Effects of 1-methylcyclopropene on superficial scald and related metabolism in ‘Wujiuxiang’ pears during cold storage

Abstract

‘Wujiuxiang’ (Pyrus bretschneideri R. × Pyrus communis L.) pears often suffer from superficial scald after long-term cold storage. In this study, harvested ‘Wujiuxiang’ pear fruits were fumigated with 1-MCP at concentrations of 0.5 μL/L and 1.0 μL/L and subsequently stored at low temperature (0 °C). The superficial scald index; flesh firmness; total soluble solids (TSS) content; respiration and ethylene production rates; relative membrane permeability; concentrations of α-farnesene, conjugated trienols (CTols), and hydrogen peroxide (H₂O₂); and activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and lipoxygenase (LOX) of the peel were investigated. The results showed that compared with control, 1-MCP reduced the index of superficial scald; maintained a higher firmness and a lower TSS content; inhibited the accumulation of H₂O₂, α-farnesene and conjugated trienols and the increase in cell membrane permeability; and maintained a higher activity of APX, SOD and CAT and a lower activity of LOX. These findings indicate that 1-MCP regulates the activities of H₂O₂-scavenging enzymes to inhibit the accumulation of H₂O₂ and thereby reduces cell membrane damage and inhibits the accumulation of conjugated trienols. Thus, 1-MCP could decrease the incidence of superficial scald in ‘Wujiuxiang’ pears.