At last! Scientific confirmation of what anyone with a palate already knew: Supermarket tomatoes, by and large, are as tasty as raw potatoes, which is to say they basically have no flavor at all.
As humans have tried to develop a tough-skinned, slow-ripening commercial tomato that would survive the rigors of long-distance transport, it appears the flavor genes got left behind, says molecular biologist James Giovannoni.
Consumers have been grousing about Flavorgate for years, Giovannoni said, especially when they compare the supermarket varieties to the tomatoes that Grandma used to grow, or even the ones they grew last summer in their yards.
"Lots of people don't know what a fresh peach should taste like because they've never grown one, but tomatoes are a little unique," he said. "If you're growing anything at your home, it's probably a tomato plant, even if it's on your balcony, so people know what a good tomato should taste like."
Nonetheless, he said, Americans continue buying blah tomatoes, to the tune of more than 20 pounds per man, woman and child in 2017, according to the U.S. Department of Agriculture, making tomatoes the second most consumed produce over - of course - potatoes.
"They add color and when you cover them with ranch dressing, you don't taste it anyway," Giovannoni joked.
But now breeders have a key for reinserting some flavor into their tomatoes, while still keeping them market tough.
Giovannoni, of the USDA's Agricultural Research Service Plant, Soil and Nutrition Research Laboratory, and fellow researcher Zhangjun Fei, a bioinformatics scientist at the Boyce Thompson Institute, both in Ithaca, N.Y., have constructed a pan-genome - basically the entire set of genes - for 725 different cultivated tomatoes and their wild relatives, discovering 5,000 previously undocumented genes.
Turns out wild tomatoes have lots of flavor but they're also tiny, around the size of a pea, Giovannoni said. Humans began cultivating larger mutants of the wild variety, that originated in South America.
The researchers discovered one particular gene - dubbed TomLoxC - that is present in 91% of the tasty wild varieties, primarily Solanum pimpinellifolium, a.k.a. currant tomatoes, which are sometimes used as a garnish in fancy restaurants, Giovannoni said, served on a stem like a cluster of tiny grapes to add a little pop of tomato flavor.
But - surprise, surprise - TomLoxC was only present in about 2% of cultivated varieties, including heirlooms.
TomLoxC actually provides more fragrance than flavor, Giovannoni said, but aromatics are a huge component of how things taste. "This isn't the only reason tomatoes have flavor. A lot of it is sugar and acids and the balance between the two. But aromatics are important. Your perception of flavor is what your taste buds are telling you and what your olfactory - smell - system is telling you."
Now that researchers have teased out a critical flavor gene, breeders can start adding it to the mix when they create new commercial varieties. And now that they know what genes provide specific qualities, they can test their new plants when they're only a few inches tall, to see if they include all the qualities they want, from long shelf life to TomLoxC aromatics.
"Breeding has been more of an art," Giovannoni said "This makes it more of a precise science."
If you don't want to wait for the breeders, here's a list of existing tomato varieties with the cherished TomLoxC gene - both heirloom and hybrid types - that you can plant at home, or look out for at specialty markets and farmers markets:
Sugar Lump has golf-ball size fruit. The rest are cherry-size tomatoes: Peacevine Cherry, Yellow Cherry, Snowberry (yellow-white), Galina (yellow), Katinka Cherry (Russian heirloom orange-red), Gardener's Delight, Marcellino Hybrid, and Super Sweet 100 Hybrid.