Abstract
Chilling injury (CI) is a critical physiological disorder which limits the storability of cactus pear fruit Opuntia ficus-indica (L.) Mill. The effects of pre-storage salicylic acid (SA) treatment at different concentrations (1.0, 1.5 and 2.0 mM) and storage temperatures (2, 5 and 8 degrees C) on CI and cactus fruit quality were examined. The results showed that salicylic acid application, especially at higher concentration (2.0 mM), significantly decreased the CI compared to control. The CI occurred mainly at 2 degrees C, slightly at 5 degrees C specifically in the control and was eliminated at 8 degrees C. The CI significantly increased as the storage period prolonged. Weight loss percentage was lower at 1.5 and 2.0 mM SA treatments than in the other treatments and was greater at higher temperature and longer storage period. Decay percentage was lower at 1.5 mM SA treatment than in the other treatments, except for the 2.0 mM SA treatment. Decay was not affected by storage temperature but was higher at longer storage period. Fruit firmness was not affected by either SA or storage temperature and period. Total soluble solids (TSS) concentration was not affected by SA treatment but was lower in fruit stored at 8 degrees C than those stored at 2 and 5 degrees C. TSS showed no significant changes during 30 days of storage and was close to the initial value but decreased after 40 days. Acidity was not affected either by SA treatment or storage temperature but significantly decreased after 40 days and was lower than the initial value. The pH of fruit juice was not affected by SA treatment but was higher in fruit stored at 5 degrees C than in those stored at 2 and 8 degrees C. The pH was higher after 40 days of storage than the other storage periods and slightly higher than the initial value. Vitamin C concentration was not affected by the SA treatment but was lower in fruit stored at 2 degrees C than in those stored at 5 and 8 degrees C. Vitamin C slightly changed during storage compared to the initial value. It was concluded that pre-storage SA treatment inhibited chilling injury and improved storability of cactus fruit.