Possible chemical mechanism and determination of inhibitory effects of 1-MCP on superficial scald of the Granny Smith apple variety

Abstract

The effects of postharvest 1-methylcyclopropene (1-MCP) treatments on α-farnesene content, incidence of scald, and ethylene content of the Granny Smith apple were evaluated in this study. Harvested apples were treated with 1-MCP at concentrations of 312.5, 625, and 1250 ppb. The 625 and 1250 ppb doses were found to be the most effective in terms of quality protection during storage. For untreated fruits, symptoms of scald development appeared after 8 weeks in cold storage, whereas 1-MCP doses of 625 and 1250 ppb were effective in decreasing superficial scald in fruit after 24 weeks of cold storage. 1-MCP can inhibit oxidation of α-farnesene, which synthesizes during storage. This induces reactive oxygen species metabolism. 1-MCP introduces competitive behavior by breaking the balance between α-farnesene production and the antioxidative defense system, due to the Schenck ene reaction.