Effect of packaging type and storage conditions on physicochemical characteristics, antioxidant activity and microbial load of ready to eat pomegranate arils

“Ready to eat” pomegranate arils in addition to unique sensory and nutritional properties, provides the possibility of increasing the pomegranate consumption. The pomegranate fruit is native to Iran, so it is important pay attention to the pomegranate processing industry. The present study investigated the effect of modified atmosphere packaging and vacuum packaging on some quality properties of pomegranate arils with response surface methodology. The extracted pomegranate arils packed with three gas concentrations of oxygen includes vacuum packaging (%0), modified atmosphere (%10) and normal atmosphere packaging (%21) and kept them in storage temperatures (4, 12 and 20˚C ( for 16 days. Measurement of total soluble solids, titratable acidity, total anthocyanin, antioxidant activity and microbial load was performed on samples in intervals of 4,10 and 16 days after packaging. Antioxidant activity decreased with storage temperature and time increasing that had direct relation with anthocyanin decreasing during storage period. The highest of total anthocyanin content and soluble solids was in modified atmosphere packaging. Also, antioxidant activity by acidity increasing in normal atmosphere packaging (control) showed a significant increase. Microbial quality is an important parameter in determining the shelf life of foods. The lowest and highest of microbial load was, respectively, in vaccum and normal atmosphere packaging (control) that titratable acidity increasing and soluble solids decreasing was due to microbial activity increasing in normal atmosphere packaging. After final optimization, the best of gas oxygen concentration, storage temperature and time for maintaining of pomegranate arils was, respectively, %7, 5°C and 11days. At the optimal point, acidity, maximum total soluble solids, maximum antioxidant activity and total anthocyanin content, minimum total count and yeastmold was determined 1.13 (gr/100ml), 17.6 (°Brix), %56.7, 224 (mgL-1), 2.98 Log cfu/g and 2.95 Log cfu/g respectively.