There's also smoked salmon. Two types: east coast cold smoked and west coast hot smoked. Cold smoked is probably not possible to bring back to China as it requires refrigeration. While the hot smoked is not as tasty, it is available in vacuum sealed packaging in lots of souvenir shops, even in airports.
Wild Rice is also a very good and affordable gift for food lovers. Best if you can find a pre-seasoned package. Or research on how to cook it and attach the instructions.