<abstract xmlns="http://www.w3.org/1999/xhtml">

Cold storage is used to improve the efficiency of storage and handling of orange fruits, but the fruits are exposed to chilling injury (CI). Antioxidant enzymes are part of the antioxidant defence system against CI of ‘Washington’ oranges during cold storage, which controls storage/handling efficiency. In this study, melatonin (ME) was used on fruits to reduce cold damage. To assess the action of ME influences; fruits were picked from the tree at the commercial maturity stage and divided into two groups that were uniform in size and colour. Then, they were immersed in ME solution at 0 mmol, 10 mmol, 100 mmol or 1,000 mmol for 20 min at 20 ± 1 °C. The treated fruits were stored at 4 ± 1 °C and 95 ± 1% RH for 4 weeks during 2019 and 2020 seasons. The physical and chemical characteristics of the stored fruits were measured every week up to the end of the storage period. Results indicated that immersing fruits in 1,000 μM ME minimised the CI-index and the water loss%, while preserving the orange peel colour (h°) during cold storage. On the other hand, the same treatment caused slight changes in soluble solid content (SSC%), maintained ascorbic acid (AA) content and the stability of total acidity (TA%), enhanced the antioxidant enzymes activities (AEAs) such as ascorbate peroxidase (APX), catalase (CAT), and superoxidase dismutase (SOD) and also reduced the rate of malondialdehyde (MDA) and ion leakage (IL) during cold storage. Moreover, it minimised hydrogen peroxide (H2O2) and superoxide anion (O2•−) production and caused pronounced results to be exhibited in antioxidant capacity. Overall, the 1,000 μM ME treatment for orange fruits afforded more tolerance against cold storage stress.
</abstract>

Cold storage is used to improve the efficiency of storage and handling of orange fruits, but the fruits are exposed to chilling injury (CI). Antioxidant enzymes are part of the antioxidant defence system against CI of ‘Washington’ oranges during cold storage, which controls storage/handling efficiency. In this study, melatonin (ME) was used on fruits to reduce cold damage. To assess the action of ME influences; fruits were picked from the tree at the commercial maturity stage and divided into two groups that were uniform in size and colour. Then, they were immersed in ME solution at 0 mmol, 10 mmol, 100 mmol or 1,000 mmol for 20 min at 20 ± 1 °C. The treated fruits were stored at 4 ± 1 °C and 95 ± 1% RH for 4 weeks during 2019 and 2020 seasons. The physical and chemical characteristics of the stored fruits were measured every week up to the end of the storage period. Results indicated that immersing fruits in 1,000 μM ME minimised the CI-index and the water loss%, while preserving the orange peel colour (h°) during cold storage. On the other hand, the same treatment caused slight changes in soluble solid content (SSC%), maintained ascorbic acid (AA) content and the stability of total acidity (TA%), enhanced the antioxidant enzymes activities (AEAs) such as ascorbate peroxidase (APX), catalase (CAT), and superoxidase dismutase (SOD) and also reduced the rate of malondialdehyde (MDA) and ion leakage (IL) during cold storage. Moreover, it minimised hydrogen peroxide (H2O2) and superoxide anion (O2•−) production and caused pronounced results to be exhibited in antioxidant capacity. Overall, the 1,000 μM ME treatment for orange fruits afforded more tolerance against cold storage stress.

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

Department of Pomology, Faculty of Agriculture

Folia Horticulturae

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Cold storage is used to improve the efficiency of storage and handling of orange fruits, but the fruits are exposed to chilling injury (CI). Antioxidant...

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

Article Category: Original Article

Published Online: Dec 13, 2021

Page range: 343 - 353

Received: Aug 17, 2021

Accepted: Nov 02, 2021

DOI: https://doi.org/10.2478/fhort-2021-0026

Keywords
antioxidant enzymes activities, ascorbic acid, catalase, ion leakage, peel colour, superoxide anion, water loss

© 2021 M. S. Aboryia et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

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

Article Category: Original Article

Published Online: Dec 13, 2021

Page range: 343 - 353

Received: Aug 17, 2021

Accepted: Nov 02, 2021

DOI: https://doi.org/10.2478/fhort-2021-0026

Keywordsantioxidant enzymes activities, ascorbic acid, catalase, ion leakage, peel colour, superoxide anion, water loss

© 2021 M. S. Aboryia et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
antioxidant enzymes activities, ascorbic acid, catalase, ion leakage, peel colour, superoxide anion, water loss