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Vol. 18 (2015 year), No. 1

Voron'ko N. G., Derkach S. R., Sokolan N. I.
Interaction of gelatin with chitosan: The influence of polysaccharide concentration

The interaction of gelatin and cationic polysaccharide chitosan with stoichiometric (bio)polyelectrolyte complexes formation inside the aqueous phase which pH is less than the isoelectric point of gelatin has been studied by capillary viscosimetry, UV spectroscopy and dispersion of light scattering methods. The aqueous dispersions of complexes show increase in the particle size of disperse phase and accordingly the relative viscosity compared with sols of the individual components – gelatin and polysaccharide. The models and mechanism of (bio)polyelectrolyte complexes formation have been discussed. The formation takes place due to the electrostatic interactions between the positive charged amino groups of chitosan and negative charged aminoacid’s residues (glutamic Glu and aspartic Asp acids) of gelatin

(in Russian, стр.10, fig. 7, tables. 0, ref 35, Adobe PDF, Adobe PDF 0 Kb)

Vol. 18 (2015 year), No. 1

Novikov V. Yu., Derkach S. R., Shironina A. Yu., Mukhin V. A.
Kinetics of the enzymatic hydrolysis of hydrobiont tissue proteins: Effect of the enzyme introduction

Kinetic laws of enzyme hydrolyze for Atlantic cod tissues have been studied. Enzyme specimen produced from hepatopancreas of Kamchatka crab Paralithodes camtschatica was used for carrying out hydrolyzes (proteolysis). A new method of protein hydrolyzate production based on multiple enzyme injection (over equal time intervals) into a reactive system has been worked out. It has been shown that this method assures increase of maximum degree of hydrolyze. A kinetic model describing the mechanism for enzyme hydrolysis of fish protein in the proposed technology has been developed. The model is based on the existence of easily and hardly hydrolyzed protein fractions. In the frame of the obtained kinetic model, the second-order constants of intermediate stage rates of proteolysis have been calculated. The content of free amino acids increases 2-fold, and dispersity of aqueous dispersions increases for the hydrolysates obtained in the multiple injection process in comparison with hydrolysate obtained in a traditional single-stage process.

(in Russian, стр.10, fig. 5, tables. 5, ref 13, Adobe PDF, Adobe PDF 0 Kb)

Vol. 20 (2017 year), No. 1, DOI: 10.21443/1560-9278-2017-20-1/1

Derkach S. R., Berestova G. I., Novikov V. Yu.,Kolotova D. S., Brichka K. M., Simonsen G
Chemical composition of Pechora Sea crude oil

The physicochemical properties of the Pechora Sea shelf oil and its chemical composition have been studied using the methods of refractometry, titrimetry, viscometry, rheometry and standard methods for the analysis of oil and petroleum products. The fractionation of oil is held at atmospheric pressure, some fractions boiling at the temperature below and above 211 °C have been received. Chemical structural-group composition of oil and its components has been investigated using a Fourier infrared (IR) spectroscopy method. The density of oil has been obtained, it is equal to 24.2 API. The chemical composition analysis shows that water content in the investigated oil sample is about 0.03 % (by weight). The oil sample contains hydrocarbons (including alkanes, naphthenes, arenes) and asphaltenes with resins; their content is equal to 89 and 10 % (by weight) respectively. Alkane content is about 66 %, including alkanes of normal structure – about 37 %. The solidification temperature of oil sample is equal to –43 °C. This low temperature testifies obliquely low content of solid alkanes (paraffin). Bearing in mind the content of asphaltenes with resins we can refer the investigated oil sample to resinous oils. On the other hand spectral coefficient values (aromaticity quotient and aliphaticity quotient) show that oil sample belongs to naphthenic oils. According to the data of Fourier IR spectroscopy contents of naphthenes and arenes are 5.9 and 17.8 % respectively. Thus, the obtained data of chemical structural-group composition of crude oil and its fractions indicate that this oil belongs to the heavy resinous naphthenic oils. The rheological parameters obtained at the shear deformation conditions characterize the crude oil as a visco-plastic medium.

(in Russian, стр.10, fig. 3, tables. 5, ref 14, Adobe PDF, Adobe PDF 0 Kb)