Effect of Aloe vera gel enriched with sesame oil, honey and Zataria multiflora Boiss essential oil on browning reduction of ber fruit

Ber fruit (Zizyphus mauritiana Lamk) contains abundant polyphenols and is highly susceptible to enzymatic browning after harvest. In order to reduce browning and maintain fruit quality of ber fruit, a factorial experiment was conducted in a completely randomized design with four replications. Experimental treatments included Aloe vera gel-based (20%) edible coating enriched with sesame oil 1%, honey 1% (ASH) and Zataria multiflora Boiss essential oil (ZEO) (0, 0.5 and 1%) and storage time (0, 7, 14, 21 and 28 days) at 6 ± 1°C and relative humidity of 90±5%. The results showed that edible coating application had significant effect on the quality characteristics of the ber fruit during storage. The combination of ASH with ZEO (0.5%), as an edible coating, significantly alleviated enzymatic browning by reducing PPO and POD activities on fruit during 28 days of storage. Fruits treated with ASH with ZEO (0.5%) reduced browning index (70%) compared to the control; while increased total phenol content and antioxidant activity (18.14%, and 31.16%, respectively) compared to the control after 28 days of storage. Also, ASH in combination with ZEO (0.5%) treatment decreased electrolyte leakage and malondialdehyde (19.7%, and 17.8%, respectively) compared to the control after 28 days of storage. These results indicated that ASH edible coating in combination with ZEO (0.5%) can be a useful method for delaying ripening and senescence, extending the storage life of ber fruit.