Mechanisms mediating the regulation of infant formula milk powder fatty acid oxidation by Fe3 + /Fe2+

As important nutrients, metal ions could affect the fat stability in infant formula milk powder. However, the specific metal ions that affect lipid oxidation and the regulatory mechanisms remain unclear. For investigating the effect of metal ions on fat oxidation in infant formula milk powder, formulated milk powders were prepared with FeSO 4 , Fe 4 (P 2 O 7 ) 3 , Cu(C 6 H 11 O 7 ) 2 , CuSO 4 , CaCO 3 , CaCl 2 , C 12 H 22 O 14 Zn, ZnSO 4 , MgSO 4 , and MgO, respectively. The results showed that Fe could significantly increase the levels of MDA and the peroxide value in milk powder. Furthermore, six types of milk powder were prepared with FeSO 4 , Fe 4 (P 2 O 7 ) 3 , C 12 H 22 O 14 Fe·2H 2 O, C 10 H 12 FeN 2 NaO 8 , C 4 H 2 FeO 4 and C 4 H 8 FeN 2 O 4 , respectively, for investigating the effect of different iron compounds on fat oxidation. The result showed that FeSO 4 group and Fe 4 (P 2 O 7 ) 3 group had the highest peroxide values and malondialdehyde content. Furthermore, Fe 2+ participated in the oxidation process of C18:1n9c, C18:2n6c and finally produced 2,5-dimethyl-Benzaldehyde, (E)-2-Octenal, Acetone, 2-heptanone, 4-methyl-Decane, (E)-2-Heptenal, Hexanal, Octanoic acid, 1-octen-3-ol. And Fe 3+ participated in the oxidation process of C18:1n9c, C18:2n6c and finally produced (E)-2-Octenal, 3-Octanone, 4-methyl-Decane, Hexanal, Octanoic acid, 1-octen-3-ol. Our findings provided a novel insight to investigate the effect and mechanism of metal ions on flavor compounds formation in milk powder. • Fe, Cu, Ca, Zn, and Mg could accelerate fat oxidation in formula milk powder, and Fe having the greatest effect on fat oxidation. • FeSO 4 could promote the oxidation of C4:0,C16:0,C18:1n9c and C18:2n6c, eventually produced 2,5-dimethyl-Benzaldehyde, (E)-2-Octenal, Acetone, 2-heptanone, 4-methyl-Decane, (E)-2-Heptenal, Hexanal, Octanoic acid, 1-octen-3-ol. • Fe 4 (P 2 O 7 ) 3 participated in the oxidation process of C18:1n9c, C18:2n6c and finally produced (E)-2-Octenal, 3-Octanone, 4-methyl-Decane, Hexanal, Octanoic acid, 1-octen-3-ol.