The effects of modified and palliflex controlled atmosphere storage on postharvest quality and composition of ‘Istanbul’ medlar fruit

• Medlar fruits were treated with 1-MCP and stored at 0 °C in palliflex storage system for 60 days.
• 1-MCP treatments and palliflex storage system extended the storage life of medlar fruits.
• Concentrations of total phenolics, total condensed tannins, ascorbic acid and antioxidant activity decreased during storage.
• 1-MCP treatments were also retarded the decline of titratable acidity in medlar fruits.

Medlar (Mespilus germanica L. cv. Istanbul) fruit were stored in palliflex controlled atmosphere storage systems of 21% O2 + 0.03% CO2 (PL-1, control), 2% O2 + 5% CO2 (PL-2), 3% O2 + 10% CO2 (PL-3) and modified atmosphere packaging (MAP) at 0 °C for 60 days to determine the effects of different O2 and CO2 concentrations on physiological properties, quality attributes and storability. Every 15 days, three replicates of each treatment were evaluated for weight loss, fruit firmness, decay, external browning index, skin color, pH, titratable acidity, total soluble solids, total phenolics, total flavonoids, total condensed tannins, ascorbic acid, antioxidant activity and organic acid and sugar contents. Taste analysis of the fruit was performed after 30, 45 and 60 days of storage. The CO2 and O2 concentrations created by the MAP stabilized at 7% and 14%, respectively. Weight loss of fruit stored in MAP was lower (<0.4% at 60 days) than for other treatments. Off-flavors were not detected in any treatment. Storage of medlar fruit under PL-3 was the least effective treatment in delaying fruit ripening (flesh firmness). The incidence and severity of browning, loss of skin color (Ch°) and retaining acceptable taste during 60 days were found the most effective in PL-2 and PL-1 compared to other treatments. Fruit pH increased and titratable acidity decreased during the storage period. Total soluble solids and sugar contents first increased then decreased in all treatments by the end of storage. The fruit stored in PL-2 had higher titratable acidity, total soluble solids and sugar contents than fruit stored in PL-1, PL-3 and MAP at all evaluations. Concentrations of total phenolics, total flavonoids, total condensed tannins, ascorbic acid, associated antioxidant activity and organic acids were affected by the storage atmosphere, decreased during storage. The concentrations of total phenolics, total flavonoids, and antioxidant activity were found the highest in PL-2, PL-1 and MAP treatments, respectively. However, in terms of ascorbic acid and total condensed tannins retention, PL-2 was the most effective treatments. The results indicated that 60 days storage of medlar fruit in the palliflex storage system at 0 °C maintained physiological and biochemical properties of medlar fruit.