Effect of timing of on-tree ethanol treatment and duration of cold storage on astringency recurrence in 'Hiratanenashi' persimmon fruit

Abstract

We investigated the effect of the timing of on-tree ethanol treatment and the duration of cold storage on astringency recurrence in 'Hiratanenashi' persimmon fruit when the flesh was heated in acid solution. We also compared astringency recurrence in on-tree treated fruit with fruit treated after harvesting with carbon dioxide and ethanol vapor and also with dried and half-dried fruit. In harvested fruit, astringency recurred more readily in fruit that had undergone later on-tree ethanol treatment. Astringency recurred less in fruit stored for longer periods at low temperatures. This tendency was more obvious in fruit treated at the early stage than at the late stage of maturation. Astringency recurred more readily in fruit that had undergone postharvest ethanol treatment than in fruit subjected to on-tree ethanol treatment. The frequency of astringency recurrence in on-tree-treated fruit was almost the same as that of fruit treated post-harvest with carbon dioxide. Dried and half-dried fruit showed the least astringency recurrence among the fruits tested in this study.