In terms of difficulty, humans find little to none when it comes to transitioning between flavours. There is, however, one instance where two flavours simply disagree with one another. Ever try drinking orange juice after brushing your teeth?
As evidenced by the existence of multiple-course dinners, set meals, and half-deceptive Franken foods, the human palate is more than capable of processing — even appreciating — multiple flavours simultaneously, regardless of how untraditional the food item put forth happens to be. But, with the case of orange juice and toothpaste, a person’s mouth simply says no, and for a perfectly scientific reason.
A Necessary Agent
According to dentists in Manchester that offer dental implants, the astringent sensation you get after introducing a sip of orange juice to a toothpaste-fresh mouth is due to sodium laureth sulfate, a toothpaste ingredient.
They say that this anionic detergent and surfactant (formally sodium lauryl ether sulfate) works as a foaming agent for toothpaste, aiding in the uniform spread of teeth-cleaning chemicals as the removal of surface stains and food debris. A quick read of common hygiene products’ ingredient lists would show how common SLS is, and how much manufacturers in the cleanliness industry depend on it.
Flavour-wise, SLS or SLES suppresses the tongue receptors in charge of detecting sweetness. Meanwhile, it enhances the function of tongue receptors in charge of detecting bitter flavours. Once something sour touches a person’s SLS-coated tongue, the bitterness receptors go into overdrive, making orange juice a big no-no post-brush.
The flavouring-altering properties of toothpaste do not last long, fortunately. Within half an hour from brushing teeth, you can now pour their glass of citrus without fear of bitterness catching them off guard. Waiting also provides teeth time to recover and helps give your dental structure a break from food and drinks.
Playing the waiting game appears to be the optimal means of approaching this ‘side-effect’, as toothpaste manufacturers are unlikely to change a composition that works, and orange juice producers are simply incapable of changing nature.