Use of enzymes is improving food quality. Give examples and explain?

Answer 1

All foods have natural enzymes to protect it. Food industries add these but doesn't really help the food and they have no business doing that. Beware them

Answer 2

presence or absence of enzymes in food can improve its quality. Example is apple. After cutting the apple it turns reddish, this is due to an enzyme, if you cut the apple and place it in boiling water (this destroys the enzyme) it stays fresh for much longer.
Enzymes actually bring about chemical changes in food, and mostly they are responsible for decreasing the quality, not improving it. so usually people try to get rid of the enzymes rather than keep them in the food, this is one reason why cooked food stays fresh longer than uncooked as cooking kills the enzymes in the food (and bacteria that produce those enzymes).
Some times enzymes also help in improving the food as well, like there is an enzyme found in a fruit (cant remember its name) this enzymes breaks down protein and is used to marinate meat before cooking.

Answer 3

I dunno in what terms do your 'improve food quality' mean, but if you meant like improving the taste and so forth, then there is some.

Papain is used to soften meat while zymase is used in fermentation.