Dialysability of trace elements in infant foods containing liver

Abstract

Response surface methodology, based on a Box–Behnken experimental design, was used to study the effect of liver and other ingredients (carrot, rice, pea and potato), on the dialysability of copper, zinc and iron in both chicken with rice (CR) and veal with carrot (VC) beikosts. Although modern nutrition programme recommend an increased intake of dietary fibre, this may be particularly problematic in infants. Fibre-increasing ingredients, especially carrot, also simultaneously increased tannin and phytic acid content and reduced the dialysability of Cu and Zn; carrot content must therefore be minimized in infant food formulas. Rice showed a strong negative effect on Cu dialysability whereas, in the formulations used, neither pea nor potato prompted any significant inhibition of trace-element dialysability. Inclusion of liver in infant food formulas significantly reduced Fe dialysability in the CR beikost (negative quadratic effect) and Cu dialysability in the VC beikost (negative linear effect); both of these findings have been linked to the presence of phytic and gallic acid in liver. The reduction in Cu dialysability was attributed to the tannin content of some of the raw materials used in the VC beikost, while reduced Fe dialysability in the CR beikost was ascribed to the presence of phytic acid or its metabolites.