Synthetic antioxidants can reduce postharvest losses, but consumers are concerned about chemical residues in the product. There is a growing interest in using natural compounds for the preservation of foods. In this study, the efficiency of juices or extracts obtained from three fruit species with high antioxidant activity as browning inhibitors was measured and then compared with that obtained from pomegranate by-product (PBP). The aim was to offer the most significant contributions concerning fresh-cut fruit preservation, using 'Shahmive' pear as the fruit model. Slices of pear were dipped in pomegranate juice (PJ) or extract (PE), kiwifruit juice (KJ) or extract (KE), grape juice (GJ) or extract (GE), PBP and chitosan before being stored at 4 °C. The total phenolic content of solutions ranged from 11 to 127.5 mg gallic acid/100 mL. Extracts of pomegranate peel and grape had the uppermost and the lowermost antioxidant activity (%DPPH), respectively. In comparison with other treatments including the control one, the minimum peroxidase (POD) activity, the maximum ascorbic acid content and the retention of firmness were seen in the fruit which was treated with kiwifruit extract. PJ + GJ treatment decreased POD and polyphenol oxidase activity and improved L* and a* values in the slices. The use of fruit juice or extracts had no adverse effect on the sensory quality of slices, with the exception of samples subjected to PJ or GJ + KJ treatments. Improving antioxidant capacity of fresh cut pear treated with KE and PJ + GJ would have a big advantage of preventing enzymatic browning.
Keywords: Antioxidants; Browning; Phenolic compounds; Postharvest disease.