Shelf life and biochemical changes of ready-to-eat arils among nineteen Iranian pomegranate cultivars (Punica granatum L.) during storage.

The objective of this study was to investigate the shelf life of arils and the changes in their biochemical compounds in nineteen Iranian pomegranate cultivars during storage. Fruits were harvested when commercially mature and the arils were removed, packaged and stored at 5 ± 1 °C, at 85-90% relative humidity in a cold room. Samples of the stored arils were examined for biochemical features in temporal checkpoints throughout a storage period that lasted for 35 days. By using the onset of decay as an index, the shelf life of arils varied among cultivars, ranging from 7 days to approximately 21 days. Considering the quality attributes of ready-to-eat arils at the beginning of the experiment, substantial variations were observed among the cultivars with regard to their titratable acidity (0.50-8.47%), total soluble solids (13-18.66 °Brix), DPPH radical scavenging activity (63-87.44%), Gallic-acid-equivalent (2.64-6.95 mg/ml) and ascorbic acid (12.21-75.09 mg/l). In general, the decay of arils gradually increased during storage, but several cultivars-which exhibited a very slow process of decay-contained the highest content of titratable acidity, Gallic-acid-equivalent and total soluble solids (since the signs of decay appeared on around the twenty-first day of storage). In addition, titratable acidity increased slightly by the end of storage, whereas the ascorbic acid content, total soluble solids and Gallic-acid-equivalent were cultivar-dependent and did not show consistent patterns of change during storage.