Effect of Hydrogen Peroxide and Phenolic Compounds on Horseradish Peroxidase‐Catalyzed Decolorization of Betalain Pigments

Abstract

ABSTRACT The effect of hydrogen peroxide and phenolic compounds on the decolorization of betanin and a betaxanthin preparation by horse‐radish peroxidase (HRP) was examined. Betanin was decolorized at a greater rate than the betaxanthm pigments and both reactions were H 2 O 2 ‐dependent. Betaxanthin was more prone to oxidatic decolorization than betanin. 2,4‐Dichlorophenol, resorcinol and o‐toluidine stimulated the decolorization of both pigments. Guaiacol enhanced the peroxidatic decolorization of both pigments to a small extent, but inhibited the oxidatic breakdown of betaxanthin. Possible implications of these results are discussed.