"Flavour enhancer" I have definitely seen on food packaging (e.g. monosodium glutamate).

"New role for MSG? For decades, researchers have been on the trail of the elusive fifth taste. Salty, bitter, sour and sweet are all accepted. But there has always been a belief that a fifth taste -- called "umami" by scientists but known more familiarly as the flavor enhancer monosodium glutamate, MSG -- deserved to be put in the same class."
http://www.sirc.org/media/archives/arch_note_jan_2000.html