mixture vs foodstuff

mixture and foodstuff both are nouns.

Word	Noun	Adjective	Verb	Adverb
mixture	Yes	No	No	No
foodstuff	Yes	No	No	No

As nouns, foodstuff is a hypernym of mixture; that is, foodstuff is a word with a broader meaning than mixture:

Other hypernyms of mixture include food product.

mixture (noun)	foodstuff (noun)
the act of mixing together	(usually plural) consumer goods sold by a grocer
an event that combines things in a mixture	a substance that can be used or prepared for use as food
any foodstuff made by combining different ingredients
a collection containing a variety of sorts of things
(chemistry) a substance consisting of two or more substances mixed together (not in fixed proportions and not with chemical bonding)