The regioselective functionalisation of the cyclodextrin matrix provides the possibility of purposefully altering the ability of cyclodextrins to form inclusion compounds, as well as to ensure their solubility, thus expanding the scope of their practical application [1, 2]. The most significant and promising trend in the selective modification of β-cyclodextrins consists in the preparation of tosyl derivatives, given that the substitution of such nucleophilic reagents as iodide, azide, thioacetate, hydroxylamine, alkylamide or polyalkylamide for the tosyl group results in the corresponding monosubstituted derivatives. In this study, we impl emented a method for the synthesis of mono-6-O-(p-toluenesulphonyl)-β-cyclodextrin, which was improved by β-cyclodextrin reacting with tosyl chloride in an aqueous medium in the presence of a base. The reaction of β-cyclodextrin with tosyl chloride in an aqueous alkaline medium produced a 58% yield of mono -6- O-(p-toluenesulphonyl)-β-cyclodextrin not requiring additional purification. The optimal concentrations of β-cyclodextrin and tosyl chloride were found to be 0.0032 mol/l and 0.0015 mol/l, respectively. It was shown that a decrease in the rate of filtering the unreacted tosyl chloride out of the reaction mixture is acc ompanied by an increase in the proportion of ditosyl derivatives and mono(3,6-anhydro)-β-cyclodextrin resulting from the intramolecular cyclisation of mono-6-O-(p-toluenesulphonyl)-β-cyclodextrin at room temperature under alkaline conditions. The structure of the obtained mono-6-O-(p-toluenesulphonyl)-β-cyclodextrin was confirmed using Proton NMR Spectroscopy. The proton NMR spectrum of the product resulting from the reaction of β-cyclodextrin with tosyl chloride contains signals corresponding to a tosyl radical: a singlet (2.42 ppm) and two doublets (7.41–7.43 ppm) produced by hydrogens of the benzene ring having radicals in the para position. Monosubstitution was confirmed by comparing the integrated intensities of signals produced by the protons of the cyclodextrin skeleton and the protons from the aromatic part of the reaction product. Their ratio indicated that only one of the seven primary hydroxyl groups of β-cyclodextrin was substituted.

In the present article the results of a study for the sorption of cerium (III) ions by a chelating synthetic sorbent are presented. Based on a copolymer of styrene with maleic anhydride and m-aminophenol, a new polymer chelating sorbent was synthesised and its sorption characteristics were studied with respect to cerium (III) ions. The synthesis of the sorbent was carried out in the presence of formalin acting as a crosslinking agent. In the course of the studies, various parameters affecting sorption were determined: optimal pH value; ionic strength; the time of complete sorption equilibrium; the effect of the initial concentration of cerium (III) ions on the sorption process. Studies have shown the maximum sorption capacity of the sorbent with respect to cerium (III) ions to be equal to 540 mg/g at pH = 5. In the course of studying the influence of ionic strength on the sorption process up to a certain value of ionic strength (0.2-1.0 mol/L), the presence of K+ and Clions was established to have no effect on the sorption capacity of the sorbent. The reverse desorption process was also studied and the optimal eluent was established using various mineral acids of the same concentration: 0.5 M solutions of HCl, HNO3, H2SO4 and CH3COOH. HNO3 solution of the 0.5 mol/L concentration demonstrated the best desorption ability with respect to cerium ions. The structure of the synthesised sorbent and the presence of certain functional groups was investigated by IR spectroscopy in the region from 400 to 4000 cm^-1.

This article presents a study on the complexation of copper (II) with 2,7-bis(azo-2-hydroxy-3-sulfo5-nitrobenzene)-1,8-dihydroxynaphthalene-3,6-disulphonosodium salt (R) in the presence of diphenylguanidine (DPG), triphenylguanidine (TPG) and non-ionic SAA Triton X-114 (TX-114), carried out by spectrophotometric method. The optimal conditions for the Cu-R complexation are established as follows: pH=3 with the maximum light absorption of the complex occurring at a wavelength of 538 nm. The yield of the Cu-R complex reaches a maximum at the R component concentration of 8·10^-3 M, while the highest value for Cu-R-DPG complex is observed at concentrations of 8·10^-5 and 1·10^-3 M for the R and DPG components, respectively. The maximum of Cu-R-TFG is noted with concentrations of the R and TPG components comprising 8·10^-5 and 8·10^-4 M, respectively. The maximum yield of the Cu-R-TritonX-114 complex was obtained at a component concentration of 8·10^-5 and 8·10^-4 M, respectively. All complexes are formed immediately following the mixing of the component solutions and differ in stability. In the presence of a third component, the maximum absorption is observed at a wavelength of 512 nm (pH=1), 491 nm (pH=2) and 572 nm (pH=2) for the Cu-R-TX-114, Cu-R-DPG and Cu-R-TPG complex, respectively. The reaction ratio of components in the composition of homogeneous (Cu:R =1:2) and mixed ligand (Cu:R:X= 1:2:2) compounds is established. The interval of obedience to Beer's law equal to 0.12–2.32 mg/mL was determined for Cu-R complexes. For Cu-R-TX-114, Cu-RDPG and Cu-R-TPG, the determined interval comprised 0.07–2.32 mg/mL. The following values of stability constant for the complexes was established using the spectrophotometric method: 8.75±0.05 (Cu-R), 9.59±0.05 (Cu-R-TX-114), 9.85±0.05 (Cu-R-DPG) and 9.92±0.04 (Cu-R-TPG). The molar absorption coefficient of the complexes was determined as equal to 10400 (Cu-R), 15000 (Cu-R-TX-114), 15500 (Cu-R-DPG) and 16000 (Cu-R-TPG). The logK_hyd= 7.5, lgK_hyd= 12.7 and lgK_hyd= 13.9 constants of the nickel ion hydrolysis were obtained. The coefficients of the calibration curve equation are determined by the method of least squares. Under optimal complexation conditions, Cu-R was titrated with a component solution (TritonX-114, DPG and TPG) using the conductometric method. The effect of impurity ions and masking substances was studied. The determination of copper (II) is practically unhindered by alkaline, alkaline-earth and some transition elements, such as Ca (II), Ba (II), Mn (II), Cr (III), Sn (IV), Ga (III), In (III) and Zr (IV). The proposed express technique is characterised by its high sensitivity and selectivity, as well as being applicable for the determination of copper in food cereals. 

A new organic reagent, (E)-2-hydroxy-3-((2-hydroxybenzylidene) (amino) benzenesulphonic acid, was synthesised on the basis of salicylic aldehyde. The complexation of iron (III) with c (E)-2-hydroxy-3-(2- hydroxybenzylidene) (amino) benzenesulphonic acid (R) was studied both in the presence and absence of the following surface-active substances (SAA): cetylpyridinium chloride, cetyltrimethylammonium bromide and Triton X-114. Fe (III) was established as forming coloured mixed-ligand complexes with the reagent in the presence of third components. The optimal complexation conditions were determined for the Fe (III)-R binary complex (pH = 4, λ_max = 353 nm), as well as for the multi-ligand complexes of Fe(III)-R-CPCl (pH = 3, λ_max = 374 nm), Fe(III)-R-CPMABr (pH = 2, λ_max = 392 nm) and Fe(III)-R-Triton X-114 (pH = 3, λ_max = 385 nm). The proportion of reacting components in the composition of Fe(III)-R homogeneous ligand iron compounds was determined to be equal to 1:2. Mixed ligand compositions were 1:1:2, 1:1:1 and 1:2:1 for Fe (III)-R-CPCl, Fe(III)-R-CPMABr and Fe(III)-R-Triton X-114, respectively. The molar absorption coefficients and stability constants of Fe(III) complexes were determined. The molar coefficients of the complexes Fe(III)-R, Fe(III)-R-CPCl, Fe(III)-R-CPMABr and Fe(III)-R-Triton X-114 comprise 10,000, 16,250, 19,000 and 11,000, respectively. The intervals of obedience to Beer's law (μg/mL) were determined to range 0.448-2.24, 0.112-4.48, 0.12-4.48 and 0.224-2.24 for Fe(III)-R, Fe(III)-R-CPCl, Fe(III)-R-CPMABr and Fe(III)-R-Triton X-114, respectively. The effect of some ions and masking substances on the formation of binary and mixed-ligand complexes of Fe(III) was studied. The presence of a surfactant was demonstrated to significantly increase the selectivity of the reaction. A technique was developed for spectrophotometric determination of Fe(III) in beans, mushrooms and briar. The data obtained using the proposed method are in good agreement with the results of atomic absorption spectrometry. The proposed method for the determination of Fe(III) with (E)-2-hydroxy-3-(2-hydroxybenzylidene)(amino)benzenesulphonic acid in the presence of cetyltrimethylammonium bromide (CTMABr) is simple, rapid and provides reliable results. 

A review of national and foreign scientific and patent literature, as well as the regulatory documents on the lyophilisation of inactivated vaccines, is presented. According to the State Register of Medicinal Products, all inactivated vaccines produced in dried form in the Russian Federation are obtained by freeze-drying. The excipients (drying media) used in the freeze-drying of vaccines are evaluated in terms of their qualitative and quantitative composition. A review of the features of the main stages of freeze-drying processes, e.g. freezing, sublimation (primary drying) and desorption (secondary drying) is given alongside an analysis of their distinctive features. The information on inactivated vaccines in the lyophilisate form registered in the Russian Federation is systematised. Available information on inactivated vaccines produced in the United States in the form of a lyophilisate is also presented. An analysis of the literature data reveals a significant variety of excipients used in lyophilisation. The influence of the sealing method of consumer packaging on the quality of preparations is considered, i.e. either in the oxygen or inert gas media or under vacuum. It is noted that the entire range of vaccines produced and registered in Russia is sealed under vacuum or in inert gas (i.e. in the absence of oxygen). A number of examples are cited to demonstrate the effect of technological freeze -drying process parameters on the quality of the preparations. It is shown that the preservation of a vaccine's properties during freeze-drying is influenced by a number of parameters, including the freezing rate and the temperature-time parameters of the primary drying and desorption processes. It is established that the correct selection of the qualitative and quantitative characteristics of the drying medium contributes to the preservation of the target properties of lyophilised preparations. The analysis of literature data allows the influence of the parameters described in the review to be considered when developing the technology for the production of immunobiological preparations for the prevention and treatment of infectious diseases.

Bacterial cellulose (BC) consists in a highly crystalline nanopolymer whose potential for application in both traditional and new industries is significant due to its unique physico-mechanical properties. In scaled BC biosynthesis processes, the use of microorganism consortia characterised by their adaptability and synergistic effects when coordinating substrate consumption appears to be promising. In the present work, the effect of inoculum dosage on BC yield during Medusomyces gisevii Sa-12 symbiotic culture on a glucose medium under optimal conditions is studied in detail. Two available methods were chosen for quality control of the BC: scanning electron microscopy, presenting an express method for confirming the origin of cellulose; and the degree of polymerisation in terms of a common method for controlling the quality of cellulose. Four experiments were carried out for the producer introduction with a dosage of 5, 10, 15 and 20% vol.. Use of the Medusomyces gisevii Sa-12 symbiotic culture provided the greatest number of acetic acid bacteria and the highest BC yield (7.5–8.0%) with an inoculum dosage of 10–20% vol. At the same time, an inoculum dosage of 20% vol. allowed the culture time to be halved, while an inoculum dosage of 5% vol. appears to be insufficient. All inoculum dosage variants were determined to provide the same three-dimensional cross-linked microfibrillar structure of BC samples. The degree of polymerisation (DP) of BC samples was first established to depend on the dosage of the inoculum and the duration of BC biosynthesis. Thus, the biosynthesis process can be controlled using such a simple parameter as inoculum dosage and BCs can be synthesised directionally with a given DP. The inoculum dosage of 10% vol. was established as providing the highest possible DP of BC (value of 5000), decreasing slightly during prolonged culture.

The traditional approach to assessing the quality of nutrient bases involves a determination of amino nitrogen and acidity. The disadvantage of this approach consists in a lack of information, i.e. an inability to detect antibiotics, growth inhibitors and other undesirable compounds. In this regard, more modern and informative methods are required to control the technological process of preparing the nutritional basis and therefore the quality of the products obtained. The aim of this work was to study the physicochemical properties of nutrient bases made from sea and river fish and squid using new approaches (NMR spectroscopy). The following raw materials were used: herring (1), roach (2), pollock (3), squid (4). The raw materials were subjected to enzymatic hydrolysis by the pancreas (according to Hottinger). The qualitative composition of the organic component of hydrolysates (1–4) was determined by ¹H, ¹³С and ¹⁵N NMR spectroscopy. All of the 1H NMR spectra had the same appearance, typical of mixtures of amino acids or amino acid sequences. In the high-field part (0.9–2.5 ppm), a set of multiplets was observed, characteristic of aliphatic fragments of molecules. Since most of the signals in the 1H NMR spectra partially overlap, a quantitative assessment of the composition of the organic component appears impossible. All four samples can be confirmed as being qualitatively similar without isolating the dominant compound. Analysis of 2D NMR spectra revealed the presence of the following free amino acids in mixtures of samples (1–4): alanine, valine, threonine, arginine, lysine, leucine, methionine, phenylalanine and glycine. The use of NMR spectroscopy demonstrated that any discrepancies in the component composition of hydrolysates (1–4) were insignificant, allowing manufacturers of nutrient media to choose the most affordable raw materials. The obtained data appear to be applicable for controlling the technological process of preparing the nutrient bases and determining the quality of the resulting products during storage. 

The aim of the present work involves a comparative analysis of the changes in the absolute content of the main fatty acid (FA) component of the total lipid amount in wheat calli (Triticum aestivum L.) under the action of low-intensity laser radiation (LILR), as well as an assessment of the influence of the FA proportion calculation method on the resultant picture of the FA change dynamics. The content of major FAs in callus tissue and its changes when exposed to LILR were determined using gas chromatography-mass spectrometry. A comparative analysis of the calculation results of the absolute (μg/g dry weight) and relative (in %wt. of the sum of the areas of chromatographic peaks) content of the target components (palmitic, stearic, linoleic and linolenic acids) was carried out. When comparing the two calculation methods, no qualitative differences in the change dynamics were observed. At the same time, significant differences were found between the quantitative indicators of the FA content in absolute and relative units. For example, the absolute amount of monounsaturated oleic acid five minutes increased by 23% following the removal of laser radiation, while the relative amount increased by only 14%. For polyunsaturated linoleic and linolenic acids, this difference was even more significant. In general, the trends in changes caused by irradiation in the main fatty acid content compared with the total callus lipids appear to be similar to the stress response of plant tissue to adverse environmental conditions. The scope of two methods for calculating the content of FAs is also discussed.

The development of food biotechnology involves the improvement and optimisation of all stages of the technological process – from the pretreatment of raw materials to the stages of biocatalysis, fermentation and derivation of finished product. Based on relevant scientific sources, a review of the prospects for the integration of thermoplastic extrusion into food biotechnological production, which has a number of technological and economic advantages, is carried out. It is shown that extrusion as a stage of pre-treatment of raw materials increases the degree of solubility, allowing further hydrolysis of starch, protein and non-starch polysaccharides, with a corresponding increase in the yield of bioconversion products. In distillation processes, the use of extruded starch-containing raw materials can become a factor in increased ethanol yield and a reduction in the formation of minor metabolites of fermentation; in brewing, it allows the expanded use of unmalted materials in the preparation of wort; while, in the deep cultivation of microorganisms (enzyme producers), it can be a factor in the increased concentration of the medium and consequent synthesis of enzymes. Positive results for the derivation of nutrient media on extruded raw materials for microbiological production of L (+) lactic acid, production of starter cultures and multicomponent fermented milk-containing products are reported. A combination of extrusion and biocatalysis in the extruder chamber allows maltodextrins to be obtained having a dextrose equivalent of up to 10 units. In addition to the processing of starchy substrates by extrusion in combination with biocatalytic treatment, a deep modification of biopolymers materials having a high protein and dietary fibre content, for example, hydrolysis with heat-stable antigenic properties of the protein fractions of glycinin and conglycinin in soybean meal, increases the functionality of the bran content of water-soluble araboxylans in specialised extruded products. The main factors affecting the degree of processing of raw materials and the quality of the target products are moisture content and extrusion temperature, as well as dosage of enzyme preparations. The possibilities of combining the processes of extrusion and biocatalysis in one reactor system or directly in the extruder chamber are described. These can significantly increase the concentration of processed biotechnological media, simplify the hardware and process composition of production lines, at the same time as increasing production capacity and energy efficiency.

The integrated protection of plants from diseases, pests and weeds is an essential element of technologies for their cultivation. Contemporary crop research involves the widespread use of fungicides, which is important not only for increasing plant productivity, but also in order to obtain a high-quality crop. Under conditions of significant spread, diseases such as wheat fusarium head blight, loose smut of wheat and rye, rye spur and others not only reduce the productivity of crops, but also prevent the use of grain crops for human nutrition or animal feed purposes. In addition to plant protection, measures aimed at managing crops are of great importance in cultivation technology. This is ensured by various technological methods, including the use of a variety of chemicals, including stimulants and regulators of plant growth and development. In addition to their main target effect, many pesticides are known to cause additional effects on plants. This is expressed not only in varying degrees of phytotoxic manifestations, but also in stimulating and growth-regulating effects. Knowledge of the direction of these effects will allow for more competent application of chemical plant protection products, as well as for obtaining positive and avoiding negative effects. Many contemporary large companies working in the field of plant protection inform agrarians about possible additional effects of the preparation. In addition to practical application, studying the influence of the physiological effects of preparations helps agriculturalists to understand the formation mechanisms of plant resistance to stress. The review discusses the physiological and biochemical effects of triazole fungicidal preparations on plants. Their retardant effect, ability to increase the content of photosynthetic pigments and sugars, effects on respiration, changes in the composition of fatty acids, increased resistance of plants to temperature stresses, water deficiency, as well as chloride salinity and oxidative stress are also clarified. The review also includes the results of our own research on the effects of tebuconazole and tebuconazole-containing protectants on the mechanisms of cold and frost resistance of cereals.

The authors investigate the sludge index, dehydrogenase activity and elimination rate for glucose and ammonium ions in activated sludge obtained from urban sewage in treatment plants in the city of Irkutsk to determine the relationship between the factors and the ability to generate an electric current in biofuel cells (BFC). A two-chamber BFC design was used to examine the electrogenic activity of sludge. BFC chambers were separated by a MF-4SK (Plastpolymer CJSC, St. Petersburg) proton-exchange membrane. Sludge sampling was carried out using a sterile syringe inserted through a specially-designed rubber plug in the side of the anode chamber. The proposed cell modification provides sampling or substrate and bioagent dosing without disturbing anaerobic conditions in the anolyte. The Ural T-22R A carbon fabric (SvetlogorskKhimvolokno OJSC, Republic of Belarus) material was used for the electrodes in the BFC under study. Activated sludge was subjected to heat treatment for 5, 10 and 15 min at 80 °С. Inactivation was additionally performed by autoclaving at 1 atm for 30 min (120 °С). The sludge index was determined by the standard method for calculating the volume and weight ratio of sludge. The sludge dehydrogenase activity was evaluated by the reduction of 2,3,5-triphenyltetrazolium chloride. The dynamics of sludge elimination for glucose (by the reduction of 2,3,5-triphenyltetrazolium chloride) and ammonium (by Nessler's reagent) was studied using photometric methods. As a result, sludge heating and autoclave inactivation negatively affected the electrical parameters of sludge-based BFC and the sludge elimination rate for glucose and ammonium nitrogen. The electrogenic activity in BFC was determined for sludge sampled from aerotanks having varying sludge index and dehydrogenase activity values. A direct relationship between the studied parameters is indicated, providing for the application of biofuel cells for the rapid assessment of the physiological state and efficiency of activated sludge.

The aim of the work was to study the application of diffuse reflection electron spectroscopy (DRES) method for obtaining the optical surface characteristics of slices and chopped muscle tissue, muscle fibre and sarcoplasmic protein extracts of wild (wild boar, elk, deer, freshwater and marine fish) and domestic (pork, beef, lamb) animal tissue depending on the following processing conditions: freezing, water extraction, lyophilisation and enzyme-microbial exposure. Electronic spectra of transverse sections of whole-piece material, ground muscle tissue, muscle fibre and aqueous extracts were recorded using a Specord M-200 spectrophotometer (AIZ Engineering GmbH, Germany) having a vertical pathway relative to the Spectralon standard in the wavelength range of 200-700 nm. During testing of biological tissues of animal origin in solid and liquid state, the high sensitivity, resolution and analytical features of the express DRES method was shown to allow the acquisition of factual information concerning changes in the spectral characteristics of their main components under experimental conditions. Regardless of the species and type of animal organism, proteins, mucopolysaccharides, lipids, pigment protein and various oxidised forms demonstrate absorption bands in four clearly differentiated regions of the electromagnetic spectrum: 200-300, 400-425, 300-380, 540-580 and 635 nm, respectively. A comparative study of the pork and beef muscle tissue demonstrated significant differences in the nature of changes in the spectral characteristics of the main components and components of muscle tissue and muscle fibre, depending on the degree of oxidation, mechanical destruction, strength of myofibrils and pigment protein myoglobin associated with them.

The question of the biological value of mushroom protein is not limited to the study of its composition. In addition, the associated problem of its digestibility and assimilability is widely discussed in the scientific community, including in the scientific publications discussed in this article. Mycoprotein derived from proteinrich unicellular fungi biomass is commonly used in contemporary food-production processes. In Russia, however, an alternative source of protein consists in the higher fungi including the common oyster mushroom (Pleurotus ostreatus). It is known that fungal proteins having a rich amino acid composition are absorbed at the level of plant proteins, since they are “packed” in the intercellular chitinous membrane. Various technological methods are used in the processing of raw fungi materials in order to destroy the membrane and release the protein macromolecule. These include traditional processing methods, such as grinding, thermal exposure, etc. In the present article, electromagnetic sterilisation of convenience foods is considered as a means of improving product safety. The authors studied the effect of ionising electron radiation on the physicochemical properties of mushroom products using the example of a heat-treated, vacuum-packaged, semi-finished oyster mushroom product. The applied radiation doses were 1, 3, 6 and 9 kGy. The obtained data showed that, when a semifinished product is irradiated with a dose of 1 to 6 kGy, a greater amount of protein is released compared to unirradiated samples; moreover, that the content of a number of essential amino acids also increases. Therefore, this method allows the biological activity of the nutrients to be increased. The sterilising effect of ionising radiation was achieved with a dose of 6 kGy due to slowing the growth of microorganisms: no pathogenic microorganisms were detected and no growth was observed over a period of 21 days. Thus, electronic ionising radiation as part of the technological process of processing mushrooms allows the biological value of the protein to be increased, preventing the growth of microorganisms and thereby extending the shelf life of mushroom products.

Paenibacillus mucilaginosus bacteria are one of the most promising soil microorganisms for obtaining microbiological fertilisers. These bacteria produce indolyl-3-acetous acid and ammonia, as well as possessing the capability of nitrogen fixation and solubilisation of undissolved soil minerals yielding potassium and phosphorus accessible to plants and consequently stimulating plant growth. P. mucilaginosus biological preparations are also useful in the form of fertiliser additives leading to immune stimulation and increase in the productivity of agricultural animals. For the cultivation of P. mucilaginosus bacterial strains, sucrose is recommended. At the same time, little research has been carried out on the influence of glucose and fructose on the growth of these bacteria. The aim of the work was to study the effect of various carbon sources in the composition of the nutrient medium on the biomass synthesis of P. mucilaginosus strains. As a result, a double growth cycle was observed under the conditions of culture on a nutrient medium with a sucrose and a glucose-fructose mixture. The specific growth rate of the bacterial strains under consideration in the assimilation of glucose is higher than in the assimilation of fructose. Accordingly, the generation time for glucose assimilation turned out to be lower than that for fructose assimilation. The growth of the considered bacterial strains on a single fructose nutrient medium was not observed. Glucose demonstrated similar effectiveness of application in culture media to sucrose for the cultivation of all considered bacterial strains of P. mucilaginosus. During culturing of P. mucilaginosus bacteria on nutrient media from glucose and sucrose, the yield of biomass and exopolysaccharides was established to be higher than for the case of a nutrient medium presented by a glucose-fructose mixture. Promising strains for industrial application include 563, 567 and 574, providing a high yield of biomass and exopolysaccharides with culture on a glucose-admixed nutrient medium, and 560, 568 and 572 strains when cultivated on a nutrient medium containing sucrose.

Since phospholipids are one of the most important classes of natural regulators of physiological processes, the search for methods allowing their analytical and preparative separation is of considerable interest. The aim of this study is to reveal principles underlying the differential centrifugation of complex lipid mixtures on the example of phospholipids. The current study uses calculation methods for estimating the Hansen solubility parameters for phospholipids, as well as instrumental research methods comprising tensometry (density measurement), dynamic laser light scattering (particle size evaluation) and IR spectroscopy with Fourier transformation. These methods were applied to samples of phospholipids isolated from calf brain tissue. The affinity of the studied phospholipids to individual solvent layers was characterised. As a result of the work performed, a mathematical model of the process of differential centrifugation of phospholipid complex mixtures in the gradient of solvent polarity is proposed on the basis of the Nernst-Brunner equations and main centrifugation equation. The established optimal parameters of the centrifugation process comprise 1500 rpm for 15 minutes at a temperature of 2–4 °С. IR spectral analysis revealed significant differences between the substances of each solvent layer, which are due to the separation of the phospholipid classes between the layers of solvents. The necessity for further research into new combinations of solvents contributing to a more specific separation of the mixture and aimed at increasing the separation efficiency of phospholipid complex mixtures, is justified. The volume modification of solvent layers and determination of its ratio with the volume of the introduced suspension also appear to be relevant further research directions. Given the simplicity and low cost of the hardware, the developed method can be easily scaled to industrial conditions for the production of biologically active substances for inclusion in food products.

Plants of the Bistorta genus manifest themselves as a rich source of phenolic compounds, exhibiting antioxidant, anti-inflammatory, antitumor effects, etc. One of the important research tasks in this connection involves the identification of the plant organ having the maximum concentration of the target substances, as well as the comparison of the content of secondary metabolites in plants of different species of the genus. The aim of this work was to study the content of phenolic compounds in the organs of individual plants of three species of the Bistorta genus growing in Siberia: B. officinalis, B. vivipara and B. attenuata. The total content of phenolic compounds in water-ethanol plant extracts was determined by spectrophotometric methods. The results of the study revealed a high level of variability of flavonols and catechins in the organs of the studied species. The average variability of tannins is noted in the inflorescences of B. attenuata and B. vivipara, as well as in the leaves and rhizomes of B. officinalis. A decrease to low variability is observed in the leaves of B. vivipara. An uneven distribution of phenolic compounds in the organs of different plant species was established. B. attenuata plants accumulate the largest number of flavonols in inflorescences, while B. officinalis and B. vivipara demonstrate the maximum value in the leaves. B. officinalis contains more catechins in rhizomes, while B. attenuata and B. vivipara demonstrate the highest catechin value in inflorescences. B. officinalis presents a unique plant species with an extremely high content of catechins (10.5%) and tannins (29.8%) in the underground organs. B. attenuata differs from the other two species in having a lower catechin content in all organs, but the highest number of flavonols in inflorescences (10.7%). The unique character of accumulation of substances in plant organs characterising each species should be taken into account when collecting raw materials for medicinal use.

Oily wastes, along with the problem of their disposal, comprise an inevitable factor in the processing and storage of oil and oil-derived products. Contemporary disposal methods such as landfill and incineration entail secondary pollution of environmental objects. However, since oily wastes contain valuable hydrocarbons, the search for new ways to extract them for use as components of the target products of oil refineries is an urgent task. The object of the study comprised oily wastes derived from an oilwell product of the commercial production of the Angarsk Petrochemical Company. According to the existing scheme, this product is combined with other oil-containing streams and sent for rectification. Thus, in 2017, 1,200 tonnes of secondary oil product were sent to the conversion unit. The transportation and processing of such a quantity of substrates leads to the release into the environment of more than 2 tonnes of harmful substances per year. The results of qualitative and quantitative analysis showed that the high content of gasoline fractions – predominantly n-alkanes C₅–С₁₀ (more than 90% by weight) – in the hydrocarbon composition suggests the possibility of using the oilwell product as a component of motor gasolines without re-processing using the rectification method. However, the quality of the oilwell product, mainly in terms of water content and colour, is rather unstable. In order to select the preliminary preparation method for the oilwell product, tests of a bottom sample having a high water content (50% vol.) were carried out. It was established that sedimentation of the sample at a temperature of 22–23 °С for 4 hours leads to the effective separation of the water component. To reduce the influence of the colour factor of the oilwell product when adding it to motor gasolines, it is proposed to dilute it with other refinery by-products. The quality of laboratory samples of AI-92 and AI-80 gasolines obtained with the involvement of the prepared oilwell product complies with the requirements of GOST 32513. In order to scale the process of preparing the substation in order to use it as a component of motor fuels, Angarsk Petrochemical Company developed a simple, affordable technological scheme, based on mixing and separation processes using available equipment. The economic effect of the implementation of this measure will be about 3.7 million rubles per year. The proposed evaluation scheme and the method of separation of water-organic by-products for further use as a component of motor fuel are generic and can be applied to similar wastes from refineries and oil depots. 

The aim of the study was to create an essential composition that improves the environmental and performance properties of contemporary diesel fuel obtained by deep oil refining including the stages of hydrotreating and hydrodesulphurisation. In order to improve the environmental properties of contemporary diesel fuels, such as cetane number and tribological characteristics, a mixture of biodiesel and low molecular weight ethers was proposed for application. Biodiesel was obtained by the transesterification reaction of triacylglycerols from non-edible (rancid) sunflower oil and methanol. By a quantum chemical calculation, the most likely attack direction of a nucleophilic reagent on a triacylglycerol molecule was determined as via a β-carbonyl carbon atom. During the chemical reaction, the absence of cis-trans isomerisation of double bonds was established in the radicals of unsaturated carboxylic acids presented in composition of both the triacylglycerols of vegetable oil and biodiesel molecules. Low molecular weight esters were obtained via the esterification reaction. The physico-chemical properties are determined for several ester mixtures consisting of biodiesel (30–90%) admixed by different saturated esters of lower molecular weight. As the content of saturated low molecular weight esters in mixtures increases, the physico-chemical characteristics of ester mixtures (for example, viscosity, density, cloud point and pour point) tend to improve. However, if the content of low-boiling saturated ethers increases to 60–70%, the boiling point becomes too low, leading to engine interruptions, e.g. the formation of air blocks. In the case of a decrease in the content of low-boiling saturated ethers to 10–30%, ester mixtures are characterised by a heavier fractional composition, as well as a density and viscosity exceeding the levels necessary for the uninterrupted operation of a diesel engine. As a result of the analysis of physico-chemical indicators, the composition of an ester mixture is proposed comprising 50 % vol. of biodiesel and 50 % vol.of low molecular weight saturated esters. The physico-chemical characteristics of such a mixture meet the requirements of the interstate standard for diesel fuels. Thus, the addition of the developed mixture of esters will lead to an increase in the cetane number of hydrotreated diesel fuels, subsequently reflecting in improvement of their lubricating and environmental characteristics.

The formation of ion-exchange composite materials based on high molecular weight precursors appears to be an intensively developing area in the synthesis of proton-conducting membranes for fuel cells. In such membranes, proton transfer is often provided by functional polymers simultaneously containing sulphonic acid groups in their composition units along with fragments of vinyl derivatives of nitrogen-containing heterocyclic bases. Proton exchange activity in the latter is determined by the possibility of doping with inorganic acids. In the framework of this study, for the further formation of hybrid composite membranes under conditions of radical initiation, copolymers of sodium 4-styrene sulphonate (SSt) with 4-vinylpyridine (VP) and 1-vinylimidazole (VIM) were obtained. The monomodal nature of the turbidimetric titration curves for solutions of copolymerisation reaction products indicates the presence of true copolymers during the process of formation. The composition and structure of the copolymers were characterised using data from elemental analysis, as well as from IR and ¹³C NMR spectroscopy. Constants of the relative activity for the monomers and the microstructure parameters of the polymer chains are calculated according to the non-linear leastsquares method using the MathCAD package. The calculated copolymerisation constant values indicate a greater reactivity of SSt in comparison with nitrogen-containing monomers. The lengths of the monomer unit blocks depend on the composition of the initial mixture and vary over a wide range from 1 to 18. The possibility of varying the length of the unit blocks in the composition of the copolymers will affect the ion-conducting properties of hybrid composites formed on their basis. The stability of the copolymers to thermal oxidative degradation by heating in air was studied using the differential scanning calorimetry (DSC) method. The copolymers demonstrated significant thermo-oxidative stability. Decomposition temperatures were 350 °С and 400 °С for SSt-VIM and SSt-VP copolymers, respectively. 

Due to their role in preserving the quality and safety of food products having a long shelf life, a study into the effectiveness of food additives with antimicrobial properties appears to be an urgent task. The purpose of the present work is to carry out a comparative assessment of the antioxidant activity of ascorbyl palmitate, alpha-tocopherol, lecithin and dihydroquercetin (taxifolin). Antioxidants were added to a sample of chopped pork fat. After the introduction of the antioxidant, the raw fat was packaged in polymer bags. Then, the sampled raw fat was stored at a temperature of 4±2 °С for 12 days. During the entire shelf life (0, 4, 6, 12 days), studies were conducted to determine the organoleptic characteristics and indicators of hydrolytic (acid number) and oxidative deterioration (peroxide and thiobarbituric number). The organoleptic test on the 6th day revealed the appearance of a yellowish tint in the raw fat admixed with ascorbyl palmitate and lecithin. Moreover, all samples corresponded to the established normalised oxidative deterioration indicator values for the 6-day period. By the end of the storage period (12 days), the samples, with exception of those prepared with the addition of alpha-tocopherol and dihydroquercetin, had a noticeable odour and greenish tinge. Obtained data agreed with the results of physical chemistry studies. Over the period of 6 days of storage, a significant increase was observed in the indices of oxiditative deterioration in all pork fat samples with exception of those admixed with alpha-tocopherol and dihydroquercetin. The most effective action of tocopherol and digidrokvertsetin was applied to the reduction in the accumulation of the second fat oxidation products, which was expressed in a reduction in the thiobarbituric number on the 12th day of storage by 37% and 70%, respectively, in comparison with the control samples. On the basis of the experimental results, it can be concluded that alpha-tocopherol and dihydroquercetin are effective antioxidants for the preservation of animal fat.