Antioxidant activity in astringent and non-astringent persimmons

SummaryCatechins, ascorbic acid and -cryptoxanthin concentrations during fruit development and the antioxidant activity in skin and flesh were investigated in astringent ‘Saijyo’ and non-astringent ‘Fuyu’ persimmons (Diospyros kaki Thunb.). The IC50 values (a midpoint of 50% between zero and full inhibition of diazo dye formation) of superoxide (O2–)-scavenging activity remained low in the skin throughout fruit development.The IC50 values of the activity increased with d after full bloom (DAFB) in the flesh of the non-astringent type, whereas values remained low until harvest in the astringent type. However, IC50 values increased sharply after the removal of astringency with ethanol spray. Catechin concentrations in the flesh also decreased after the removal of astringency, whereas the concentrations in the skin did not decrease. Ascorbic acid concentrations in the skin and flesh were high at the beginning and middle of fruit development, but -cryptoxanthin in the skin and flesh increased toward harvest. ...