Effect of 1-methylcycloprene on tomato flavour components, shelf life and decay as influenced by harvest maturity and storage temperature

Authors: Baldwin, Elizabeth - Liz; Plotto, Anne; Narciso, Jan; Bai, Jinhe

Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2010
Publication Date: 3/18/2011
Citation: Baldwin, E., Plotto, A., Narciso, J., Bai, J. 2011. Effect of 1-methylcyclopropene on tomato flavour components, shelf life and decay as influenced by harvest maturity and storage temperature. Journal of the Science of Food and Agriculture. 91:969-980.

Interpretive Summary: Consumers are not happy with the flavor of fresh tomatoes. Tomato flavor quality has declined due to genetics, storage at low temperature and due to the fact that the fruit are harvested immature. The low storage temperature and the harvesting of green tomatoes ensures an adequate shelf life for the fruit to make it through the marketing chain before they ripen and soften, resulting in less damaged fruit. This study looked at the effect of harvest maturity (harvesting tomatoes with color), and storage of tomatoes at a higher temperature than currently practiced commercially. To extend the shelf life of tomatoes harvested with color and stored at a higher temperature, the fruit were treated with a ripening inhibitor. Results showed that tomatoes that are harvested later and stored at a higher temperature had better flavor quality and adequate shelf life if treated with the ripening inhibitor.

Technical Abstract: For years there have been reports of consumer dissatisfaction with fresh market tomatoes (Solanum Lycopersicon; formerly known as Lycopersicon esculentum). In Florida, tomatoes are harvested green (GR), which includes mature green (MG) and immature green (IG) fruit, gassed with ethylene and stored at low temperature (13 °C) resulting in poor flavor. Flavor improvement might be achieved if fruit were harvested with some color (to eliminate immature green fruit) and/or stored at a higher temperature with the aid of the ethylene action and ripening inhibitor, 1-methylcyclopropene (1-MCP). To this end, the effect of 1-MCP, harvest maturity and storage temperature on tomato flavor components was evaluated. In the fall season, ‘Florida 47’ tomatoes were harvested at the GR (included MG and IG fruit), breaker (BR), turning (TR) and pink (PK) stages; treated or not with 1-MCP (+/- MCP) and stored at 13ºC or 18 °C. After ripening, fruit were evaluated for flavor components, color and decay. Since there were negligible differences due to harvest maturity, a second experiment the following spring compared BR tomatoes (+/- MCP), stored at 13 °C , or 18 °C for 6 days then ripened at 18 °C, to compare with MG and IG-harvested tomatoes stored 6 days at 13 °C, then ethylene treated and ripened at 18 °C to simulate commercial conditions. For shelf life in the fall experiment there was a gain of 1-6 days depending on harvest maturity and storage temperature due to 1-MCP. Storing at 18 °C resulted in an increase in internal red color, soluble solids (SS) to acids (TA) ratio, and levels of 10 out of 17 volatiles studied compared to 13 °C. Treatment with 1-MCP had little effect on SS, TA or volatiles, but slightly enhanced internal red color, and PK-harvested fruit ripened with slightly more red color than earlier harvest maturities. Shelf life was similar for BR (+) MCP stored at 13 ºC as for MG fruit (4 days longer than untreated BR tomatoes stored at 18°C ), but not as long as for IG fruit. IG fruit exhibited lowest levels of SS and TA and seven volatiles (and with MG was lower than BR fruit for another 3 volatiles). Therefore, harvesting tomatoes with color, thereby eliminating IG fruit (BR), treating with 1-MCP, storing initially at 13 °C and ripening at18 °C resulted in better quality than IG fruit stored under commercial conditions, with shelf life similar to GR fruit.