I have been trying , unsuccessfully to make Bran muffins with a very delicate, almost crumbly texture ( similar to a corn muffin type crumb). I have tried various types of flour and grains but nothing comes close to the professional varieties. Does anyone have any suggestions? I am not over mixing in my preparations... this is not the problem. My end product is light and airy like a bread texture...but this is not the texture I am trying to achieve. Anyone have any ideas?

What flours have you tried? Corn muffin crumb is different because, of course, the texture of the corn meal is different from that of regular flours. It's more coarse. Is the bran that you are using a coarse ground? You can try coarse ground whole wheat flour in your recipe and maybe that would help. I really don't know if that stuff exists to tell you the truth. I'll ask around to some of the bakers that I know and maybe they'll have some idea. I really think that the coarse texture of the bran has something to do with it.

I just did some research and here's a link that tells you all about flours and how to replace regular flours with them in your recipes. It even gives some gluten contents!

http://www.switcheroo.com/Flour.html#durum%20wheat