Iron bioavailability in tambaqui (<i>Colossoma macropomum</i>) desiccated gill and liver powder: Study in rats

Abstract

This study assessed iron bioavailability in rats from diets enriched with desiccated tambaqui gill and liver powders using the hemoglobin depletion-repletion method. Tambaqui (Colossoma macropomum) liver and gills were bought at Manaus. After processing the livers and gills were placed on trays and desiccated in a ventilated incubator at 60°C. The rats were given free access to chow and water. The moisture, protein, fat, and iron contents of the chow were determined three times. Iron bioavailability was measured by the hemoglobin depletion-repletion method. We used 24 anemic animals, which were randomly selected and distributed into three groups of eight animals each: 1) Control Group – anemic rats fed a casein-based diet (AIN 93); 2) Experimental Group – anemic rats fed AIN 93 and desiccated tambaqui liver; 2A) Experimental Group – anemic rats fed AIN 93 and desiccated tambaqui gill; and 3) Pair-feeding Group – anemic rats, distributed in random blocks according to hemoglobin concentration and weight, fed the average amount of AIN 93 consumed by the Control group. Gills are high in lipids. In addition to high lipid content, gill powder had considerable levels of protein and iron. The baseline hemoglobin of Groups 2 (liver) and 2A (gills) did not differ. After seven days, only Group 2 (liver) reached appropriate hemoglobin levels. In conclusion, iron in desiccated tambaqui liver powder is highly bioavailable. The iron in desiccated tambaqui gill powder is not as bioavailable as rats consuming this powder did not reach appropriate hemoglobin levels within the experimental period.

 Key words: Bioavailability, iron, powder, liver, gills, tambaqui.