Relationship between Chilling Injury of Grapefruit and Moisture Loss during Storage: Amelioration by Polyethylene Shrink Film

Abstract

Polyethylene shrink film reduced pitting type chilling injury in ‘Marsh’ grapefruit ( Citrus paradisi Macf.) stored at low temperatures. The film did not restrict heat exchange between the fruit and air in the storage room. Chilling injury occurred most rapidly in fruit stored at 5° and 7.5°C, but after 5 weeks the severity of injury was greatest in fruit stored at 2.5°. The pattern of response to temperature was the same for unsealed fruit and sealed fruit. Prestorage conditioning of the fruit for 8 days at 21° prior to storage at 5° reduced chilling injury. Restricting moisture loss with shrink film during the prestorage conditioning treatment did not negate the beneficial effects of conditioning. Restricting moisture loss following chilling had no effect on chilling injury. Thus, although moisture loss is a contributing factor, it does not appear to be the primary factor in chilling injury of grapefruit. In order to minimize chilling injury, moisture loss should be prevented during fruit exposure to chilling temperatures.