Glass transition temperature of protein/polysaccharide co-dried mixtures as affected by the extent and morphology of phase separation
The glass transition temperature of whey proteins concentrate (WPC)/hydroxypropyl methylcellulose (HPMC) co-dried mixtures with different degrees of phase separation and morphologies were determined by differential scanning calorimetry. To this end the phase separation of aqueous mixtures of WPC (12...
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todo:paper_00406031_v487_n1-2_p65_Jara2023-10-03T14:51:05Z Glass transition temperature of protein/polysaccharide co-dried mixtures as affected by the extent and morphology of phase separation Jara, F.L. Pilosof, A.M.R. Confocal scanning light microscopy Differential scanning calorimetry Glass transition temperature Hydroxypropyl methylcellulose Phase behaviour Whey protein concentrate Calorimeters Confocal microscopy Curing Differential scanning calorimetry Glass Glass transition Laser interferometry Mixtures Phase interfaces Phase modulation Polysaccharides Scanning Superconducting transition temperature Confocal scanning light microscopy Glass transition temperature Hydroxypropyl methylcellulose Phase behaviour Whey protein concentrate Phase separation The glass transition temperature of whey proteins concentrate (WPC)/hydroxypropyl methylcellulose (HPMC) co-dried mixtures with different degrees of phase separation and morphologies were determined by differential scanning calorimetry. To this end the phase separation of aqueous mixtures of WPC (12 wt% or 20 wt%) and HPMC (2 wt% or 3 wt%) at pH 5 or 6, was arrested at different times before freeze-drying. Confocal microscopy allowed to characterize the morphology of phase separation. Co-dried mixture from quenched phase-separated systems exhibited different numbers of Tgs, according to the degree of phase separation. Two Tgs were observed in the fully phase-separated systems. A single Tg was detected during the first stages of phase separation (i.e. below a 50% of phase separation). It is proposed to ascribe the observed single Tg to the predominance of the extremely large mixed protein/polysaccharide interface present, that would dominate the mobility of the whole system because acting as a network for the entanglement between the protein-rich and the polysaccharide-rich phases. WPC (12 wt%)/HPMC (2 wt%) co-dried mixture at pH 5, with a degree of phase separation above 50%, exhibited three Tgs which were related respectively to the mixed interface, protein-rich phase and polysaccharide-rich phase. The non-phase-separated WPC (6 wt%)/HPMC (1 wt%) co-dried mixture also showed a single Tg with a reasonable agreement to the predicted value by a theoretical model. © 2009 Elsevier B.V. All rights reserved. Fil:Jara, F.L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Pilosof, A.M.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00406031_v487_n1-2_p65_Jara |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Confocal scanning light microscopy Differential scanning calorimetry Glass transition temperature Hydroxypropyl methylcellulose Phase behaviour Whey protein concentrate Calorimeters Confocal microscopy Curing Differential scanning calorimetry Glass Glass transition Laser interferometry Mixtures Phase interfaces Phase modulation Polysaccharides Scanning Superconducting transition temperature Confocal scanning light microscopy Glass transition temperature Hydroxypropyl methylcellulose Phase behaviour Whey protein concentrate Phase separation |
| spellingShingle |
Confocal scanning light microscopy Differential scanning calorimetry Glass transition temperature Hydroxypropyl methylcellulose Phase behaviour Whey protein concentrate Calorimeters Confocal microscopy Curing Differential scanning calorimetry Glass Glass transition Laser interferometry Mixtures Phase interfaces Phase modulation Polysaccharides Scanning Superconducting transition temperature Confocal scanning light microscopy Glass transition temperature Hydroxypropyl methylcellulose Phase behaviour Whey protein concentrate Phase separation Jara, F.L. Pilosof, A.M.R. Glass transition temperature of protein/polysaccharide co-dried mixtures as affected by the extent and morphology of phase separation |
| topic_facet |
Confocal scanning light microscopy Differential scanning calorimetry Glass transition temperature Hydroxypropyl methylcellulose Phase behaviour Whey protein concentrate Calorimeters Confocal microscopy Curing Differential scanning calorimetry Glass Glass transition Laser interferometry Mixtures Phase interfaces Phase modulation Polysaccharides Scanning Superconducting transition temperature Confocal scanning light microscopy Glass transition temperature Hydroxypropyl methylcellulose Phase behaviour Whey protein concentrate Phase separation |
| description |
The glass transition temperature of whey proteins concentrate (WPC)/hydroxypropyl methylcellulose (HPMC) co-dried mixtures with different degrees of phase separation and morphologies were determined by differential scanning calorimetry. To this end the phase separation of aqueous mixtures of WPC (12 wt% or 20 wt%) and HPMC (2 wt% or 3 wt%) at pH 5 or 6, was arrested at different times before freeze-drying. Confocal microscopy allowed to characterize the morphology of phase separation. Co-dried mixture from quenched phase-separated systems exhibited different numbers of Tgs, according to the degree of phase separation. Two Tgs were observed in the fully phase-separated systems. A single Tg was detected during the first stages of phase separation (i.e. below a 50% of phase separation). It is proposed to ascribe the observed single Tg to the predominance of the extremely large mixed protein/polysaccharide interface present, that would dominate the mobility of the whole system because acting as a network for the entanglement between the protein-rich and the polysaccharide-rich phases. WPC (12 wt%)/HPMC (2 wt%) co-dried mixture at pH 5, with a degree of phase separation above 50%, exhibited three Tgs which were related respectively to the mixed interface, protein-rich phase and polysaccharide-rich phase. The non-phase-separated WPC (6 wt%)/HPMC (1 wt%) co-dried mixture also showed a single Tg with a reasonable agreement to the predicted value by a theoretical model. © 2009 Elsevier B.V. All rights reserved. |
| format |
JOUR |
| author |
Jara, F.L. Pilosof, A.M.R. |
| author_facet |
Jara, F.L. Pilosof, A.M.R. |
| author_sort |
Jara, F.L. |
| title |
Glass transition temperature of protein/polysaccharide co-dried mixtures as affected by the extent and morphology of phase separation |
| title_short |
Glass transition temperature of protein/polysaccharide co-dried mixtures as affected by the extent and morphology of phase separation |
| title_full |
Glass transition temperature of protein/polysaccharide co-dried mixtures as affected by the extent and morphology of phase separation |
| title_fullStr |
Glass transition temperature of protein/polysaccharide co-dried mixtures as affected by the extent and morphology of phase separation |
| title_full_unstemmed |
Glass transition temperature of protein/polysaccharide co-dried mixtures as affected by the extent and morphology of phase separation |
| title_sort |
glass transition temperature of protein/polysaccharide co-dried mixtures as affected by the extent and morphology of phase separation |
| url |
http://hdl.handle.net/20.500.12110/paper_00406031_v487_n1-2_p65_Jara |
| work_keys_str_mv |
AT jarafl glasstransitiontemperatureofproteinpolysaccharidecodriedmixturesasaffectedbytheextentandmorphologyofphaseseparation AT pilosofamr glasstransitiontemperatureofproteinpolysaccharidecodriedmixturesasaffectedbytheextentandmorphologyofphaseseparation |
| _version_ |
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