Iron bioavailability of the açaí (Euterpe oleracea Mart.) and the iron-fortified manioc flour in rats

Abstract

Objective: This study evaluates the bioavailability of iron derived from açaí (Euterpe oleracea Mart.) and from iron-fortified manioc flour, using the hemoglobin iron-depletion-recovery method in rats. Methods: A casein-based diet (American Institute of Nutrition - 93G), without added iron in the saline mixture, was fed to female Wistar rats during the 21-day lactation period; it was also fed to the pups, for 7 days after weaning (depletion period). Simultaneously, a control group of female rats and pups received a commercial feed. In the 14 days repletion period, male rats (n=40) were randomly distributed in five groups and fed one of the diets: control (açaí control and American Institute of Nutrition - 93) or experimental (açaí and iron-fortified manioc flour). The hemoglobin concentration was determined weekly. The iron bioavailability was obtained through the heme-iron/iron intake ratios, calculated for each group. Results: The mean hemoglobin concentration of 4.7 ± 0.5g/dL at the end of the depletion period demonstrated the effectiveness of the iron-depletion method used in the study. It was observed that the greatest iron bioavailability was drawn from the fortified manioc flour (44.6 ± 3.6%), in contrast with the low iron bioavailability derived from açaí (12.1 ± 5.5%). Conclusion: The iron present in the açaí was not effective in recovering the hemoglobin concentration in the rats. Hence, any recommendation for the use of açaí as a source of iron should be treated with caution.