'Conference' and 'Abbé Fétel' pears treated with 1-methylcyclopropene: physiological and quality implications of initial low oxygen stress and controlled atmosphere storage.

Superficial scald is a disorder developed in cold storage by 'Conference' and 'Abbé Fétel' pears and it has been related to the presence of oxidation products, mainly conjugated trienols (CTols), of which α-farnesene is primary, acting on epidermal cells. Among tested postharvest methods to control scald, there is treatment at harvest with 1-methylcyclopropene (1-MCP) and initial low oxygen stress (ILOS). The investigation presented here studied, in 'Conference' and 'Abbé Fétel' pears treated with 1-MCP (300 µL L-1), the physiolological and quality implications of storage in controlled atmosphere (CA, 2 kPa O2 + 0.7 kPa CO2, -0.5°C) after two 2-weeks ILOS (0.3-0.5 kPa O2) periods at three-week intervals after 13 and 21 weeks of storage and shelf life at 20°C up to seven days. Results showed that 1-MCP treatment severely reduced α-farnesene, CTol269, CTol281 and ethanol after ILOS treatment in both cultivars, and ethyl acetate in 'Abbé Fétel' pears. Furthermore, it impaired fruit softening, delayed skin yellowing and reduced ethylene production in shelf life. At sensory analyses, 1-MCP treated 'Conference' and 'Abbé Fétel' pears were described as being firmer and less juicy, sweet and aromatic than untreated fruit. 1-MCP treated pears did not develop superficial scald and soft scald in 'Abbé Fétel', nor superficial scald and black speck after 21 weeks of storage in 'Conference'. [ABSTRACT FROM AUTHOR]