Aromatic substances (6)
I believe the answer is:
spices
'aromatic substances' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for spices that I've seen before include "Pungent food additives" , "Food flavour enhancers" , "Food flavours for Pisces" , "Adds piquancy" , "They add zest, to food or life" .)