Influence of pre-harvest calcium spray on fruit quality of apple cultivars during cold storage

Effect of pre-harvest calcium chloride (CaCl2) treatment on fruit quality attributes of three apple cultivars (`Golden Delicious Reinders (R)', `Granny Smith' and `Red Chief') at harvest and after two and four months of cold storage during two consecutive years was studied. Trees were sprayed four times starting from the beginning of June at 20-day intervals. After harvest, fruits were stored in a regular atmosphere (RA) for further analysis. Measurements included fruit weight, weight loss, firmness, total soluble solids (TSS), titrable acidity (TA), total sugars (TS), TS/TA, total phenolic content (TPC) and antioxidant activity (AA). CaCl2 had a positive impact on fruit firmness of all cultivars in both years. Higher values of TSS and TS of `Golden Delicious Reinders (R)' were determined in CaCl2 treatment in both years. TSS, TS and TS/TA were increased by prolonging storage in `Red Chief' in CaCl2treatment and control, in both years. TSS and TS proved similarly stable in `Granny Smith' during storage in CaCl2 treatment and control in the second year of examination, but a decrease of TA and TS/TA has been detected in both years of storage. The AA of cultivars `Golden Delicious Reinders (R)' and `Red Chief' was stronger affected by the storage compared to CaCl2 treatment. Through a comprehensive analysis of apple cultivars it can be concluded that pre-harvest application of CaCl2 in cultivars `Golden Delicious Reinders (R)' and `Red Chief' can be used to improve fruit quality during storage.