Effects of repeated applications of low concentrations of 1-MCP on storage and ripening of ‘Bartlett’ pears
E. Mitcham , J.H. Bower, and W.V. Biasi
Proceedings of 26th International Horticultural Congress. Volume of Abstract . Toronto, Canada, 11-17 August, 2002. Abstract S09-P-35. pp. 236.
2002
บทคัดย่อ
Application of 1-methylcyclopropene to ‘Bartlett’ pear fruit may extend storage life by reducing storage scald and loss of firmness. However, it is critical that pear fruit ripen fully prior to consumption, and develop the characteristic flavor and buttery texture.We explored the use of repeated applications of 1-MCP on the storage quality and ripening characteristics of ‘Bartlett’ pear fruit. In earlier studies, fruit treated with 1ppm 1-MCP did not ripen, while fruit treated with 0.25 and 0.5 ppm showed intermediate levels of ripening inhibition. Freshly harvested ‘Bartlett’ pear fruit were cooled overnight to 0 0C, then exposed to 0, 0.2 or 0.4 ppm 1-MCP for 12 hours at 0oC. Fruit were stored at –10C for 4 or 6 weeks. After storage, half the fruit were removed for assessment, and the remaining fruit were treated again with the same concentration of 1-MCP as at harvest. Retreated fruit were stored for a further 4 or 6 weeks, doubling their time at 1- 0C before assessment. Pears were evaluated upon removal from storage and after 6 days at 20 0C. After 4 weeks of storage, the fruit treated with 1-MCP yellowed and aoftened slower than control fruit. However, fruit that were retreated after 4 weeks of storage showed increased differences between the treatments. Fruit that were treated twice with 0.4 ppm 1-MCP showed little color change during ripening, while those treated twice with 0.2 ppm were intermediate between the 0.4 and control fruit. Fruit treated twice with 1-MCP (at 4 and 8 weeks) yellowed and softened slower than fruit treated once (at 4 weeks) with the same concentration. These results suggest that the ability of the fruit to produce new ethylene binding sits diminished during storage. Whereas previous work showed that 1-MCP had a greater effect on fruit softening than on color development, in this case there appeared to be a somewhat greater effect on color.