Thanks John, I'll visit the curezone newsletter forum.
I tried to find fresh Quark but couldn't find it anywhere (No one seemed to know what I was talking about!). The product I've ended up with is the best I could do but I'm not going to use it until I make sure I've got the right one. Better nothing than something harmful.
Apparently some of the preservatives are okay (as in natural) but like you I have no idea what the numbers mean so hopefully someone else can shed some light.