Loking at a couple of your other posts it seems you are going to Shanghai. No need to be taking any 'safe' food at all.
I'm not sure whether you are talking about 'safe' in terms of quality or in terms of not including things like '100 year old cured donkey penis' and the like - but either way you have no need to worry. But if you are worried, Carrefour has a load of imported stuff, and notwithstanding that there are plenty of plain/bland Chinese dishes you can always head for the Golden Arches!!
And cartons of milk in your checked bags really isn't a good idea!