Characterization of iron reducibility of soy protein amyloid fibrils and their applications in iron fortification

• Published in: Food chemistry Vol. 353; p. 129420
• Main Authors: Xiang, Ning, Wu, Sihong, Wei, Zhengxun, Shao, Ping, Sun, Peilong
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.08.2021
• Subjects: Amyloid fibrils; Fibril-iron nanoparticle composites; Iron fortification; Iron nanoparticle; Reducing effect; Soy protein; NaBH4; IDA; AFM; SPI; Fe-Fib11S; Fe-Fib7S; EDTA-Fe; Fe-FibSPI; FTIR; Fe-nano; Amyloid fibrils; FePO4 NPs; βLG; DTNB; Reducing effect; Fe3O4 NPs; Th T; Soy protein; Fibril-iron nanoparticle composites; 11S; Iron fortification; Iron nanoparticle; 7S; TEM; FePP
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2021.129420

•Soy protein fibrils made from SPI, 7S and 11S exhibited reducing effect on Fe (III).•11S showed the most significant iron reducibility.•Iron nanoparticle can be produced in situ on the surface of soy protein fibrils.•7S showed the optimal result for in situ generation of iron nanoparticle on fibrils.•Fibril-iron hybrids had high stability, dispersibility without distinct color change. Iron deficiency is a common nutritional disorder worldwide. Iron fortification of food is an effective strategy to control iron deficiency anemia (IDA), however, traditional iron fortificants usually provoke undesirable organoleptic changes or have limited colloid stability. In this research, we investigated iron reducibility of soy protein amyloid fibrils made from soy protein isolates (SPI), soy β-conglycinin (7S) and soy glycinin (11S), and explored their applications in iron fortification. All three protein fibrils showed iron reducibility. The reducibility was utilized to generate fibril-iron nanoparticle composites. The iron reducibility was affected by fibril concentration, degree of fibrillation and reducing amino acid composition. We identified 11S had the most significant effect on reducing Fe (III) to more bioavailable Fe (II) state, whereas 7S showed the optimal result for generation of iron nanoparticle on fibrils in situ. The resulted fibril-iron nanoparticle hybrids showed high dispersibility in various liquid foods, without distinct color change.