Dynamic controlled atmosphere (DCA): interaction between DCA methods and 1-methylcyclopropene on 'Fuji Suprema' apple quality

- DCA by respiratory quotient and chlorophyll fluorescence has been studied.
- Higher fermentative products are correlated with DCA-QR2.
- DCA induce fermentative pathway which could decrease the ethylene metabolism.
- DCA- RQ1.5 maintain higher 'Fuji Suprema' apple quality than CA stored fruits.
- 1-MCP application leads to a reduction in ethylene and fermentative products.

The objective of the present work was to evaluate the appropriate respiratory quotient (RQ) value to achieve a safe lowest oxygen limit (LOL), during storage of 'Fuji Suprema' apples, in dynamic controlled atmosphere (DCA), treated with or without 1-methylcyclopropene (1-MCP). The apples were stored in DCA-RQ, a new technology for storing fruits, and were compared with the HarvestWatch™, a system based on chlorophyll fluorescence DCA (DCA-CF), and static controlled atmosphere. DCA-RQ1.5 is the most suited for the storage of 'Fuji Suprema' apples. In this condition fermentative products were induced, which reduced ethylene production and respiration rate; however, it did not increase physiological disorders, and the concentration of ethyl acetate was below the odour threshold. 1-MCP application maintained higher flesh firmness and reduced the anaerobic metabolism, although it decreased fruit quality due to the occurrence of cavities, therefore its application is not recommended for 'Fuji Suprema' apple stored in DCA conditions.