[Rheology and spinning of alkaline solutions of sunflower seed globulin and casein]. / Zur Rheologie und Verspinnung alkalischer Lösungen aus Sonnenblumensaatglobulin und Casein

The specific demand of sodium hydroxide is determined for the dissolution of sunflower seed globulin, casein and a mixture of them to equal parts. In low protein-containing solutions it depends for sunflower seed globulin very much on the sodium chloride concentration. From sunflower seed globulin, casein and a mixture of them to equal parts are prepared with sodium hydroxide high protein-containing alkaline solutions. Sunflower seed globulin forms temporally a gel phase. After this phase the solution of sunflower seed globulin shows like casein and a mixture of sunflower seed globulin/casein (I:I) pseudoplastic flow. The flow curves of the pseudoplastic solutions are described mathematically with the OSWALDian power statement. By alkaline solutions of casein and sunflower seed globulin/casein (I:I) the flow exponent n is distributed statistically about 0.9, by solutions of sunflower seed globulin a distribution exists about the mean values n = 0.85 and n = 0.50. lg k depends in all protein solutions on the concentration of protein, sodium chloride, sodium hydroxide and on the temperature and time. For all protein solutions exists a linear relation between the logarithm of viscosity and the reciprocal temperature for lg k and I/T, which is derived normally for NEWTONian flow behaviour. In a suitable scope of spinning for all protein solutions are carried out complete factorial experiment, which guide to regression equations of lg k; in the case of sunflower seed globulin are calculated also a regression equation of the flow exponent n. Going out from the parameters of the spinning process the properties of the spun sunflower seed globulin/casein (I:I) fibers are described.

[Spinning of rapeseed proteins]. / Untersuchungen zur Verspinnung von Rapssaatproteinen

Alkaline solutions of a mixture from rapeseed globulin and casein show plastic flow, which is influenced by protein concentration, relation of rapeseed globulin and casein, temperature and time of storage of the protein solution. The sodium hydroxide concentration with a great variability doesn't take effect on the rheological properties. With increasing content of casein in such alkaline solutions of rapeseed globuline and casein results an approach to NEWTONian flow. The spinnability of alkaline solutions of a mixture from rapeseed globulin and casein and the properties of the corresponding spun protein fibers are influenced by protein concentration, relation of rapeseed globulin and casein of the spinning solution and temperature of coagulating bath. The sodium hydroxide content of the spinning solution and the hydrochloric acid concentration of the coagulating bath with a great variability don't take effect. The spinnability of alkaline solutions of a mixture from rapeseed albumin starchsulphate and casein and the properties of the corresponding spun protein fibers compared to rapeseed globulin-casein mixtures are influenced additionally by sodium hydroxide concentration of the spinning solution and hydrochloric acid content of coagulating bath. The favourable influence on the properties of spun rapeseed albuminstarchsulphate-casein fibers isn't increased by a growth of the rapeseed albumin starchsulphate content more then 4% of the protein concentration of the spinning solution.