Food company involved in ban (5)
I believe the answer is:
bacon
'food' is the definition.
(bacon is a kind of food)
'company involved in ban' is the wordplay.
'company' becomes 'co' (abbreviation).
'involved in' indicates putting letters inside.
'co' going into 'ban' is 'BACON'.
(Other definitions for bacon that I've seen before include "modern artist" , "gammon" , "Painter; cured meat" , "Processed pig-meat" , "Old scientist" .)