Effect of Modified Atmosphere Packaging on Aril Physico-chemical and Microbial Properties of Two Pomegranate Cultivars (Punica granatum L.) Grown in Iran

Background and Objectives: Edible parts of pomegranate fruits are a rich source of bioactive compounds. The present research examines the effect of modified atmosphere packaging on the fruit physico-chemical and microbial properties of two commercial pomegranate cultivars grown in Iran. Materials and Methods: The arils were packaged and stored under four different atmospheres. All of the packaged samples were stored at 4 °C for 15 days. Results: The results revealed an increase in total acidity of all treatments. The highest total soluble solid (TSS) was observed in ‘Yousef-Khani’­ stored in 10% O2 + 15% CO2, while ‘Malas-e-Saveh’ treated with 20% O2 + 5% CO2 showed the highest degree of TSS. The mean value of a* in ‘Malas-e-Saveh’ arils packed with normal and (15% O2 + 10% CO2 + 75% N2) atmosphere increased significantly. The L* showed a decrease in ‘Yousef-Khani’­. Total phenolic compounds gradually increased during storage. After storage, decreases in total anthocyanin contents ranged from 12 to 30% for ‘Yousef-Khani’­. The overall antioxidant activity of arils in ‘Yousef-Khani’ showed a 6-15% increase during storage. However, a reverse effect was observed for ‘Malas-e-Saveh’. The lowest microbial counts were recorded under the atmosphere containing 10 and 15% CO2. Conclusions: Packaging of ‘Malas-e-Saveh’ arils in 15% O2 + 10% CO2 and ‘Yousef-Khani’ in 15% O2 + 10% CO2 or 10% O2 + 15% CO2 is recommended to extend the shelf-life of ready-to-eat arils. Keywords: Pomegranate, Modified atmosphere, Phenolic compounds, Anthocyanin, Antioxidant activity