Fruit left as something valuable (5)
I believe the answer is:
pearl
'something valuable' is the definition.
(pearls are valuable)
'fruit left' is the wordplay.
'fruit' becomes 'pear' (pear is a kind of fruit).
'left' becomes 'l' (common abbreviation).
'pear'+'l'='PEARL'
'as' is the link.
(Other definitions for pearl that I've seen before include "Smooth lustrous round structure of calcium carbonate" , "prized example" , "greatly valued" , "Object of great worth" , "Precious jewel from the oyster" .)