1144 GMT February 23, 2020
"About 30 compounds are important in creating a full-bodied tomato flavor", said study coauthor Harry Klee of the University of Florida in Gainesville.
He and colleagues have identified 13 important molecules that have dwindled away in many mass-market varieties, sciencenews.org wrote.
Some of the flavor compounds deliver such a thrill to the human sensory system that even a modest increase could make a big difference, the researchers reported.
Alisdair Fernie, who was not part of the study but has studied tomato chemistry at the Max Planck Institute of Molecular Plant Physiology in Potsdam, Germany, said, "I think this will definitely help.
“Taste is incredibly complex, so creating more appealing commercial varieties for certain, requires a holistic approach."
To achieve that holistic view, the researchers teamed up with geneticists at China’s Agricultural Genomics Institute in Shenzhen, who determined the full genetic makeup of a whopping 398 kinds of tomatoes, wild as well as heirloom and commercial.
The scientists ran 96 varieties of tomatoes through taste-testing panels, looking for genetic and chemical similarities among those varieties ranked tastiest.
Much of what makes some tomatoes taste better is actually smell, Klee pointed out. Tongues can detect relatively few qualities, such as sweetness, acidity and softness.
Chemical detectors in the nasal passages are far more varied and sensitive. So what really puts the 'Mmmm' into a tomato is the whoosh of air forced up into the nasal passages as someone swallows.
Airborne compounds, known as volatiles, are abundant in tomatoes, and Klee looks to them for flavor magic.
Of these volatile compounds, some appear in even the tastiest tomatoes at minuscule levels — only parts per trillion. But human senses respond so strongly to the odors that a little bit goes a long way.
"Tomatoes should taste noticeably better if researchers can breed just four or five heirloom versions of volatile-producing genes back into commercial varieties", Klee said.
Increasing the sweetness of today’s tomatoes, on the other hand, may be tougher. About 80 percent of the sugar in commercial tomatoes comes from the leaves and is transferred to the big red globes as they mature. Because breeders have done such a great job of maximizing the number of fruits on a plant, the plants would need lots of leaves to sweeten them all. So the price of sweeter tomatoes would be making them smaller, and fewer.
Klee said, “Now we come to the real crux of the problem. I have to fix the flavor, but I can’t compromise all of the stuff that breeders have done to the modern tomatoes to make them healthier, more productive, more disease resistant and more shippable."