EFFECTS OF 1-METHYLCYCLOPROPENE AND CONTROLLED ATMOSPHERE STORAGE ON THE QUALITY OF 'HONEYCRISP' APPLES

The objective of this study was to investigate the effects of 1-methylcyclopropene (1-MCP) and controlled atmosphere (CA) storage on the physical and sensory quality of ‘Honeycrisp’ apples during storage. Fruit were harvested from a commercial orchard, treated with or without 1-MCP (1 µl L^-1) for 24 h at 8-10°C, held for 5 days at 10°C, and then stored at 3°C in air or CA (3.0 kPa O₂ + 1.5 kPa CO₂) for 8 months. Physical and sensory attributes were evaluated during subsequent holding at room temperature (~22°C) within 1 week. ‘Honeycrisp’ stored in CA or treated with 1-MCP had lower IEC and higher SSC. Fruit held in CA also had less peel greasiness, while those treated with 1-MCP had higher titratable acidity. The interaction of 1-MCP×CA resulted in inconsistent differences in fruit firmness. Internal CO₂ injury was the most prevalent disorder, with the highest incidence in apples treated with 1-MCP and stored in CA. Sensory evaluations revealed that ‘Honeycrisp’ treated with 1-MCP had lower perceived intensities of oxidized red apple, earthy flavours, skin thickness and chewy textures than their counterparts without 1-MCP. In addition, apples treated with 1-MCP were rated overall as higher in lemony, fresh green apple flavours and acid taste. Fruit not treated with 1-MCP and stored in air were rated higher for oxidized red apple, earthy flavours compared to all other fruit, while CA-stored apples with 1-MCP were rated the highest for fresh green apple flavour and acid taste.