Effects of Sodium Alginate Plus Pomegranate Peel Extract Based Edible Coating on the Antioxidant Properties of Pear Fruit During Low Temperature Storage

Pear fruit undergoes intense metabolic activities during postharvest storage due to its climacteric character, resulting in alteration in antioxidant properties of fruit. Thus, in the current study the influence of sodium alginate (SA; 1% and 2%) coating blended with pomegranate peel extract (PPE) or as pure coatings was investigated to assess their potential in the maintenance of antioxidant content in pear fruit cv 'Punjab Beauty' under low temperature storage. As compared to control, the SA + PPE coatings were effective in maintaining the higher total antioxidant activities (TAA), total phenolics content (TPC), ascorbic acid (AsA) and titratable acidity (TA) in stored pears. Further, the combined coatings suppressed internal browning (IB) throughout the 67 days of storage and lowered polyphenol oxidase (PPO) activity in fruits. The activity of PPO on the 45th day of storage was 35.42% lower in SA 2% + PPE coated fruit than in the control fruit. Thus, the coatings of SA + PPE emerged as a promising approach in maintaining antioxidant properties of pears during low temperature storage.