BIOAVAILABILITY OF ZINC IN GROUND-BEEF

Based on zinc uptake in chick tibia, Zn bioavailability in cooked ground beef was equal to that of Zn in an inorganic standard (ZnSO4), whether Zn supplements were added to a soy-concentrate diet containing phytate or to a phytate-free egg-white diet. With both diet types, total tibia Zn was a linear (P < .01) function of supplemental Zn intake from ZnSO4, but the slope of the linear regression line was twice as great for the egg-white diet as for the soy-concentrate diet that contained phytate. At 10 mg/kg of supplemental Zn, freeze-dried ground beef produced the same tibia Zn concentration (and total Zn content) as that obtained with ZnSO4. The results suggest that the relative bioavailability of Zn in cooked ground beef is as great as that in ZnSO4, whether consumed in diets with or in those without phytate.