Abstract:

Cara cara navel orange (Citrus sinenisis L.‘Cara cara’) was used to investigate effect of pre- harvest salicylic acid (SA) spray treatment on antioxidant activity in pulps at harvest stage and during storage. Results indicated that SA spray treatment significantly increased the content of antioxidant components (lycopene, β-carotene, total phenols and flavonoids) and antioxidant capability (FRAP value) at harvest stage of fruits. Moreover, these effects were in a concentration-dependent manner. During fruit storage, the contents of lycopene and β-carotene exhibited a decrease, whereas total phenols and flavonoids exhibited a constant increase. However, fruits subjected to SA spray treatment before harvest were observed a significant increase of antioxidant components during storage period and the optimal concentration of SA for pre-harvest treatment was 2.0 mmol/L. The antioxidant activity revealed an initial increase and final decrease. The peak of antioxidant activity was observed at 45 d of storage. Furthermore, FRAP value in fruits with 0.5, 1.0 and 2.0 mmol/L SA pre-harvest treatment was significantly higher than that in control fruits.

Key words: Cara cara navel orange, salicylic acid, pre-harvest treatment, storage, antioxidant activity