Ripening, Chilling Injury, and Respiratory Response of ‘Hass’ and ‘Fuerte’ Avocado Fruits at 20°C following Chilling1

Abstract

The ripening, chilling injury and respiratory responses of ‘Hass’ and ‘Fuerte’ avocado fruit ( Persea americana L.) were determined at 20°C subsequent to 0 to 5 weeks storage at 10°, 5° and 0°. Fruit held at 10° showed no chilling injury symptoms and were ripe by the third week. No softening or chilling injury symptoms occurred during the 5 weeks at 5° or 0°. However, after transfer to 20° fruit held at 5° and 0° longer than 1 week developed chilling injury and the severity increased as the exposure period increased. Short exposures to 5° and 0° tended to hasten ripening at 20° compared with fruit placed directly at 20°, but fruit held 5 weeks at 5° and 0° took longer to ripen at 20° than control fruit. Fruit placed directly at 20° showed a typical climacteric respiratory pattern which was associated with ripening. Chilling at 5° and 0° for more than 1 week resulted in high initial respiratory rates at 20°, followed by decreasing respiratory rates with no climacteric pattern associated with ripening.