Hello!

So I was watching a Youtube Video of Nile Red, a quite young guy, who is doing all sort of Chemistry stuff. Check his videos here.

In one he was extracting theobromine from cocoa powder. It seems there are a lot of Tannins in there and they are quite unwanted, what you would typically call fats in a natural substance extraction. So he told you can just throw in MgO-powder, which is weakly lewis-acidic. It will basically bind all the Tannins with their OH-groups and make them water-soluble or at least insoluble in most organic solvents.

I have no clue where Tannins are naturally a problem for Nexus people, but maybe this may help out someone at some time - haven't heard of this method before. And in case nobody is interested in using this, then you may still watch that video, its cool.

Certainly better to use MgO than lead acetate, the latter of which I've used when extracting caffeine from tea many moons ago. (The caffeine was purified by sublimation so the lead won't have been a problem.)

Lots of metals form insoluble complexes with tannins but the degree of aggregation can vary. Lead tannates were easy enough to filter. Don't use lead unless you're performing a sublimation