This test was conducted using Prior, a popular brand in Norway. As is the case with many meats, the version with the skin has a lower ORAC than the version without. In the case of grilled chicken drumsticks, how much of a difference it makes is profound: 50% more antioxidant on the grilled drumstick without skin.
Research Support, Non-U.S. Gov't: Carlsen MH, Halvorsen BL, Holte K, et al. Nutrition Journal NIH Jan 2010