fresh food vs food

fresh food and food both are nouns.

Word	Noun	Adjective	Verb	Adverb
fresh food	Yes	No	No	No
food	Yes	No	No	No

As nouns, food is a hypernym of fresh food; that is, food is a word with a broader meaning than fresh food:

fresh food: food that is not preserved by canning or dehydration or freezing or smoking
food: any solid substance (as opposed to liquid) that is used as a source of nourishment

Other hypernyms of fresh food include solid food.

fresh food (noun)	food (noun)
food that is not preserved by canning or dehydration or freezing or smoking	any substance that can be metabolized by an animal to give energy and build tissue
	anything that provides mental stimulus for thinking
	any solid substance (as opposed to liquid) that is used as a source of nourishment