Hot tomato? Engineered “spicy tomato” could boost capsaicinoid content, research suggests

08 Jan 2019 --- Researchers have proposed engineering a “spicy tomato” variety that will significantly up the production of capsaicinoids to be used for commercial purposes. An opinion article published in the journal Trends in Plant Science, notes that besides its potential to become a new culinary trend, the “spicy tomato” may boost the production and use of capsaicinoids. This is a component originally found in chili peppers that has nutritional and antibiotic properties and is used in painkillers and pepper spray.

Tomatoes and chili peppers both derive from a common ancestor 19 million years ago and still share some of the same DNA. The tomato split off to become fleshy, nutrient-rich and easy in its cultivation, while the chili pepper turned defensive, developing capsaicinoids to ward off predators and is challenging to produce in large quantities.

Using modern gene-editing technology may allow us to engineer the capsaicinoid pathway to the tomato and make it easier to mass produce large quantities of capsaicinoids for commercial purposes, say the researchers.

“Engineering the capsaicinoid genetic pathway to the tomato would make it easier and cheaper to produce this compound, which has very interesting applications,” claims Agustin Zsögön, senior author and Plant Biologist at the Federal University of Viçosa in Brazil, whose research group is working toward this goal.

“We have the tools to engineer the genome of any species; the challenge is to know which gene to engineer and where,” notes Zsögön.

The news of innovative research has been welcomed by some in the tomato processing industry. “Anything that could revamp and expand the tired tomato products category may prove beneficial for the industry and I feel positive towards any new product development that will enrich our category,” Maria Nomikos, Group Sales Director for D.Nomikos tomato processing company, tells Nutritioninsight. “With good marketing and communication consumers will become interested,” she adds.

The “spicy” taste that capsaicinoids induce, is not a taste at all but rather a reaction to pain. Capsaicin activates nerve cells in the tongue that deal with heat-induced pain, that the brain translates as a burning sensation.  

Evidence suggests that the evolution of capsaicinoids helped chili peppers deter small mammals from eating their fruit. There are at least 23 different types of capsaicinoids, which originate from the pith of the chili pepper. The spiciness of a pepper is determined by the genes that regulate capsaicinoid production and less pungent peppers have mutations affecting this process. 

Previous gene sequencing work has shown that tomatoes have the genes necessary for capsaicinoids but don't have the machinery to turn them on.

“In theory, you could use these genes to produce capsaicinoids in the tomato,” says Zsögön. 

“Since we don't have solid data about the expression patterns of the capsaicinoid pathway in the tomato fruit, we have to try alternative approaches. One is to activate candidate genes one at a time and see what happens, which compounds are produced,” he adds.

Tomato genome sequencing has allowed for a lot of innovation to come forward, most recently with Lycored’s Lycomato, a proprietary blend for supplements, being marketed as the first tomato extract to carry the Non-GMO Project Verified seal. 

Tomato and the chili pepper sequencing in combination, pave the way to engineering a spicy tomato. Triggering the genes responsible for pungency in tomatoes may open up a whole lot of possibilities, the researchers say. This way, they hope to better understand the evolution of this unique botanical trait and allow for the development of tomato capsaicinoid biofactories. Moreover, they believe it could extend to the production of several new produce varieties that may in the future become grocery aisle staples.