H2O2-mediated pigment decay in strawberry as a model system for studying color alterations in processed plant foods

Phenolic and pigment (anthocyanin) stability in processing-ripe strawberrie s in response to aging under mildly oxidizing conditions, provoked by exoge nous application of H2O2, has been studied to design a simplified model sys tem to study color alterations (pigment decay) that occur in strawberry-der ived foods during processing and storage. The results showed that phenolic metabolism in strawberry slices during aging under mildly oxidizing conditi ons may be either oxidative (independent of exogenous H2O2) or peroxidative (dependent on exogenous H2O2), and that feeding strawberry slices with H2O 2 stimulates the oxidative phenomena which take place in their absence, suc h as the processes of anthocyanin and catechin degradation. The results als o showed that because both (+)-catechin and anthocyanin levels in strawberr y slices fall as H2O2 increases, both p-hydroxybenzoic acid and brown polym eric compounds are formed. Comparison of these results with controls in the absence of H2O2 suggests that peroxidase may play an important role in cat echin consumption and in anthocyanin degradation and brown polymer formatio n during the aging of strawberry slices under mildly oxidizing conditions.