"Change in meat’s smell after it is out in the sun for some time" is a _______?

"Change in meat’s smell after it is out in the sun for some time" is a _______?

گوشت کی بو میں تبدیلی کچھ وقت کے لئے دھوپ میں ختم ہونے کے بعد کیا _______ ہے؟
Explanation

The smell change in meat is due to decomposition and bacterial action, which alters its chemical composition.

This indicates a chemical change, not just a physical one.