PARTICIPATION OF REACTIVE OXYGENS IN THE FORMATION OF A PURPLE PIGMENT, HORDEUMIN, FROM BARLEY BRAN-FERMENTED BROTH

A high-molecular weight condensed tannin-like purple pigment, hordeumi n, was formed from the fermented broth of barley bran. The formation o f hordeumin was promoted in light and an oxidation state from the ferm ented filtrate containing hordeumin precursors. When hydrogen peroxide that promoted the formation of a hydroxyl radical was added to the fe rmented filtrate, the formation of hordeumin was accelerated with an i ncrease in deoxyribose oxidation. The formation of hordeumin was suppr essed by the Fe-ion chelating agent DETAPAC and several hydroxyl radic al scavengers. Based on these results, it is assumed that the formatio n of hordeumin is an oxygen-mediated reaction and that reactive oxygen s participate in one of these reactions.