Influence of ethanol patch attachment position and storage orientation on astringency removal and storability in ‘Hiratanenashi’ persimmon (Diospyros kaki Thunb.) fruits

We investigated the influence of ethanol patch attachment position and placement orientation of fruit during and after treatment for astringency removal, flesh softening, and storability in ‘Hiratanenashi’ persimmons. A silica-ethanol patch was attached to either the surface of the fruit apex, the equator of the fruit, or the calyx lobes; the fruits were kept, variously, with the patch-attached side at the top, side, or bottom. After 3 days, the patch was removed, and the fruits were kept in the same orientation during storage. The astringency removal efficiency varied with the patch attachment position. In fruits with a patch on the fruit apex or the calyx lobes, astringency was removed thoroughly by 10 days, whereas astringency remained in fruits with a patch on the equator. Fruits with a patch on the apex or equator of the fruit retained initial flesh firmness during de-astringecy treatment, while those with a patch on the calyx lobes softened gradually. Different placement orientations of fruits, however, had little effect on the efficiency of astringency removal. The rates of softened fruit during storage increased earlier when a patch was attached to the calyx lobes than when attached to the fruit apex or the equator of the fruit. When patches were attached to the fruit apex or equator, slight stains developed at the patch-attachment location of the peel, which reduced the esthetic appeal.