gluten vs wheat gluten

gluten and wheat gluten both are nouns.

Word	Noun	Adjective	Verb	Adverb
gluten	Yes	No	No	No
wheat gluten	Yes	No	No	No

As nouns, wheat gluten is a hyponym of gluten; that is, wheat gluten is a word with a more specific, narrower meaning than gluten:

gluten: a protein substance that remains when starch is removed from cereal grains; gives cohesiveness to dough
wheat gluten: gluten prepared from wheat

Other hyponyms of gluten include corn gluten.

gluten (noun)	wheat gluten (noun)
a protein substance that remains when starch is removed from cereal grains; gives cohesiveness to dough	gluten prepared from wheat