I thought it was due to a particular carbohydrate in beans that humans lack the enzyme to digest. As a result it passes unscathed into the large intestine, where it gets broken down by bacteria who create gas in the process.
This is why anti-gas tablets like Beano work. They supply the missing enzyme so the carb gets broken down before it enters the large intestine, thus no gas.
This is the first I’ve heard of the protein theory.
Same. I’m going to need to see some research before believing this.
More likely, the washing stage after grinding is washing away enough of that carbohydrate to make a difference.
On a related note, a few years ago I stumbled across a bean that doesn’t cause gas. The “Beefy Resilient Grex Bean”, developed by Carol Deppe. It’s not available on a large scale yet, but I’m working on developing a strain that can be machine-harvested. Until then, the only way to get it is to grow your own.
It’s entirely possible that the carb that causes gas is a big contributor to the “beany” flavor. That could be why Beefy Resilient taste so different, and why the article above says the beans taste like potatoes after the recommended treatment process.
This stuff as well:
https://en.wikipedia.org/wiki/Asafoetida