Role of oxate, phytate, tannins and cooking on iron bioavailability from foods commonly consumed in Mexico

Abstract

The objectives of this research were to assess the bioavailability of iron in foodstuffs found in the Mexican diet, to provide data on the content of iron absorption inhibitors present in plant origin products and to assess the inhibitory effect of these compounds and of cooking on iron bioavailability; therefore, total content and bioavailable iron, tannins, phytic and oxalic acid were determined in vegetables, cereals, legumes and animal products, before and after cooking. Vegetables, although rich in iron, have poor iron bioavailability and a high content of inhibitory factors; cooking reduced the content of iron and inhibitory factors, whereas in animal products the treatment of cooking did not significantly reduce it. Iron bioavailability, phytate content and the phytate to iron molar ratio predicted poor iron bioavailability and, therefore, a negative impact on the nutritional status of people who rely on them as staple foods could be expected.

Keywords::

• Cooking
• foods
• iron bioavailability
• oxalic acid
• phytic acid
• tannins

Acknowledgements

This research was supported by the Dirección General de Asuntos del Personal Académico (DGAPA) project PE-200505. L. González-Osnaya thanks the postdoctoral grant from CONACyT of Mexico.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.