Subtitles section Play video
-
You may have been told that putting tomatoes in your fridge will ruin them.
-
It turns out, that's kind of true.
-
Scientists have shown that reducing a tomato's temperature to below 20°C alters its gene expression,
-
which in turn reduces its yummy tomato smell.
-
So putting tomatoes in the fridge actually does make a lot of their ripe, juicy flavor disappear!
-
You might think a food's flavor is determined by the specific mix of chemicals that lands on your tongue.
-
And it is… partially.
-
But by definition, flavor is the overall impression you get from consuming a food or beverage,
-
an impression which results from both taste and smells.
-
There are only a handful of distinctive tastes that your taste buds can differentiate:
-
sweet, salty, sour, bitter, and umami.
-
Scents, on the other hand, are practically limitless.
-
Some research suggests the average person's nose can distinguish between one trillion
-
different odors, and all that variety could explain why scent is the largest determinant of flavor.
-
It's like when you were a kid and your parents made you eat something you didn't like,
-
and you would hold your nose while you downed it.
-
Plugging your nose and blocking the smell of something is actually enough to
-
seriously diminish the flavor because flavor is so reliant on smell.
-
Which brings us back to those tomatoes.
-
A tomato's flavor is the result of a combination of tasty sugars and acids, as well as chemicals
-
called aroma compounds, the molecules that easily leap into the air to give things their distinct smell.
-
And even after picking, the fruit continues to make some of these and break down others.
-
It's still full of living cells, so the overall flavor of the tomato can change over time.
-
In a 2016 study, when researchers put ripe tomatoes in the fridge for 7 days,
-
volunteers rated the taste of those chilled tomatoes as much less yummy than fresh ones.
-
But the sugar and acid levels, those key components of taste, didn't differ between the fresh and chilled fruits.
-
What did change were those aroma compounds: refrigerated tomatoes produced 65% less of them.
-
That led the team to conclude that the change in the tomato's flavor is caused by a reduction in its odor molecules,
-
not due to a change in its actual taste!
-
When they dug deeper, they found that the refrigerated tomatoes had reduced expression
-
of genes related to the synthesis of certain molecules, including branched amino acids,
-
fatty acids and esters, three key compounds that are important for aroma compound synthesis.
-
The researchers hypothesized that this could be an evolutionary response for conserving
-
energy when it is cold, though they'd need further evidence to confirm that idea.
-
It's not just tomatoes that are ruined by refrigeration, of course.
-
You might have noticed that a lot of different fruits seem to taste worse after a stint in
-
the fridge, but this is generally thought to be because lower temperatures halt the ripening process.
-
As a fruit ripens, it produces different aroma compounds, and it gains sugars and other tasty molecules.
-
So the less ripe a fruit is, the less yummy it will be.
-
But if you take these fruits out of the fridge and put them on the counter,
-
they will start ripening again and recover most of their flavor.
-
And once they're ripe, you're supposed to be able to put them back into the cold
-
to keep them at that tasty sweet point for longer.
-
But the researchers in this study weren't starting with under-ripe tomatoes—
-
they were starting with ripe ones.
-
So the loss of flavor wasn't because they prevented them from becoming fully ripe.
-
And taking the tomatoes out of the fridge didn't fully fix things.
-
So basically, there's no point in a tomato's ripening process where you can refrigerate them without losing flavor.
-
It's possible, or even likely, this kind of cold-induced flavor loss happens in other ripe fruits, too.
-
But as of yet, no one has really looked.
-
Either way, if you want the best-tasting produce, you should probably leave your fruits on the
-
counter until they are ripe, and never ever put your tomatoes in the fridge.
-
Though, if you really want the tastiest tomatoes, you should probably go for more colorful ones,
-
because the rosiest red tomatoes you see in stores just don't taste as good.
-
Check out our episode on Why Tomatoes Are So Bland to find out why!
-
And as always, thanks for watching, and don't forget to subscribe!