Effects of pre-cooling and modified atmosphere packaging on storability of pomegranate (Punica granatum 'Hicaznar') fruit

Preserving quality to extend the product availability in the markets are becoming more and more important as pomegranate production rapidly increases. This study is carried out to determine the effects of pre-cooling and modified atmosphere (MA) packaging on quality changes and pathological and physiological losses in pomegranate fruit. Pomegranates ('Hicaznar') were harvested at full maturity and packed with two different modified atmosphere packages (MA1 and MA2). Fruits were pre-cooled for 24 h at 3 different conditions; a) pre-cooled at 6°C and 90-95% relative humidity (RH) right after harvest b) at 6°C 90-95% RH after 2 days of storage at 14°C 70% RH; and c) at 10°C and 90-95% RH after 2 days of storage at 14°C 70% RH. Packages were sealed after pre-cooling and stored under 6°C 90% RH conditions for 5 months. In storage, the weight loss in MA2 package was significantly higher than those in MA1 package. After 5 months of storage, decay development was higher in MA1 compared to those in MA2. On the other hand, sensory evaluation scores of fruits were lower in MA2 at the end of the storage period. The weight loss of fruits pre-cooled immediately after harvest were found lower, however decay development was slightly higher than the fruit pre-cooled after 2 days. Effects of the tested modified atmosphere packages and pre-cooling conditions were found similar on in-package atmospheric composition, total soluble solids, titratable acidity, total phenolic contents and antioxidant activity. Limited effects were determined on peel and aril color. The results prove that selecting proper MA packages and pre-cooling conditions according to the storage duration is important to obtain a better performance.