1.Cook pasta in a large saucepan of boiling salted water until just tender, drain.
2.Meanwhile, drain tuna, reserve 2tbsp of the oil. Combine pasta, tuna, corn, capsicum, onion, celery and parsley in a large bowl.
3.Combine mayonnaise, yoghurt, garlic, rind, juice, mustard and reserved tuna oil in a small bowl or jug. Add to pasta mixture, toss gently. Season to taste with salt and pepper before serving.