New 'Thermometer' for Chili Peppers

Most of the capsaicinoids (compounds that give peppers their spiciness) are hidden inside the pepper's white flesh. (Image credit: stock.xchng)

Testing the hotness of a habanero chili pepper just went digital.

A team of chemists has developed a mathematical computer model to measure the "heat" inside a chili pepper, a process that could provide quicker and cheaper information to certain food and drug industries. For instance, some arthritis medications contain chemicals from hot peppers.

Peppers get their hotness from a family of chemicals called capsaicinoids, with two members (capsaicin and dihydrocapsaicin) of the group making up 90 percent of the capsaicinoids.

The spiciness of each pepper depends on the relative amounts of these hot compounds hidden inside the pepper's flesh.

“Capsaicinoids are the active ingredient in pepper spray, tear gas and some arthritis medications, not to mention spices and foods like salsa, so a wide range of industries could find this new approach useful,” said lead scientist Kenneth Busch, a chemist at Baylor University in Texas.

Currently, the standard test of pepper hotness relies on a process called high-performance liquid chromatography. This method is expensive and time consuming (each sample can take 10 minutes to run), because the machine chemically separates all the different compounds before spitting out a reading.

Busch and his colleagues developed a computer model that can calculate the hotness of a pepper based on information gleaned from spectroscopy, which measures how a substance absorbs light. The program is set up so that when a scientist feeds a "spectra" into it, the program disregards components uninvolved in spicy heat and focuses only on the capsaicinoid factors.

The research will be published in an upcoming issue of the Journal of Agricultural and Food Chemistry.

Jeanna Bryner
Live Science Editor-in-Chief

Jeanna served as editor-in-chief of Live Science. Previously, she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species. She also received an ocean sciences journalism fellowship from Woods Hole Oceanographic Institution.