Browning Reaction at Apple

The example of experiment of oxidation and reduction reaction (Redox) using household is browning reaction. Browning reaction is colour change from white to be brown at apple. This reaction is redox reaction.
Raw Material:
1. Apple
2. Citrate acid or Vitamin C

Apparatus:
1. Becker glass
2. Knive

Experiment Method:
1. Makes Vitamin C or Citrate acid solution by dissolve vitamin C or citrate acid into water
2. Cut apple into two part. The first part is enter into becker glass that contains solution, the second part left at free air
3.Look and observe

Explanation:
Apple that left at free air is faster to become brown than apple at solution, it caused the activation of Polypenol Oxidase (PPO) enzyme react with oxygen to produce O-quinon. O-kuinon group makes the color of apple become brown. Vitamin C solution makes enzyme inactive so the browning reaction is not progress

Look this Video: