Chilling Injury and Quality of Peach in Relation to Season of Fruit Maturity and Low Temperature Storage

The occurrence of chilling injury (CI) symptoms and fruit quality in different maturing peach (Prunus persica L.) cultivars were investigated during fruit ripening before and after low temperature storage. Peach fruit [Florida King (FK), Peach Selection No.3 (PS-3) and Florida Gold (FG) (early maturing cultivars), and Maria Delezia (MD) and Indian Blood (IB) (late maturing cultivars)] were harvested at commercial maturity and were stored at 0 ± 1^oC for 0, 10 and 20 days. Following low temperature storage fruit were allowed to ripe at ambient temperature. The incidence of CI and fruit physio-chemical quality characteristics were studied at fully ripe (eating soft) stage. All cultivars did not show any symptoms of CI during fruit ripening before storage. FG (early maturing) and MD (late maturing) cultivars exhibited better postharvest shelf life and quality during ripening before low temperature storage as compared to other peach cultivars. The fruit of FG were sweeter with highest soluble solid content (SSC), SSC: titratable acidity (TA) ratio, but these fruit exhibited 50% and 75% CI after 10 and 20 days of storage respectively. The fruit of PS-3 exhibited higher fruit firmness, Vitamin-C contents with better taste up to 10 days of storage later on it decreased with higher incidence of CI. Fruit SSC, SSC: TA ratio, reducing sugars, non-reducing sugar, total sugars, percent weight loss, flesh color and color around the stone increased with increase in the fruit storage period. However, a significant decrease was found in fruit firmness, percent TA and level of vitamin-C with increase in the storage period. Among all the cultivars the IB fruit stored best at 0 ± 1^oC up to 20 days with higher fruit firmness; lower percent weight loss; acceptable SSC, SSC;TA ratio, Vitamin-C content and total sugars; and without any symptom of CI during low temperature storage.