Bread and other foods of plant origin as a source of iron

Contaminant Iron in Water and Soil Samples and in Vitro Availability Studies

The iron content from 24 well water samples in tropical southern Nigeria ranged from 0.05 to 3.1 μg per millitre. Iron extracted from soil samples in deionized water, 0.1 M NaOH, 0.1 N HCI, and 0.1 N HCl-ascorbic acid averaged 79. 7, 146.3, 809.8, and 1,268.1 μg of iron per 100 g of soil sample respecfively. Extraction of iron from the soil samples was significantly affected (p < .05) by the addition of ascorbic acid. The dialysable iron in some meals containing contaminant iron from the samples compared favourably with a standard meal with ferric chloride. Dialysable iron was influenced significantly (p<.05) by the components in the meals. Meat and ascorbic acid enhanced the dialysability of contaminant iron sources in both the semi-synthetic meals and some tropical food items. The contribution of these contaminant iron sources to the diet of Nigerians in relation to the high frequency of iron-deficiency anaemia is discussed.

Iron sources used in food fortification and their changes due to food processing

The effect of food processing on the biological availability of iron in iron-fortified foods is critically reviewed. Studies on changes in the chemistry of the iron in processed foods are examined. Various iron sources currently used in food fortification in the U.S. are defined with emphasis on their biological availabilities under various conditions. The availability of iron in foods depends upon numerous factors, most of which are not fully understood. A factor which is often overlooked is the interaction of the iron with the food during events such as cooking or processing. Chemical changes in the iron compounds occur which may correlate with changes in the biological availability.