased in composite systems in the presence of proteins or polysaccharides. Lipids can ease the iron transport through intestinal cells. Lipid-based carriers stabilized by proteins and polysaccharides enhance the mucoadhesive features to obtain a triggered release, increased iron solubility and bioavailability as well as mucosal transport.

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