Some factors affecting the in vitro binding of zinc by isolated soya-bean protein and by α-casein

& Vohra (1959) showed that the dietary Zn requirement of turkey poults was slightly reduced when autoclaved isolated soya-bean protein was used in place of untreated protein, but that a much greater reduction in the Zn requirement occurred when the disodium salt of ethylenediamine tetraacetic acid (EDTA) was added to the diet. Subsequently, O'Dell & Savage (1960) suggested that the presence of phytic acid in isolated soya-bean protein may be a factor contributing to the low availability of Zn from diets containing this protein, for it is known that phytate accounts for about