Universidad de Córdoba BIODISPONIBILIDAD MINERAL DE ...

Biodisponibilidad mineral de menús escolares
investigations point to no clear interaction between zinc and copper to
nutritional dose (Lönnerdal 1996).
It has been indicated that a zinc-iron interaction can affect mineral
availability of both elements. However, controversy exists to this respect, since
certain studies have demonstrated, using isotopes of zinc, that iron fortification
did not suppose any negative effect on zinc absorption (Davidsson et al,1995;
Fairweather - Tait et al,1995). Considering this possible interaction, it could be
prevented when zinc or iron is binding to certain caseinophosphopeptides, such
as 1-25 of β-casein, also improving iron absorption (Pérès et al, 1997). This 1-
25-caseinophosphopeptide, a product of β-casein hydrolysis in human intestinal
lumen after ingestion of milk or yogurt (Chabancey et al, 1998), has four or five
phosphoserine residues of native protein that can bind divalent cations such as
zinc, iron or calcium (Bouhallab et al, 1991; West, 1986). Iron absorption was
studied in rats fed with ferrous gluconate or iron bind to 1-25-βcaseinophosphopeptide
in presence of zinc sulphate or zinc also bind to 1-25-βcaseinophosphopeptide
to different ratios of Fe:Zn (Pérès et al, 1999a).
Inhibition of ferrous gluconate absorption by zinc sulphate occurred to a ratio
1:1.5. However, when iron was bound to 1-25-β-caseinophosphopeptide
inhibition was not observed until a ratio of 1:5. When the zinc was bound to 1-
25-β-caseinophosphopeptide, any inhibition on iron absorption was observed
inside ratios Fe:Zn studied neither with ferrous gluconate nor iron bound to
caseinophosphopeptide. Protection offered for binding of trace elements to this
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