The absolute threshold for tastes is lower than that for tastes.

"The absolute threshold for bitter tastes is lower than that for sweet tastes".

The feeling of taste is comparable to excitation of taste receptors, and receptors for a substantial number of particular chemicals have been distinguished that add to the gathering of taste. In spite of this unpredictability, five sorts of tastes are generally perceived by people:
Sweet - Umami - Salty - Sour - Bitter...