And a lot of it gets pitched out. It is a cost of doing business. They are making THOUSANDS and HUNDREDS OF THOUSANDS of dollars and the food they use to demonstrate isn't a drop in the bucket. A lot of it is smeared with stuff to make it look good, and a lot i'm sure sits out too long to chomp on.
I don't know who'd want to eat all that Germack after that lady has run her fingers through everything! That's always a turn off for me. Maybe they package it up and give it to the night crew.
They have a merchandising agreement with Wegmans. Wegmans provides all the food for the demos and their labels are displayed prominently (when they sell can openers, etc.)