For sauce, drain plums, reserving liquid. Pit plums. In a food processor bowl or blender container, combine the pitted plums, reserved plum liquid, the orange juice concentrate, hoisin sauce, soy sauce, ginger, and the 1/4 teaspoon pepper. Cover and process or blend until mixture is nearly smooth.
Transfer the mixture to a saucepan. Bring to boiling; reduce heat. Simmer, uncovered, about 15 minutes or until slightly thickened. Stir in the sesame seed.
Cover and grill for 20 minutes or until an instant-read thermometer inserted into thickest portion of a wing reads 180 degree F and juices run clear. Brush wings occasionally with sauce during grilling. Heat any remaining sauce and pass with wings. Makes 8 to 10 servings.