INHIBITORY EFFECT OF PHENOLICS ON CAROTENE BLEACHING IN VEGETABLES

Lipoxygenase is known to be involved in the indirect oxidation of carotene, and some phenolic compounds are known to prevent lipoxygenase activity. Inhibitory potencies of major phenolics in vegetables on carotene oxidation were studied by using both a model system and various vegetables. Catechin and epicatechin were the highest and p-coumaric and ferulic acids were the lowest in inhibitory efficacy. In general, in a model system flavans showed the highest inhibitory effect followed by flavonols and acidic phenolic compounds. The concentration of phenolics in vegetables appeared to have a high correlation with the inhibitory effect on carotene bleaching, in general, but spinach, which contains the highest concentration of phenolics among vegetables studied, did not show the same level of inhibitory potencies. This may be due to the fact that spinach phenolics consist mainly of methylated flavones and p-coumaric derivatives, compounds that have low inhibitory effects. © 1990, American Chemical Society. All rights reserved.