Iron bioavailability from bouillon fortified with a novel ferric phytate compound: a stable iron isotope study in healthy women (part II)

Susanne Dold,Jasmin Tajeri Foman,Brigitte Rey,Christophe Zeder,Dominik Grathwohl,Sylvie Merinat,Michael B Zimmermann,Magalie Sabatier,Nicola Galaffu,Diego Moretti,Frederike Jeroense,Edwin Habeych

doi:10.1038/s41598-020-62307-1

Susanne Dold, Jasmin Tajeri Foman + Show 10 more

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https://doi.org/10.1038/s41598-020-62307-1

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Abstract

Bouillon cubes are widely consumed and when fortified with iron could contribute in preventing iron deficiency. We report the development (part I) and evaluation (current part II) of a novel ferric phytate compound to be used as iron fortificant in condiments such as bouillon. Ferric pyrophosphate (FePP), is the compound of choice due to its high stability in foods, but has a modest absorption in humans. Our objective was to assess iron bioavailability from a novel iron fortificant consisting of ferric iron complexed with phytic acid and hydrolyzed corn protein (Fe-PA-HCP), used in bouillon with and without an inhibitory food matrix. In a randomised single blind, cross-over study, we measured iron absorption in healthy adult women (n = 22). In vitro iron bioaccessibility was assessed using a Caco-2 cell model. Iron absorption from Fe-PA-HCP was 1.5% and 4.1% in bouillon with and without inhibitory matrix, respectively. Relative iron bioavailability to FeSO4 was 2.4 times higher than from FePP in bouillon (17% vs 7%) and 5.2 times higher when consumed with the inhibitory meal (41% vs 8%). Similar results were found in vitro. Fe-PA-HCP has a higher relative bioavailability versus FePP, especially when bouillon is served with an inhibitory food matrix.

Highlights

Bouillon cubes are widely consumed and when fortified with iron could contribute in preventing iron deficiency
Our objectives were: (1) to determine fractional iron absorption (FIA) and relative iron bioavailability (RBV) from a new iron fortificant based on monoferric phytate in combination with hydrolyzed corn protein (Fe-phytic acid (PA)-HCP), in comparison to Ferric pyrophosphate (FePP)-and FeSO4-fortified reconstituted bouillon with and without the addition of an inhibitory meal rich in phytate; (2) to compare the RBV of Fe-PA-HCP in bouillon with the inhibitory meal and; (3) to validate in vitro relative bioaccessibility (IVRBA) of Fe-PA-HCP, FePP and FeSO4 in bouillon and the inhibitory meal as determined with a Caco-2 cell assay against the in vivo data
The main finding of this study is that Fe-PA-HCP, a novel iron fortificant consisting of ferric iron complexed with phytic acid and hydrolyzed corn protein, had significantly higher bioavailability than FePP, the compound currently used for condiment fortification

Summary

Introduction

Bouillon cubes are widely consumed and when fortified with iron could contribute in preventing iron deficiency. Ferric pyrophosphate (FePP) is the compound of choice for bouillon cube fortification due to its high stability in food preparations[3], iron absorption from FePP tends to be low compared to ferrous sulfate (FeSO4), the reference compound for assessing iron bioavailability[5,6,7,8]. Biological systems have been proposed as carriers for iron fortification, such as the use of iron-enriched yeast or the use of iron-enriched Aspergillus oryzae[15,16] Another approach is the addition of enhancers for iron absorption such as organic acids for FePP fortification of rice[17], galacto-oligosaccharides[18] and, in bouillon cubes, phosphates[19,20]. While iron complexation and chelation with organic ligands (e.g. ferrous bisglycinate, sodium iron ethylenediaminetetraacetic acid, and ferrous picolinate) has been proposed, the use of these compounds is matrix dependent, limiting their applicability[7,21]

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