Dynamic controlled atmosphere (DCA) and 1-MCP: Impact on volatile esters synthesis and overall quality of ‘Galaxy’ apples

Abstract

Abstract We aimed to evaluate the MdACCO1, MdADH1, MdLOX1, MdAAT1 expression, quantify the main esters and its precursors, and evaluate the overall quality of ‘Galaxy’ apples after 6 and 9 months of storage plus 7 d shelf life at 20 °C. DCA or CA + 1-MCP has a suppression effect on MdACCO1 expression and consequently reducing the ethylene production and fruit ripening. The expression of MdAAT1 appears to be regulated by ethylene in CA, but in DCA – RQ 1.5 (dynamic controlled atmosphere based on respiratory quotient 1.5) its expression should be induced by another signal, because even when fruit are treated with 1-MCP the expression of MdAAT1 is increased by the storage under DCA – RQ 1.5 as compared to CA. This explains why the oxygen reduction to obtain an RQ 1.5 increases the ester production in ‘Galaxy’ apples. Higher volatile compounds were detected when fruit were stored under CA and DCA – RQ 1.5. 1-MCP application suppressed the esters accumulation in almost all storage conditions.