Place the orange juice in a medium saucepan. Bring to a boil. Add orange zest and lemon juice. Dissolve cornstarch in 1 tablespoon of cold water. Add to orange juice mixture; stir until sauce thickens. Gently boil carrots in water seasoned with salt and sugar until crisp-tender. Shock in ice water. Mix carrots into the sauce and reheat. Serve hot.