LOW TEMPERATURE BREAKDOWN IN KIWIFRUIT

The effect of postharvest temperature management on the quality of kiwifruit was studied with specific reference to the occurrence of internal breakdown symptoms.
Compared to passive cooling, precooling significantly increased the occurrence of breakdown symptoms, whereas the incidence and severity of symptoms was significantly decreased by delays at ambient conditions prior to coolstorage.
Fruit temperatures at the end of precooling, and the time taken to reach 0°C after precooling also had a significant effect on the occurrence and severity of breakdown symptoms.
The higher the fruit temperature after precooling and the longer the time taken to reach 0°C after precooling the lower the incidence of breakdown symptoms.
Over a temperature range -0.5°C to 2.5°C, breakdown symptoms were significantly lower in fruit stored at temperatures above 1 °C than in fruit stored at or below 0°C. Overall, the response of kiwifruit to temperature treatments are consistent with a chilling response than to senescent breakdown.

It is concluded that fruit of Actinidia deliciosa cv Hayward, are chilling sensitive, and that small differences in storage temperatures, and the time to reach the storage temperature after precooling have a significant effect on the quality of kiwifruit.
It is suggested that the term low temperature breakdown (LTB) be used to describe the symptoms of chilling injury, which includes the development of a ring or zone of granular, water soaked tissue in the outer pericarp at the stylar end of the fruit.
Chilling injury may also involve the development of diffuse pitting in association with the development of a dark scald-like appearance in the skin.

III International Symposium on Kiwifruit

N. Lallu

https://doi.org/10.17660/ActaHortic.1997.444.89