Mechanical properties and solubility of fibre obtained from liquid two‐phase systems water‐casein‐sodium alginate

Abstract

The mechanical properties (tensile strength and deformation under uniaxial tension and shearing strength) as well as the stability against dissolution of the fibre obtained from the liquid two-phase system, water-caseinsodium alginate, can be much better than the properties of the fibres produced from binary systems, watercasein and water-sodium alginate, when concentrations of the macromolecular components and pH of the system are the same. These properties can be controlled by varying the composition of the system and by additional treatment in a 10% solution of CaCI, at 100 "C.In papers [I -61 it is shown that proteins can be processed into macroscopic monofilaments filled with ultra-thin (from 2 to 5 pm) continuous fibres, from liquid two-phase systems,

Some physicochemical approaches to the problem of protein texturization

“…The limited TDC of proteins with polysaccharides was examined in greater detail on casein (Antonov et al, 1975(Antonov et al, , 1977 and soybean globulins (Antonov et al, 1979). Figures 5 and 6 represent phase diagrams for several protein-acidic polysaccharide-water and protein-neutral polysaccharide-water systems.…”

“…It has been found out that matrix casein-alginate fibers are much stronger and hydrothermally more stable than casein fibers (Antonov et al, 1980(Antonov et al, , 1982b.…”

Inducing Demixing of Semidilute and Highly Compatible Biopolymer Mixtures in the Presence of a Strong Polyelectrolyte

“…But whether phase separation is desired or not, it is important for practical applications to understand the underlying mechanisms and molecular interactions governing the phase behavior of a given system . Despite the considerable amount of research in the field of segregating polymer mixtures, the molecular interactions in the systems are inadequately understood, although theoretical models have been proposed. − There have, as of yet, been comparatively few studies on phase separation in mixtures of similarly charged polyelectrolytes. , Such systems may have advantages over uncharged systems in the separation of proteins due to the tunable charge in the system arising from the dissociated counterions of the polyelectrolytes. , Although the majority of biopolymer mixtures show phase separation, , in most cases the phase separation takes places at critical total concentrations, which are much higher (7−12 wt %) , compared with those of synthetic polymers (less than 1−2 wt %). Unlike synthetic polymers with flexible chains, many proteins are known to be relatively symmetric compact molecules and are usually able to form solutions that can still be considered dilute for concentrations 10-fold higher than for synthetic polymers of the same molecular weight…”

“…In the present work, we focus our study on the phase transitions in aqueous semidilute homogeneous sodium caseinate/sodium alginate systems (SC−SA) with the total concentration of biopolymers being 1.5−2.5 wt %, that is, much below the critical concentrations for phase separation . The phase state of the SC−SA mixtures is not sensitive to changes in pH, ionic strength, and temperature in the quiescent state , and under shear flow . Therefore, the effect of demixing that can be reached for this system can be easily reproduced for other emulsions in which the phase equilibrium is more sensitive to physicochemical parameters.…”

Mechanical and functional properties of anisotropic geleous fibres obtained from the two‐phase system of water — casein — sodium alginate

“…This process makes use of spinning solutions composed of two-phase disperse liquid systems, i.e. mixtures of thermodynamically incompatible proteins and anionic polysaccharides [3]. When a jet of a two-phase spinning solution is fixed in the coagulation bath, gelation of both phases is possible.…”