Briefly want sugar magnate to produce food for young (7)
I believe the answer is:
lactate
'produce food for young' is the definition.
(to lactate is to produce milk)
'briefly want sugar magnate' is the wordplay.
'briefly' means to remove the last letter.
'want' becomes 'lack' (synonyms).
'sugar magnate' becomes 'Tate' (as in Tate and Lyle, British sugar company).
'lack' with its last letter removed is 'lac'.
'lac'+'tate'='LACTATE'
'to' is the link.
(Other definitions for lactate that I've seen before include "(Of female mammal) secrete milk" , "Exude milk" , "Produce milk" .)