Gel Chromatography of Residue and Extract Obtained from Starch Granules by Hot Aqueous 1 ‐Butanol Solution Treatment

Starch granules of corn starches (normal, waxy, amylo and amylowaxy) and potato starch were treated with hot aqueous solution saturated with 1‐butanol and fractionated. These fractionated starches were subjected to an advanced gel chromatography with a column system of Toyopearl HW 75 F. Amylose of normal maize and potato starches was perfectly leached out from the granules, but that of amylo maize was not perfectly extracted. Amylo and amylowaxy maize starches were proved to have large amount of low‐molecular weight material. Normal and amylo maizes, and potato starches contained a high‐molecular‐weight material recognized as amylose type, and it is strongly suggested that amylopectin of normal maize is not same as that of waxy maize. It was found that the GPC analysis was a very important step to estimate an amylose content since a part of amylopectin made a precipitable complex with 1‐butanol.