I would definitely check with the airline on taking anything like baby food in hand luggage. The definition of 'liquids' is very wide (eg. toothpaste) so soft baby food may be prohibited. Baby milk is OK provided you taste it yourself in front of the security staff.

Even if you can take it on (which I doubt) you will have further problems at customs with anything that has been opened and left unfinished.

I'm not sure but I think you will be OK with unopened baby food in your checked bags.