Molecular structures of rice starch

✍ Scribed by Susumu Hizukuri; Yasuhito Takeda; Nobuhisa Maruta; Bienvenido O. Juliano

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 560 KB
• Volume: 189
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(89)84099-6

✦ Synopsis

New procedures for the structural analysis of starches are described. The beta-amylolysis limit of the branched component of seven rice amyloses was estimated to be 39% from the relationship between the beta-amylolysis limit and the number of branched molecules. The d.p., and the proportions of the linear and branched molecules were estimated on the basis of the structures of the amyloses and their beta-limit dextrins. The limiting viscosity numbers [T] showed good correlation with the proportions of the linear and branched molecules, but not with their molecular sizes. The iodine affinity and the [v] of eight rice amylopectins were dependent on the longest chain component, which is lacking in waxy amylopectin but abundant in some indica varieties. The [v] of rice amylopectin showed a good correlation with the proportions of the components with the longest and shortest chains. but not with the molecular size.