I sometimes have trouble distinguishing ingredients in these games too - it all depends on how they are depicted graphically. I don't really think there's any help for this, unfortunately, other than practice and getting used to how it is supposed to look.
I also saw this comment on Big Fish:
Could anyone tell me, in the NEWEST version, does the sandwich glitch still exist? Where you can't see what kind of sandwich people are ordering, I mean?
It sounds like the game has its problems. I have never tried to play it, so otherwise I can't be of any help here.