Effects of temperature conditioning on reducing chilling injury in pomegranate fruits during storage

Experiments were conducted to evaluate the effect of temperature conditioning on reducing chilling injury in pomegranate fruits. In the first experiment (1997), fruits of cultivars Malas Yazdi and Malas Saveh were thawed at 38°C for 0 (control), 12, 24 and 36 h before storage. Treated fruits were then stored at 1.5°C and 85±3% relative humidity for 4.5 months. In 1998, fruits of ‘Malas Yazdi’ were thawed at 55°C for 0 (control), 30, 60, 90 and 120 min and stored at 1.5°C and RH=85±3% for 3 months. The results showed that fruits conditioned at 38°C for 24 and 36 h had significantly less chilling injury symptoms (browning) and weight loss but had no significant effect on electrolyte leakage, total soluble solids, total acidity, ascorbic acid and pH of fruits after removal from the storage. Thawing at 55°C significantly reduced chilling injury symptoms, electrolyte and K⁺ leakage but no significant effect on fruit juice characteristics.