Have you ever brushed your teeth and then drank a cold, refreshing, sweet glass of orange juice, only to find that it tastes horribly bitter?
What is going on here? This phenomenenon was investigated by the American Chemical Society and prompted them to create a brilliant animated video explaining why. In short, one of the main ingredients of toothpaste, sodium lauryl sulphate (also known as sodium dodecyl sulphate), which is responsible for producing the foamy effect we all like, interferes with the sweetness sensing cells on the tongue.
SDS blocks the “sweet” taste buds and therefore the orange juice only stimulates the “bitter” sensors!