This article was originally posted on RealClearScience.
Back in the 90’s, Keystone Beer ran a very popular commercial warning against the dangers of “bitter beer face.”
Of course, Keystone’s solution was to drink Keystone beer. I disagree. Mass-produced American beers suck. They taste like fizzy water with a couple of rusty nails thrown in for flavor. There’s got to be a way of enjoying superior beers while simultaneously avoiding the social stigma associated with beer bitter face.
Thankfully, a new study in PLoS ONE by Dutch scientists provides hope for the future. The researchers have discovered that some compounds called flavanones can block (“antagonize”) the bitter taste receptors found on our tongues.
The researchers conducted the experiments in vitro using a human cell line called HEK293, which is easily manipulated in the lab. They expressed a human bitter taste receptor called hTAS2R39 in the cells. The cells could then be activated by adding a bitter compound found in green tea, called epicatechin gallate (ECG). The bitter taste receptor would bind to ECG, and the cells would then trigger an intracellular release of calcium ions. In the experimental system used by the researchers, this calcium release would cause fluorescence, which could be detected. Any flavanone that, in the presence of ECG, reduced the amount of fluorescence was therefore blocking the bitter taste receptor.
One of their experiments is shown below. (Ignore the “non-induced” conditions.)
The experiment shows that bitter compound ECG activates the cells, but compound #6 (4′-fluoro-6-methoxyflavanone) successfully blocked the bitter receptor. At even higher concentrations of 4′-fluoro-6-methoxyflavanone, the bitter receptor was completely blocked. The implication is that, if fed to humans, 4′-fluoro-6-methoxyflavanone may be able to greatly reduce the perception of bitterness in foods.
There are limitations to this study. First and foremost, it was conducted in cell culture, not in actual humans. Second, there are many different kinds of bitter taste receptors on our tongues, so blocking only one of them will not totally eliminate bitter tastes. (Besides, the specific receptor in this study is not involved in detecting the bitter molecules found in beer.) Third, it is unknown if 4′-fluoro-6-methoxyflavanone is actually safe for human consumption. And fourth, there is no known natural source of 4′-fluoro-6-methoxyflavanone, and producing it would require costly chemical synthesis.
Still, these findings are promising, not just for bitter foods but for medications, as well. And some day, perhaps “bitter blockers” could be added to your favorite beer, lest you acquire the dreaded bitter beer face.
Source: Roland WSU, Gouka RJ, Gruppen H, Driesse M, van Buren L, et al. (2014) 6-Methoxyflavanones as Bitter Taste Receptor Blockers for hTAS2R39. PLoS ONE 9(4): e94451. doi:10.1371/journal.pone.0094451