Question

Brown colour of apple after cutting is due to chemical change or physical change

Answer 1

When an apple is cut (or bruised), oxygen is introduced into the injured plant tissue. When oxygen is present in cells, polyphenol oxidase (PPO) enzymes in the chloroplasts rapidly oxidize phenolic compounds naturally present in the apple tissues to o-quinones, colorless precursors to brown-colored secondary products...so it's a chemical change..

Answer 2

According to the question;

"Brown colour of apple after cutting."

Ans:- this phenomenon is caused by chemical change.

Reason:

When we cut the apples, the atmospheric oxygen touches the injured apple tissues. With the presence of this atmosphere oxygen, polyphenol oxidase enzyme oxidises the phenolic compounds which are already present in the apple cells.

That's why the brown colour appears and this is a chemical reaction based phenomenon so it is a chemical change not a physical change.