Reduction of chilling injury of ‘Washington’ navel orange fruits by melatonin treatments during cold storage

Abstract Cold storage is used to improve the efficiency of and handling orange fruits, but fruits are exposed chilling injury (CI). Antioxidant enzymes part antioxidant defence system against CI ‘Washington’ oranges during cold storage, which controls storage/handling efficiency. In this study, melatonin (ME) was on reduce damage. To assess action ME influences; were picked from tree at commercial maturity stage divided into two groups that uniform in size colour. Then, they immersed solution 0 mmol, 10 100 mmol or 1,000 for 20 min ± 1 °C. The treated stored 4 °C 95 1% RH weeks 2019 2020 seasons. physical chemical characteristics measured every week up end period. Results indicated immersing μM minimised CI-index water loss%, while preserving peel colour (h°) storage. On other hand, same treatment caused slight changes soluble solid content (SSC%), maintained ascorbic acid (AA) stability total acidity (TA%), enhanced activities (AEAs) such as ascorbate peroxidase (APX), catalase (CAT), superoxidase dismutase (SOD) also reduced rate malondialdehyde (MDA) ion leakage (IL) Moreover, it hydrogen peroxide (H 2 O ) superoxide anion (O •− production pronounced results be exhibited capacity. Overall, afforded more tolerance stress.