Wholemeal, we note, has high temperature inside (7)
I believe the answer is:
wheaten
'wholemeal' is the definition.
(synonyms)
'we note has high temperature inside' is the wordplay.
'note' becomes 'n' (abbreviation).
'has' means one lot of letters go next to another.
'high temperature' becomes 'heat' (synonyms).
'inside' indicates putting letters inside.
'we'+'n'='wen'
'wen' going around 'heat' is 'WHEATEN'.
(Other definitions for wheaten that I've seen before include "corny!" , "Like bread" .)