Relationship between volatiles and antioxidant compounds in scald on ‘Alexander Lucas’ pear in different postharvest conditions

ABSTRACT

This study aimed to evaluate the effects of storage conditions on the development of superficial and senescent scald and its relationship with volatiles and antioxidant compounds in ‘Alexander Lucas’ pears (Pyrus communis) harvested at two maturity stages in three orchards. A two-factorial design combined two maturity stages with five storage conditions: standard oxygen plus cold storage (control; 20.9 kPa O₂, 0.03 kPa CO₂), controlled atmosphere (low O₂) ( 2.0 kPa O₂, 0.7 kPa CO₂), each without and with 1-MCP (300 nl·L^-1), and ultra-low O₂ atmosphere (0.7 kPa O₂, < 0.7 kPa CO₂). The fruit were grown in three regions in Germany and stored for seven months (0 °C; 94% relative humidity) plus seven days simulated shelf-life. Scald development was positively correlated to the 6-MHO and α-farnesene (after three months of storage) and negatively correlated to an ascorbate level. The application of 1-MCP led to a reduction in the production of volatile compounds and antioxidants, except by ascorbate, which appeared to be associated with delayed ripening and the less severe development of scald. Ultra-low O₂ reduced the scald, but the effects depended on the production region.

Key words ultra-low oxygen; 6-methyl-5-hepten-2-one; 1-methylcyclopropone; α-farnesene; phenolics content; controlled atmosphere