Actually, I always thought that the food was in essence replicated using transporter technology. If you look quite closely at the light pattern produced by the grill you mentioned in the previous post, you will see that it almost exactly duplicates the pattern that would be cast by the dividers used in the TOS transporter room. You know, the onse that are about 3 inches wide, black and white, and look like a bunch of film frames and run top to bottom between the drum wrap which was used on the back wall. Looking at the lighting grid pattern produce in the food transporters in the very first pic on this post, you can even make out the secondary "sprocket holes" which are smaller and to both sides of the "frame hole".
Wow, I have been spending entirely too much time scrutinizing background shots! Thanks Greg, for making me see things I've never noticed before!