Leguminous ferritin, a natural protein for iron supplementation, Pickering emulsion formation and encapsulation of bioactive molecules

Ferritin is a naturally occurring iron storage protein. Leguminous ferritins exhibit unique structural features, including diverse subunit composition and an extension peptide, which contribute to superior thermal stability compared to animal ferritins. The high iron content, remarkable effectiveness, low risk of oxidative damage and thermal stability make the leguminous ferritin an attractive candidate for iron supplementation. Moreover, apoferritin is an excellent nanosized carrier for encapsulating bioactive compounds due to its inherent inner cavity, water solubility, biocompatibility, and reversible self-assembly behavior. However, the harsh condition during encapsulation by unmodified ferritins may cause damage to sensitive bioactive compounds. Thus, different processing methods are employed to alter the leguminous ferritin structures, including chemical, enzymatic, mild heat treatments, and nonthermal processing to achieve gentler encapsulation conditions for a wide range of bioactive compounds. Another challenge is to improve the stability of leguminous ferritin to withstand gastric digestion. The degradation of ferritin by proteases may lead to premature release of bioactive compounds. Recent works demonstrated that certain phenolic compounds such as proanthocyanidin-induced protein association, thereby enhancing digestive stability of ferritins, leading to a sustained release and a potentially greater bioavailability of bioactive compounds. Leguminous ferritin also has the potential to serve as a stabilizer for the Pickering emulsion, where the hydrophilic and hydrophobic compounds can be encapsulated in the ferritin nanocages and oil phase, respectively. The release and absorption of bioactive compounds in encapsulates and emulsions will need to be further demonstrated through in vivo studies.