INTERACTIONS OF FE(II), CA(II) AND FE(III) WITH HIGH DIETARY FIBER MATERIALS - A PHYSICOCHEMICAL APPROACH

Interactions of Fe(II), Ca(II), and Fe(III) with five natural food mat erials, which should be used as fibre sources in the diet, such as pom aces from the production of white wine, cider and olive oil, and lemon peel and pulp, were investigated in vitro. The extent of mineral bind ing by these concentrates of fibre depended both on the nature and che mical composition of the sample used and on the type of mineral elemen t studied; however, the majority of these samples exhibited a higher c apacity to bind Fe(II) than Ca(II) and Fe(III). Two graphic methods ha ve been used to provide basic information on the mineral binding mecha nisms for the interactions of these cations with the high-fibre sample s: the Scatchard plot, for examining binding by complex formation, and the equation of Langmuir, to predict cation retention by physical ads orption.