Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2005
Publication Date: 8/1/2005
Citation: Bai, J., Baldwin, E.A., Goodner, K.L., Mattheis, J.P., Brecht, J.K. 2005. Response of Four Apple Cultivars to 1-Methylcyclopropene Treatment and Controlled Atmosphere Storage. HortScience. 40(5):1534-1538. Interpretive Summary: A new compound, 1-methylclyclopropene (1-MCP), has been approved for postharvest use on apple fruit. This compound slows down ripening and extends the storage life of many fruits. Apples are currently stored in a controlled atmosphere of relatively low oxygen and high carbon dioxide at low temperature for up to a year. In this study analyzed treating or not treating apples with 1-MCP and then storing in regular air compared to controlled atmosphere. Results showed that controlled atmosphere storage was not really necessary if the apples are treated with 1-MCP for maintaining apple quality (firmness and acidity) during extended low temperature storage.
Technical Abstract: Apples ('Gala' , 'Delicious', 'Granny Smith' and 'Fuji'), pretreated or non-treated with 1-methylcyclopropene (1-MCP, 0.625 -1.0 µL L-1 for 18 h at 20 °C), were stored in controlled atmosphere (CA, 1-1.5 kPa O2; 1-2 kPa CO2) or in regular atmosphere (RA) for up to 8 months at 1 °C. Firmness, titratable acidity (TA), soluble solids content (SSC), and volatile abundance were analyzed every month directly or after transfer to air at 20 °C for 1 week to simulate marketing conditions. The CA +/- 1-MCP treatments delayed ripening and prolonged storage life as indicated by delayed loss of firmness and TA in all four varieties during storage. The CA +/- 1-MCP also slightly delayed loss of SSC for 'Gala' but had no effect on SSC levels for the other varieties. There were differences among treatments for firmness and TA content [(1-MCP + RA) > CA] for 'Gala', 'Delicious', and 'Granny Smith' apples (especially after transfer of fruit to 20 °C), but not for 'Fuji'. A combination of 1-MCP + CA was best [(1-MCP + CA) > (1-MCP + RA) or CA] for maintaining 'Delicious' firmness and TA. The treatments that were most effective at retaining TA and firmness retained the least volatiles. The results indicate that the efficacy of 1-MCP and CA in maintaining apple quality factors is variety dependent.