The artichoke source tested was Mario's brand, which are a product of Spain. Ideally, test results from US-canned artichokes would be best for comparing to fresh, but regardless this ORAC test proves that even artichokes in a can contain a very high amount of antioxidants. That's especially a good thing since boiling raw artichokes can be a time intensive process that wouldn't always make sense for simple dishes, such as adding them to your salad.
ORAC Source
Research Support, Non-U.S. Gov't: Carlsen MH, Halvorsen BL, Holte K, et al. Nutrition Journal NIH Jan 2010