reset rotation after a event

in my unity project i m rotating a object with touch ,default object rotation is set to (0,270,0) .when i rotate the object ,it rotate on y axis, say i rotate it to (0,210,0) now when i release my finger it stay on(0,210,0) but i want it to go on (0,270,0)

my code for rotation is

if(Input.GetTouch(i).phase == TouchPhase.Moved && tochy.istouch==false)
                  {
	 				targetItem.transform.Rotate(0, theTouch.deltaPosition.x * rotationRate,0,Space.World); // on xy plane finger is being moved on x axis .
	 				} 

my code code for release

    if (Input.GetTouch(i).phase == TouchPhase.Ended  ) 
                     {
// i need to do rotation reset here

}

On function Start ,save your preferred default rotation as a value , then you can use that value to reset it.

transform.localEulerAngles = new Vector3(x,y,z);

Where x,y,z should be your saved values .