Complexes of Starch and its Related Materials with Organic Compounds. Part. X. X‐Ray Diffraction of Amylose‐Fatty Acid Complexes

Abstract

Abstract X‐ray diffraction analyses of the complexes of amylose with a wide variety of fatty acids were carried out. The unit cell dimensions of the complexes were calculated for both the wet and dry states. Both the 6 1 ‐ and 7 1 ‐helical conformations of amylose were found in these complexes, and the conformation seems to depend on the linear chain length of the acid molecules. The orthorhombic unit cell was proposed for the 7 1 ‐helical structure of the wet complexes. The dibasic acid gave the crystal modification of the complexes exhibiting the diffraction pattern of hexagonal or orthorhombic nature. It was also found that complexations with n‐propionic acid give rise to three kinds of the patterns, depending on the amount of n‐propionic acid added to aqueous solution of amylose.