Note. 1-MCP Effect on Chilling Injury Development in ‘Nova’ and ‘Ortanique’ Mandarins

Abstract
The aim of this work was to evaluate the effect of 1-methylcyclopropene (1-MCP) on chilling injury (CI) incidence, ethylene production, phenylalanine ammonia-lyase (PAL) activity and quality changes on mandarin hybrids, ‘Nova’ and ‘Ortanique’, during cold storage. Fruits were treated for 24h with 1-MCP at 0.5 L/L and then stored at 1 ºC. 1-MCP markedly reduced CI incidence in both cultivars, this effect being more accentuated in ‘Nova’ mandarins, which presented lower tolerance to cold storage. 1-MCPtreated fruit presented less PAL activity parallel to a significant increase in ethylene production. These results suggested that ethylene played an important role in citrus fruit CI development and 1-MCPinduced ethylene production might act as a protector of the fruit against chilling damage. 1-MCP reduced ethanol concentration slightly decreased CO2 production and had no effect on fruit quality characteristics such as TSS, acid content or texture for both cultivars.