Number of branch points in α-limit dextrins impact glucose generation rates by mammalian mucosal α-glucosidases.

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.