This morning, I found some sausages in the fridge that had been there all week. The top of the sausage (that is, the surface of the skin facing upwards) had turned brown. I initially thought that if I just fried them long enough, this would be fine; however, while frying I did a quick search on the web, got spooked and threw them away.
My question is: what causes this discolouration and, have I needlessly thrown three very tasty looking sausages in the bin?