Sorry to jump in without reading the entire thread. I am pretty sure Dark Wolf is talking about inulin, which is found in Jerusalem Artichokes.

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I have jerusalem artichokes growing in my back yard.

I got them because they are a perfect survival food...I didn't know they have insulin in them.

They spread like crazy, they outgrow any weed...and they're pretty tasty.

They taste like a potato that's a tiny bit sweet (but not a sweet potato).