Wrap it or store it in an airtight container

When avocados are cut, the pulp's PPO and a group of antioxidants known as phenolic compounds are exposed to oxygen. The phenols subsequently change into quinones, which are compounds that produce color.

Quinones and their byproducts then undergo a number of reactions to produce the brown pigment. In other words, PPO, phenolic compounds, and oxygen are the only three factors that may initiate the enzymatic browning reaction. By taking away the oxygen from the cut surface, it may be avoided. Therefore, limiting oxygen exposure and delaying browning may be done by wrapping a cut avocado in plastic wrap or storing it in an airtight container. However, if you take the avocado out of the container and re-expose it to oxygen, browning will start to occur again.