The Science of New High Flavor Tomatoes

When I was a child, during the months of July and August the family laundry basket would get a workout. With me on one side and my little sister on the other, we’d lug bushels of garden tomatoes from the yard to the kitchen. We lived just outside of Chicago, and the rich soils and my family’s greenish thumbs brought us an annual bounty of tomatoes that we’d eat fresh, then process the rest in jars for the long winter.

In that warped blue plastic basket, my mom would shift the fruits around and select a perfect sun-warmed tomato. She’d look at it for a few seconds, then place the red ripe fruit on a worn cutting board under our sharpest knife. As the skin would yield to the slice, a drip of sweet red-orange juice would race down the edge, ending as an aromatic puddle. She’d sprinkle on a little salt, then eat it with a fork, one tiny bite at a time. It was a delicate and tasty slice of summer, and a moment to savor. The familiar fruit was in its finest form.

Yesterday I stood at a local sandwich shop and watched a corporately-festooned employee deal out funny pink “tomato” slices from a neat stack in an icy incubator onto a bed of anemic white lettuce. This was a tomato in its modern form, a remarkable departure from the red orb of the family garden, now a half-ripe, pathetic slab of sandwich decoration. The definition of “tomato” had officially shifted, moved from a prized fruit to a clownish condiment.

Why have tomatoes changed so much? Consumers demand uniform, affordable, safe fruit, and they want it 365 days a year. But tomatoes, like any fruit, are difficult to produce. Tiny fragile plants must be nurtured in acres of production plantings. These plants are then under assault from nature, as weather and plant diseases haunt even the most pristine fields. Growing, harvesting, shipping, and retailing perishable fruit is not an easy business, and to have a slice of tomato in January, on a Winnipeg fast-food hamburger, is almost a little miraculous.

So how can we make that large-scale production tomato on par with the ones from my family garden? Today scientists use their knowledge to improve the tomato, orchestrating the unlikely marriage of the best heirloom sensory traits with the qualities required for wide-scale production. It is using good-old plant sex to move genes, followed by arduous searching for the rare vine in fields of failures that yields fruits with production quality and sensory excellence.

The search for the perfect tomato has been going on at the University of Florida’s Horticultural Sciences Department. There, Dr. Harry Klee has spent decades pondering the perfect tomato. Now science tools have finally caught up with his ambitions, providing new molecular tricks that make the elusive tomato variety more likely to be found. It is as if he’s looking for the proverbial needle in a haystack — but now he’s armed with a powerful magnet. This should make things easier.

The perfect fruit or vegetable is a rare combination of what consumers want, the genetics of a plant that makes production possible, and the flavor and aroma compounds available in the final product.

The new tools are DNA sequencing resources. In short, it is now relatively cheap and easy to obtain the entire genetic code for a given plant. Klee now has biological blueprints of hundreds of tomato varieties. He also has information about the volatile chemicals, acids, and sugars naturally present in tomatoes that heighten the sensory experience. Together with faculty in the Plant Innovation Center, he has collected disk drives of consumer preference data that show how those chemical profiles influence consumer reaction.

Information about consumer desire and knowledge of influential flavor compounds and the genetic blueprints allow intricate comparisons to be made. Scientists look for trends that match consumer taste experience to certain genes or certain compounds. Once those genes or aromatic chemicals are identified, it makes it easier to select parent plants to eventually bundle all the best qualities into one plant.

Two new tomato varieties were released last year that are primarily targeted to the home garden. These varieties, called “Garden Gem” and “Garden Treasure,” are the result of a cross from an outstanding Florida production tomato-parent and a specific heirloom. The production variety brings disease resistance, firmness, and size. The heirloom brings flavor and aromas. Together they make a nearly perfect tomato.

This year Dr. Klee will release a new tomato variety where one parent provided a gene to produce a deep red color. The color is the result of lycopene, a natural compound producing attractive red colors in fruits and vegetables. Lycopene has potential roles in human health, and also is processed into an array of other compounds, several contributing to flavors. In short, this year’s garden invention doesn’t just taste better, it might be better for you.

Klee’s efforts in studying tomato DNA blueprints, and using them to make decisions about plants to cross, dramatically decrease randomness and chance in the process of new variety development. He’s one of many plant scientists searching for that new molecular recipe that rapidly improves products for consumers, while being feasible for farmers to grow. Understanding the consumer, the compounds that stimulate the senses, and now tomato genetics, all allow scientists to rapidly create new exciting varieties with tantalizing flavors and aromas. While “Garden Gem” and “Garden Treasure” tomato varieties are not yet for sale, seeds can be obtained as a thank-you gift for a $10 donation to Dr. Klee’s tomato breeding program.  

First published February 2016