On the organization of chains in amylopectin

• Published in: Die Stärke Vol. 65; no. 3; pp. 191 - 199
• Main Authors: Chauhan, Falguni, Seetharaman, Koushik
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag 01.03.2013; WILEY-VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Subjects: Absorption; amylopectin; Amylopectin model; Amylopectin structure; Applied sciences; Biological and medical sciences; dextrins; Exact sciences and technology; Food industries; Fundamental and applied biological sciences. Psychology; Iodine; Iodine binding; Limit dextrin; Lintner; Natural polymers; Physicochemistry of polymers; Starch and polysaccharides; Starch and starchy product industries; Studies; Limit dextrin; Amylopectin model; Amylopectin structure; Lintner; Amylopectin; Supramolecular structure; Iodine binding; Oside polymer; Experimental study
• ISSN: 0038-9056; 1521-379X
• DOI: 10.1002/star.201200132

The visualization of organization of chains in amylopectin remains a subject of debate. The traditional and backbone model are the two currently cited models, but there have been no attempts to provide experimental evidence to test the validity of either model. This study tests the hypothesis based on iodine binding by lintners and limit dextrins. Data show that starch lintners bound iodine in amorphous blocklets below the large blocklets, based on AFM. Based on the absorption maxima observed, it suggested that chains in the amorphous blocklets likely pre‐exist as loose helices and are of DP 19–24 that can bind iodine. Further investigations using limit dextrins and their sequential hydrolysis products clearly provide contrast between the traditional and backbone models. Data in this study suggests that it is unlikely that the internal chains in traditional model can bind iodine, due to steric hinderances and result in the absorption maxima observed here.