Does the Oxygen Permeability affect the Equilibrium Gas Concentrations in Passive Modified Atmosphere Packaged Pomegranate Arils?

The effect of oxygen permeability of packaging material on shelf life of minimally processed and passive modified atmosphere packaged pomegranate arils, cv “Wonderful” as well as some quality attributes were investigated. Packaging materials having Oxygen transmission rate (OTR) as low as 125–290 cm3/m2/day were found to provide the gas concentration requirements of 2–5% O2 and 3–10% CO2 for passive modified atmosphere application of fresh fruits and vegetables. Although color, firmness, anthocyanin, total phenolic content and sensorial and microbial properties significantly changed there was no significant change in pH, total soluble solids and antioxidant activity during storage period at 5C. Microbial counts of total aerobic bacteria did not exceed the legal limit during storage period but sensorial values were below the limit of threshold on 11th day of storage. OTR of packaging material of pomegranate arils should be as low as 125–290 cm3/m2/day under passive modified atmosphere and its shelf life was determined as 10 days at 5C and 90% Relative humidity (RH). Practical Applications The results of this project can be utilized by producers of fresh pomegranate arils to decide on packaging material having appropriate oxygen permeability. Thus the fresh cut producers prefer to use packaging materials having higher oxygen transmission rate since minimally processed fruits and vegetables are more susceptible to microbiological and sensorial deterioration because of the higher surface area leading to enhanced respiration rate. However, this situation is not valid for fresh pomegranate arils since the respiration rate of fresh pomegranate arils is lower compared to whole pomegranates. Producers will also get the opinion that shelf life period of fresh pomegranate arils is about 10 days and sensorial properties are more potent than the microbiological properties to determine the end of shelf life due to the nature of pomegranate arils.