TY - JOUR
T1 - Phase behaviour of oat β-glucan/sodium caseinate mixtures varying in molecular weight
AU - Agbenorhevi, Jacob K.
AU - Kontogiorgos, Vassilis
AU - Kasapis, Stefan
PY - 2013/5/1
Y1 - 2013/5/1
N2 - The isothermal phase behaviour at 5 °C of mixtures of sodium caseinate and oat β-glucan isolates varying in molecular weight (MW) was investigated by means of phase diagram construction, rheometry, fluorescence microscopy and electrophoresis. Phase diagrams indicated that the compatibility of the β-glucan/sodium caseinate system increases as β-glucan MW decreases. Images of mixtures taken at various biopolymer concentrations revealed phase separated domains. Results also revealed that at the state of thermodynamic equilibrium, lower MW samples yielded considerable viscosity in the mixture. At equivalent hydrodynamic volume of β-glucan in the mixtures, samples varying in molecular weight exhibited similar flow behaviour. A deviation dependent on the protein concentration was observed for the high MW sample in the concentrated regime due to the size of β-glucan aggregates formed. Results demonstrate that by controlling the structural features of β-glucan in mixtures with sodium caseinate, informed manipulation of rheological properties in these systems can be achieved.
AB - The isothermal phase behaviour at 5 °C of mixtures of sodium caseinate and oat β-glucan isolates varying in molecular weight (MW) was investigated by means of phase diagram construction, rheometry, fluorescence microscopy and electrophoresis. Phase diagrams indicated that the compatibility of the β-glucan/sodium caseinate system increases as β-glucan MW decreases. Images of mixtures taken at various biopolymer concentrations revealed phase separated domains. Results also revealed that at the state of thermodynamic equilibrium, lower MW samples yielded considerable viscosity in the mixture. At equivalent hydrodynamic volume of β-glucan in the mixtures, samples varying in molecular weight exhibited similar flow behaviour. A deviation dependent on the protein concentration was observed for the high MW sample in the concentrated regime due to the size of β-glucan aggregates formed. Results demonstrate that by controlling the structural features of β-glucan in mixtures with sodium caseinate, informed manipulation of rheological properties in these systems can be achieved.
KW - β-Glucan
KW - Mixed systems
KW - Phase separation
KW - Rheology
KW - Sodium caseinate
UR - http://www.scopus.com/inward/record.url?scp=84870717889&partnerID=8YFLogxK
U2 - 10.1016/j.foodchem.2012.10.073
DO - 10.1016/j.foodchem.2012.10.073
M3 - Article
C2 - 23265533
AN - SCOPUS:84870717889
VL - 138
SP - 630
EP - 637
JO - Journal of Micronutrient Analysis
JF - Journal of Micronutrient Analysis
SN - 0308-8146
IS - 1
ER -