Why do avocados turn black after cutting and how to avoid it?

Question

Learn why avocados turn black and discover the best methods to stop them from browning. Keep your cut avocados green and fresh for longer.

Answer 1

Avocados turn black after cutting due to enzymatic browning, a reaction between enzymes in the avocado and oxygen in the air. To prevent this, limit oxygen exposure by covering the cut surface or using an acid like lemon juice.

Detailed Explanation:

When an avocado is cut, cells are damaged, releasing enzymes called polyphenol oxidases (PPO). These enzymes react with phenolic compounds also present in the avocado flesh, in the presence of oxygen. This reaction leads to the formation of melanins, which are brown pigments. This process is similar to what happens when apples or potatoes are cut and exposed to air. The browning is harmless, but it can make the avocado look unappetizing. Several methods can slow down or prevent this enzymatic browning:

1. Lemon or Lime Juice: The citric acid in lemon or lime juice lowers the pH on the surface of the avocado, inhibiting the enzyme activity. Brush the cut surface with a thin layer of juice.

2. Olive Oil: A thin layer of olive oil can create a barrier, preventing oxygen from reaching the avocado flesh. Brush the cut surface with olive oil.

3. Water Immersion: Submerging the cut avocado in water can limit oxygen exposure. However, this can slightly affect the texture of the avocado if stored for a long time.

4. Plastic Wrap: Press plastic wrap directly onto the cut surface of the avocado, ensuring there are no air pockets. This minimizes oxygen exposure.

5. Storing with Onion: Some people claim that storing cut avocado with a piece of red onion in an airtight container helps prevent browning. The sulfur compounds in the onion may inhibit the enzymatic reaction.

6. Avocado Saver Containers: These specially designed containers minimize air exposure and help keep cut avocados fresh for longer.

Pro Tip:

When storing half an avocado, leave the pit in the half you're storing. The pit covers a portion of the surface, reducing the area exposed to air and slowing down the browning process.