Microencapsulation performance of Fe-peptide complexes and stability monitoring

• Published in: Food research international 2019-11, Vol.125, p.108505-108505, Article 108505
• Main Authors: Filiponi, Marília Pinheiro, Gaigher, Bruna, Caetano-Silva, Maria Elisa, Alvim, Izabela Dutra, Pacheco, Maria Teresa Bertoldo
• Format: Article
• Language: English
• Subjects: Enzymatic proteolysis; Maltodextrin; Microstructure; Morphology; Polydextrose; SEM/EDX
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2019.108505

Iron supplementation presents several challenges, such as low bioavailability, high reactivity and a metallic taste. Iron absorption is enhanced by complexing with organic compounds such as peptides, while microencapsulation is an alternative to protect the mineral and mask undesirable flavors. Fe-peptide complexes were obtained by reacting small whey peptides (< 5 kDa) with iron (from ferrous sulfate) under controlled conditions. Maltodextrin (MD) and polydextrose (PD) were used as the wall materials and spray dried to form particles containing the active Fe-peptide. The conditions of enzymatic hydrolysis with the bacterial endopeptidase produced from Bacillus licheniformis were optimized to achieve a high degree of cleavage (~20% degree of hydrolysis). The physicochemical and structural properties of the microparticles were evaluated during storage (365 days). The encapsulation process showed high efficiency (84%) and process yield (≥90%). The iron dialyzability and uptake by Caco-2 cells from microparticles were at least 3-fold higher than the ferrous sulfate. The water content and water activity varied from 3.0 to 5.7% and from 0.29 to 0.44, respectively, after 365 days. SEM revealed morphological stability during storage and EDX showed the presence of iron ions at the surface of the microparticles, which could be free or complexed. The microparticles can be an alternative of higher bioavailable iron besides the further protection and iron stability which the microparticles may present when compared with the Fe-peptide complexes. Future studies could demonstrate the feasibility of applying these microparticles in formulation for food supplementation, concerning bioavailability and sensory aspects. [Display omitted] •Microparticles containing Fe-peptide as active were developed to delivery Fe.•Microparticles showed structural and physical-chemical stability over 1-year storage.•The Fe-peptide active did not interact with wall-material, maintaining its stability.•EDX technique can be an effective tool to observe iron ions on the particle surface.•These particles may be used as an ingredient for iron delivery in dry mixtures.