How different are the recoveries of fatty acids from different matrices, i.e., pork and beef or butter vesus margarine? Anyone have a review article or practical experience?

More information needed: do you mean free fatty acids/metal soaps or the triglycerides themselves, as extraction scheme would be different. Also, with butter, must use different extraction/GC because of short chains such as C4 not found in pork & beef at any appreciable levels. I work in company that manufactures both meat products and soaps, well-experienced in FAME analyses..