I take it cooking the syrup (pizza baking) would "kill off" the antioxidants?
Since the article I referenced was a BakingBusiness article, I took that to mean that in a baking context maple syrup would retain its antioxidant benefits even after baking. As I understand it, and as noted by Craig, heat does not destroy all antioxidants. For example, green tea, which is touted as being high in antioxidants, apparently retains that benefit even when made into a drink. Also, I understand that some antioxidants, such as lycopene, increase when subjected to heat. Given a choice, I try to use all foods that are high in antioxidants in their most basic and natural form. This includes just about all berries, wine, coffee, tea, high percentage cacao chocolate, beans, prunes, dates, nuts, olive oils, etc.