Dynamics of Quality and Metabolic Activity of Stored ‘galaxy’ Apples Affected by Maturity and 1-Methylcyclopropene

To preserve the quality traits of late-harvested 'Galaxy' apples during extended storage, the effects of 1-methylcyclopropene (1-MCP) treatment and storage conditions on postharvest quality were analysed. Alongside quality measures, indicators like ethylene production, respiration rate, aminocyclopropane-1-carboxylic acid oxidase (ACO) activity, and membrane permeability were assessed. Apples were harvested at an optimal harvest date or later and stored for 7 months at 1 degrees C under regular atmosphere or controlled atmosphere. Treatments with 1-MCP at 300, 600 or 900 nL L-1 were applied pre- or post-storage. After 7 days shelf-life, apples subjected to 1-MCP and controlled atmosphere exhibited reduced ethylene production, respiration rate, and ACO activity compared to untreated or regular atmosphere counterparts. While the time of 1-MCP application and its concentration did not impact the respiration rate during shelf-life, controlled atmosphere effectively decreased it. The combination of controlled atmosphere and 1-MCP pre-storage was most effective in lowering ACO activity. Irrespective of conditions, 1-MCP curtailed ethylene production, respiration rate, and ACO activity during shelf-life, alleviating firmness and acidity loss. Only controlled atmosphere preserved quality and minimised disorders for optimally harvested apples, not late-harvested ones. None of the treatments maintained late-harvested apples' quality after long-term storage plus shelf-life.