title: Morphological, Thermal, and Rheological Properties of Starches from Maize Mutants Deficient in Starch Synthase III.
abstract: Morphological, thermal, and rheological properties of starches from maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were studied and compared with the wild type. SSIII deficiency reduced granule size of the starches from 16.7 to ∼11 μm (volume-weighted mean). Thermal analysis showed that SSIII deficiency decreased the enthalpy change of starch during gelatinization. Steady shear analysis showed that SSIII deficiency decreased the consistency coefficient and yield stress during steady shearing, whereas additional deficiency in granule-bound starch synthase (GBSS) increased these values. Dynamic oscillatory analysis showed that SSIII deficiency decreased G' at 90 °C during heating and increased it when the paste was cooled to 25 °C at 40 Hz during a frequency sweep. Additional GBSS deficiency further decreased the G'. Structural and compositional bases responsible for these changes in physical properties of the starches are discussed. This study highlighted the relationship between SSIII and some physicochemical properties of maize starch.
authors: School of Chemical Sciences, University of Auckland , Private Bag 92019, Auckland 1142, New Zealand.
authors: Fan
authors: F
authors: Zhu
authors: Department of Food Science and Nutrition, University of Minnesota , 1334 Eckles Avenue, St. Paul, Minnesota 55455, United States.
authors: Eric
authors: E
authors: Bertoft
authors: School of Chemical Sciences, University of Auckland , Private Bag 92019, Auckland 1142, New Zealand.
authors: Guantian
authors: G
authors: Li
mesh_terms: D006358:Hot Temperature; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012212:Rheology; D013213:Starch / Q000737:chemistry* / Q000378:metabolism; D013214:Starch Synthase / Q000235:genetics* / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D013213:Starch; D013214:Starch Synthase
keywords: dull maize mutant; granule morphology; rheological property; starch synthase III; thermal property