APPLICATION OF ENZYMES FOR METAL SPECIATION ANALYSIS OF IRON AND MANGANESE IN FOODSTUFFS

In order to investigate on the chemical bonds of iron and manganese in foodstuffs, the protein, pectin, and lipid splitting enzymes pepsin, pectinase, papain, bromelain, and lipase have been used in stepwise extraction procedures. Milk powder, wheat germ, oat flakes, lentils, rice and rye flour, with Fe contents between 1-8 mg/100 g and Mn contents between 0.1-12 mg/100 g, were examined. The use of enzymes in the extraction procedures indicated distinct differences in the solubility of the two minerals. as for instance of Fe and Mn by pectinase from oat flakes and of Fe by papain/lipase from wheat germ. The different enzymatic effects with regard to the composition of foodstuffs and the extractability of the metals are discussed as a precursor to a biochemical, i.e. enzymological, method for metal-speciation analysis of foodstuffs.