Phase separation in mixtures of ovalbumin and konjac glucomannan: Physicochemical and microscopic investigations

Abstract The phase behavior and microstructure of ovalbumin (OVA)/konjac glucomannan (KGM) mixtures were studied at pH 7.0. Phase diagrams were established by centrifugation and visual observation. Micro-phase separation of the OVA/KGM mixtures was quantified by measuring the turbidity. The microstructures of the phase separated mixtures were studied by measuring rheological property and confocal laser scanning microscopy (CLSM). The phase behavior of OVA/KGM mixtures appeared to be one single phase or two separated phases depending on the content of OVA and KGM. OVA had a pronounced effect on turbidity of OVA/KGM mixtures. The particle size of mixtures increased with increasing OVA and KGM concentration, which was the largest (119.1 μm) at 0.25 wt.% KGM and 5 wt.% OVA. The G′ and G″ cross-over at a mixture of 0.20 wt.% KGM and 4 wt.% OVA demonstrated the buildup of microstructure during phase separation. The association of OVA aggregates could be observed under CLSM.