ANTIOXIDANT PROPERTIES AND FRUIT QUALITY DURING LONG-TERM STORAGE OF ROCHA PEAR: EFFECTS OF MATURITY AND STORAGE CONDITIONS

Free radical scavenging activity and the content of ascorbic acid and glutathione were investigated during long-term storage of the pear (Pyrus communis L. 'Rocha') fruit harvested at different maturity stages, stored in air or under controlled atmosphere and subjected to postharvest treatments with diphenylamine (DPA) and 1-methylcyclopropene (1-MCP). Harvest maturity had a significant effect on storage disorders, fruit firmness, soluble solids content and acidity. Differences in ascorbate content and free radical scavenging activity at harvest did not persist during storage. Controlled atmosphere and DPA strongly reduced the incidence and severity of browning disorders and superficial scald, whereas 1-MCP provided the most effective control. Neither DPA nor 1-MCP affected the free radical scavenging activity or the levels of ascorbate and glutathione in the pear. These results suggest that the benefits of 1-MCP on internal breakdown are not directly related with its effects on the antioxidant levels and that, under good storage conditions, the antioxidant properties of the Rocha pear can be maintained for up to 8 months.