Effect of atmospheric oxidation on bioavailability of meat iron and liver weights in rats.

Iron bioavailability of diets containing oxidized turkey and oxidized beef meat was investigated in two experiments. Lyophilized, uncooked turkey meat and beef meat were allowed to oxidize at room temperature. In experiment 1, rats were made anemic and fed diets containing uncooked lyophilized turkey meat which had been exposed to air for 0, 48, 96, 144, 216 or 264 hours. In experiment 2, anemic rats were fed diets composed of basal, basal + iron, basal + iron + formaldehyde, 100% fresh beef, 75% fresh-25% oxidized beef, 50% fresh-50% oxidized beef, 25% fresh-75% oxidized beef, 100% oxidized beef and 100% fresh beef + formaldehyde. The diets were prepared so that meat was the only source of iron. Hemoglobin regeneration served as the basis for measuring iron utilization. The length of oxidation time of the turkey meat did not significantly affect the growth of the rats or the bioavailability of the meat iron. Rats fed severely oxidized beef diets had decreased body weight, enlarged livers and depressed hematinic responses. Formaldehyde did not significantly affect iron utilization in rats fed basal diets, but depressed liver iron storage in rats fed fresh beef.