EFFECT OF POSTHARVEST TREATMENTS ON QUALITY AND STORABILITY OF FRESH CUT CANTALOUPE

Abstract

Two storage experiments were conducted during two successive seasons (2013 and 2014) in the laboratory of Vegetable Handling Research Department, Horticultural Research Institute, ARC at Giza, on the fruits of cantaloupe (Cucumis melo L. cv. Galia). Fruits were obtained from private farm in Ismailia governorate. The fruits of the carried investigation obtained from plants grown under plastic tunnel conditions during winter seasons. The fruits were harvested at yellow green color stage. Fruits were selected with uniformity of size, color, weight (700-750g) and free from any visible damage or defects. The selected fruits were divided into two principal groups to conduct the two storage experiments.

5.1. First experiment: Effect of chitosan and potassium permanganate on quality and storability of cantaloupe fruits This experiment was carried out on whole cantaloupe fruits to study the effect of dipped in chitosan at 1000 or 2000 ppm for 3 minutes or packed with potassium permanganate sachets contained 2.5 or 5 g per box on quality attributes of fruits during storage for 28 days at 5°C and 90-95% relative humidity in addition to 2 days at 10°C (shelf life).

The results could be summarized as follows: 1- Cantaloupe fruits dipped in chitosan at 2000 ppm or packed with 5 g potassium permanganate led to decrease weight loss percentage of fruits during all storage periods and shelf life as compared to other treatments or untreated control. 2- No decayed fruits were observed in cantaloupe fruits dipped in chitosan at 2000 ppm or packed with 5g potassium permanganate till 28 days of the storage at 5°C or 21 days at 5°C plus 2 days at 10°C. 3- Cantaloupe fruits dipped in chitosan at 2000 ppm or packed with 5g potassium permanganate did not exhibit any changes in their appearance till the 14 days at 5°C plus 2 days at 10°C and gave good appearance after 21 days at 5°C plus 2 days at 10°C, mean while fruits dipped in chitosan at 1000 ppm or packed with 2.5g potassium permanganate showed good appearance after 14 days at 5°C plus 2 days at 10°C and dropped to poor level at the end of shelf life period. 4- Cantaloupe fruits dipped in chitosan at 2000 ppm were the most obvious in maintaining fruit firmness at end of the storage period or shelf life. 5- The highest L values were obtained from fruits dipped in chitosan at 2000 ppm followed by fruits packed with 5g potassium permanganate, resulted in lighter color. However, the lowest L values were obtained from control. 6- The surface color of fruits dipped in chitosan at 2000 ppm followed by chitosan at 1000 ppm or packed with 5g potassium permanganate never exceeded light yellow color (the highest b value) at the end of shelf life condition (28 days at 5°C plus 2 days at 10°C). 7- Cantaloupe fruits dipped in chitosan at 2000 ppm did not appear changes in their taste till 21 days of the storage at 5 °C and gave typical flavor cantaloupe fruits at end of the storage period (28 days). However, during shelf life cantaloupe fruits dipped in chitosan at 1000 ppm or packed with 5g potassium permanganate independently gave a slight change in flavor after 21 days of the storage at 5°C plus 2 days at 10°C, while untreated control resulted in non score after the end of shelf life. 8- Cantaloupe fruits dipped in chitosan at 2000ppm or packed with 5g potassium permanganate gave the higher TSS percentage with no significant differences between them, after 28 days at 5°C plus 2 days at 10°C of storage, while untreated control gave the lowest ones at the same period. 9- Cantaloupe fruits treated with various applied treatments had the highest values of total sugars content with no significant differences between them in the second season during storage and in the two seasons during shelf life, while untreated control gave the lowest ones at the same period. 10- All used postharvest treatments retained more ascorbic acid content compared to untreated control without significant differences between them during all storage period at 5°C or shelf life condition.

5.2. Second experiment: Effect of chitosan, carboxy methyl cellulose, calcium chloride and wrapping materials on quality and storability of fresh cut cantaloupe.