Most foodies warn against storing tomatoes in the fridge, saying it saps them of their flavour. New research confirms this culinary opinion, revealing the way cold temperatures prevent critical flavour-enhancing genes from doing their job.
To extend the shelf-life of agricultural products like tomatoes, many of us resort to the tried-and-true practice of cold storage. Putting our produce in the fridge may prolong freshness and inhibit decomposition, but for at least one fruit (yes, tomatoes are a fruit), there's an important tradeoff to consider: taste.
New research published in Proceedings of the National Academy of Sciences shows that the practice of chilling tomatoes below 34 degrees Fahrenheit (12 degrees Celsius) inhibits their ability to generate substances that contribute to aroma and flavour. The study, conducted by researchers from the University of Florida, Cornell University, and several other institutions, explains why commercial tomatoes — which are often preserved in low-temperature storage — tend to be bland.
In an effort to investigate a potential link between genetics and chilling-associated flavour loss, the researchers stored a variety of red ripe tomatoes at 41 degrees F (5 degrees C) for one, three, and seven days, after which the fruits were stored at room temperature for either one or three days.
The tomatoes stored for one and three days still managed to retain their flavour, but the tomatoes stored for a week under cool conditions exhibited dramatically reduced levels of volatile compounds, the chemicals associated with aroma and taste. In some cases, levels of these compounds dropped by as much as 65 per cent. Storing these tomatoes for three days at room temperature did nothing to restore the volatiles to normal levels. In follow-up taste tests, a panel of 76 judges found the chilled tomatoes to be far less flavorful than those harvested the day before.
The reason for the lack of flavour has to do with the way that cold temperatures reduce the functionality of several genes associated with the production of volatile compounds, as well as epigenetic switches responsible for fruit ripening.
Armed with this knowledge, the researchers are now looking into the possibility of creating tomatoes that don't lose this ability in the cold. Until then, the researchers recommend leaving tomatoes on the counter or in a shaded area, adding that tomatoes have a decent shelf life. [PNAS]