Graphic representation of xantoprotheic reaction

[Weissritter]

Homework Statement

O hai,[STRIKE] my minions.
[/STRIKE]
So...we made the xantoprotheic reaction in the lab, but I have to attach the representation of the reaction. I haven't found it anywhere. So I came to you.

Homework Equations

Protein + NaNO₃→(180s@373K)→(room temp) + NaOH→ Weird yellow precipitate, possibly more than two compounds

The Attempt at a Solution

I'm clueless about the answer. It could be NaNO₃, but that salt is white, and not yellow, so something else could appear in the final result. What I am missing?

 

[Borek]

I was able to google the answer is 2 minutes. It is not a salt. Protein gets modified in a way that makes it insoluble (and no, it is not just a simple denaturation).

 

[Weissritter]

After some weird results, the answer is apparently a xanthoprotein. Most of sources, however, simply say "the yellow thing is a xanthoprotein", while never saying how it is made. On another source, it simply says "becomes yellow because nitro-compounds are formed.
But wait! Borek said they become insoluble...that means it is either a very high, or very low density compound, which could mean the huge protein is...broken into not-so-huge aromatic, carboxylic acids, possibly?
Also, they become sort of solid, which means the yellow thing, if organic, is a long-chain compound, which makes it solid. The long chain also means it becomes apolar and water-non-soluble.
So...aromatic generic carboxyacids, maybe? Maybe that's a xanthoprotein.
And yes, I looked at the preffix 'xantho-'. It is a category of crabs. Not very useful,