I am conducting a student experiment of finding the amylose to amylopectin ratio of certain samples using an iodine colorimetry method. In order to calculate the actual ratios, I need a standard to base my calculations on.
Ideally I would use a pure amylose standard, but due to practical limitations, am not able to obtain this. Instead, I am considering using a few different commercially available starches (potato, tapioca, wheat), and treating literature values for amylose : amylopectin ratio as a standard.
My concerns are whether the ratios of the starches I purchase would be consistent with literature values, and possible discrepancies between species; I am hoping that tapioca starch at the least would be reliable, as it is the only species of Manihot esculenta.
Would this method be reliable at all, and are there any alternatives?