The Quest to Return Tomatoes to Their Full-Flavored Glory Read

[Keiththibodeaux]

1/28/2017 The Quest to Return Tomatoes to Their Full★Flavored Glory | Science | Smithsonian

http://www.smithsonianmag.com/scienc...733;180961933/ 1/4

Smithsonian.com
The Quest to Return Tomatoes to Their Full★Flavored Glory
We’ve bred the original tomato taste out of existence. Now geneticists are asking:
Can we put it back?
The bigger the tomato, the blander the taste. (Vladislav Gudovskiy / Alamy)
By Brian Handwerk
smithsonian.com
January 26, 2017
For most city dwellers, the luscious taste of a vine★ripened garden tomato bursting in the mouth is little more than a distant
memory. Sadly for supermarket shoppers, the standard grocery varieties have grown bigger, blander and hardier for cross★country
shipping and storage. Now scientists have charted the genetic path that made today’s tomatoes nearly unrecognizable from their
more flavorful predecessors.
By uncovering the tomato's genetic journey, researchers have identified key flavor★enhancing genes that have dwindled or
disappeared as the tomato changed over the years. Armed with this new knowledge, they believe they can return that taste to
today’s supermarket tomatoes—with a little genetic fiddling.
Tomatoes are the world's highest★value fruit or vegetable crop, with farmers producing more than 170 million tons of them
worldwide in 2014, according to the Food and Agriculture Organization of the U.N. But our insatiable appetite for this bright
1/28/2017 The Quest to Return Tomatoes to Their Full★Flavored Glory | Science | Smithsonian
http://www.smithsonianmag.com/scienc...733;180961933/ 2/4
fruit has had consequences. The mass★produced varieties regularly available in world markets travel well, store for weeks, and
cost relatively little—but they’ve also lost what made them so desirable in the first place.
Today's fruit simply doesn't pack the flavor of the old★fashioned tomato, finds a new genome study published today in the journal
Science. “Genomic technologies, like the ones the authors used in this research, really enable us to study what happened to the
tomato in a very effective way,” says Esther van der Knaap, a plant geneticist at the University of Georgia who was not involved
in the new study. “What did we leave behind, and what are we carrying through?”
To trace the fruit's genetic history from its ancient Andean ancestors to today, crop genetics researcher Harry Klee and colleagues
sequenced the genomes of 398 tomato varieties and relatives—a mix of modern commercial, heirloom and wild plants. Then,
they asked panels of taste testers to rate the characteristics of 101 tomato varieties.
Comparing the genetic fingerprints of each fruit with taster reviews and preferences revealed dozens of chemical compounds, and
the corresponding genes behind them, that tasters heavily associated with flavor—many of which have been lost over centuries of
breeding.
The results also revealed something unusual about the essence of true tomato taste: It’s incredibly complex. Flavor is already an
intricate combination of what the tongue tastes and the nose smells. But the tomato's flavor is especially layered, involving
chemicals like acids and sugars (which switch on taste receptors) as well as compounds known as volatiles (which get our smell
receptors in gear).
It's this beguiling combination of taste and smell that delivers the distinctive tomato flavor—and is largely responsible for the
taste problem tomatoes face today. “The tomato is not like many of the common fruits you might think of, like bananas or
strawberries, where if I just gave you one volatile you’d say ‘Oh, that's a banana,’” explains Klee, of the University of Florida.
“There are at least 25 different volatile chemicals, the aroma compounds, that all contribute to the flavor of a tomato.”
Flavor is a delicate dance of taste and aroma, and today's tomatoes lack both. (springtime78 / iStock)
In all that complexity, two factors may have outsize importance for tomato flavor: size and sugar. As you might expect, sugar
makes tomatoes taste better. And the bigger a tomato, the less sugar you tend to find in it.
The new study revealed in minute genetic detail how tomatoes simultaneously grew larger and less sweet over time. Thanks to
modern breeding techniques, tomatoes have expanded in size as much as 1000★fold since they were domesticated. Scientists
previously pinpointed the genes responsible for the explosion in tomato sizes after domestication, including one named fw2.2 and
another, called fasciated, that can boost tomato sizes by up to 50 percent.
But modern farmers aren't entirely to blame, the genetic study found. “The selection for big fruit and against sugar is dramatic in
the modern varieties,” says Klee. “But it goes way back to pre★Columbian days when the Native Americans were already
1/28/2017 The Quest to Return Tomatoes to Their Full★Flavored Glory | Science | Smithsonian
http://www.smithsonianmag.com/scienc...733;180961933/ 3/4
selecting for bigger fruit with lower sugar content.”
Putting more tasty sugar back into mainstream tomatoes may simply not be feasible with today’s production realities, says Klee.
That's because most growers aren't paid for flavor; they're paid by the pound. It costs just as much to have a worker pick a small
tomato as to pick a huge one, which is a big reason why today's commercially★produced tomatoes (Solanum lycopersicum) can be
so much more massive than their tiny wild ancestors.
“The breeders have selected plants to produce massive amounts of fruit, all at the same time, and they want bigger fruit on to the
plant. The plant just can't keep up with that, so what happens is you dilute out all of the flavor chemicals,” says Klee.
The study also revealed another surprise in the tomato’s path to blandness. Much of the dilution of tomato flavor over time wasn’t
just the necessary result of breeding for larger fruit—it was an accidental side effect. Since breeders aren’t regularly genetically
testing their tomatoes, it’s easy for any of the 25 different chemicals involved in tomato aroma to simply drop out one by one
over the generations, when the allele for poorer flavor choice is randomly selected.
It seems that, in the case of tomatoes, no one noticed this slow dilution until the cumulative impact of all those lost genes became
obvious. “Out of the 25 volatiles 13 of them are significantly reduced in the modern varieties, “ Klee says. “Its almost exactly
what you'd predict would occur randomly, but the net effect is that you've diluted out flavor.”
Klee likens this tomato tragedy to the piecemeal dismantling of a symphony orchestra: “If you pull out a single instrument and
then listen you don't notice the difference. Then you pull out a second instrument, and you don't notice, until if you keep going all
of a sudden you reach a point where you say wait a minute, this just doesn't sound right.”
How can we restore those lost instruments? Fortunately, bringing back tomato aroma doesn't seem to involve the same trade★offs
that plague the sugar★size relationship, says Klee.
“There's no obvious tie with things that needed to be selected to improve the crop, like shelf life or firmness, so I think we can do
it without undoing that good work that the breeders have done,” he says. “Humans are exquisitely sensitive to smells and the
levels of these compounds in the fruit are actually quite low, even though we can detect them quite readily. So doubling the levels
of a lot of these compounds, even just pushing them back to the level where there were in an heirloom tomato 50 years ago, is
probably not all that challenging.”
Klee believes that restoring heirloom quality flavor to standard tomatoes would require a drop in the yield, meaning farmers
would only be able to produce perhaps 90 percent of their current crop size. Prices on those tomatoes would also have to rise
accordingly. The question is: Will these high★taste, high★quality, and inevitably higher★cost tomatoes sell? Klee, for one, believes
they will. “Look at craft beers, or what's happened with coffee, over the past couple of decades,” he says.
But beyond specialty tomatoes, there are limits to what can be done to the average commercial tomato, which is bred to endure
travel and long periods of storage. “A really good tasting tomato is one that ripens on the vine, so they are always going to be
soft,” says van der Knaap. “They cannot be produced over long distances, and can't be stored in a grocery store for four weeks
without rotting.”
How tomatoes are handled also influences their ultimate flavor—both along the way from farm to store and also in the buyer's
home. “If you want to destroy the flavor of a tomato it's simple: Just put them in the refrigerator,” she says.
Still, both researchers believe it’s feasible to make significant improvements to your average run★of★the★mill grocery tomato. “If
those tomatoes can be even slightly improved it will be a big gain for consumers, and this study certainly shows a road map of
how that can be done,” says van der Knaap.
Klee's University of Florida lab is now going further than just making a road map. They’re testing varieties, with a little help
from home gardeners. For a donation to the tomato research project, citizen tomato scientists can receive a package of the group's
Garden Gem and Garden Treasure tomato seeds to plant them and document for the project. Of course, volunteers also get to
enjoy eating the fruits of their labor, even if grocery shoppers won't enjoy quite the same taste.
“I think that we're not going to produce heirloom flavor in a commercial tomato. Because the growers aren't going to be able to
budge on yield and reducing yield is the only way to get more sugars,” Klee says. “It's not going to be like a fresh Brandywine
picked in your backyard, but it is going to be a lot better.”

[Nan_PA_6b]

Good! Glad to know someone's working on the problem!

Nan

[MissS]

A nice read. It goes back to the development of Garden Gem and Garden Treasure. Has anyone grown their seeds of these out?

[kameronth]

Here is the link to Dr. Klee's University of Florida lab site mentioned in the article. It looks like it's a $10 donation to get both varieties. I may give them a shot.

http://hos.ufl.edu/kleeweb/newcultivars.html

[kurt]

Originally Posted by MissS

A nice read. It goes back to the development of Garden Gem and Garden Treasure. Has anyone grown their seeds of these out?

I keep 3/4 of both each year for salads,perfect size when quartered.And as homage to our industry here in FL.This below piqued my interest.

http://www.tomatoville.com/showthrea...ghlight=Garden

[pmcgrady]

Start from scratch! Trying to improve an inferior product is a waste of time!

[KarenO]

No matter what they do, if they continue to gass them ripe and ship them in refrigerated trucks. I think a large part if the problem is in the handling. Even my Good homegrown tomatoes would suffer in flavour if handled like a commercial tomato.
KarenO

[jpop]

Originally Posted by KarenO

No matter what they do, if they continue to gass them ripe and ship them in refrigerated trucks. I think a large part if the problem is in the handling. Even my Good homegrown tomatoes would suffer in flavour if handled like a commercial tomato.
KarenO

Agreed, I wonder how these fare as they ship to other states although grown within 50 miles of myself.

http://www.farmhousetomatoes.com/Home.php