Politics2 mins ago
Apples
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If an apple goes brown when it is cut , then it is oxidising . Does this mean apple skin is not permeable for oxygen molecules?
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For more on marking an answer as the "Best Answer", please visit our FAQ.Yes - it is oxidation, but it is an extremely slow reaction. The browning is caused by enzymes (released from damaged cells) which greatly speed up the oxidation reaction. You can easily stop it by deactivating the enzyme. One way to do that is to lower the pH by covering the cut surface with fresh lemon juice. The apple will then not go brown.
The skin plays no part in the process, If an apple is dropped onto a hard surface, the apple will bruise even if the skin remains intact. The damaged cells in the bruised area will release enzymes that will brown the flesh.