The ‘Empire’ apple, a major apple cultivar in Northeast US and
Canada, can develop a firm flesh browning that is assumed to be a
chilling injury , and current recommendations for this cultivar are to use storage temperatures about 2 C to reduce risk of injury development. However, application of the inhibitor of ethylene perception, 1-methycyclopropene (1-MCP), used commercially to maintain quality characteristics such as firmness and acidity, can increase
flesh browning incidence of ‘Empire’ apples at these warmer storage temperatures. Development of flesh browning has become a serious
limiting factor for the long term CA storage of the cultivar. 1-MCP induced flesh browning of ‘Empire’ apples has been investigated from a number of aspects including antioxidant metabolism and metabolomic
analysis , but understanding of the causal reasons remain unclear. It has been hypothesized that flesh browning may result from inhibition of ethylene production by the fruit that results in abnormal metabolism; this inhibition may occur either at low chilling-injury inducing temperatures (0.5 C) with and without 1-MCP, or at warmer temperatures (3–4 C)
when fruit has been treated with 1-MCP.