In the U.S., it's extensively regulated by both Federal and State laws, though the amount of regulation varies from state to state, and even county. The regulations don't just cover how the food is processed, but also where the food is stored and the vehicles the food is transported in.

Very few foods can be processed outside of a licensed cannery. Usually only items that don't require refrigeration to stay fresh, for example dried foods or preserves that don't have large pieces of low-acid fruit.