A rather interesting article in 750Daily, as linked by WineTerroirist:
750Daily:Sulfites&WineChemistry .
It's a pretty generalized article and rather short on specifics. But it does introduce us to the term "metabolomics". Metabolomics is a technique to provide a detailed map of all the chemical compounds present in the wine. It appears the timing of the SO2 additions are very important on the ultimate sensory characteristics of a wine and that a wine remembers this timing of SO2 additions. This is, of course, the kind of stuff that drives SweetAlice apoplectic..you don't use SO2 additions in making real wine.
I can hardly wait to being in a gathering of wine geeks and toss out the term "metabolomics" and watch them all nod in knowing agreement so they don't appear ignorant!!