ingredient vs foodstuff

ingredient and foodstuff both are nouns.

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

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

Other hypernyms of ingredient include food product.

ingredient (noun)	foodstuff (noun)
a component of a mixture or compound	(usually plural) consumer goods sold by a grocer
an abstract part of something	a substance that can be used or prepared for use as food
food that is a component of a mixture in cooking