Most gardeners know the flavor and nutritional quality of fresh tomatoes is best if you grow your own. New research from France shows that the temperature at which fruit ripens can also affect the taste and chemical composition. Researchers in Avignon, France, harvested mature green tomatoes from a greenhouse and ripened the fruits in light or dark rooms at either 70 or 79 degrees F. Six days later when the fruits were fully ripe, they measured the concentration of various nutrients.
Concentrations of carotenoids -- including the cancer-fighting compound lycopene -- were highest with fruits ripened in light rooms at 70 degrees. However, higher levels of sugar and lower levels of acidity were recorded when the fruits were ripened in light rooms at 79 degrees. While you can't regulate the temperature outdoors in the garden, you can adjust the indoor temperature where you ripen those green fruits harvested before the first fall frost. For the highest nutrient content, keep the tomatoes at 70 degrees. For sweeter fruits, keep them at 79 degrees.
For an abstract of this research, go to: Journal of Agriculture and Food Chemistry.