title: Bioavailability of zinc from a diet based on isolated soy protein: application in young men of the stable isotope tracer, 70Zn.
abstract: With the aid of the stable isotope, 70Zn, as a tracer and neutron activation analysis, a combination of extrinsic labeling of meals and fecal monitoring of isotope excretion was used as a safe and noninvasive approach for assessing the effects of the vegetable (soy) and animal (milk, beef) proteins on the absorption of zinc in healthy, adult human volunteers. A known amount of 70Zn was added as ZnCl2, to six consecutive meals over a 2-day period during which either one of three isonitrogenous liquid formulas (skim milk; soy isolate; or a 50:50 mixture) or one of two bologna sausages (soy isolate of beef) were given. The mean absorption of 70Zn from milk, soy and soy/milk was 41 +/- 4, 34 +/- 4, and 41 +/- 7% (mean +/- SEM), respectively, the presence of soy protein having no effect on absorption of the extrinsic label. For beef bologna and soy bologna, fractional absorption of the 70Zn tracer was 41 +/- 4 and 30 +/- 3%, respectively. Beef might favor absorption of extrinsic zinc. The kinetics of isotope excretion, pooling procedures, for stool samples and the utility of fecal markers were also evaluated.
mesh_terms: D000328:Adult; D000818:Animals; D002417:Cattle; D004032:Diet; D004044:Dietary Proteins / Q000494:pharmacology*; D005243:Feces / Q000032:analysis; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects; D007501:Iron / Q000008:administration & dosage; D008297:Male; D008460:Meat; D008894:Milk Proteins / Q000494:pharmacology; D009753:Nutritive Value; D014674:Plant Proteins, Dietary / Q000494:pharmacology; D013025:Glycine max; D015032:Zinc / Q000008:administration & dosage / Q000378:metabolism*; D015033:Zinc Isotopes
chemical_list: D004044:Dietary Proteins; D008894:Milk Proteins; D014674:Plant Proteins, Dietary; D015033:Zinc Isotopes; D007501:Iron; D015032:Zinc