Study of the spinnability of emulsions based on a two‐phase water‐casein‐sodium alginate system

Abstract

The spinnability of emulsions basing on a two-phase water-casein-sodium alginate system (pH 7.2) was studied as a function of the compositions of the co-existing phases and of the ratio of their volumes by measuring the maximum fiber take-up velocity. It has been established that the spinnability of the emulsion is practically independent of the compositions of the co-existing phases. The dependence of the spinnability of the emulsion on the ratio of the volumes of the phases can be illustrated by an S-shaped curve: except for the phase inversion region, the spinnability of the emulsion is determined by the spinnability of the continuous (matrix) phase, and in the phase inversion region, changes sharply from one constant level to another. A 2.2% solution of sodium alginate was spun through spinnerets of different channel diameters at constant linear extrusion rate. It was shown that a variation of the jet cross section has no effect on the maximum fiber take-up velocity. On this basis it was assumed that beyond the phase inversion region the effect of the content of the disperse phase on the spinnability of the emulsion is equivalent to a change in the effective cross section of the matrix phase. The universal character of these assumptions has been confirmed by experiments in spinning of a silicone oil/sodium alginate solution emulsion.

Some physicochemical approaches to the problem of protein texturization

“…Investigations of several systems containing albumins and neutral polysaccharides have revealed a limited thermodynamic compatibility (TDC) of proteins with polysaccharides (Grinberg and Tolstoguzov, 1972). Based on the microrheology of model two-phase liquid systems, it has been suggested that they could be used to generate fibers and form anisotropic gels without spinnerets (Tolstoguzov et al, 1973;Antonov et al, 1980;Suchkov et al, 1980).…”

“…The spinnability studies of emulsions based on twophase casein-sodium alginate-water systems (Suchkov et al, 1980) have demonstrated that spinnability is very dependent on the phase composition and volume ratio (Figure 14). Away from the phase inversion point, emulsion spinnability is governed by the spinnability of the dispersion medium, i.e., by the continuous matrix phase, whereas in the phase inversion region, the spinnability switches from one constant value to another.…”

Formation of Fibrous Materials from Dense Calcium Caseinate Dispersions

“…Typically, the resulting fibers (∼100 μm) are coagulated in baths containing acid and salt solutions, and then washed. Hydrocolloids, such as carrageenan , and alginate, , or vegetable proteins, such as soy or field bean protein, were used in combination with casein in a two-phase blend to decrease the solubility in water of the casein-based fibers produced. In the case of spun pea and fababean protein, fibers with a granular core and strand-like cortex were formed .…”