What if lubricants and metal get into the food?
Most every ready to eat meal you’ve ever had from a supermarket (frozen, canned, freeze-dried, boiling bag, etc.) came from a machine.
(So, parts of human fingers aren't a problem?)
From what I understand, in the food packaging business, one of the last tests a unit of food goes through is a metal detector. (Not sure how cans and other metallic containers are screened).
As for lubricants, they are probably natural/digestible. Back in the early days of steam engines, pig fat was used.
(And FWIW, I believe the first use of a steam engine in the food industry was in the early part of the nineteenth century by Joseph Fry, the big kahuna of the burgeoning chocolate industry in England. He used one to power the cacao bean grinder.)
I’d think a lot of the food you eat now has been processed by machines somewhere along the line.
Bakery, canned goods, packaged foods.
A lot of your fresh foods are harvested by ag machines.
I’d think a hamburger is nicely suited to automation because of the geometry.