title: Understanding starch gelatinization: The phase diagram approach.
abstract: By constructing a detailed phase diagram for the potato starch-water system based on data from optical microscopy, synchrotron X-ray scattering and differential scanning calorimetry, we show that gelatinization can be interpreted in analogy with a eutectic transition. The phase rule explains why the temperature of the gelatinization transition (G) is independent on water content. Furthermore, the melting (M1) endotherm observed in DSC represents a liquidus line; the temperature for this event increases with increasing starch concentration. Both the lamellar spacing and the inter-helix distance were observed to decrease with increasing starch content for starch concentrations between approximately 65 wt% and 75 wt%, while the inter-helix distance continued decreasing upon further dehydration. Understanding starch gelatinization has been a longstanding challenge. The novel approach presented here shows interpretation of this phenomenon from a phase equilibria perspective.
authors.affiliation: Biomedical Science, Faculty of Health & Society, Malmö University, SE-20506 Malmö, Sweden; Biofilms Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden. Electronic address: jonas.carlstedt@mah.se.
authors.forename: Jonas
authors.initials: J
authors.lastname: Carlstedt
authors.affiliation: Biomedical Science, Faculty of Health & Society, Malmö University, SE-20506 Malmö, Sweden; Biofilms Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden. Electronic address: wojtasz@chalmers.se.
authors.forename: Joanna
authors.initials: J
authors.lastname: Wojtasz
authors.affiliation: Magle AB, Fjälkestadsvägen 336-15, SE-291 94 Kristianstad, Sweden. Electronic address: pf@magle.se.
authors.forename: Peter
authors.initials: P
authors.lastname: Fyhr
authors.affiliation: Biomedical Science, Faculty of Health & Society, Malmö University, SE-20506 Malmö, Sweden; Biofilms Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden. Electronic address: vitaly.kocherbitov@mah.se.
authors.forename: Vitaly
authors.initials: V
authors.lastname: Kocherbitov
mesh_terms: D002152:Calorimetry, Differential Scanning; D005780:Gelatin / Q000737:chemistry*; D008853:Microscopy; D044367:Phase Transition; D053838:Scattering, Small Angle; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D005780:Gelatin; D013213:Starch
keywords: Calorimetry; Gelatinization; Microscopy; Phase diagram; Starch; Synchrotron X-ray scattering