There is RS3 present in potato starch once cooked then cooled. This study analyzes the RS3 content of the potato:
Here is a little excerpt: "RS2 was almost completely transformed into rapidly digested starch upon cooking, but upon cooling, the content of resistant starch again increased. Because this latter form of RS must have been regenerated from the almost completely digestible form (RDS) present in the potatoes immediately after cooking, it is resistant starch Type III (RS3), or retrograded starch".
I've read that rs2 will turn into rs3 upon cooking and cooling. I just am unsure if this is true for the processed rs2 like Potato starch.
All Mark scisson says is. "Any idea if heating the potato starch (like using it as a thickening agent in soups/stews) negates its RS function?
Yes, the RS will be completely negated. Sorry. It does make a good thickener, though."
Read more: http://www.marksdailyapple.com/resistant-starch-your-questions-answered/#ixzz3i5H8sIDn
He doesn't mention if the potato starch is then cooled.
Also, on freetheanimal in this article
it seems to say that heating the potato starch makes it quick digesting.
There is no mention as to what happens when it is cooled again.
Ooh I see what you're saying. Hmm..there wasn't anything regarding cooking and cooling starch that has already been extracted and refined. On Mark Sisson's website he says, "I donâ€™t think it works like that. For retrograde RS to form, it has to be in its whole form â€“ potatoes, not potato starch; cassava, not tapioca starch; rice, not rice flour." He doesn't cite any scientific journals, however.
That is an interesting thought, though.. Perhaps someone will do an experiment to test this sometime in the near future.