Is bread crust concentrated fibre?

Neither. Crust come from a reaction between sugars and proteins. It has a higher level of fiber, but crustiness is a unique chemical reaction.

It is browned dough, not burnt dough. Many times an egg wash is added to give it that nice brown crust.

Neither.

Heat causes a lot of interesting reactions in food chemistry. The browning of sugars is one of these. Browned sugars do not contribute extra fiber to the body when consumed, but they are considered attractive and, in some cases, delicious.

It’s even more interesting that when you heat the proteins in an egg, they denature (unravel). But cooling the egg back down doesn’t return the proteins to their original state. The proteins are permanently changed. This is true of metals, glass and plastics too. Heat is a very important tool in modern manufacturing.

ty; to everyone who had replied :)