What type of apple is most nutritious? If you compare red delicious vs. granny smith vs. gala vs. golden delicious, the one among those which yields the highest antioxidant content is red delicious. This isn't surprising because its intense red color skin is rich with anthocyanins, a potent antioxidant. That is exactly why the peeled version of the fruit will contain less than eating the exact same fruit but with the skin on.
ORAC Source
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010