“Refrigeration is the enemy of the tomato as it nullifies flavor and turns the flesh mealy. The culprit is a compound called Z-3 hexenel, which accounts for the tomato’s scent and taste. The development process which turns tomato’s linolenic acid to the Z-3 that makes our mouth and nose sing is hindered by cold. If you must refrigerate a tomato, take it out about an hour before using it to let it return to room temperature to revive any lurking Z-3.” –explanation provided by about.com:homecooking.
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