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Biomedical subjects

W B Tolstogusow

Publications and source records attributed to W B Tolstogusow.

5 recordsLinked to original sources

[Complex gels of proteins and acid polysaccharides].

The authors studied the thermomechanical properties of complex gels of gelatin and sodium alginate which had been produced on the basis of their insoluble (type I) and soluble (type II) complexes. Compared to gelatin gels of the same concentration, the complex gels I have higher melting points. The latter depend on the pH value at which the insoluble complexes of gelatin and sodium alginate were separated. Up to temperatures from 70 degrees--80 degrees C., no melting of the complex gels II was observed. The aging time and the composition of the soluble complexes of gelatin and sodium alginate exert no marked effects on the properties of the complex gels II. The soluble complexes of gelatin and sodium alginate can form gels in 7 M urea solutions.

Alginates

[Artificial macaroni. 2. Biological value of synthetic macaroni].

The authors determined (in vitro) the amino-acid composition and the enzymatic cleavage of protein and starch as well as (in vivo) the biological value of synthetic macaroni produced on the basis of casein, soybean protein and cotton-seed protein. The products based on casein and soybean protein have a great biological value. Cotton-seed protein has a toxic effect. The biological value of synthetic macaroni is mainly determined by the composition of the initial mixture. The processes of production and culinary processing exert no essential effects on protein content, amino-acid composition of the protein and enzymatic cleavage.

Amino Acids

[Structure and properties of complex gels of gelatin and pectin].

The authors studied the effects of aging time and composition on the thermomechanical properties of complex gels of gelatin and pectin which had been produced on the basis of complexes obtained at pH values below the isoelectric point of gelatin. With aging for up to 7 days, the elasticity of the gels decreases and the melting points are raised by 2--4degreesC. An increase in the relative content of pectin in the complex leads to a considerable rise of the melting point of the complex gel. The increase in heat stability of these gels is explained by the development of an ion lattice, which is due to the interaction of the oppositely charged groups of the pectin and the gelatin. Furthermore, hydrophobic interactions between the non-polar groups of the components might be involved.

Gelatin

[Effect of acid polysaccharides on properties of pancreatic proteases].

The use of acid polysaccharides (sodium alginate, pectin, carrageenan, etc.) as gel-forming agents in the manufacture of artificial foods excites the interest in the study of their effects on the enzymes of the gastrointestinal tract. In this connection, the authors investigated the action of various acid polysaccharides on the kinetics of the hydrolysis of low-molecular substrates catalyzed by pancreatic proteinases. It was shown that the intereactions between acid polysaccharides and enzymes produce effects which can be fully explained by changes in the apparent ionization constants of the ionogenic groups which participate in the catalytic reaction. The extent of the effects observed in presumably determined by the strength of the electrostatic potential which is generated by polyanions.

Alginates

[Interaction between proteins and acid polysaccharides].

The intereaction between proteins and acid polysaccharides is electrostatic in nature and leads to the formation of soluble charged and insoluble neutral complexes. The complex formation in the system casein-dextran sulphate is followed by means of turbidimetric titration. It depends on the pH value and the electrolyte concentration. On free electrophoresis, complexes formed below the isoelectric point of the protein exhibit anodic mobility, whereas pure casein migrates to the cathode. The protein in the complex is not able to bind amido black. Consequently, it cannot be detected electrophoretically by dyebinding. The results from viscosity and diffusion measurements are indicative of an increased hydrodynamic volume of the complexes.

Amido Black