A retractable device is placed against the plastic (or glass) packaging, which turns some of the oxygen inside into ozone. It then remains in this form for a couple of hours and kills any bacteria/mold/fungi it encounters before reverting back to oxygen.
The end result is packaged food with a lot less bacteria contained within it and a treatment that has no impact on its taste. In real terms, it means the food gains at least an extra 24 hours of shelf life"
Link to Original Source