IRON-CATALYZED OXIDATION OF (-CATECHIN IN MODEL SYSTEMS())

Autoxidation of (+)-catechin in wine-like model solutions containing 0 -20 mg L(-1) of ferrous iron was monitored by HPLC with diode array de tection. The rate of catechin oxidation and the extent of browning inc reased with the iron level. Some of the oxidation products were formed in larger amounts at higher iron concentrations. These included color less compounds and yellow pigments with absorbance maxima between 440 and 460 nm. The iron-catalyzed reactions leading to these compounds co mpeted with iron-independent reactions generating different products w hich are presumably identical Ca those formed in enzymically oxidized catechin solutions.