Über den Feinbau von Kartoffel‐ und Weizenstärke

The submicroscopic radial structure of the starch granule can be explained by folded‐chain crystals better than by microfibrils. Such microfibrils described especially by Sterling and also observed by myself may be artefacts which are caused by steps of carbon coated fracture planes of starch granules. The partly submicroscopic tangential shell structure of the starch granule is probably caused by a periodical change of higher and lower molecular fractions both of amylose and amylopectin. This conclusion follows from staining and fluorochroming as well as from phosphoric tungstic acid contrasting experiments in light and electron microscopy. The more crystalline layers consist exceedingly of high molecular fractions. The less tight and more amorphous regions of layers which are easier oxydated (e. g. by periodic acid) and hydrolysed (by a‐amylase) are composed of lower molecular fractions rich in phosphorus and nitrogen containing compounds (especially in wheat starch) and therefore are more hydrophilic and abounding in water.