Reactivity of Fe(III)-containing pyrophosphate salts with phenolics: complexation, oxidation, and surface interaction
Publication date
2023-05-01
Authors
Bijlsma, Judith
Moslehi, Neshat
Velikov, Krassimir
Kegel, Willem
Vincken, Jean Paul
de Bruijn, Wouter J.C.
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Document Type
Article
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Abstract
Mixed pyrophosphate salts with the general formula Ca2(1-x)Fe4x(P2O7)(1+2x) potentially possess less iron-phenolic reactivity compared to ferric pyrophosphate (FePP), due to decreased soluble Fe in the food-relevant pH range 3–7. We investigated reactivity (i.e., complexation, oxidation, and surface interaction) of FePP and mixed salts (with x = 0.14, 0.15, 0.18, and 0.35) in presence of structurally diverse phenolics. At pH 5–7, increased soluble iron from all salts was observed in presence of water-soluble phenolics. XPS confirmed that water-soluble phenolics solubilize iron after coordination at the salt surface, resulting in increased discoloration. However, color changes for mixed salts with x ≤ 0.18 remained acceptable for slightly water-soluble and insoluble phenolics. Furthermore, phenolic oxidation in presence of mixed salts was significantly reduced compared to FePP at pH 6. In conclusion, these mixed Ca-Fe(III) pyrophosphate salts with x ≤ 0.18 can potentially be used in designing iron-fortified foods containing slightly water-soluble and/or insoluble phenolics.
Keywords
Flavonoids, Food fortification, Iron supplementation, Mixed calcium-iron (III) pyrophosphate salts, Polyphenols, Analytical Chemistry, Food Science
Citation
Bijlsma, J, Moslehi, N, Velikov, K P, Kegel, W K, Vincken, J P & de Bruijn, W J C 2023, 'Reactivity of Fe(III)-containing pyrophosphate salts with phenolics : complexation, oxidation, and surface interaction', Food Chemistry, vol. 407, 135156, pp. 1-11. https://doi.org/10.1016/j.foodchem.2022.135156