DETERMINATION OF IRON-BINDING PHENOLIC GROUPS IN FOODS

A spectrophotometric assay was developed with the specific aim of determining the content in foods of iron-binding phenolic compounds. Foods were extracted with dimethylformamide (50%) and an iron-containing reagent was added. The resulting color was due to formation of Fe-galloyl and Fe-catechol complexes. These complexes had different absorbance maxima and could thus be separately determined by readings at two wavelengths. The method was simple and had good precision, accuracy and analytical recovery. The new method was compared with two commonly used methods for determination of phenolic content in cereals, fruits, vegetables, spices and beverages.