S A Dassenko

Ferrous fumarate fortification of a chocolate drink powder

An evaluation was made into the usefulness of ferrous fumarate as an iron fortificant for an experimental chocolate drink powder targetted to children and adolescents. Organoleptically ferrous furmarate was acceptable when the chocolate drink powder was reconstituted in milk or water that was heated to less than 80 degrees. Unacceptable colour changes occurred, however, when boiling milk or water were used. In human Fe absorption studies when the Fe compounds were added to the chocolate drink immediately before consumption, ferrous fumarate was 3.31% absorbed compared with 2.82% for ferrous sulphate and 2.11% for ferric pyrophosphate. When the Fe compounds were processed during the manufacture of the chocolate drink powder, the absorption of ferrous furmarate was 5.27%, ferrous sulphate 2.62% and ferric pyrophosphate 0.55%. Ascorbic acid had little or no effect on the absorption of ferrous furmarate. It is concluded that food processing can influence the relative absorption of fortification Fe and that, if not reconstituted with boiling milk or water, ferrous fumarate could be a useful compound for the fortification of chocolate drink powders.

Serum transferrin receptor as an index of iron absorption

Summary. Recent studies indicate that serum transferrin receptor levels are a quantitative index of tissue receptor mass. To determine whether the latter plays a role in the regulation of iron absorption, we examined the relationship between serum receptor, serum ferritin and iron absorption in healthy subjects. Using radioisotopic techniques we measured absorption of inorganic iron in 174 subjects and dietary nonhaem iron in 60 subjects. With both forms of iron, the correlation with absorption was far lower for serum receptor than for serum ferritin and was no longer significant when subjects with depleted iron stores were excluded. These results indicate that in normal subjects the iron store is the main physiological determinant of iron absorption and that in the absence of iron deficiency, tissue receptor mass, reflected by serum transferrin receptor levels, has no discernible influence.

The Effect of Dietary Proteins on Iron Bioavailability in Man

Normal iron nutriture in human beings depends on an adequate supply of bioavailable dietary iron. The. quantity of food iron absorbed from any meal is determined not only by the amount, but also the form of iron present, and the composition of the meal (Monsen et al., 1978). The complex diets of adults living in Western countries generally contain relatively large amounts of animal tissue and ensure both a stable iron supply and adequate absorption. Factors affecting bioavailability may be a much more important determinant of adequate iron nutrition in the relatively monotonous vegetable diets of developing countries (Bothwell et al., 1979). Unfortunately, even in Western nations, the diets of infants and children (infant formulas, infant cereals, and weaning foods) tend to be less varied. They contain little animal tissue and do not always include foods that naturally promote iron absorption. An adequate supply of bioavailable iron is essential during this period of life because of the iron demands of growth (Stekel, 1984) and because iron stores have not yet been accumulated. Therefore, careful attention must be paid to iron content and its bioavailability in foods prepared for infants and children.

The effect of soybean phosphate and phytate content on iron bioavailability

Abstract To study the inhibitory effects of soybeans on nonheme iron absorption soybeans were grown in hydroponic culture and labelled intrinsically with radioactive iron. Culture conditions were adjusted to produce seeds with high, intermediate, and low phosphate and phytate content. No effect of phosphate/phytate content on iron absorption was observed in radioiron absorption studies in rats. Absorption tests in human volunteers comparing hydroponically cultured low phosphate/phytate beans with moderate phosphate and phytate beans also failed to demonstrate a significant inhibitory effect of the phosphate or phytate. These observations do not support the hypothesis that phytate is the factor in soybeans and soy protein products that reduces iron bioavailability.