How exactly do sulfites prevent oxidation of wine?

Question

I know that sulfites are used in wines to prevent oxidation, but how exactly does this happen, which reactions take place and where do the products go?

Answer 1

Sulfite, SO₃^2- is an antioxidant because it will easily be oxidized so that other ingredients present will not be oxidized. The chemical reaction is essentially SO₃^2- ==oxidation==> SO₄^2-

The sulfate ion (SO₄^2-) remains in the wine.