Lemon Juice and fruit browning

[janhen]

How does lemon juice prevent the browning of fruit?

I know that catecholase, an enzyme turns fruits and vegetables brown once they are peeled, and the product of this reaction, benzoquinine (this forms red and brown pigments on food) is supposedly highly sensitive to acids, such as lemon juice. Why is it sensitive though?

[janhen]

Does anyone know? I really need this...

[MrMistery]

1,4-Benzoquinone is sensitive towards both strong mineral acids and alkali, which cause condensation and decomposition of the compound.