No 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 FeSO 4 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. Iron fortification of condiments like bouillon cubes has the potential to reach large populations in sub-Saharan Africa 1-3. It has been estimated that per capita bouillon cube intake ranges from 1.9 g/day in Cameroon to 8.6 g/ day in urban Senegal 1,4. Challenges when fortifying bouillon with iron include iron bioavailability and product stability. Currently, ferric pyrophosphate (FePP) is the compound of choice for bouillon cube fortification due to its high stability in food preparations 3 , however, iron absorption from FePP tends to be low compared to ferrous sulfate (FeSO 4), the reference compound for assessing iron bioavailability 5-8. Alternative iron compounds with higher bioavailability and similar stability in products would therefore be valuable for fortification of condiments like bouillon cubes 9,10. Several approaches have been proposed to increase iron bioavailability, especially in diets containing significant amounts of inhibitors, such as phytic acid (PA), while keeping stable sensory properties in the chosen food vehicles. Microencapsulation of bioavailable iron may be used to separate the iron fortificant from the food matrix, reducing sensory changes. Potential drawbacks are the reduction of bioavailability as well as the cost-increase due to encapsulation 7. Degradation of PA in staple foods may be used to increase iron absorption, however, virtual elimination of the PA is needed 7,11,12. Particle size reduction of poorly soluble compounds like ferric phosphate or ferric oxides can improve their rate of dissolution in gastric juices and, therefore, bioavailability may be increased 13 , but regulatory uncertainty on the use of nanoparticles has limited their applicability 14. Further, biological systems have been proposed as carriers for iron f...

In a series of two studies, we report the development (this study) and evaluation (part II) of a novel ferric phytate compound designed as a condiment iron fortificant. Condiments are used as iron fortification vehicles to reduce the prevalence  of iron deficiency. The challenge for iron fortificants in e.g. a bouillon matrix is to avoid undesired sensory effects and to ensure a reasonable cost. We added phytic acid to chelate iron, and hydrolysed protein to counteract the inhibiting effect of phytic acid on iron bioaccessibility. We characterised four novel ferric phytate compounds, destabilised by hydrolysed plant protein or amino acids. Colour stability of fortified bouillons with ferric phytate compounds was superior to bouillons fortified with ferrous sulfate. The iron-phytate-hydrolysed corn protein compound (Fe-PA-HCP) resulted in highest cellular ferritin induction in Caco-2 cells, in both vegetable (36.1 ± 13.40 ng/mg protein) and chicken (73.9 ± 19.93 ng/mg protein) bouillon matrices as observed in the human Caco-2/HepG2 cell model. Iron uptake (as estimated by ferritin production) from the Fe-PA-HCP compound was about 55% (chicken bouillon) and 66% (vegetable bouillon) of the iron uptake from ferrous sulfate. Based on this study, the Fe-PA-HCP compound was chosen for further evaluation (part II).

Short-chain a-(1,4)-D-glucan samples were generated by debranching of potato amylopectin and fractionation on gel permeation chromatography. The collected fractions were gathered to generate two samples with an average DP n of 32 and 42, respectively. The samples were recrystallized at 280 and 17C for three days (10%, w/w) and the resulting structures and related digestibility were assessed. The results revealed that the slowly digestible starch (SDS) content was affected by both chain length and recrystallization temperature. The highest SDS level (49%) was obtained at 2807C from the sample with the lowest average DP n . Its structure showed B-type polymorphic crystallites with a substantial amorphous part and a melting temperature of 857C. Such a melting temperature was close to that already reported in the literature and appears characteristic of recrystallized SDS structures.