Amyloses subfractionation

It is often important to examine the solids which can be isolated from the supernatant liquors obtained during a fractionation, as it would appear that subfractionation of amylose can occur.28... 

Table VII shows some results of the subfractionation (by particle size) of the amylose obtained from a single fractionation cycle. Increase of the starch concentration increases the average particle-size of the precipitated amylose fraction. Systems containing degraded starch (for example, soluble starch), irrespective of the rate of cooling, always yield amylose precipitates of very fine particle-size (about 0.2 micron).

Mechanical Subfractionation of Amylose Particles Obtained by Fractional Precipitation of Potato Starch from an Aqueous Solution of Magnesium Sulfate... 

Although separation of amylose from amylopectin is the main purpose of the process described, it has been observed that subfractionation of at least one of the two components of starch (namely, amylose) likewise occurs. In this connection, it is to be noted here that the experimental results strongly indicate that fractionation of amylose into its different molecular-weight species is remarkably efficient in salt solutions. In view of the great disparity in solvent power between the precipitant and the solvent in the case of aqueous salt solutions, this conclusion seems to confirm some predictions of Flory s. "... 

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