- radiation that can only heat,
- radiation that can additionally ionize,
- and radiation that can actually make stuff radioactive.
XRays are the second kind, ionizing radiation, meaning they may alter some molecules (i.e. the arrangement of atoms), but will not affect the atoms themselves(so no radioactivity is created).
The altering of molecules may also happen to the DNA molecule, which is why XRays are kept to a minimum. So the apple sent through the machine might get a mutation, but the chance of that being a problem to the apple are remote, and the mutated apple being a problem to you is virtually nonexistent. Sending old school films through an old school XRay might be a problem for the film (film is coated with molecules that are easily altered, because detecting (visible)radiation is it's job, and old XRays used higher power sources).
Your association of XRay machines with radioactivity might come from the hazard sign above, that is sometimes quite prominently displayed on Xray machines.
It simply warns of ionizing radiation, which can, as stated, damage your DNA, thereby giving you cancer, etc, depending on strength. It's popular meaning of "Danger! Radioactivity" came about because radioactive materials emit ionizing radiation (that's actually why it's called radioactive, the ionizing radiation messes with radio-equipment). So Radioactive materials emit ionizing radiation, but ionizing radiation does not produce radioactivity.