The adsorption of orthophosphate onto casein-iron precipitates

Vikas A Mittal; Ashling Ellis; Aiqian Ye; Patrick J B Edwards; Harjinder Singh

doi:10.1016/j.foodchem.2017.06.035

The adsorption of orthophosphate onto casein-iron precipitates

Food Chem. 2018 Jan 15:239:17-22. doi: 10.1016/j.foodchem.2017.06.035. Epub 2017 Jun 7.

Authors

Vikas A Mittal¹, Ashling Ellis², Aiqian Ye³, Patrick J B Edwards⁴, Harjinder Singh⁵

Affiliations

¹ Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4474, New Zealand. Electronic address: v.a.mittal@massey.ac.nz.
² Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4474, New Zealand; Massey Institute of Food Science and Technology, Massey University, Private Bag 11 222, Palmerston North 4474, New Zealand. Electronic address: a.ellis@massey.ac.nz.
³ Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4474, New Zealand; Massey Institute of Food Science and Technology, Massey University, Private Bag 11 222, Palmerston North 4474, New Zealand. Electronic address: a.m.ye@massey.ac.nz.
⁴ Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North 4474, New Zealand. Electronic address: p.j.edwards@massey.ac.nz.
⁵ Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4474, New Zealand; Massey Institute of Food Science and Technology, Massey University, Private Bag 11 222, Palmerston North 4474, New Zealand. Electronic address: h.singh@massey.ac.nz.

PMID: 28873555
DOI: 10.1016/j.foodchem.2017.06.035

Abstract

This study explored the interactions of orthophosphate with casein-iron precipitates. Casein-iron precipitates were formed by adding ferric chloride at ≥10mM to sodium caseinate solutions ranging in concentration from 1 to 3%(w/v). The addition of different concentrations of orthophosphate solution to the casein-iron precipitates resulted in gradual adsorption of the orthophosphate, causing re-dispersion of the casein-iron complexes. The interactions of added orthophosphate with iron in the presence and absence of caseins are postulated, and new mechanisms are proposed. The re-dispersed soluble complexes of casein-iron-orthophosphate generated using this process could be used as novel iron fortificants.

Keywords: Adsorption; Casein; Dipotassium hydrogen orthophosphate (PubChem CID: 24450); Ferric chloride hexahydrate (PubChem CID: 24380); Hydrochloric acid (PubChem CID: 313); Iron; Orthophosphate; Phosphoserine; Sodium azide (PubChem CID: 33557); Sodium hydroxide (PubChem CID: 14798); Solubility.

MeSH terms

Adsorption
Caseins
Iron
Phosphates / chemistry*

Substances

Caseins
Phosphates
Iron