Effect of Calcium chloride and 1-MCP (Smartfresh™) postharvest treatment on ‘Golden Delicious’ apple cold storage physiological disorders

Abstract

Calcium (Ca2+) and 1-methylcyclopropene (1-MCP) appear to have opposite effects on the development of bitter pit. However, both post-harvest treatments seem capable of influencing fruit ripening, reducing superficial scald and improving post-storage quality. The objective of this work was to investigate the effect of calcium chloride and 1-MCP alone or combined on the incidence and development of physiological disorders and the delay of ripening of apples during storage (at 0.5°C in air) and subsequent shelf-life at room temperature ≈22°C. ‘Golden Delicious’ apples were harvested in 10 orchards and treated with calcium chloride (1.5%, w/v), 1-MCP (625nLL−1), calcium chloride plus 1-MCP, and without any treatment (control). Physiological disorders and quality parameters were evaluated at harvest and after 6 months storage as well as after 7 d shelf-life. The 1-MCP treatment was effective to prevent superficial scald, slow softening, increase soluble solids content and reduce electrolyte leakage and color changes associated with ripening, during storage and shelf-life. However, this treatment also enhanced the development of bitter pit, especially the moderate and severe symptoms in some orchards, which may be attributable to orchard cultivation techniques. CaCl2 alone and CaCl2 plus 1-MCP reduced bitter pit intensity by reducing moderate and severe incidence, maintained higher lightness and had firmer fruit than control.Postharvest dips of ‘Golden Delicious’ apples in CaCl2 before 1-MCP application (CA+MCP), may be a good solution to prevent scald, and reducing the bitter pit which is enhanced by 1-MCP alone.