Tasty juice a princess rejected (5)
I believe the answer is:
sapid
'tasty' is the definition.
(I've seen this before)
'juice a princess rejected' is the wordplay.
'juice' becomes 'sap' (I've seen this before).
'a princess' becomes 'di'.
'rejected' says the letters should be written backwards.
'di' back-to-front is 'id'.
'sap'+'id'='SAPID'
(Other definitions for sapid that I've seen before include "Full of flavour" , "savoury'" , "Tasty" , "excellent taste" , "Engaging" .)