If this flavouring is made from any part of the pig, then it is undoubtedly haraam, because Allaah says (interpretation of the meaning):
“Say (O Muhammad صلى الله عليه وسلم): “I find not in that which has been revealed to me anything forbidden to be eaten by one who wishes to eat it, unless it be Maytah (a dead animal) or blood poured forth (by slaughtering or the like), or the flesh of swine (pork); for that surely, is impure”
Allaah has forbidden pork because it is impure and unclean.
But if it is manufactured artificially and is not made from pork, then it is at least makrooh, because it is an imitation of something that Allaah has forbidden. What the believer should do is keep away from haraam things and shun them, and not enjoy them or look for foods that are similar to them.
Moreover that may be a means of getting used to the taste of pork, which would make it easier to eat it later on.
And Allaah knows best.