title: Structural and thermal transitions during the conversion from native to granular cold-water swelling maize starch.
abstract: Native maize starch was gradually converted into granular cold-water swelling starch (GCWSS) by aqueous ethanol treatments at elevated temperatures. At a treatment temperature of 95°C, decreasing ethanol concentrations from 68 to 48% (v/v) led to decreased post-treatment gelatinization enthalpies in excess water, reflecting remaining original A-type crystals. Concomitantly to native A-type crystal melting, VH-type crystals appeared. At an ethanol concentration of 48%, a granular cold-water swelling maize starch was successfully produced. All crystals in its intact granules were of the VH-type and appeared birefringent when studied in ethanol under polarized light. Removal of all residual solvent by high temperature drying did not influence swelling power, proving that a high temperature drying step is not necessary to induce cold-water swelling capacity. Based on in situ calorimetric measurements, the thermal requirements to produce GCWSS from different ethanol:water mixtures were elucidated. This work is the first to demonstrate that the amylose fraction contributes almost exclusively to VH-type crystal formation in GCWSS.
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium; Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, B-3001 Leuven, Belgium. Electronic address: Dorien.Dries@biw.kuleuven.be.
authors.forename: D M
authors.initials: DM
authors.lastname: Dries
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium; Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, B-3001 Leuven, Belgium. Electronic address: Sara.Gomand@biw.kuleuven.be.
authors.forename: S V
authors.initials: SV
authors.lastname: Gomand
authors.affiliation: Polymer Chemistry and Materials, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium; Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, B-3001 Leuven, Belgium. Electronic address: Bart.Goderis@chem.kuleuven.be.
authors.forename: B
authors.initials: B
authors.lastname: Goderis
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium; Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, B-3001 Leuven, Belgium. Electronic address: Jan.Delcour@biw.kuleuven.be.
authors.forename: J A
authors.initials: JA
authors.lastname: Delcour
mesh_terms: D013213:Starch / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D014867:Water; D013213:Starch
keywords: Cold swelling; Differential scanning calorimetry; Polarized optical microscopy; Starch; V-type crystallinity; X-ray diffraction