The culprit for this offensive reaction is Sodium Lauryl Sulfate, the foaming agent found in almost all toothpastes. Sodium Lauryl Sulfate suppresses your sweet taste receptors on your tongue. Since sweetness blocks bitter and sour flavors, its absence enhances the bitterness and sourness of orange juice.
Additionally, Sodium Lauryl Sulfate destroys Phospholipids. These fatty compounds act as inhibitors on your bitter taste receptors.
By inhibiting sweet receptors and destroying Phospholipids, Sodium Lauryl Sulfate dulls the sweetness and promotes the bitter taste in orange juice.
Now that you know the science behind this offensive taste, comment on the the strategies you use to avoid this.