Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Proceedings
Publication Acceptance Date: 2/13/2004
Publication Date: 4/1/2004
Citation: Bai, J., Baldwin, E.A., Mattheis, J.P. 2003. Effect of 1-mcp pretreatment, ca storage and subsequent marketing temperature on volatile profile of 'gala' apple. Proceedings Of Florida State Horticultural Society. 116:400-404. Interpretive Summary: Apples are maintained for months after harvest by storing at near freezing temperatures in a special atmosphere of relatively low oxygen and high carbon dioxide (controlled atmosphere). 1-Methylcyclopropene (1-MCP) is a compound that has been recently approved for apples because pre-treatment of the fruit with this compound delays ripening of the fruit during storage. This study evaluated the effect of storage of apples at low temperature with regular air or controlled atmosphere with or without pretreatment with 1-MCP on apple aroma. Results showed that both 1-MCP and controlled atmosphere caused a reduction in apple aroma, but maintained firmness and acidity. Aroma was further reduced after the apples were removed from cold storage and held for one week at marketing (ambient) temperatures, especially for those pre-treated with 1-MCP.
Technical Abstract: 'Gala' apples pretreated or non-treated with 1-methylcyclopropene (1-MCP, 0.625 µL L-1) were stored under controlled atmosphere (CA, 2 kPa O2 + 2 kPa CO2) or regular air (RA) for 6 months at 1°C. Aroma compounds (measured by gas chromatograph and electronic nose) were analyzed every month directly and after transferring to 20°C for one week to simulate marketing conditions. The effect of 1-MCP was stronger than CA after transfer of fruit to room temperature. For electronic nose data, canonical discriminant analysis separated the storage treatments (1-MCP + CA, 1-MCP, CA, RA), indicating that the aroma profile was different in apples from each treatment. This was confirmed by GC analysis. Fruit lost most of the esters but not alcohols after transferring apples from 1°C to 20°C for all treatments. 1-MCP + CA inhibition of volatile production was greater, and did not show any benefit for maintaining firmness and acidity, compared to 1-MCP alone. Therefore, 1-MCP alone was the best treatment for storing 'Gala' apples with minimal loss of volatiles, while maintaining firmness and acidity.