Effects of Different Storage Temperatures and Humidity on Storage Performance of Kiwifruit ‘Donghong’

Appropriate low temperature and high humidity storage conditions were crucial for successful long-term cold storage of kiwifruit (Actinidia spp.), as they had significant effects on fruit softening, weight loss and storage disorders. In order to clarify the impacts of different storage temperatures and humidity levels on the storage performance of kiwifruit ‘Donghong’, the experiments with four storage temperatures (0.5, 1.0, 2.0, and 3.0 ℃) and three relative humidity (RH) levels (100%, 97%, and 78% RH) were carried out in this study, and the changes of fruit firmness, soluble solids content and weight loss among different treatments during cold storage were analyzed, as well as the storage disorder incidence after the end of storage. The results showed that different storage temperatures had significantly effects on fruit softening and storage disorders incidence (P<0.05). Fruit softening rate decreased with lower storage temperatures, and even a 0.5 ℃ or 1.0 ℃ difference could result in a significant gap in firmness (up to 46 N). The time taken for the fruit firmness to decline to the edible level of 10 N varied by up to 8 weeks among the four treatments. The 0.5 ℃-stored fruit had a higher incidence of chilling injury and other storage disorders, while the 3.0 ℃-stored fruit exhibited the highest decay rate (though only 5.99%). Intermediate temperatures (1.0~2.0 ℃) showed moderate disorder incidence. Meanwhile, different humidity treatments also revealed significant impacts on fruit weight loss, softening rate, and storage disorders. The low humidity (78%) treatment caused the fruit to lose water more easily, soften faster, and have a higher incidence of storage disorders, particularly fruit shriveling and decay. Therefore, it is suggested to avoid storage temperatures below 0.5 ℃ and RH levels below approximately 80% for the long-term cold storage of kiwifruit ‘Donghong’.