The Effects of H2O2 and Tea Polyphenol Treatments on Reactive Oxygen Metabolism and Ageing in Postharvest Strawberry Fruit

Purpose The study was to discuss the effect of reactive oxygen on senescence of strawberry fruit.Method The effects of soaking fruit with hydrogen peroxide (H2O2) and tea polyphenol(TP) on reactive oxygen metabolism and ageing were studied in postharvest ‘Hongyan’ strawberry fruit.Results In ageing process, rot index and rotting rate of H2O2 treatment, TP treatment and CK all continued to increase, rot index and rotting rate of H2O2 treatment were all higher than those of CK all the time,while rot index and rotting rate of TP treatment were all lower than those of CK all the time. In ageing process, lipoxygenase (LOX) activity, H2O2 content, superoxide anion radical(O2·-)production rates, malondialdehyde (MDA) content of H2O2 treatment, TP treatment and CK all increased. Furthermore, in whole ageing process, O2·- production rates, MDA content of H2O2 treatment were all higher than those of CK, while activities of CAT and APX were all lower than those of CK. O2·- production rates, MDA content of TP treatment were all lower than those of CK, while activities of CAT and APX were all higher than those of CK.Conclusions Promoting reactive oxygen lead to the decline of protective enzyme activities and intensified the accumulation of reactive oxygen,consequently accelerated fruit aging. However,eliminating reactive oxygen enhanced protective enzyme activities and relieved the accumulation of reactive oxygen, and postponed fruit aging.