There are three causes of this:
Toothpaste contains sodium lauryl sulfate, a detergent and foaming agent used in everything from shampoo to engine degreaser. This chemical can block your tongue's sweet taste receptors* for up to an hour after use.
The fluoride used in toothpaste can come in three forms: stannous fluoride, sodium fluoride, and acidulated phosphate fluoride. The acetic acid in orange juice can break down stannous flouride, leaving a layer of tin on your tongue.
Most toothpaste is mint flavor, which really doesn't go well with orange.
So, if you want your breakfast to taste better in the morning, avoid toothpastes that contain stannous fluoride or sodium lauryl sulfate or have a minty flavor.
*Taste buds are distributed evenly on your tongue, not in flavor-specific areas as once thought. You cannot taste sweet by avoiding the tip of your tongue when you brush.
Posted 3480 day ago