Have you ever noticed that buying a tomato (or a number of other fruits and vegetables) that has anything resembling taste can be very difficult? It’s not just because it’s winter. Most tomatoes sold in supermarkets are bred to be bland, and some scientists are trying to find a way back to good taste.
The number one reason why tomatoes taste more like paste is because of shipping and storage requirements. Breeders have been successful at creating tomatoes that can ship virtually everywhere without bruising or breaking down, but that sturdiness comes at the expense of flavor. Sturdy tomatoes also grow much faster, which doesn’t allow time to develop the chemicals that add flavors.
It’s a volatile issue
What are these flavor-enhancing chemicals? While all tomatoes have acids and sugars and affect how we taste them, another important component of a good-tasting tomato is the volatile compound—a chemical that easily becomes a gas and therefore can be smelled. The volatiles, which are lacking in most mass-bred tomatoes, are what give a tomato its sweet taste, and are also what are bred out of most store-bought tomatoes. What’s been put in their place? Water. Yawn. This means that mass-produced tomatoes not only don’t taste very good, but they don’t have as much nutritional value as their slower-bred brethren.
Harry Klee, a biologist at the University of Florida, and his colleagues identified six volatile compounds that impart better taste in a tomato. Moreover, these compounds add a sweet taste to the tomato without adding sugar. Klee, who presented his findings at the American Association for the Advancement of Science meeting in Boston last week, experimented with 100 tomato varieties with 13 panels of 100 people, who rated each tomato according to taste and sweetness. Surprisingly, much of that taste came from the volatile compounds and not from sugar. Klee found that the volatiles, working through sensors in the nose, convinced the brain that a certain tomato was sweeter than another. Not all volatiles make things sweet, however—some create a dirty sock smell, for example—so selecting the right ones is important!
Klee’s findings show that breeders can create sweeter tomatoes, without using genetic engineering methods or adding sugars. However, since the tomato genome was sequenced last year, this advance will make it easier for breeders to identify the genes behind the right volatile compound production, and make sure their plants are expressing those genes.
So, what to do?
To get sweeter and more nutritious tomatoes, try farmers markets and look for heirloom varieties (pictured). Farm markets tend not to cater to mass-produced produce, and heirloom tomatoes are bred more slowly, allow the development of these key volatile compounds (that’s why they can be more expensive).
An important step not to take is refrigeration. While this may make a tomato last longer, it arrests the ongoing process of creating volatiles that continues in a tomato after it’s picked.
Photo: Greenmarket Recipes
Tieman D, et al. (2012). The chemical interactions underlying tomato flavor preferences. Current biology : CB, 22 (11), 1035-9 PMID: 22633806
tasteless vegetables, vegetable breeding, tomato breeding, insecticides in fruits and vegetables