A Comparative Study of Iron Bioavailability in Rats From Soybean and Cottonseed Protein Isolate Diets

The purpose of this research was to determine the relative iron bioavailability from soybean and cottonseed protein isolates by using an iron depletion/repletion method. Iron stores of rats were depleted so that any iron introduced in the diet would be utilized at a maximum and linear rate for hemoglobin regeneration. A comparison of iron utilization from cottonseed and soy to the reference standard could then be made. Between 40 and 47% of the iron consumed from the soy diet was converted to hemoglobin iron. The cottonseed diets had a significantly lower (29 to 34%) conversion efficiency (P < 0.05) in comparison to casein but were not significantly different from the soy diets.