Will the dark roasts have a lower amount of antioxidants?

As coffee is roasted, the content of chlorogenic acids (which do indeed act as antioxidants) decreases but at the same time, the content of high molecular compounds, and melanoidins (which are also antioxidant in nature) increases.

Coffee from Guatemala and Colombia, where we source our beans, are 2 of the top three coffees studied for antioxidant content (Brazil being the third).