One of the secret ingredients in toothpaste is a small amount of one particular chemical that helps clean your teeth. Know what it does? For a short period of time after brushing your teeth, it keeps the taste buds in your mouth from sensing any sweet taste. For some reason, the chemical doesn’t turn off bitter or sour tastes just sweet. So your taste buds sense only a portion of the variety of tastes that make orange juice so delicious. The good news is that it doesn’t take long for the chemical’s effect to disappear — and then O.J. tastes deliciously sweet and satisfying all over again!