2,3-Octanedione is a very interesting compound. It has been found in warmed-over flavors such as beef and lamb, which wouldn't really compel me, personally, to use this compound. However, it is also found in the fat volatiles of grass-fed sheep, sardines and trout. One the other side of the dinner plate, 2,3-octanedione is found in cooked asparagus and mushrooms. It has potentially been found in tangerines, and so I might be tempted to look there, too. However, the most interesting place where 2,3-octanedione has been found is in milk.