In small bowl, combine sauce ingredients; blend well. Refrigerate until serving time.
Spray large nonstick skillet with nonstick cooking spray. Add bell peppers, onion and garlic powder; cook over medium-high heat for 2 to 3 minutes or until vegetables are crisp-tender.
Stir in turkey, corn and beans. Reduce heat to medium-low; cover and cook 4 to 6 minutes or until thoroughly heated. Spoon turkey mixture onto center of heated pitas; top with sauce. Fold pitas over filling.