Studies on Starch Granules

In X‐ray diffractometric studies on starch granules of many kinds of plant species, we found a variety of intermediate C‐type patterns. In particular, specimens of sweet potato starch granules varied from nearly the A‐type pattern to nearly the B‐type pattern. In these studies, we also found that spheroids of short chain amylodextrin showed very sharp diffraction patterns and that we could form amylodextrin spheroids with various types of X‐ray diffraction patterns by varying the conditions of recrystallization. Then we showed that the X‐ray patterns and physical properties of many kinds of cereal and root starches varied to some extent depending on the environmental conditions prevailing during the growth period. We examined the formation and the growth of starch granules in corn endosperm and the inner structures of these granules from the beginning to the end of their maturation by electron microscopic observations. We proved also, the appositive growth of starch granules using radio‐active carbon dioxide. Then we tried to form starch granules in vitro. But the spheroids obtained from solutions of starch components were entirely different from natural starch granules. From the findings in these experiments, an ultramacromolecular concept of the starch granule is proposed.