Hi Peter:

I am sure there is no significant nutritional difference in honey that is
unheated and honey that has been gently heated, say to less than 120 deg F.
There is a significant difference to the taste, however, and it does not
take a very developed palate to notice it.  Some people prefer the raw taste
and others prefer the heated taste. I keep some of each kind around.

                                    Best regards

                                    Donald Aitken