Researchers identify new bitter compounds in mushroom

Researchers have identified three previously unknown bitter compounds in the bitter bracket mushroom, a nontoxic but inedible species. The study examined how these substances interact with human taste receptors and could help expand knowledge of sensory evolution and receptor functions throughout the body.

The research team extracted five bitter compounds from the mushroom, including two already known. Instead of tasting the extracts, they exposed them to an artificial system built from human taste receptors inserted into embryonic kidney cells. One newly identified substance activated receptors at a concentration of 63.3 micrograms per liter.

Humans have about 25 types of bitter receptors, located not only in the mouth and throat but also in the lungs, digestive tract, and brain. Four receptors have no known natural activators. Lead author Maik Behrens of the Leibniz Institute for Food Systems Biology says that identifying new activating compounds can provide insight into receptor evolution.

Previous studies have focused on bitter substances from flowering plants, which evolved later than bitter receptors in animals. Behrens says mushrooms, being older, may offer new leads. Although the bitter bracket mushroom did not activate any of the four unknown receptors, the analysis provided new chemical findings.

Physiologist Nirupa Chaudhari of the University of Miami, who was not involved in the study, notes that bitter taste receptors can influence physiological responses such as insulin release and stomach acid production. She calls the work a first step toward broader bitter receptor research.

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