In a medium bowl, mix flour and pepper. Dredge the chicken breasts in the mixture to coat, and set aside.
Melt butter and heat oil in a large skillet over medium heat. Place coated chicken in the skillet, and cook about 10 minutes per side, until no longer pink and juices run clear. Remove from heat, and set aside.
Increase skillet heat to high, and pour in the orange juice. Cook until reduced by about 1/2.
Stir in the orange zest, capers, and parsley. Return chicken to the skillet, and coat with the orange juice mixture to serve.