title: Derivatization patterns among starch chain populations assessed by ion-exchange chromatography: a model system approach.
abstract: Reaction patterns of wheat starch derivatized with a fluorescent probe (model reaction system) were investigated over the course of a reaction period (0.5, 4, 12, or 24h). Debranched derivatives were fractionated into three populations (Unbound, Bound-1, Bound-2) based on charge density via anion-exchange chromatography, with each ion-exchanged fraction further analyzed by size-exclusion chromatography (refractive index [RI] and fluorescence [FL] detection) to assess proportions and patterns of reaction on amylose (AM) and amylopectin (AP) long (LC), medium (MC), and short (SC) branch chains. Approximately 11-12% of the total chains accounted for 63-75% of the FL recovered in the two bound fractions. FL peaks representing AM, AP-LC, AP-MC, AP-SC, and intermediate material (eluted with AM based on molecular size, but reacted more akin to AP-LC) were monitored over the reaction period. Fractionation behaviors varied amongst starch chains, attributable to the impact of the granule structure on molecular reaction patterns.
authors.affiliation: School of Food Science, University of Idaho, P.O. Box 442312, Moscow, ID 83844-2312, USA.
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Hong
authors.affiliation: School of Food Science, University of Idaho, P.O. Box 442312, Moscow, ID 83844-2312, USA. Electronic address: huberk@byui.edu.
authors.forename: Kerry C
authors.initials: KC
authors.lastname: Huber
mesh_terms: D000687:Amylopectin / Q000737:chemistry*; D000688:Amylose / Q000737:chemistry*; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D008970:Molecular Weight; D012031:Refractometry; D013213:Starch / Q000737:chemistry*; D014961:X-Ray Diffraction; D003313:Zea mays / Q000737:chemistry*
chemical_list: D013213:Starch; D000688:Amylose; D000687:Amylopectin
keywords: Amylopectin; Amylose; Fluorescent probe; Size-exclusion chromatography; Starch intermediate material; Starch modification