ARS | Publication request: BIOAVAILABILITY OF ELEMENTAL IRON POWDERS IN BREAD ASSESSED WITH AN IN VITRO DIGESTION/CACO-2 CELL CULTURE MODEL

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 13, 2004
Publication Date: March 17, 2005
Citation: Yeung, C., Miller, D.D., Zhiqiang, C., Glahn, R.P. 2005. Bioavailability of elemental iron powders in bread assessed with an in vitro digestion/caco-2 cell culture model. Journal of Food Science. 70:5199-5203.

Interpretive Summary: Two types of wheat flour (low-extraction and high-extraction) were fortified with 10 different commercial elemental iron powders and baked into breads. Iron bioavailabilities from the resulting breads were assessed with a model system that simulates gastrointestinal digestion and measures iron uptake in cultures of human intestinal cells. Uptake of iron by these cells, known as enterocytes, represents the first step in iron absorption and is a predictor of availability of iron for humans. The elemental iron powders were evaluated with and without added ascorbic acid, and compared to FeSO4 as the control. Bioavailabilities of several powders were comparable to FeSO4, but there was no consistent trend as to which production method produced the most bioavailable powder. In general, ascorbic acid enhanced, whereas the baking process reduced iron bioavailability from bread. Our results suggest that some powders are promising but further human studies are needed to validate these powders for food fortification programs.

Technical Abstract: Two types of wheat flour (low-extraction and high-extraction) were fortified with 10 different commercial elemental iron powders and baked into breads. Iron bioavailabilities from the resulting breads were assessed with an in vitro digestion/Caco-2 cell culture model, with and without added ascorbic acid, and evaluated using FeSO4 as the control. Bioavailabilities of several powders were comparable to FeSO4, but there was no consistent trend as to which production method produced the most bioavailable powder. In general, ascorbic acid enhanced, whereas the baking process reduced iron bioavailability from bread. Our results suggest that some powders are promising but further human studies are needed to validate these powders for food fortification programs.