Bioavailability and Stability of Microencapsulated Ferrous Sulfate in Fluid Milk: Studies in Mice

Iron deficiency is the most important nutritional problem all over the world. Fluid milk is an attractive vehicle for iron fortification, since it is a food with a high nutritional value, accessible to the whole population and easy to be given to children. Fortification of this food with iron has the disadvantage of the interaction of the iron with the constitutive elements of milk, diminishing its bioavailability and changing its sensorial properties, making it unacceptable. Nowadays, this problem can be overcome by the implementation of a new technological procedure, which consists in the microencapsulation of the ferrous sulfate with lecithin, thus avoiding the interaction of iron with the food. The absorption obtained in mice for milk-ferrous sulfate was 7.9 +/- 3.2%, while for microencapsulated ferrous sulfate-milk the result was 11.6 +/- 4.5%. Comparing these data with those obtained with the ferrous ascorbate in water 13.1 +/- 4.9% and ferrous sulfate in water 13.2 +/- 4.3%, both of them considered as reference standards, no statistically significant difference between them and the microencapsulated ferrous sulfate in milk can be observed. However, this difference becomes significant (p < 0.01) when these products are compared to the non-encapsulated ferrous sulfate in milk. On the other hand, we demonstrated that this product is stable to heat-processing (100 degrees C, 30 min) and storage at a room temperature up to 6 months that lacteous products are usually submitted to.