Role of Heat Treatment , Calcium Chloride and Potassium Permanganate on Storage Life and Fruit Firmness of Golden Delicious Apple (Malus domestica Borkh)

‘Golden Delicious’ apples were vacuum infiltrated (250 mm Hg) with 0, 4, and 6% solutions of CaCl2 followed by heat treatment for 0, 48 and 72 hours at 38oC. Treated fruits were stored at 0oC with RH of 85-90% for 2.5 and 5 months, followed by one week of storage at 20C. The results showed that fruits treated with 4 and 6% of CaCl2 significantly increased calcium content of fruits after 2.5 and 5 months of storage at 0oC. With increasing calcium content, fruit firmness also increased. There was a positive relationship between fruit firmness and calcium content and regression coefficients after 2.5 and 5 months of storage at 0oC were 0.77 and 0.83, respectively. Heat treatment for 48 and 72 hours at 38oC significantly increased fruit firmness. Calcium chloride at 4 and 6%, plus heat treatment, significantly increased fruit firmness of those fruits held for one week at 20oC after removal from cold storage. In the second experiment, vacuum infiltrated fruits with 4 and 6% solutions of CaCl2 plus potassium permanganate (0, 10, and 20 g/bag) had no significant effect on fruit firmness, but potassium permanganate alone significantly increased fruit firmness.