تأثیر کاربرد منابع مختلف کلسیمی بر فعالیت آنتی‌اکسیدانی، آنزیمی و خصوصیات کیفی سیب (Malus domestica)

In order to determine the effect of different Ca sources, in improving enzymatic activity and some qualitative properties of red apple (Malusdomestica) an experiment was carried out in a completely randomized design. Apple trees were sprayed 5 times with CaCl2, CaO, Ca-EDTA and Ca(NO3)2 salts with an interval of 20 days from late June until early October. After harvesting fruits were kept in cold storage at standard condition for 150 days. Nitrogen, phosphorus, potassium, calcium, magnesium, ascorbic acid, total soluble solids, firmness, total acidity, catalase enzyme activity and total antioxidant activity at harvest time, 50, 100 and 150 days after cold storage were measured. The results showed that the effect of foliar application on catalase enzyme activity, total antioxidant, pH, soluble solids, total acidity, calcium, firmness and ascorbic acid was significant. At the end of storage period, calcium amount of fruits at the presence of Ca-EDTA, CaCl2, Ca(NO3)2 and CaO treatments increased by 77.5, 27.5, 22.3 and 10.1 percent, respectively. Catalase enzyme activity in Ca-EDTA treatment increased 91.8 percent after 150 days of storage compared to control. At the end of the storage period, the highest content of ascorbic acid was found in Ca-EDTA treatment (6.04 mg per 100 g FW). It is concluded that spraying of apple fruit with Ca-EDTA can improve and maintain most fruit qualitative properties and increase enzymatic and antioxidant activity during storage time.