温州ミカンの選果荷造過程における損傷要因と損傷防止に関する研究 (第1報)

Abstract

The incidence of mechanical injury produced during the processes of sorting, washing, and packing, and effects of pertaining factors on fruit quality were determined experimentally with satsuma mandarin fruit.1. Under the quasi-static load of 10kg, various types of surface abrasion and internal bruises were caused in the treated fruit. Collapse of the oil gland and partial rupture of peels were observed as the first signs of mechanical injury. Inside the fruit, separation and rupture of locular membranes and breakdown of juice sacs were produced, which necessarily caused exudation of juice from sacs into intervesicular spaces of fruit.2. When quasi-static loads of more than 10kg were applied to the M-sized fruit, the peel was readily ruptured. The rupture of locular membranes and breakdown of juice sacs were produced by the application of loads of more than 8kg and 4kg, respectively. When accompanied with rotating treatment of fruit, juice sacs were broken with loads as low as 2kg.3. The severity of breakdown of juice sacs was evaluated conveniently by determining the amount of exudate produced by infliction of pressures. The amount of exudate contained in the intervesicular spaces could be determined by measuring the weight increment of blotting paper sheet which had absorbed the exuded juice when peeled pulp segments were pressed lightly on the blotting paper.4. In order to determine the effects of factors pertaining to mechanical injury, behavior of traveling fruit in the packing line, intensity of loads inflicted on the fruit, and bruises produced in the line were examined. Most types of mechanical injuries were produced mainly in the processes of mixing, washing, waxing, sizing, and packing of fruit and sealing and stacking of boxes. Dropping impact, compression, and surface abrasion were the main factors of fruit deterioration.5. The rupture of peels due to artificial dropping was diminished by preparatory drying of fruit. In the line processes of the actual packing house, however, preparatory drying did not show any preventive effects against mechanical injury.