Genetics Play Role in How People Taste Sweeteners

21 Aug 2013 --- Genetics may play a role in how people's taste receptors send signals, leading to a wide spectrum of taste preferences, according to a new study published in the journal Chemical Science. The findings suggest these varied, genetically influenced responses may mean that food and drink companies will need a range of artificial sweeteners to accommodate different consumer tastes.

"Genetic differences lead to differences in how people respond to tastes of foods," said John Hayes, assistant professor, food science and director of the sensory evaluation center at Penn State University.

Based on the participants' genetic profile, researchers were able to explain the reactions of subjects in a taste test when they sampled Acesulfame-K—Ace K—in the laboratory. Ace K is a man-made non-nutritive sweetener commonly found in carbonated soft drinks and other products. Non-nutritive sweeteners are sweeteners with minimal or no calories. While some people find Ace K sweet, others find it both bitter and sweet.

The researchers said variants of two bitter taste receptor genes—TAS2R9 and TAS2R31—were able to explain some of the differences in Ace K's bitterness. These two taste receptor genes work independently, but they can combine to form a range of responses.

Humans have 25 bitter-taste receptors and one sweet receptor that act like locks on gates. When molecules fit certain receptors like keys, a signal is sent to the brain, which interprets these signals as tastes—some pleasant and some not so pleasant.

In another study recently published in the journal Chemosensory Perception, the researchers had 122 participants taste two stevia extracts, Rebaudioside A (Reb A) and Rebaudioside D (Reb D). The researchers found that Reb A and Reb D bitterness varies greatly across subjects, but this was not related to whether or not participants found Ace K bitter. Likewise, variation in the TAS2R9 and TAS2R31 genes did not predict Reb A and Reb D bitterness. They also found that of the stevia extracts, the participants considered Reb D to be much less bitter than Reb A.