title: Number of branch points in α-limit dextrins impact glucose generation rates by mammalian mucosal α-glucosidases.
abstract: α-Amylase first hydrolyzes starch structures to linear maltooligosaccharides and branched α-limit dextrins, then complete hydrolysis to glucose takes place through the mucosal α-glucosidases. In this study, we hydrolyzed waxy corn starch (WCS) by human pancreatic α-amylase to determine the digestion and structural properties of different size fractions of the branched α-limit dextrins. The α-amylolyzed WCS was separated by size exclusion chromatography, and the analyzed chromatograms showed four main hydrolyzate fractions. The first three eluted peaks (regions I-III) corresponded to branched α-limit dextrins, while region IV was the linear maltooligosaccharides. Based on the chromatographic and NMR analyses of the individual peaks, Region I, II, and III had multiple (>2), two, and one α-1,6 linkages, respectively, and region I was the most slowly hydrolyzed to glucose by mucosal α-glucosidases (hydrolysis rate: Region I<II<III<IV). This study shows the possibility of producing slowly digestible oligosaccharides that may decrease postprandial glycemic response and control glucose delivery to the body, to address metabolic syndrome-associated diseases.
authors.affiliation: Department of Food Science & Biotechnology, College of BioNano Technology, Gachon University, Sungnam 13120, South Korea.
authors.forename: Byung-Hoo
authors.initials: BH
authors.lastname: Lee
authors.affiliation: Department of Food Science, Whistler Center for Carbohydrate Research, Purdue University, West Lafayette, IN 47907, USA. Electronic address: hamakerb@purdue.edu.
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Hamaker
mesh_terms: D000818:Animals; D003912:Dextrins / Q000737:chemistry*; D005947:Glucose / Q000096:biosynthesis*; D006868:Hydrolysis; D013213:Starch / Q000378:metabolism; D000516:alpha-Amylases / Q000378:metabolism; D000520:alpha-Glucosidases / Q000378:metabolism*
chemical_list: D003912:Dextrins; D013213:Starch; D000516:alpha-Amylases; D000520:alpha-Glucosidases; D005947:Glucose
keywords: Human α-amylase; Slow digestion; Starch; α-glucosidases; α-limit dextrins