The Compendium of Caraka 1.26.8

1.26.8

eka eva rasa ityuvāca bhadrakāpyaḥ yaṃ pañcānāmindriyārthānāmanyatamaṃ jihvāvaiṣayikaṃ bhāvamācakṣate kuśalāḥ sa punarudakādananya iti /

“Taste is only one,” said Bhadrakāpya, “which the experts declare to be one of the five sense-objects, an entity falling within the domain of the tongue; and it is non-different from water.”