Abstract:

Purpose: To study the effect of different postharvest treatments with 1-methylcyclopropene (1-MCP) or wax on
the activities of protective enzymes in Pyrus communis L. cv. ‘Doyenne du Comice’. Methods: The pear fruits were treated
respectively with 1-MCP at 0.5 and 1 μL/L and wax after harvest and then stored in a cold room at (0 ± 0.5) ℃. The activities
of protective enzymes in flesh and peel during 90 days of storage at low temperature and during shelf life storage at 25 ℃
after 60 and 90 days of cold storage were assayed. Results: During cold storage, both 1-MCP and wax treatments improved
superoxide dismutase (SOD) activity in flesh and reduced the activities of ascorbate peroxidase (APX) and peroxidase (POD)
in flesh and catalase (CAT) activity in peel. During shelf life storage, wax treatment could improve SOD activity in flesh
and POD activity in peel. Conclusions: 1-MCP treatment has a positive effect on the physiology of pear fruits during cold
storage, which is more effective at 0.5 μL/L than at 1 μL/L for flesh, while the contrary result was observed for peel. Wax
treatment shows a better effect on peel during shelf life. In addition, the activities of protective enzymes SOD, CAT, APX
and POD in peel are much higher than in flesh during 90 days of cold storage and also during 5 days of subsequent storage at
room temperature.

Key words: Pyrus communis L. cv. ‘Doyenne du Comice’, protective emzyme activity, flesh, peel, storage time, shelf life