If one were to eat substances from blandest to nastiest, the bracket fungus, Amaropostia stiptica, would sit at the farthest end of the unpleasant spectrum.
A team of scientists determined just what makes that particular fungus so aggressively distasteful, a group of researchers report in the Journal of Agricultural Food Chemistry. They identified a compound called oligoporin D in the bracket fungus that activates the human bitter taste receptor TAS2R46. The substance is so strong that even barely detectable amounts would probably cause humans to spit it out and desperately search for something to rinse the rancid taste out of their mouths.
The authors report that no human subjects were nauseated by this study. Instead, they grew cells that harbored an assortment of human bitter taste receptors. Think of them as a tongue in a petri dish.
What Causes Bitterness?
The researchers were driven to explore this topic because of what is essentially a bitterness knowledge gap. We have a fairly broad and simplistic understanding of what causes bitterness and why certain substances might exhibit it.
“Bitter taste perception cautions humans against the ingestion of potentially toxic compounds,” according to the paper. “However, current knowledge about natural bitter substances and their activation of human bitter taste receptors (TAS2Rs) is biased toward substances from flowering plants, whereas other sources are underrepresented. Although numerous mushrooms taste bitter, the corresponding substances and receptors are unexplored.”
Read More: 5 Tastes We've Developed and Why We Now Include Umami
Bitterness Doesn't Always Mean Poisonous
The researchers hypothesize that some fungi evolved bitterness to avoid being eaten by humans and animals, both of which devour mushroom.
“Therefore, it is not surprising that some mushrooms synthesize powerful bitter substances to prevent their consumption,” the paper continued.
Somewhat surprisingly, though, bitterness level doesn’t necessarily mean something is poisonous. “In fact, some of the most bitter mushrooms such as the bitter bolete (Tylopilus felleus) are not poisonous, whereas the taste of the deadly death cap (Amanita phalloides) is described as pleasant and nutty,” the paper concluded, making the relationship between taste and toxicity “tenuous at best.”
After the scientists determined which substances they tested were the most bitter, they determined their molecular structure — presumably so food scientists will know what flavors not to emulate.
Read More: How Our Sense of Taste Evolves and Adapts
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Journal of Agricultural Food Chemistry. Taste-Guided Isolation of Bitter Compounds from the Mushroom Amaropostia stiptica Activates a Subset of Human Bitter Taste Receptors Activates a Subset of Human Bitter Taste Receptors
Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.
