Effect of Calcium Chloride Treatments on Quality Characteristics of Blackberry, Raspberry and Strawberry Fruits After Cold Storage

Abstract

Post-harvested blackberry, raspberry and strawberry fruits were immediately treated with 1% and 2% calcium chloride by immersion at 20 ± 1°C for 2.5 min and kept for 8 days at 0 ± 0.5°C and relative humidity (RH) 90 ± 5%. The application of calcium did not significantly effect on total titratable acidity, pH and total soluble solids. Maximum weight lost was observed for untreated berries and minimum lost was observed for fruits treated with 2% calcium chloride. After storage, ascorbic acid content was significantly higher in samples of blackberry, raspberry and strawberry fruits subjected to 2% calcium chloride dip. Treatment of blackberry, raspberry and strawberry fruits with calcium chloride had a positive effect on retention of total polyphenols content during the storage period. Depletion of antioxidant capacity of untreated fresh blackberry fruits during 8 days cold storage was 25%; raspberries and strawberries - 34 and 26 % respectively. Whereas depletion of antioxidant activity in the 2% calcium chloride treated samples of these fruits was 8, 22 and 11% respectively. In case of storage of untreated blackberry fruits content of cyanidin-3-O-monoglucoside decreased by 6.33 mg per 100 g of fruit. While, in fruit samples treated with 1 and 2% calcium chloride content of cyanidin-3-O-monoglucoside decreased by 32.06 and 11.35 mg per 100 g of fruit, respectively. Content of pelargonidin 3–O- monoglucoside increased by 2.29 mg per 100 g of the untreated blackberry fruits and by 26.87 and 8.45 mg per 100 g of fruits treated with 1 and 2% calcium chloride respectively. Change of content of cyanidin 3–O- (6 - p – coumaroyl - glucoside) in blackberry fruits was not statistically significant.