It may be my imagination but whenever I do a longer simmer to make bone broth-- say over 7 hours-- it seems like the fat in the broth begins to smell and taste slightly rancid. Possibly more so with chicken or turkey broth which I know are higher in PUFAs. But I've never heard this cautioned about bone broth, in fact, most people say the longer cooking the better.
The question is, why wouldn't several hours of cooking turn the PUFAs in chicken broth rancid? If some rancidity is an issue, is it best then to skim out the fat in long-cooked poultry broths (which as a huge fathead I usually don't do)?