I don't know about the food freshness thing, but you speak of the toothy edge like it's a tree saw. Even though the edge is toothy, the "teeth" are extremely small requiring a microscope to see the uneven edge. I find it hard to believe it could effect food freshness. The edges are very sharp and slice beautifully.
As far as rusting, maybe at a theoretical level because there is microscopically more surface area right on the edge. But for all practical intents and purposes I wouldn't think it is a concern at all.
In your case I suggest simply providing your customers with what they want. They will be happy and you won't have to worry these theoretical minute details. If you want you could give them a couple of toothy edges to try. They will either like it or not and you can proceed from there.
Toothy or polished is a simply personal preference and the pros/cons have been endlessly debated. Some folks like me prefer toothy, others enjoy polished.
As far as rusting, maybe at a theoretical level because there is microscopically more surface area right on the edge. But for all practical intents and purposes I wouldn't think it is a concern at all.
In your case I suggest simply providing your customers with what they want. They will be happy and you won't have to worry these theoretical minute details. If you want you could give them a couple of toothy edges to try. They will either like it or not and you can proceed from there.
Toothy or polished is a simply personal preference and the pros/cons have been endlessly debated. Some folks like me prefer toothy, others enjoy polished.