Can’t Handle The Heat? A Potential “Anti-Spice” Could Tame Spicy Food

A chili pepper’s spiciness is known as its “pungency”; basically, its ability to produce the familiar burning sensation that comes when you eat them. The sensation is a form of chemesthetic perception, which is the sensitivity of our skin or mucus membranes to chemicals, especially those that trigger temperature, tactile, or pain sensations.

The heat of chili peppers has been attributed to two members of a class of compounds called capsaicinoids: capsaicin and dihydrocapsaicin. Traditionally, their overall pungency has been calculated based on each pepper’s concentration of these two compounds, based on what are known as Scoville Heat Units (SHU), a standard unit of measurement for spiciness that was developed over a century ago.

However, the new research from Ohio State University has identified three compounds in a range of pepper samples that actually lower heat intensity, which undermines the effectiveness of SHU as a measurement system.

The results have several potential applications, including customizing chili pepper breeding, offering alternative pain relief options to capsaicin, and even potentially a new condiment for cooking.

“If you’re at home and you’ve ordered cuisine that has spice to it that’s a little too hot for some tastes, you can just sprinkle on a form of chili pepper that has got these suppressant agents in them that will dial it down,” Devin Peterson, professor of food science and technology at The Ohio State University, explained in a statement.

“I think the idea of using a natural material as an anti-spice, especially for somebody with kids, would have value as a household ingredient.”

In their work, Peterson and colleagues took 10 cultivars of chili peppers and determined their Scoville units based on their capsaicinoid content. They then normalized the samples by preparing them in dried powder form, each with the same number of Scoville units. The team then added the standardized powders to tomato juice and gave them to a panel of trained testers to judge their pungency.

“They’re all in the same base and all normalized, so they should have had a similar heat perception, but they didn’t,” Peterson added. “That is a pretty clear indication that other things were at play and impacting the perception.”

In order to identify what was going on, the team created statistical models and examined molecular structures in existing libraries of chemicals. This allowed them to identify five potential compounds that may be responsible for lowering the pepper’s perceived punch.

With this information in hand, a second group of trained testers was employed to compare the pungency of a range of capsaicinoid samples that had varying levels of these candidate compounds. In these tests, different samples of the compounds were placed on each side of the tongue simultaneously.

In addition to the taste-testers, the team also examined the samples using high-resolution mass spectrometry and nuclear magnetic resonance (NMR) experiments. This latter method uses magnetic fields and radio waves to study properties of atomic nuclei, which offers valuable information about the molecular structure, behavior, and chemical environment of a sample. This allowed the team to narrow down the heat-supressing compounds to three candidates: capsianoside I, roseoside, and gingerglycolipid A. 

These results describe a mechanism that affects chili pepper heat levels, but they are not exclusive to any specific chili pepper varieties.

The results could have implications for helping to make foods taste better for different people without the need of adding sugar, salt, or fats.

“What is maybe underappreciated from a science perspective is how important food flavor is to your dietary patterns and your enjoyment in life,” Peterson said. “So part of what we focus on is, how do we make healthy eating less difficult?”

But while the identification of these three compounds make help with culinary efforts in the future, there is also a pain management angle that comes from it.

The TRPV1 receptors in our oral cavity are responsible for perceiving chili pepper pungency. They are triggered by molecules like capsaicin, which causes the painful heat sensation. These receptors are present throughout our bodies, meaning that capsaicin in supplements and topical treatments can be used to alleviate pain. This works by initially exposing the receptors to the irritant which eventually desensitizes them to the stimulus so pain goes away.

Although it is too early to say for sure, the newly identified heat-suppressing compounds may offer the same desensitizing benefits, but without the initial irritation.

The study is published in the Journal of Agricultural and Food Chemistry.