RESEARCH ARTICLE


Tempe Fermentation of Whole Grain Barley Increased Human Iron Absorption and Iron Availability



Charlotte Eklund-Jonsson*, 1, Ann-Sofie Sandberg1, Lena Hulthén2, Marie Larsson Alminger1
1 Department of Chemical and Biological Engineering, Food Science, Chalmers University of Technology, SE 412 96 Göteborg, Sweden
2 Department of Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy at Göteborg University, PO Box 459, SE 405 30 Göteborg, Sweden


© 2008 Eklund-Jonsson et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Chemical and Biological Engineering, Food Science, Chalmers University of Technology, SE 412 96 Göteborg, Sweden; E-mail:charlotte.eklund-jonsson@chalmers.se


Abstract

In this study, iron absorption from a tempe fermented whole-grain barley meal was measured, and results were compared to in vitro estimation of available iron from an equivalent meal. The tempe meal (TM) was prepared from barley fermented with Rhizopus oligosporus to reduce the phytate content <0.5 µmol/g. Boiled barley with preserved phytate content was used as reference meal (BBM). Iron was added to obtain a total content of 3 mg meal in the human study, and to the in vitro meals 7 mg of iron was added. The iron absorption from TM and BBM was 5.5±1.5% and 3.0±0.7% respectively, and in vitro iron availability was 4.9±0.2% in TM and 1.7±0.1% in BBM (absorbed fraction of total iron/meal).

To conclude, iron absorption from a barley meal was improved by reducing the phytate content via tempe fermentation, and iron absorption was predicted by direction in the in vitro experiments.

Keywords: Iron absorption, in vitro iron availability, whole grain, vegetarian, tempe, tempeh fermentation.