I'm issuing a challenge for people to buy a junk food burger, take it out of the wrapper, put it in a ziplock bag with a tiny opening in the zipper for air to keep it fresh, and just leave it out in the sun (or if it's cold maybe on your counter) and just take photos of it every 3 days or every day. And make a note of how it smells when you put your nose up to the little air hole in the bag's small zipper opening.