Changes in antioxidant activity and postharvest quality of sweet pomegranates cv. Hicrannar under modified atmosphere packaging

• Hicrannar sweet pomegranates were stored in two different MAP conditions.
• MAP drastically reduced weight loss, decay and decay index and maintained visual appearance of pomegranates for a longer duration.
• During long term storage, a decrease in L* and C* values and an increase in h° values of pomegranates were found in all treatments.
• Total phenolics, total anthocyanins and antioxidant activity were always higher in control fruit.

The effects of different modified atmosphere packaging (MAP) on antioxidant compounds and storage quality of ‘Hicrannar’ sweet pomegranates were investigated during long term storage. Pomegranates were harvested at the commercial harvest stage and packed in two different types of MAP (MAP1 and MAP2). After packaging, all fruit were stored at 6 °C and 90–95% RH for 120 days, then removed from storage for different quality analyses. Some fruit were kept at 20 °C for 3 days to simulate a period of shelf-life. Fruit weight loss, decay index, skin color, total titratable acidity, total soluble solids content, total phenolics, total anthocyanins and antioxidant activity were determined. Internal atmospheres created by the MAP were periodically assessed during cold storage, and CO2 concentrations increased and O2 concentrations decreased inside the MAP. MAP significantly reduced weight loss after both 120 days of cold storage and shelf-life. MAP2 was the most effective packaging in reducing weight loss. Storage of pomegranates in MAP also reduced decay and the decay index, and maintained visual appearance compared to control fruit. During storage, a decrease in L* and C* values and an increase in h° values were observed in all treatments. However, fruit stored in MAP2 had higher L*, C* and lower h° values than in other treatments. Titratable acidity and total soluble solids decreased after cold storage and shelf-life, and no significant differences among treatments were found. Total phenolics, total anthocyanin contents and antioxidant activity increased during the storage period in control fruit.