Effect of pre-storage salicylic acid, calcium chloride and 2,4-dichlorophenoxyacetic acid dipping on chilling injury and quality of ‘Taify’ cactus pear fruit during cold storage

Abstract

The effects of pre-storage salicylic acid (SA) calcium chloride (CaCl₂) and 2,4-dichlorophenoxyacetic acid (2,4-D) treatments on chilling injury (CI) and quality of cactus pear fruit during storage were investigated. The results showed that SA application at 2.0, 3.0 or 4.0 mM significantly decreased CI index compared to all the other treatments. Increasing SA rate to 3.0 or 4.0 mM did not result in a further reduction in CI index. However, CaCl₂ (at 2, 3, and 4%) and 2,4-D (at 100, 150 and 200 ppm) had no effect on CI index. CI increased during storage and was higher at 30 than at 10 and 20 days of storage. Weight loss was not affected by any of the treatments but was higher at 10 than at 20 and 30 days of storage. Decay was not affected by any of the treatments but was higher at 30 than at 10 and 20 days of storage. Firmness was higher at 200 ppm 2,4-D than all the other treatments. Fruit acidity was not affected by any of the applied treatments but was lower at 20 and 30 days than at 10 days of storage. The pH of fruit juice increased during 30 days of storage and was lower in the SA treatments than the control. Total soluble solids (TSS) concentration was higher in the control than all the other treatments, except for the SA at 4.0 mM treatment. TSS concentration was higher at 10 than at 20 and 30 days of storage. Vitamin C concentration was lower at 20 than at 10 and 30 days of storage and was lower in the CaCl₂ treatments than the control. Total phenols concentration increased during 30 days of storage and was lower in the CaCl₂ and 2,4-D treatments than the control. It was concluded that pre-storage SA dipping at 2.0 mM reduced chilling injury and retained quality of cactus fruit.

Key words: Cactus pear, salicylic acid, CaCl₂, 2,4-D, chilling injury, storage.