Heston B did some experiments for BA on just that and in the end found that flavour 'Unami' had to be much stronger at altitude to taste as it should. I seem to remember +2.25 being the strength. He also experimented with nasal douches (eurgh!!) to help the taste buds and nose.
The problem with airline food is that there will only ever be a limited selection available and has been seen in many threads on here over the years, passengers likes/dislikes are so varied that it is a culinary nightmare for them. SQ has attempted to improve things with their "Book the Cook" offering but even that has a limited menu
http://www.singaporeair.com/en_UK/flyin ... oklanding/