Microwave arcing?

Question

I've asked this question in the chemestry section with no results.

What chemical reaction happens in gingerroot that causes it to arc in a microwave?

I peel and freeze fresh gingerroot, defrost it in the microwave.
It doesn't matter which dish I use -- after about 10 seconds the root starts arcing, buzzing, and at the point of arc the ginger piece is blackened. This has happened everytime and only with gingerroot.
Why?

A piece is approx 1 x 1"

Answer 1

I'm not going to say I know what is going on but this sounds interesting. I think this may be dielectric resonance. It is a way for microwave current to flow without metal. Are the roots always the same length? What happens when they are cut into small pieces?

Answer 2

Yeah, I'll go with the conductivity idea. So, here is the Nobel Prize experiment. Borrow an ohmmeter from somebody, cheap one will do. Cut same-sized pieces of different root veggies and compare their resistance. Try fresh potatoe, carrot, raddish, whatever you have, and see how ginger root compares. We expect a full report.

Answer 3

My guess is that the soil that the ginger root is being grown in is rich in some kind of minerals - so it ends up with semi-metallic properties.