John, per the CFR, it's
http://edocket.access.gpo.gov/cfr_2002/aprqtr/21cfr101.22.htm(3) The term natural flavor or natural flavoring means the essential
oil, oleoresin, essence or extractive, protein hydrolysate, distillate,
or any product of roasting, heating or enzymolysis, which contains the
flavoring constituents derived from a spice, fruit or fruit juice,
vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf
or similar plant material, meat, seafood, poultry, eggs, dairy products,
or fermentation products thereof, whose significant function in food is
flavoring rather than nutritional. Natural flavors include the natural
essence or extractives obtained from plants listed in Secs. 182.10,
182.20, 182.40, and 182.50 and part 184 of this chapter, and the
substances listed in Sec. 172.510 of this chapter.
meaning flavor derived from non-synthetic sources