脱渋方法の違いがカキ‘平核無’果実の収穫•脱渋後の品質及び貯蔵性に及ぼす影響

Abstract

Fruit quality and storage life of Japanese persimmon (cv. ‘Hiratanenashi’) were studied following three types of treatment for removal of astringency (postharvest alcohol treatment, postharvest CO2 treatment and on-tree alcohol treatment) and followed by storage of the fruit at cold (2°C) or at room temperature (20°C).Development of peel color of fruit treated with alcohol on the tree was reduced by cold storage, whereas in fruit treated with alcohol after harvest, peel color developed progressively regardless of storage temperature. In fruit treated with CO2, color development was intermediate.The firmness of flesh of fruit treated with alcohol on the tree slowly declined under cold storage. Fruit treated with alcohol after harvest softened more quickly than fruit treated with CO2, but there was no effect of storage temperature on the rate of softening in the two treatments. When stored at 2°C, watery breakdown of fruit occurred in all treatments in about 2 weeks.A conciderable amount of alcohol remained in the flesh of fruit treated with alcohol after harvest at either storage temperature.Total sugar content in all fruit changed only slightly during storage, but the level of sucrose declined gradually. Loss of sucrose occurred more quickly at 20°C than at 2°C.Ascorbic acid content in all treatments changed slightly during storage at both temperatures.Judged by appearance and flesh firmness, storage life at 20°C was best in fruit treated with alcohol on the tree, followed by fruit treated with CO2, and then by fruit treated with alcohol after harvest.