Iron absorption from experimental infant formulas based on pea (Pisum sativum)-protein isolate: the effect of phytic acid and ascorbic acid.
Infant formula based on pea (Pisum sativum)-protein isolate has been suggested as an alternative to soybean formula in countries where soybean is not a native crop, or when soybean protein cannot be used due to allergic reactions or intolerances. In the present study, Fe absorption from experimental infant formulas based on pea-protein isolate was measured in healthy non-anaemic young women. The influence of phytic acid and ascorbic acid on Fe absorption was evaluated, using a stable-isotope technique based on incorporation of Fe stable-isotope labels into erythrocytes 14 d after administration. Geometric mean Fe absorption increased from 20.7 (+1 SD 41.6, -1 SD 10.3) % to 33.1 (+1 SD 58.6, -1 SD 18.7) %; (P < 0.0001; n 10) after enzymic degradation of virtually all phytic acid. Doubling the molar ratio Fe:ascorbic acid from 1:2.1 to 1:4.2 in the infant formula with native phytic acid content also increased Fe absorption significantly (P < 0.0001; n 10); geometric mean Fe absorption increased from 14.8 (+1 SD 32.1, -1 SD 6.8) % to 22.1 (+1 SD 47.2, -1 SD 10.4) %. These results confirm the inhibitory and enhancing effects of phytic acid and ascorbic acid respectively on Fe absorption, but also indicate relatively high fractional Fe absorption from the pea-protein-based formulas. After adjusting for differences in Fe status, our data indicate that Fe absorption from dephytinised pea protein might be less inhibitory than dephytinised soybean protein as measured in a previous study (Hurrell et al. 1998).
Davidsson
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L
Laboratory for Human Nutrition, Institute of Food Science, Swiss Federal Institute of Technology, Rüschlikon, Switzerland. davidsson@ilw.agrl.ethz.ch.
Dimitriou
T
T
Walczyk
T
T
Hurrell
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RF
D000328:Adult; D001205:Ascorbic Acid / Q000494:pharmacology; D005260:Female; D006801:Humans; D007223:Infant; D007225:Infant Food; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D007408:Intestinal Absorption / Q000187:drug effects; D007501:Iron / Q000493:pharmacokinetics*; D018532:Pisum sativum; D010833:Phytic Acid / Q000494:pharmacology; D010940:Plant Proteins
D010940:Plant Proteins; D010833:Phytic Acid; D007501:Iron; D001205:Ascorbic Acid