title: Hydration and the phase diagram of acid hydrolyzed potato starch.
abstract: We investigated hydration of acid hydrolyzed potato starch (maltodextrin) employing a multi-method approach. In particular, synchrotron radiation X-ray scattering and differential scanning calorimetry were used, and, for the first time, the material was investigated with sorption calorimetry and a newly developed quartz crystal microbalance with humidity scanning. The dry starch was found to be in an amorphous state. During hydration it exhibits a glass transition in both bulk and thin film samples, followed by an exothermic event where the starch crystallized. Recrystallized bulk samples displayed neither a pronounced glass transition nor crystallization upon hydration whereas both events occurred in thin film samples. The hydration-driven crystallization resulted in an X-ray pattern consistent with the coexistence of A and B type crystallites; however, at higher water concentrations only the B form occurred. The results were used to construct the first ever acid hydrolyzed starch-water phase diagram.
authors.affiliation: Malmö University, Faculty of Health and Society, Biomedical Science, Malmö SE-205 06, Sweden. Electronic address: jonas.carlstedt@mah.se.
authors.forename: Jonas
authors.initials: J
authors.lastname: Carlstedt
authors.affiliation: Malmö University, Faculty of Health and Society, Biomedical Science, Malmö SE-205 06, Sweden. Electronic address: joanna.wojtasz@gmail.com.
authors.forename: Joanna
authors.initials: J
authors.lastname: Wojtasz
authors.affiliation: Magle AB, Fjälkestadsvägen336-15, Kristianstad SE-291 94, Sweden. Electronic address: pf@magle.se.
authors.forename: Peter
authors.initials: P
authors.lastname: Fyhr
authors.affiliation: Malmö University, Faculty of Health and Society, Biomedical Science, Malmö SE-205 06, Sweden. Electronic address: vitaly.kocherbitov@mah.se.
authors.forename: Vitaly
authors.initials: V
authors.lastname: Kocherbitov
mesh_terms: D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D005898:Glass; D006813:Humidity; D006868:Hydrolysis; D008855:Microscopy, Electron, Scanning; D011134:Polysaccharides / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques; D053838:Scattering, Small Angle; D011198:Solanum tuberosum / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D013696:Temperature
chemical_list: D011134:Polysaccharides; C008315:maltodextrin; D013213:Starch
keywords: Crystallization; DSC; Glass transition; QCM-D; Sorption calorimetry; X-ray scattering