The paper summarizes current approaches to the development of xanthan (XG)-oriented immobilization systems that ensure effective retention of bioactive compounds and heavy metal ions as bioactive toxicants. For the first time, the features of the formation of "xanthan-(modifier)-immobilization object" systems are considered. It is established that non-covalent interactions playa key role in the stabilization of immobilized objects. It is shown that the carboxyl, pyruvate, acetyl, and hydroxyl groups of xanthan provide effective interaction with cations of both biogenic and toxic metals, as well as with protonated functional groups of bioactive (including pharmaceuticals) and toxic (including dyes) compounds, ensuring their reliable retention within a three-dimensional hydrogel matrix. Such a structure creates prerequisites for controlled release and targeted delivery of bioactive substances, as well as for the binding and subsequent biodegradation of toxicants. The paper presents a classification of immobilization types based on retention mechanisms. The key role of ion-exchange immobilization in forming a porous polymer network capable of physically retaining additionally introduced molecules bioactive molecules is highlighted. The prospects for the application of such systems in pharmaceutical technologies and environmental processes are analyzed. Special attention is paid to composite materials with magnetic nanoparticles, which enable controlled transport and recovery of immobilized components. Previously, we established the absence of a unified protocol for quantum chemical modeling (QCM) as a tool for predicting interactions in "xanthan-(modifier)-immobilization object" systems. Therefore, this study substantiates the feasibility of applying QCM methods, in particular for determining stable conformations and identifying active binding sites. It is shown that the lack of such studies limits the systematization of results, necessitating the development of standardized approaches based on simplified structural fragments. The proposed approaches provide a theoretical framework for the targeted design of innovative functional materials.
Objective. The aim of the study was to develop a scientifically substantiated technology for producing plant-based imitation foie gras with enhanced biological value and improved sensory properties. Methods. The authors analyzed the chemical composition of raw materials and the finished product, optimized the formulation of the plant-based foie gras analogue, determined physicochemical parameters, calculated the amino acid score, the essential amino acid index, and the energy value of the product. Organoleptic, physicochemical, and biochemical research methods were used to assess product quality. Results. The researchers developed formulations of imitation foie gras based on sprouted legumes (lentils and chickpeas), champignon mushrooms, nuts, vegetable oils, and spices. It was established that sprouting legumes increased the protein content from 24 to 26 %, raised the essential amino acid index from 1.66 to 1.80, and improved the amino acid profile by 12 % compared to unsprouted raw materials. The developed product demonstrated the following physicochemical characteristics: protein content-6.11 %, fat-22.20 %, carbohydrates-13.23 %, fiber-4.41 %, ash-1.56 %, moisture content-51.76 %, and energy value-277.16 kcal/100 g. Sensory evaluation showed that the sample with the addition of champignon mushrooms had the closest taste, aroma, and creamy texture to traditional foie gras. The product contained no cholesterol, and its lipid fraction was predominantly represented by unsaturated fatty acids. Conclusions. The authors created a technology for producing a plant-based analogue of foie gras that is close to the traditional product in sensory characteristics and meets the requirements for functional foods in terms of nutritional value. The nutritional adequacy of the developed product is confirmed by a balanced amino acid composition of proteins, the absence of cholesterol, and a high content of unsaturated fatty acids and dietary fiber. The proposed formulation can be used in the production of health-oriented and vegan food products.
Resources of collagen-containing raw materials are quite significant. These include products of secondary fish processing that are not used and not recycled. Therefore, it is necessary to apply special methods of processing collagen-containing raw materials, in particular scales, fins, heads and bones, to obtain a protein product with proper functional and technological characteristics. Today, there are many ways to influence collagen-containing raw materials and obtain collagen preparations for use in the food industry, cosmetology, medicine, etc. The purpose of the work is to scientifically substantiate and experimentally confirm the possibility of obtaining high-quality protein products from collagen-containing raw materials (in particular from fish) by using various methods of its processing. The study used modern standard and generally recognized methods for determining physicochemical and structural and mechanical properties. Studies of the chemical composition of the starting raw materials (fish waste of various species of fish) were conducted. The results of the study indicate the possibility of using this raw material as a component of additive formulations. A study of collagen-containing fish scales was conducted, confirming the possibility of using collagen-containing products as stabilizers. Collagen hydrolysate in the composition of the supplement affects the quality characteristics of finished products. It can be concluded that the use of fish scales to obtain collagen hydrolysate for the production of supplements is possible only if they are pre-processed, namely separated from the fish carcass. The method of obtaining these products determines the directions of their further use. It is possible to use a supplement with collagen hydrolysate obtained from secondary fish raw materials in food production.
Establishing the features of acid-base and electrochemical behavior in "sulfur dioxide - 1,3,5-tris-(2-hydroxyethyl)hexahydrotriazine - water" solutions is undoubtedly an actual and important task. A pH-, redox-, and conductometric studies of protolytic equilibria were carried out for the solutions containing 1,3,5-tris-(2-hydroxyethyl)hexahydrotriazine (TZ; the reaction product of monoethanolamine with formaldehyde interaction), its protonated form (TZH(+)), N-(2-hydroxyethyl)aminomethanesulfonic acid (HEAMSA), and its anion, N-(2-hydroxyethyl)aminomethane-sulfonate (HEAMS) at a constant total content of amine nitrogen 0.1 mol/L with varying content of absorbed sulfur dioxide 0 pound Q(SO2) pound 0.12 mol/L at temperature range 273-313 K. It was shown that the addition of formaldehyde to solutions of "sulfur dioxide - monoethanolamine - water" leads to a decrease in their pH by 0.09-4.75 units, which is obviuosly caused by the formation of HEAMSA. The symbiotic nature of the change in DpH values with temperature (SO2 : N < 1.0 : 2.0) is noted at the same content of components in the solutions. Conductometry data indicate the association of free monoethanolamine, its ammonium sulfites and hydrosulfites into less mobile TZ, TZH(+), HE & Acy;& Mcy;SA and HEAMS(-). Based on the developed mathematical model using pH-metry data, the ion-molecular component composition of "sulfur dioxide - 1,3,5-tris-(2-hydroxyethyl)hexahydrotriazine - water" solutions at 273-313 K was calculated. The concentration dependences on the ionic strength of the solutions were obtained. The concentration constants of TZ protonation and HEAMSA dissociation were estimated. It was shown that under the experimental conditions the thermodynamic dissociation constant of HEAMSA is practically independent on temperature and is equal to 10.14 +/- 0.08. The obtained results are recommended to be used in the development of effective chemisorbents of sulfur dioxide.
Expanding the range of artisanal soft cheeses made from unpasteurised goat's milk on the food market meets consumer demand for healthy nutrition and requires the development of criteria for assessing their quality, biological value, age, and authenticity. This involves determining the dynamics of their fatty acid composition and the quality of milk fat during the ripening process. The experiment used artisanal brine Feta cheese with a ripening period of 30 months and artisanal Chevre cheese with white noble mould with a ripening period of 40 days, made at one of the eco-enterprises of the Kyiv region (Ukraine). The study was conducted from May 2022 to December 2024 using gas chromatography. 15 fatty acids were detected in Feta and Chevre cheeses, of which 11 were saturated and 4 were unsaturated. The basis of saturated fatty acids in Chevre and Feta cheeses was palmitic, stearic, capric, and myristic. The proportion of oleic acid in Feta cheese was inversely correlated with the ripening period (r = -0.920 +/- 0.074, P < 0.001). The value of omega 3/omega 6 PUFA during the ripening period varied for Feta cheese within the range of 1 : 4.96-5.74 and for Chevre cheese-1 : 4.47-43.16. A distinctive feature of Chevre cheese was an increase in the content of linolenic acid by 0.88-0.94% and linoleic acid by 0.73-1.21% on the 40th day of ripening. According to fat quality indicators, Feta cheese was characterized by the highest dietary properties from the 7th day to the 18th month of ripening, and cheese Chevre-on the 40th day of ripening. The fatty acid profile of artisanal goat cheeses Feta and Chevre can be used as one of the criteria for assessing their age and authenticity in combination with physicochemical and microbiological indicators.
The article presents the results of a scientific study aimed at improving the technology of cooked sausage products by introducing functional ingredients of natural origin-rosemary extract and chia seed powder. Particular attention is paid to their effect on physicochemical, technological, microbiological indicators andlipid oxidation indicators (acid and peroxide values) during storage. As part of the experiment, traditional raw materials were partially replaced in two ways: 50 % of vegetable oil was replaced with oil containing 80 % rosemary extract, and semi-fat pork was replaced with gel made from chia seed powder in quantities of 2.5%, 5 % and 7.5 %. The study was conducted on the basis of a control sample manufactured in accordance with the current DSTU. Qualitative and quantitative indicators were assessed using physicochemical, organoleptic, technological and microbiological criteria, as well as oxidative processes dynamics in the lipid fraction of the product. The results showed that the addition of functional ingredients does not worsen , but, stabilises microbiological indicators and does not accelerate oxidative processes during storage. The most balanced functional, technological, sensory and antioxidant properties were found in the sample with 5 % chia powder, where an optimal ratio of moisture retention capacity, structure, oxidation intensity and organoleptic characteristics was observed. The use of oil with rosemary extract provided a pronounced antioxidant effect, increased lipid stability and colour stability, while chia seed powder contributed to a reduction in the proportion of animal fats and an increase in the nutritional and biological value of the products. The practical significance lies in the possibility of implementing the proposed recipe and technological modification in industrial conditions without changing production equipment, which makes the approach technologically and economically feasible. The results obtained can be used to create a line of functional cooked sausage products with improved safety, stability and value.
The paper presents a comprehensive evaluation of ultraviolet (UV) disinfection systems by integrating maintenance, spectral, and operational coefficients into a unified analytical model. The study addresses the progressive decline in UV radiation efficiency caused by lamp aging, surface contamination, and changes in the reflective properties of operating environments. The proposed methodology extends the classical Maintenance Factor (MF) model defined in CIE standards by incorporating additional coefficients that account for spectral effectiveness (SEF), temperature influence (TCF), ballast performance (BF), irradiation geometry (UF), and dose compliance (DCF). Experimental data obtained for various UV systems (TUV15WG13, HNS15G13, TUV36WG13, ZW20D15Y, ZW20D15W) demonstrated that overall system efficiency decreases to 27-36 % of the initial level after 6,000 operating hours. The dominant loss factors were identified as UF (17-38 %), RFMF (20-35 %), and LMF (18-28 %), while RSMF, TCF, and BF contributed minor yet consistent effects. The developed integrated approach provides a more accurate prediction of degradation processes, allowing preventive maintenance scheduling, optimization of energy consumption, and stable disinfection efficiency throughout the service life of UV systems.
Using the Paal-Knorr reaction, 1-[1-(4-methoxyphenyl)-2-methyl-5-phenyl-pyrrole-3-yl]ethanone was produced. The main stages of synthesis and yield of the target compound are described. The temperature dependence of the solubility of the synthesized compound in the temperature range 275.70-299.40 K was investigated experimentally. The use of the gravimetric method for studying solubility at atmospheric pressure in solvents of different classes is described. Using the Van't Hoff equation, the obtained data were converted to standard molar enthalpies and entropies of dissolution. The enthalpy and entropy of fusion of the obtained substance were determined by the differential thermal method. The equations for converting the research results to standard conditions (298.15 K) are given, and the results are used to calculate the thermodynamic parameters of the mixing and dissolution process of the studied ketone compound with organic solvents. The solubility of 1-[1-(4-methoxyphenyl)-2-methyl-5-phenyl-pyrrole-3-yl]ethanone in all solvents increased with increasing temperature, and these data are in good agreement with the literature data for similar substances. The interaction characteristics of the synthesized substance with solvents of different polarity were established, and the dependencies of the thermal effects of dissolution were obtained. This study of the pyrrole derivative 1-[1-(4-methoxyphenyl)-2-methyl-5-phenyl-pyrrole-3-yl]ethanone is aimed at optimizing the synthesis processes of this compound, its further purification and processing for various uses.
Boiled sausages are popular meat products among consumers. At the same time, the question arises of increasing the nutritional value, in particular, in terms of protein content, of boiled sausages. The purpose of this work is to substantiate the use of sodium caseinate, amaranth flour, collagen protein, psyllium as dietary fiber, dihydroquercetin and sea salt in the technology of boiled sausage. It was found that the experimental sample had an increased protein content by 2.7 %, a reduced fat content by 4.1 %, and moisture by 2.5 %; improved moisture-retaining (94.8 %) and moisture-binding (82.7 %) capabilities compared to the control sample. Increasing the pH to 6.34 compared to the control sample (6.19) contributed to reducing moisture loss during heat treatment and improving texture. The experimental sample exceeded the control in terms of mass fractions of all essential amino acids: valine-by 128 mg, histidine-by 57 mg, leucine-by 176 mg, isoleucine-by 99 mg, threonine-by 83 mg, lysine-by 147 mg, methionine + cystine-by 63 mg, tryptophan-by 27 mg, phenylalanine + tyrosine-by 196 mg. The experimental sample had an increased content of individual minerals compared to the control: calcium-by 9.1 mg, iron-by 308 mu g, magnesium-by 11.5 mg, phosphorus-by 32.5 mg, potassium-by 20.9 mg, sodium-by 16 mg, zinc-by 0.13 mg, selenium-by 0.76 mg. Thus, a new technology of boiled sausage with an increased content of complete amino acid composition of total protein and minerals has been developed. The developed boiled sausage will expand the range of meat products for people with an active lifestyle.
Modern technological capabilities are causing concern due to the creativity of approaches to the falsification of food products and their components, in particular essential oils. The struggle for quality and safety of end products calls on the global scientific community to improve and create more diverse methodologies with mandatory mathematical comparative analysis of the impact on the same system under changing influencing factors. The aim of the research was to create additional criteria for preventing falsification through spectrophotometric analysis of the intensity of light absorption by ethanol solutions of essential oils of bitter hops. Individual graphical-positional anomalies of wavelengths and spectral intervals were determined, and equations of functions of changes in the concentration of terpene complexes in the studied samples were calculated, coefficients were determined, and the error values were experimentally proven. A rational ratio (oil-ethanol) for dissolution without opalescence was empirically established. The spectra and changes in the optical density of hop oil were evaluated in basic units of light absorption and in percentages in the wavelength range from 190 nm to 900 nm discretely, with a wavelength determination step of 0.05-1 nm. Based on the study of known-quality samples, a wavelength range of 456-780 nm was established, at which the fluctuation in the intensity of the absorbing activity of the main terpenoid compounds facilitates the authentication of other samples of ethanol solutions of hop oils. In addition, fluctuations in the coefficients of mathematical systems for monitoring changes in light absorption intensity in ethanol solutions of hop oil provide an opportunity for comparative control of these changes and, accordingly, create additional criteria for preventing counterfeiting.
The influence of nonionic surfactant Triton X-100 on the analytical signal in atomic absorption determination of copper, zinc, and nickel in pharmaceutical substances was investigated. The sensitivity and precision of analyte determination were increased by using Triton X-100 (w = 4 %) solutions, calibration solutions based on metal acetylacetonates, and treating the analyzed samples with ultrasound for 20 min. The sensitivity of atomic absorption determination of copper increases by 1.80 times, zinc by 1.60 times, and nickel by 1.70 times. The content of analytes in multicomponent samples was determined by atomic absorption and atomic emission spectrometry with inductively coupled plasma. The results obtained by two independent methods were compared using F- and t-criteria. It was shown that there is no significant discrepancy in these results, the difference is insignificant and is due to random statistical error. The accuracy of the analysis results was verified by varying the sample weight and using the "added-found" method. The detection limit for copper (C-min = 0.002 mu g/ml, C-lit = 0.004 mu g/ml), zinc (C-min = 0.003 mu g/ml, C-lit = 0.004 mu g/ml), and nickel (C-min = 0.003 mu g/ml, C-lit =0.004 mu g/ml) was calculated by atomic absorption method.
To synthesize a bifunctional catalyst on an Al2O3 support, the initially used adsorbent Al2O3 was regenerated at 600 degrees C for 360 minutes in the absence of atmospheric oxygen. A process model for synthesizing bifunctional catalysts on regenerated Al2O3 support was developed using Ni, Co, Mo, and P precursors. According to the elemental composition analysis of the regenerated adsorbent by XRF (X-ray fluorescence) method, it was determined to consist of 81.5 % Al2O3 . Using the regenerated Al2O3 as the support, (NH4)6Mo7O24 & centerdot;4H2O, Ni A process model was developed to synthesize a bifunctional catalyst using salts such as Ni(NO3)(2)& centerdot;6H(2)O, Co(NO3)2 & centerdot;6H(2)O, and H3PO4 acid, and based on this model, three types of catalyst samples were synthesized. To determine the morphological changes and textural properties of the surface of the obtained catalyst samples, analyses were performed using SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), and BET (Brunauer-Emmett-Teller) model-based methods. These analyses were applied to evaluate morphological changes and textural characteristics of the prepared catalyst samples.
The relevance of the study is to determine the chemical composition of wastewater and its impact on the technical condition of the sewage system. Aim. The aim of the work was to investigate the chemical composition of wastewater and its effect on reinforced concrete structures of the sewage system. Methods. X-ray diffractometric, colorimetric, fluorimetric, gravimetric, titrimetric. Results. The study of the chemical composition of wastewater showed a shift in pH to the alkaline side, the suspension of dry substances in water was above the norm in the fourth sample by 5.3 %, in the fifth - by 36.3 %; the dry residue in the first sample by 31.3 %, in the second - by 20.2 %, in the third - by 13.9 %, in the fourth - by 9.3 % and in the fifth - by 27.4 %. The content of ammonium nitrogen was higher in the fourth experimental sample by 52.3 %, and in the fifth by 54.1 %. The level of nitrite ions in the first sample was higher by 9.1 %, in the second by 6.0 %, in the third and fifth by 42.4 %, and in the fourth by 36.4 %; the increase in nitrate ions in the first sample was by 11.1 %, in the second by 21.6 %, in the third by 16.0 %, in the fourth by 19.5 %, and in the fifth by 22.4 %. Conclusions. The implemented measures to reduce wastewater pollution were effective and reduced the load on concrete sewage structures. The scientific novelty of the results obtained lies in the field study of wastewater from a settling well of a pharmaceutical enterprise before and after preventive measures.
The aim of the work was to determine the region of periodic phenomena during currentless and anodic passivation of copper in CuCl2 solutions and to identify the influence of various factors on the process. Copper dissolution (grade M-99) was studied using the rotating disk electrode method. It is shown that periodic phenomena occur during chemical and anodic dissolution of copper in chloride electrolytes as a result of the formation of CuCl passive film with a certain thickness under conditions of the removal of diffusion limitations through an induction period lasting up to 2 min. An increase in the concentration of Cl--ions causes a shortening of the induction period of oscillations; in highly concentrated NaCl solutions the induction period increases. The oscillations have a sawtooth shape with no homogeneity; the overall process is a superposition of oscillations with different amplitudes. With an increase in the current density to 3000 A/m2, sub-oscillations disappear. Over time, the oscillation amplitudes equalize and the potential value stabilizes at the level of the upper amplitude value. An increase in the concentration of chloride ions to a certain value reduces the frequency of oscillations and the value of the stationary potential of the copper electrode at which they occur, prolongs the oscillations in time and reduces their amplitude; an increase in the concentration of Cu(II) ions has the opposite effect on the amplitude value. A rise in temperature increases the frequency and chaotic state of oscillations, reduces their induction period and amplitude, and reduces the concentration limit of Cl--ions above which oscillations do not occur. With an increase in the density of the anode current, the frequency of oscillations increases to a certain value and then stabilizes A mechanism of oscillations is associated with alternation of the processes of formation and dissolution of the passive layer.
Aim. The purpose of the work is to study the functional, technological, and culinary properties of wild boar meat and to establish the influence of different heat treatment methods on sensory parameters and product yield. Methods. The study focused on wild boar meat obtained through traditional hunting in the hunting grounds of the Sumy region, Ukraine. Results. The protein content was 21.56-22.68 %, fat-2.25-2.64 %, which affected the energy value of the meat: 112-118 kcal/100 g. It was found that the meat of female wild boars under the age of one year has a slightly lower nutritional value (112 kcal/100 g) compared to the meat of males, which is due to the lower protein and fat content and higher moisture content. When comparing the functional and technological parameters of raw meat between male and female wild boar, no significant differences were found, indicating a lack of special strategies for processing or marketing meat of animals of different sexes. Cooking wild boar meat by frying (180 degrees C for 5-10 min) proved to be the most effective heat treatment method for preserving optimal quality characteristics, particularly in terms of sensory and textural characteristics preferred by consumers. Conclusion. Based on the results of the study of the functional, technological, and culinary properties of wild boar meat of both sexes and the establishment of the influence of various heat treatment methods on sensory indicators and losses during cooking, it can be concluded that wild boar meat has high nutritional value, sufficient functional indicators, and has a favorable sensory assessment during culinary processing.
This study presents an exact analytical solution for the transient magnetohydrodynamic (MHD) free convection flow of an incompressible, electrically conducting fluid confined between two infinite inclined plates. The analysis incorporates the combined influence of an externally applied magnetic field aligned with the flow, thermal radiation, and chemical reactions. The inclination of the plates introduces a gravitational component that alters buoyancy-driven flow dynamics, adding complexity to heat and mass transfer mechanisms. The investigation focuses on oscillatory flow conditions, which are crucial for modeling time-dependent phenomena in geophysical systems, industrial chemical processes, and thermal management applications. The Lorentz force, generated by the interaction between the magnetic field and fluid motion, is examined to assess its effects on velocity and temperature distributions. Thermal radiation is approximated using the Rosseland model, while a first-order chemical reaction term is included in the species concentration equation. The governing partial differential equations for momentum, energy, and mass transfer are solved analytically under specified initial and boundary conditions. The results demonstrate the significant impact of key parameters, including magnetic field strength, thermal radiation, chemical reaction kinetics, and plate inclination angle, on flow behavior, temperature profiles, and concentration distribution. This research advances the understanding of unsteady MHD convection flows under thermal and chemical influences, offering insights for optimizing high-temperature systems and electromagnetically controlled reactive processes. The findings have potential applications in enhancing industrial cooling systems, chemical reactors, and geophysical flow modeling.
The growing accumulation of polymer waste has become a global environmental challenge, necessitating the development of sustainable mitigation strategies. Bioremediation, based on the use of microorganisms to degrade pollutants in soil and water, is considered a promising approach. This study provides a theoretical analysis of current research on the ability of soil microbiota to decompose synthetic polymers and proposes a method for polymer waste degradation using a combined biological system. The approach involves the joint application of Eisenia foetida culture and bacterial strains of the genus Pseudomonas. Polymer-polymer blends based on corn starch were selected as model materials, specifically ethylene-vinyl acetate copolymer (EVA) and chlorinated polyethylene (CPE). Experimental substrate variants were inoculated with Pseudomonas chlororaphis subsp. aurantiaca UKM-9 and Pseudomonas chlororaphis subsp. aureofaciens UKM B-109 at a concentration of 1.1 & times;10(7) CFU/g of dry substrate. The results demonstrated that E. foetida significantly enhances microbial development, increasing the total microbial count from 10(7 )to 10(9) CFU/g. This indicates a high adaptive potential of the microbiota to substrates obtained via vermiculture. The biochemical characteristics and taxonomic affiliation of the bacterial strains were confirmed using the oxidase test. It was established that physicochemical parameters of the substrate, including temperature, moisture, electrical conductivity, and pH, play a key role in regulating microbial activity and growth. Significant changes in electrical conductivity (up to 3999 mu S/cm in CPE samples) suggest polymer bond cleavage, ion release, and the formation of soluble degradation products. Optical analysis confirmed substantial biodegradation levels, reaching 72.1 % for CPE and 67 % for EVA. The findings demonstrate the high efficiency of combined biological systems in polymer degradation and underline their potential for developing environmentally safe technologies for the management of synthetic polymer waste.
All morphological parts of the oak tree, including fruit, bark, wood and leaves, have many uses. Acorns are rich in nutrients, making them an important raw material resource. Since ancient times, oak fruits have been a valuable food product and today have great potential for use in various industries. Acorn flour is an important gluten-free component of bakery, flour confectionery and pasta products. Acorn starch can be used not only for food purposes, but also find application in the production of bioethanol, in paper production, in the manufacture of composites and polymer films. Acorn extracts exhibit antioxidant properties and are used for medicinal purposes. Oak fruit protein isolates have prospects in the production of food water-fat emulsion products, acorn oil is a source of valuable fatty acids. Acorn drinks - coffee substitutes - are becoming increasingly popular. The analysis of recent publications has shown that the issue of using oak fruits as a multipurpose raw material is given considerable attention. Scientific research is focused on individual processes, or the study of the properties and areas of application of certain compounds of oak fruits. The work is carried out using advanced research methods, they are characterized by the depth of study of the nutritional and technological characteristics of the resulting acorn products. The predictability of their behavior in multicomponent systems is an important characteristic that affects the technology and implementation of innovations in food production. An important task is not to implement separate processes for extracting acorn components, but a comprehensive, ecologically and economically justified waste-free processing of oak fruits into food, pharmaceutical and technical products. Solving this task requires systematization of research results and the formation of flexible approaches to the issue of complex processing of oak fruits.
Developing environmentally friendly and highly effective adhesive compositions is a pressing challenge in modern materials science. This study synthesized and comprehensively characterized a new adhesive based on oxalic acid, formaldehyde, and phthalimide. These compounds were chosen as starting materials due to their expected adhesive properties and relative environmental friendliness. The resulting sample was analyzed using infrared (IR) and ultraviolet-visible (UV-Vis) spectroscopy to identify characteristic functional groups and intermolecular interactions. Additionally, a quantum-chemical analysis using density functional theory (DFT) was performed to evaluate the electronic structure, chemical bonding characteristics, and molecular stability. IR spectroscopy confirmed the presence of absorption bands corresponding to esterification and amide bonds, while UV-Vis spectroscopy data indicated the formation of conjugated systems that provide structural strength. Theoretical calculations are consistent with experimental observations and confirm the favorable electronic properties of the molecule. A combined experimental and theoretical approach provided a comprehensive understanding of the molecular architecture and potential adhesive properties. Thus, the adhesive based on oxalic acid, formaldehyde, and phthalimide exhibits good adhesion strength and is environmentally friendly to synthesize, making it promising for a wide range of industrial and sustainable applications.
Using ab initio density functional method at the PBE1PBE/6-31G(d,p) level of theory, the features of the tautomeric equilibrium of open syn-forms for some aryl- as well as hetarylacyl azides have been investigated, which turned out to be more stable than the corresponding cyclic forms containing an oxatriazole fragment. Further analysis of individual sections for the thermal Curtius rearrangement potential energy surfaces using the model compound 2,6dimethylpyridine-3,5-diacyl diazide as an example demonstrated the presence of a reaction pathway corresponding to the stepwise transformation of the syn,syn-form for the starting compound into the corresponding diisocyanate as the final reaction product. In this case, the sequential transformation of both acyl azide groups has been accompanied by intramolecular migration of the hetaryl fragment with simultaneous cleavage of the nitrogen molecule at each of the reaction stages. The results of calculations are in good agreement with data of this type obtained earlier and indicate a low sensitivity of the reaction to structural modifications of the substrate, among which the greatest contribution is made by the manifestations of the "ortho-effect" of methyl substituents in the aromatic fragment of the molecules. The overall increase in the reactivity of the studied systems is also shown under the acid catalysis conditions with simultaneous consideration of nonspecific solvation effects of the benzene solution. This approach allows for the detailed conditions of the target transformation and can be actively used to predict the behavior of related systems within the selected computational approximation.
