Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2004
Publication Date: 4/10/2005
Citation: Kondo, S., Setha, S., Mattheis, J.P., Rudell, D.; Buchanan, D. 2005. Aroma volatile biosynthesis in apples affected by 1-MCP and methyl jasmonate. Postharvest Biology and Technology 36(1):61-68. Interpretive Summary: Aroma is an important component of apple fruit quality. Each apple variety has a characteristic aroma that is the product of a complex series of metabolism during fruit ripening. A number of factors control production of compounds that contribute to aroma including fruit ripeness at the time of harvest, storage duration, storage environment, and fruit exposure to compounds that accelerate or reduce the rate of fruit ripening. Two plant produced compounds that advance ripening, ethylene and methyl jasmonate, can under some circumstances actually result in reduced production of compounds that contribute to aroma. This seems to occur due to interference with the normal process of ripening and effects from these ripening stimulants is dependent on the stage of fruit ripenss when the materials are applied.
Technical Abstract: Effects of 1-methylcyclopropene (1-MCP) and methyl jasmonate (MeJA) on production of aroma volatile compounds and ethylene in 'Delicious' and 'Golden Delicious' apples [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] during ripening was investigated. Forty-three volatile compounds in 'Delicious' and 40 compounds in 'Golden Delicious' were detected. Among volatiles classified as alcohols, esters, ketones, aldehydes, acetic acid, and a-farnesene, esters were the most prevalent compunds followed by alcohols. Aroma volatile production was high in untreated controls and ethephon treatment. In contrast, 1-MCP decreased the production of all volatiles by both cultivars. Volatile production by 1-MCP-treated fruit was lower compared to untreated controls throughout the evaluation period. The impact of MeJA application on volatile production was cultivar dependent. The combination of ethephon with MeJA reduced volatile production by 'Delicious' compared to ethephon only, but this treatment combination stimulated volatile production by 'Golden Delicious' with the exception of esters. In genral, the effect of MeJA on volatile production correlated to the effect of MeJA on internal ethylene concentration. The results suggest that the effect of MeJA on aroma volatiles in apple fruit may be mediated by ethylene. Furthermore, the effect of MeJA on volatiles may depend on the growth stage of the fruit when treated with MeJA.