Effects of 1-MCP in combination with Ca application on aroma volatiles production and softening of 'Fuji' apple fruit

1-Methylcyclopropene (1-MCP) can maintain the physical quality of climacteric fruits, such as apple and pear, but inhibit aroma volatile production and fruit flavor. In this study, the effects of calcium (Ca) in combination with 0.6 and 1.0 mu L L-1 1-MCP on flesh firmness and aroma volatiles has been investigated on 'Fuji' apples stored at room temperature. Results from electronic nose detection and texture evaluation showed that 1-MCP of reduced concentration (0.6 mu L L-1), but not 1.0 mu L L-1, presented an interactive effect with Ca application on promoting volatile emission and reducing softening. The amount of branched and straight esters and total aroma volatiles, as well as related enzymes including aromatase-related acyltransferase (AAT), alcohol dehydrogenase (ADH), and pyruvate decarboxylase (PDC), were significantly higher in fruit treated with (1-MCP 0.6 + Ca) than 1-MCP 1.0 after 50 and 100 days storage. There was no significant difference between two treatments of (1-MCP 0.6 + Ca) and 1-MCP 1.0 in maintaining fruit firmness. Fruit treated with (1-MCP 0.6 + Ca) had higher aroma quality than 1-MCP 1.0 according to sensory evaluation, but showed no significant difference in terms of texture quality. In conclusion, 1-MCP of reduced concentration combined with Ca treatment had synergetic effect on the aroma formation and softening inhibition of apple fruit, resulting in advanced sensory quality.