As discussed previously, amylopectin is a large molecule composed of two distinct populations of chain lengths. The smaller chains are thought to be in such close proximity that they interact strongly, resulting in crystalline regions that are quite extensive and arranged regularly with respect to each other throughout the granule. The model in Figure 1-8, describing the arrangement of the amylopectin molecule within a growth ring of a starch granule, has been proposed by French and Kainuma (9).
These radially oriented amylopectin “clusters” are also believed to be associated with amylose, which is interwoven throughout the crystalline and amorphous areas. The location of amylose within the granule remains one of the unknown facts required to complete our picture of the internal structure of the starch granule.