Effects of Polyethylene Packaging on the Occurrence of Rind-oil Spot and the Physiological and Chemical Changes in Tangor 'Kiyomi' Fruits

Abstract

Tangor 'Kiyomi' (Citrus sinensis×C. tangerina) fruits were stored at 5°C for 2 or 3 months and transferred to 8°C or 20°C. Effect of polyethylene (PE) packaging after transferring on the occurrence of rind-oil spot injury and the physiological and chemical changes were determined.
The fruits transferred to 20°C showed more severe injury than those to 8°C after transferring, and sealing in PE bag reduced the injury in both fruits held at 8°C and 20t°C. The difference in thickness (20μm or 50μm) of PE film showed little effect. In organoleptic evaluation, the appearance of sound fruit was superior to injured fruit, but the taste of both fruits did not differ.
The concentrations of carbon dioxide and ethylene in central cavities of injured fruit were higher than those of sound fruits, and that of oxygen in injured fruit was lower. The respiration rate of injured fruit was higher than sound fruit.
The free amino acid content in peel of fruit increased as the injury developed after transferring, and phenols accumulated in injured fruit peel. Contents of alcohol insoluble substances in injured fruit was higher than that of sound one.