saltiness vs taste sensation

saltiness and taste sensation both are nouns.

Word	Noun	Adjective	Verb	Adverb
saltiness	Yes	No	No	No
taste sensation	Yes	No	No	No

As nouns, taste sensation is a hypernym of saltiness; that is, taste sensation is a word with a broader meaning than saltiness:

saltiness: the taste experience when common salt is taken into the mouth
taste sensation: the sensation that results when taste buds in the tongue and throat convey information about the chemical composition of a soluble stimulus

Other hypernyms of saltiness include gustatory perception, gustatory sensation, taste, taste perception.

saltiness (noun)	taste sensation (noun)
the property of containing salt (as a compound or in solution)	the sensation that results when taste buds in the tongue and throat convey information about the chemical composition of a soluble stimulus
the taste experience when common salt is taken into the mouth
language or humor that is down-to-earth