Journal of Chemistry and Technologies

AUTOMATION OF A LABORATORY ELECTRIC AUTOCLAVE USING A PROGRAMMABLE LOGIC CONTROLLER

Oleg V. Radchuk — 2025-04-15

The article analyzes the use of an electric autoclave with the proposed automated control system for implementation in the educational process. An analysis of the implementation of the technological process of sterilization of canned food in an electric autoclave was carried out on the automated stand for controlling the electric autoclave called. Options for operating modes of the Programmable Logic Controller (PLC) OWEN PR200 with an electric autoclave are considered. The principle of debugging an automated stand for sterilizing canned food by students is given. It has been experimentally proven that the heating of an electric autoclave is started either by a directly programmable logic controller or by a computer with a Supervisory Control and Data Acquisition (SCADA) program. For distance learning students, there is the possibility of using remote access to monitor parameters and control the operation of the autoclave using a cloud web server. This allows students to access and control this object anywhere in the world with an Internet connection. Modeling was conducted in the MATLAB environment to determine the PLC settings, and the control system was modeled using MATLAB/Simulink. It has been studied that the electric autoclave is heated within the time specified by the technological process to the specified parameters. An example of using the stand for option №8 is given. The need to improve the quality of autoclave control has been identified. Using a Proportional-Integral-Differential (PID) regulator instead of a PLC two-position relay regulator is proposed. The advantages of using the Proportional-Integral (PI)-law regulation are presented. PID regulation through the PLC's analog output effectively produces canned food from vegetable ingredients. A further research direction may be using a controller based on fuzzy logic and its discretization.

EFFECTIVE IMPROVEMENT OF HYDROGEN SULFIDE ADSORPTION FROM BIOGAS BY MEANS OF WATER TREATMENT SLUDGE AFTER ITS ZINC MODIFICATION

Vo Thi Thanh Thuy — 2025-04-15

In this study, waste sludge from different water treatment plants in Ho Chi Minh City, Vietnam, was used as adsorbents for H₂S filtration in biogas. The results of the experimental process showed that the sludge calcined at 200 °C then modified with Zn(NO₃)₂.6H₂O could reach an H₂S adsorption capacity of 235.54 mg/g with operating conditions at 1775±169 ppm of H₂S inlet concentration, 5 g of adsorbent, and 1 L/min of flow rate. Under the best conditions, the maximum adsorption capacity estimated by the Langmuir adsorption isotherm model can be up to 333.30 mg/g. Brunauer-Emmett-Teller method, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy and energy-dispersive X-ray spectroscopy were the techniques used to determine material characteristics before and after adsorption. These results prove that sludge from wastewater treatment plants is a potential resource for the production of cheap but effective materials for environmental treatment.

VIBRATIONAL RESONANCE DURING CO-OXIDATION ON PLATINUM CATALYST SURFACES

S. Siva Sakthi Pitchammal — 2025-04-15

Vibrational resonance is a nonlinear phenomenon in which two external signals, a low-frequency signal (ω) and a high-frequency signal (Ω), interact cooperatively, with Ω significantly larger than ω. This interaction strengthens the response of the weaker, low-frequency signal. In this paper, we investigate the application of vibrational resonance in a surface catalytic reaction model, specifically focusing on the oxidation of Carbon Monoxide (CO) on a platinum catalyst. By performing numerical simulations, we examine how the introduction of a low-frequency periodic signal superimposed on a high-frequency signal affects the catalytic reaction dynamics. The results reveal that vibrational resonance reduces the energy barrier for CO oxidation, which leads to enhanced reaction rates compared to conditions without resonance. This effect occurs due to the optimal synchronization of the two frequencies, which facilitates more efficient energy transfer and reaction processes. Ultimately, this research demonstrates that vibrational resonance can significantly improve catalytic activity in CO oxidation reactions, offering insights into optimizing catalytic performance.

SOLUBILITY STUDY OF 3-(1-(4-METHYLPHENYL)-5-PHENYLPYRROL-2-YL)PROPANOIC ACID IN ORGANIC SOLVENTS

Dmytro S. Shevchenko — 2025-04-15

In this study solubility temperature dependence of 3-(1-(4-methylphenyl)-5-phenylpyrrol-2-yl)propanoic acid in the temperature range of 271.0–318.2 K using the gravimetric method at atmospheric pressure was experimentally determined for the first time in eight organic solvents, namely methyl acetate, ethyl acetate, acetone, acetonitrile, n-propanol, isopropanol, n-butanol, isobutanol. The primary results of experimental studies of the solubility temperature dependence for each of the studied solution systems were used to calculate the standard molar enthalpy and entropy of dissolution according to the Van't-Hoff equation. The enthalpy and entropy of fusion at the melting point were determined using the results of differential thermal analysis. The equations for the recalculation of the enthalpy and entropy of fusion to a temperature of 298.15 K are presented. Using the calculated values of enthalpy and entropy of fusion to 298.15 K, the thermodynamic parameters of the process of mixing the studied acid with organic solvents were calculated. The nature of intermolecular interactions between the solvent and the dissolved substance was analysed using thermodynamic parameters of mixing. The present study contains fundamental thermodynamic values that are of practical importance for the optimisation of processes of synthesis, processing and purification of the investigated N-substituted derivative of 3-(5-phenylpyrrol-2-yl)propanoic acid.

NIR-LUMINESCENCE OF YTTERBIUM IONS IN ISOMERIC TETRAPHENYLPORPHYRIN MODIFIED EDTA COMPLEXES

Nikolay M. Semenishyn — 2025-04-15

New ytterbium complexes were synthesized on the base of tetraphenylporphyrin modified with ethylenediaminetetraacetic acid at the ortho- and para-positions of only one phenyl ring. Such modification avoids the problem of lability of traditional lanthanide-porphyrin core-coordinated complexes. A new selective synthetic route for the mono para-nitro-derivative of tetraphenylporphyrin (the main precursor of the target compound) has been proposed. 4f-Luminescence in the near-infrared range as well as non-quenched molecular fluorescence of porphyrin, are observed in all synthesized complexes, which makes these complexes dual-emissive. Since the obtained results show that both Yb-porphyrin isomers have no changes in terms of fluorescence effectiveness in comparison to their corresponding ditopic porphyrins, it proves the absence of ISC and ISD acceleration in these systems. It was also found that the 4f-luminescence intensity of the ortho-isomer is higher compared to the para-isomer. This is due to changes in the spatial structure, leading to the edta-Yb fragment being closer to the porphyrin core. Additional experiment of luminescence quenching by strong paramagnetic ion was performed. When the copper (II) acetate was added to the modified porphyrin isomers, a significant difference in the efficiency of luminescence quenching was observed as the result of non-core interaction; thus, the luminescence intensity decreased more for the ortho-isomer than for the para-isomer. This also proves that the efficiency of interaction between porphyrin and the peripheral substituent is very sensitive to the distance changes between them. Enhancing of 4f-luminescence effectiveness can be explained simultaneously by both decreasing the donor-acceptor distance and the absence of notable ISD acceleration which is typical for core-coordinated compounds.

STUDY OF THE PHOSPHATE ADHESION ON STAINLESS STEEL SURFACES: INVESTIGATION OF CLOGGING AND GEOGRAPHICAL SETTINGS

Mustapha Adar — 2025-04-15

Clogging, a physicochemical adhesion phenomenon, occurs between material surfaces, prompting our investigation into phosphate adhesion on steel surfaces and its associated clogging. Phosphate pellets, produced under varying pressures (80–340 bars) with 25 % water content, were analyzed after drying at 60 °C. Physicochemical interactions were explored through contact angle measurements, showing a decrease from 71° to 65° as compaction pressure increased, and surface energy calculations indicated an increase from 49 mJ/m² to 52.5 mJ/m². The phosphate originated from the extraction zone of the OCP in Ben Guerir, Morocco. Contact angle measurements on stainless steels (304, 304L, and 316) revealed that 316 steel exhibited hydrophobic behavior (contact angle 94°, surface energy 35 mJ/m²), while 304 and 304L were hydrophilic with contact angles of 68° and 70°, and surface energies of 48 mJ/m² and 45 mJ/m², respectively. Atomic force microscopy (AFM) revealed that 316 steel had the highest roughness (Ra = 45 nm) compared to 304 and 304L (R_a = 32 nm and 34 nm). A predictive adhesion model showed that 316 steel promotes phosphate adhesion (negative free energy of adhesion), while 304 and 304L steels displayed positive free energies, indicating weaker adhesion. These findings provide key parameters for understanding phosphate fouling on solid supports.

SYNTHESIS AND ELECTRICAL CONDUCTIVITY OF FLUORIDE-CONDUCTING PHASES SrSnF4 AND PbxSr1-xSnF4

Anton A. Nahornyi — 2025-04-15

In the article it is proposed to synthesize free of impurity phases complex fluoride SrSnF₄ by sintering lead and strontium fluorides in an equivalent ratio at temperatures higher than temperature of its phase transition from cubic modification into tetragonal (623 K). The duration of synthesis to obtain SrSnF₄ free from impurity phases at 773 K is 1 hour, and at 823 K – half an hour. Synthesis at temperatures lower than temperature of phase transition is associated with the formation of impurity phases different in composition and structure from SrSnF₄. The conductivity of such samples at 293 K is almost an order of magnitude higher than the conductivity of SrSnF₄, which is free from impurity phases (1.18∙10^-5 S/cm, Ea = 0.28 eV). The synthesis of fluoride-conducting phases Pb_xSr_1-xSnF₄ is proposed to be carried out by the method of sintering the initial components in a given ratio in two stages. First, the initial mixture is sintered in the temperature range of 423÷473 K for an hour. Then the temperature is raised to 773÷823 K and the reaction mixture is sintered for another hour. The crystal lattice of Pb_xSr_1-xSnF₄ samples of solid solutions of the isovalent substitution synthesized in this way, with the content of the substituent of 0 ˂ x £ 0.25, corresponds to tetragonal lattice (P4/nmm) and is similar to SrSnF₄. At a higher content of the substituent (0.25 ˂ x £ 0.30), the symmetry of the crystal lattice does not change, but corresponds to another structural type (β-PbSnF4). The highest conductivity (1.12∙10^-3 S/cm at 293 K) and the lowest activation energy (0.063 eV) has the Pb_0.25Sr_0.75SnF₄ phase, which corresponds to the region where the structural type of the crystal lattice is rearranged with increasing of content of the substituent.

ELECTROCHEMICAL DISCHARGE OF NICKEL WITH LOW INTERNAL STRESSES

Yuri E. Sknar — 2025-04-15

The work is devoted to the current topic of electrochemical separation of nickel with low voltages from sulfate electrolytes of electroextraction. Scrap processing of strategic nickel-containing superalloys with electroextraction of nickel is an urgent task today. Electrochemically deposited nickel is characterized by high internal tensile stresses, which leads to its delamination from the cathode surface. To reduce the internal stresses of nickel deposits obtained in such systems, it is proposed to use sulfur-containing organic compounds of sodium allylsulfonate, sodium orthoarylsulfonate, and sodium propynylsulfonate. It was established that allylsulfonate and orthoarylsulfonate practically do not affect the kinetics of nickel release. Propynyl sulfonate with a concentration of more than 5 mmol/l significantly inhibits the process of electrodeposition of nickel, which is related to the adsorption capacity of this compound with the triple bond present in the molecule. It is shown that due to the presence of a sulfo group in the composition of the molecules, the used organic additives contribute to the reduction of the internal stresses of nickel deposits. It was established that allyl sulfonate and orthoaryl sulfonate are the most promising reagents that contribute to reducing the internal stresses of electrodeposited nickel. Low-stress nickel deposits can be obtained in the range of current densities from 2 to 7 A/dm2 at a concentration of these additives from 15 to 30 mmol/l.

SYNTHESIS OF SILVER NANOPARTICLES AND THEIR CONJUGATE WITH CEFTRIAXONE USING CHAENOMELES JAPONICA, CHARACTERIZATION, AND ACTIVITY AGAINST STAPHYLOCOCCUS EPIDERMIDIS

Nina O. Khromykh — 2025-04-15

Silver nanoparticles (AgNPs) synthesized on the base of biological matrices are being actively studied, especially as antimicrobial agents against resistant pathogens. The paper reports the biosynthesis of AgNPs using Chaenomeles japonica aqueous leaf extract. Production of Ch-AgNPs and ceftriaxone-conjugated Ch-AgNPs-Cfx was confirmed by UV-Vis spectroscopy with the surface Plasmon resonance peaks at 472 and 475 nm respectively. SEM micrographs showed the fabricated AgNPs with a round, nearly spherical shape, and an average size of 30 – 35 nm. Fourier transform infrared (FTIR) spectroscopy designated the involvement of hydroxyl and carboxyl functional groups of phenolics, flavonoids, terpenoids, alcohols, and carboxylic acids from Ch. japonica extract into bioreduction process of Ag⁺ to Ag⁰, and participation of protein carbonyl and amine groups in the capping and stabilization of AgNPs, as well as the binding of β-lactam ring of ceftriaxone with Ch-AgNPs-Cfx. Raman spectroscopy of Ch-AgNPs detected the significant SERS effect for Rhodamine 6G registered at 10^-7 M, which confirmed the suitability of phytosynthesized AgNPs as the effective substrates in development of new biosensors. Antibacterial activity of Ch-AgNPs and Ch-AgNPs-Cfx against Staphylococcus epidermidis clinical strain, resistant to several common cephalosporins, was dose-dependent (in the range 2.5–20.0 μg/disc) in the absence of ceftriaxone antibacterial activity, indicating the potential ability of both biosynthesized nanomaterials to overcome the antibiotic resistance of St. epidermidis. Further research is needed to confirm the applicability of Ch-AgNPs and Ch-AgNPs-Cfx for development the new antibacterial drugs against the resistant bacterial strains.

EVALUATION OF THE CHEMICAL COMPOSITION, ANTIOXIDANT CAPACITY, AND ANTIBACTERIAL ACTIVITY OF ESSENTIAL OIL FROM MANDARIN PEELS (CITRUS RETICULATA L.) GROWN IN DONG THAP PROVINCE, VIETNAM

Pham My Hao — 2025-04-15

Citrus reticulata L. essential oil (CrEO) is widely used in food technology, cosmetics, and pharmaceuticals due to its distinct aroma and bioactive properties. In this study, Citrus reticulata L. was collected in Dong Thap province, Vietnam and its peel essential oil was extracted through distillation. Several physicochemical properties of the oil were analyzed, including acid, saponification, and ester values, as well as relative and absolute density, freezing point, and fragrance retention. The results showed that CrEO exhibited an acid value of 0.748 mg KOH/g, a saponification value of 67.320 mg KOH/g, and an ester value of 66.572 mg KOH/g, with fragrance retention lasting over 33 h. The chemical composition of CrEO was determined by gas chromatography-mass spectrometry (GC-MS), and the results revealed six main components namely α-Pinene (0.93 %), β-Pinene (0.61 %), β-Myrcene (1.88 %), D-Limonene (96.09 %), Linalool (0.16 %), and α-Terpineol (0.33 %), which are monoterpenes. Furthermore, the study showed the weak antioxidant capacity of oil and strong antibacterial activities against pathogenic bacteria were determined using the paper disc diffusion method.

A COMPUTATIONAL EVALUATION OF STRUCTURES AND PROPERTIES OF NUCLEIC ACID BASE – WATER COMPLEXES

Takia Smith — 2025-04-15

Electronic properties, electron affinity and ionization potential, binding energies, and conformational changes of neutral, cationic, and anionic DNA base-water complexes, [Base (H₂O)_n] ^(0,+) (n = 0, 4, 8, 14) have been investigated in gas and aqueous phases using the DFT/M06-2X hybrid functional method with 6-31++g(d,p) basis set implemented in the Gaussian09 software package. We find that the electronic properties of DNA bases are strongly influenced by implicit and explicit solvation. While purines show high electron affinity, pyrimidines show the greatest ionization potential at the hydration levels observed. Data also reveals that binding energy lowers in implicit solvation. Additionally, the molecular electrostatic potential surfaces of each compound were calculated to identify the most favorable sites for water binding. The ESP charges, derived from the electron density, indicate that regions of the highest electronegativity do not always correspond to the lowest charge, suggesting complex interactions in the solvation processes. These results provide significant insight into the effects of hydration on the electrostatic properties of DNA nucleobases.

PHYSICO-CHEMICAL STUDY, MOLECULAR MODELING AND ANTIBACTERIAL ACTIVITY OF α- AND β-ANOMERS OF XYLOSE ESTERS

Fatma Loulou — 2025-04-15

Non-ionic surfactants obtained from renewable resources represent a new challenge in biotechnology and have a range of applications in many industries. In this context, the α- and β-anomers of synthesized D-xylose-based bio-surfactants with various chain length were easily separated and characterized through analytical methods. Their surface and emulsifying properties were evaluated. To study the reactivity of the two anomers of synthetized biosurfactants, the spatial conformations of the prepared acyl-xylopyranose were obtained by molecular modeling with Gaussian 9 software using the density functional theory method. Compounds α are the softest so more reactive than the β ones. The antibacterial activity of sugar fatty acid ester anomers was also studied. The results obtained indicate the importance of anomeric form and chain length for the stability of the synthesized compounds.

METAL COMPLEXES OF PHENOLIC COMPOUNDS FROM PURPLE CONEFLOWER

Volodymyr S. Fedenko — 2025-04-15

The results of the study of the ability of purple coneflower Echinacea purpurea (L.) Moench preparations to bind to Pb(II) and Cd(II) are presented. Complex formation involving the catechol site of phenolic compounds in extracts and herbal preparation was confirmed using the spectrophotometric method. The presence of a pronounced long-wavelength maximum in the difference absorption spectra confirmed the formation of a more conjugated chromophore system due to the coordination of metal ions. Complexes of phenolic compounds with Pb(II), Cd(II) and Pb(II)+Cd(II) were obtained using extracts of rhizomes with roots and aerial parts. The methods of reflectance spectroscopy in the visible range and colorimetry were used to characterize the preparations. The complex structure of the band with the presence of a longer-wavelength maximum in the solid phase compared to solutions is associated with the formation of a more conjugated chromophore system. This fact can be explained by the property of chicory acid (predominant component) to self-assemble into various supramolecular structures with the possibility of stacking interaction of catechol fragments. The established chelating ability expands the idea of the biological activity of echinacea preparations, which can provide metal-ligand homeostasis during chelation therapy in case of intoxication of the body with various metals. The results obtained can be used to obtain promising materials from renewable plant raw materials.

SUPEROXIDE ANION CONTRIBUTION IN THE INHIBITION OF RADICAL CHAIN OXIDATION OF CUMENE BY POLYPHENOLS

Irina V. Efimova — 2025-04-15

Antioxidants of the phenolic type are able to prevent the cytotoxic effect of reactive oxygen species. Therefore, questions regarding the behavior of active oxygen formations and mechanisms that prevent their toxic effect in the presence of phenolic inhibitors remain relevant. The purpose of the study is to compare the action of different types of phenolic antioxidants in the presence of superoxide anion in the processes of radical-chain oxidation by molecular oxygen. The research was carried out using gas volumetric, spectrophotometric and electrochemical methods. The effect of phenolic antioxidants in the radical-chain oxidation of isopropylbenzene initiated by azodiisobutyronitrile in the presence of an anion-oxygen radical by С-Н was considered. The effect of reducing the effectiveness of inhibitors in the presence of oxygen radical anion was revealed. Possible mechanisms of superoxide anion participation in radical chain oxidation were analyzed. A conclusion was made regarding the effectiveness of antioxidant action in the reaction of radical-chain oxidation along C-H bonds with the participation of peroxyl radicals. It can significantly decrease in the presence of superoxide radical anion in the reaction system. The degree of reduction depends on the chemical structure of the antioxidant.

SPECTROPHOTOMETRIC DETERMINATION OF THIAMINE USING OXIDATION REACTION WITH 18-MOLYBDODIPHOSPHATE

Andriy B. Vishnikin — 2025-04-15

A simple and highly sensitive method for the determination of thiamine in pharmaceuticals has been developed. It is based on the reaction between thiamine and 18-molybdodiphosphate heteropoly complex (18-MPC), which occurs at pH≈10, created by the addition of 10 % sodium carbonate. The reaction takes place at room temperature. 7-minutes are sufficient for the complete reduction of 18-MPC. The stability of heteropolyblue is limited and absorbance significantly decreases after 10 minutes of reaction. The optimal concentrations of 18-MPC and sodium carbonate were found to be 0.64 mM and 2.4 %, respectively. The ratio of 18-MPC to thiamine in the reaction is 2 : 1, which is shown by the method of continuous variations. Four electrons are accepted by the thiamine molecule during the oxidation of 18-MPC. In this case, a two-electron heteropolyblue is formed with an absorption maximum at 820 nm. The calibration dependence is linear in the range of thiamine concentrations from 2 to 80 μM with a detection limit of 0.8 μM using a cuvette with 0.5 cm path length. The proposed method has been successfully applied to the determination of vitamin B1 in three different pharmaceutical formulations containing other B vitamins, vitamin B6 and vitamin B12.

OPTICAL CHEMOSENSOR BASED ON METHYLDIMERCAPTOTHIOPYRON FOR SPECTROPHOTOMETRIC DETERMINATION OF PALLADIUM(II)

Svitlana М. Khudyakova — 2025-04-15

An optical chemical sensor for the determination of palladium(II) by spectrophotometry is proposed, which is manufactured by immobilizing 3-methyl-2,6-dimercapto-1,4-thiopyrone (MDT) in a polyvinyl chloride matrix. The influence of various parameters was studied, the conditions for spectrophotometric detection of Pd(II) were optimized, and methods for its determination were developed using a calibration graph method, for which the linearity range (μg L⁻¹) was set: 0.02−1.60, detection limits 0.016 μg mL⁻¹ in a sample volume of 20 mL. The developed highly selective methods are based on the formation of a colored Pd(II) complex compound in the indicator polyvinyl chloride matrix of a sensitive element with an absorption maximum of 465 nm. The accuracy of the developed method was assessed by analyzing a certified reference material (platinum-palladium alloy), the relative standard deviation was 2.4 %. The proposed optical chemosensor can be used for quantitative and qualitative measurement of Pd(II) ions in various real samples without any significant interference from a significant excess of various ions, including chalcophilic metals, and including a number of noble metals, easily regenerated and offered for multiple use. The developed method was tested in the analysis of drinking water, water of the Dnipro river and was successfully applied to determine Pd in the sewage sludge of a palladium electroplating bath, the relative standard deviation did not exceed 3 %.

CHEMICAL AND STRUCTURAL CHARACTERISTICS AND SORPTION PROPERTIES BIOCHAR FROM WASTE COFFEE GROUNDS

Taisiia Sokolova — 2025-04-15

The processing of waste coffee grounds is a global problem, and its transformation into a target secondary product is an urgent and promising task. The aim of the study is to produce biochar that can be used in the process of anaerobic digestion of food waste from a hotel and restaurant complex to produce biogas and to determine its sorption characteristics. The chemical composition of the raw materials and biochar obtained by pyrolysis and microwave irradiation showed that the proportion of lignin and ash increases with increasing temperature. Studies of the interaction of lead ions with plant material and its modified forms show that sorption by biochar is much higher than by raw materials, probably due to differences in chemical composition, surface properties, etc. Comparison of the data on the sorption of lead ions by modified forms (biochar) allows us to conclude that the method of preparation has a significant effect on the sorption value. The pyrolysis temperature of the biochar has a favourable effect on the sorption properties of the samples. The obtained adsorption isotherms are of the L-type. The maximum sorption values are observed under the experimental conditions at an initial concentration of lead ions of 1.00 mg/ml. The study of the kinetic parameters of the processes of lead ion sorption by biochar preparations based on the curve of residual lead ion concentrations shows that equilibrium in the system is achieved in a few hours. The maximum sorption values are observed after 2.5-3 hours of incubation.

INVESTIGATION OF THE EFFECT OF DIFFERENT PRETREATMENTS ON DRYING CHARACTERISTICS IN FREEZE DRYING OF SALMON

Ezgi Midik — 2025-04-15

Atlantic salmon is regarded as a high-quality protein source for human consumption and is high in essential amino acids and Omega-3 fatty acids. In this study, the effect of different pretreatment applications on the drying kinetics in freeze drying of salmon was examined. The samples were treated with ten pretreatments such as blanching, blanching in saltwater, saltwater immersion, and ultrasonication at different application times and salinity rates. Drying rates and effective moisture diffusion (D_eff) values of the samples were calculated and the three mathematical models showing the highest agreement among thirteen well-known models were determined. Since the preservation of color values is an important parameter in food processing, color analysis was performed to examine the color change. Drying processes were completed between 240–540 minutes and D_eff values were found between 1.71–5.91×10^-10m²/s. The lowest drying time and the highest D_eff value were found in the samples with blanching pre-treatment, and it was observed that the D_eff value increased as the pre-treatment time increased. The most compatible model for all pretreatments and the control sample was found to be the Midilli & Kucuk model. Additionally, among the pre-treatments applied, saltwater immersion was determined to be the most effective pre-treatment in preserving color values.

IMPROVING THE EFFICIENCY OF VEGETABLE OIL EXTRACTION BY BIOCATALYTIC TREATMENT OF OILSEED RAW MATERIALS

Pavlo O. Nekrasov — 2025-04-15

Conventional technology for processing vegetable oilseeds is typically characterized by exposing the processed product to intense heat and humidity. Such methods have an adverse effect on the beneficial components of oil-containing raw materials, irreversibly degrading the quality and yield of the resulting product, while increasing the cost of edible oil production. The above drawbacks can be eliminated through preliminary enzymatic treatment of oilseed raw materials. Owing to their protein nature, enzymes operate under mild conditions, increasing the yield of finished products, improving their quality and nutritional value. This paper suggests an improved method for preparing sunflower seed meats for pressing by treating it with a complex of enzyme agents such as Alcalase 2.4 L FG and Viscozyme L. To analyze the collected data and optimize the parameters, the response surface methodology was chosen based on the central composite rotational design. This research has shown the feasibility of using a hydrolase complex in preparing sunflower seed meats for oil extraction aimed at increasing the efficiency of the pressing process. A mathematical model has been designed to predict the oil yield based on the parameters of biocatalytic raw material treatment. We found the most suitable parameters for obtaining the maximum oil yield: the enzyme complex content was 0.37 % by the meats weight; the temperature was 57 °C; and the duration of meats treatment was 115 minutes. Under these predictor values, the product yield was 77.3 % ± 1.4 % of the total oil content of the raw material, which is almost 16 % higher than the average value of this figure for control experiments not subjected to enzymatic treatment.

INFLUENCE of SYNTHESIS pH on STRUCTURAL, DIELECTRIC and MAGNETIC PROPERTIES of MnFe2O4

Liliya A. Frolova — 2025-04-15

Dispersed manganese ferrite particles were obtained by a combined co-precipitation method at different pH of the initial solution (7–12). The structural, morphological, optical and magnetic properties of the synthesized nanoparticles were characterized using X-ray diffraction, scanning electron microscopy, and vibrational magnetometry. The XRD results showed that MnFe₂O₄ has a cubic spinel crystal structure with an average crystallite size of ~14–65 nm. The presence of additional phases is observed at low pH and pH greater than 12. Ferritization significantly depends on pH, which affects the phase composition of the products and the size of the crystallites. In addition, with an increase in pH from 7 to 12, the percentage of microstresses and the density of dislocations decreases. The obtained MnFe₂O₄ samples exhibit ferrimagnetic properties, the highest saturation magnetization value of 56.8 Emu/g is achieved at pH 10. In addition, the coercive force changes from 5 to 50 Oe with increasing pH due to the increase in crystallite size.

INNOVATIVE TECHNOLOGIES FOR FROZEN SEMI-FINISHED PRODUCTS FROM APPLES WITH REDUCED ENERGY VALUE

Iryna L. Zamorska — 2025-04-15

Freezing is an effective way to preserve the quality of fruit and vegetable products and is widely used for the production of quick-frozen foods, semi-finished products and ready-to-eat meals. However, the quality of frozen products can undergo undesirable changes that can be prevented by pretreatment. The aim of the study was to evaluate the effect of a polysaccharide coating of pectin solution of different concentrations on the physicochemical properties of partially osmotically dehydrated frozen semi-finished apple products. Jonagold (Wilmuta) apples were peeled, core removed, and cut into 20⨯20 mm slices, blanched in a 0.1 % citric acid solution at 85 °C for 2–5 min, dried, and immersed in a pectin solution with a concentration of 1, 2, 3, 4, 5 %, followed by drying. The prepared apple particles were kept for 30 min in a 30 % aqueous sucrose solution before freezing. Uncoated apple particles were used as a control. The apples were frozen in bulk at minus 30 ± 1°C, packed in plastic film bags, and stored for 6 months at minus 18±1 °C. The application of a food coating from a pectin solution to apple semi-finished products before partial osmotic dehydration and freezing inhibited the increase in dry soluble substances during dehydration by 1.4–2.0 %. The cryoresistance of the semi-finished product samples was recorded at 87.9–95.8 %, with an increase in the values of the studied indicator by 0.8–7.9 % in the coated samples. The use of a food coating made of a pectin solution contributed to a decrease in product weight loss during freezing by 0.2–1.1 % and dry soluble substances by 0.2–0.4 %. The presence of the food coating had a positive effect on the appearance and consistency of the semi-finished products. Semi-finished products with food coating in a pectin solution of 5 % concentration were of better quality.

USE OF KOMBUCHA AS A BASIS FOR THE PREPARATION OF SMOOTHIES FOR RESTAURANT ESTABLISHMENTS

Оlha S. Dulka — 2025-04-15

The article contains the research results in developing a smoothie recipe as a health drink with characteristic organoleptic properties. We used kombucha, pumpkin, and non-traditional raw material – chia seeds. Kombucha was prepared by fermenting the tea wort with a deposited culture of microorganisms Medusomyces gisevii DP-21. Turmeric was used to enrich the drink with beta-carotene. Chia seeds and pumpkin were used to give the drink an original appearance and structure and increase its biological value. The metabolic scheme of Medusomyces gisevii culture is given. The products of its metabolism, in particular microbiological cellulose, were characterized. The general indicators of chia seeds, particularly the chemical composition, were determined. The scheme of gel formation by chia seeds and water-holding capacity are given. Physico-chemical indicators of pumpkin and its use in smoothies in fresh, balanced, and baked form are given. The selection of components for the preparation of smoothies was carried out, considering the consumption of taste descriptors. The organoleptic profile of the smoothie was determined, and the optimal ratios of ingredients were: kombucha – 35 %, chia seeds – 10 %, turmeric – 1 %, and pumpkin – 54 %. The sensory analysis results for color, appearance, smell, taste, and consistency are given. As a result of the conducted research, a drink recipe was developed, and the perspective of using kombucha as a basis for preparing smoothies, as well as chia seeds, turmeric, and baked pumpkin, was proven, which ensures obtaining a qualitatively new food product in restaurants establishments.

USE OF LIGNOCELLULOSE RAW MATERIALS IN THE PRODUCTION OF BIOETHANOL

Kateryna O. Danilova — 2025-04-15

Wheat straw and corn stalks are considered potential raw materials for bioethanol production as an alternative fuel due to their high cellulose and hemicellulose content, as well as their wide distribution and availability. The aim of the work is to study the pretreatment of wheat straw and post-harvest corn waste by steam explosion and organosolvent delignification methods to obtain the maximum ethanol yield. A combination of steam explosion as a method of pretreatment of straw for the destruction of lignin bonds and organosolvent delignification for the separation of cellulose is proposed. The obtained explosive defibration products and the solid phase after organosolvent delignification were subjected to enzymatic hydrolysis with cellulase and fermented with Saccharomyces cerevisiae yeast. For delignification, 50 % ethyl alcohol was used with the addition of sulfuric acid as a catalyst in an amount of 3 %. A study of the quantitative yield of delignification products at each stage of raw material processing was conducted. Analysis of the physicochemical parameters of the obtained explosive defibration products showed an increase in the cellulose content from 42 to 63 %, but the residual lignin content was 12 %. Organosolvent delignification led to almost complete destruction of lignin bonds with the release of cellulose in a form available for enzymatic hydrolysis. Enzymatic hydrolysis of cellulose with a complex of cellulolytic enzymes before fermentation increases the ethanol content in the fermented mashes by 4 times. Improvements in the pretreatment of lignocellulosic raw materials, especially through combinations of different processes, and advances in biotechnology aimed at creating effective enzyme preparations and yeast strains with high enzymatic activity and resistance to inhibitors, will lead to an increase in the economic efficiency of second-generation bioethanol production by 50 %.

FLUOROPOLYMER MATERIALS FOR FRICTION KNOTS MODERN MACHINES AND MECHANISMS

Oleg S. Kabat — 2025-04-15

Inmodern machine-building in Ukraine, quite significant difficulties arise, which are connected with the war between Ukraine and Russia. In particular, this concerns the shortage of some polymer materials of Russian production, which were previously widely used in Ukraine. Such polymers include fluoropolymer polytetrafluoroethylene, trademark “фторопласт-4”. This material is quite widely used in friction units of machines and mechanisms. Therefore, the urgent task is to find analternative to “фторопласт-4” produced by the countries of the European Union, the USA, China, etc. Inthework, the following polytetrafluoroethylenes were chosen as an alternative to fluoroplastic-4: PTFE Powder101 and PTFE Powder161 manufactured by Stargetfluoro (Beijing, China). Studiesoftheir physico-mechanical, thermophysical and tribological properties have be enconducted and it has been establishedth at the studied materials exceed the norm at the same levelas “фторопласт-4” in term soft heir level. This allows ustoassert that PTFE Powder101 and PTFE Powder161 fluoropolymersareanalternativeto “фторопласт-4”, whicharefully capable of replacing it in the friction units of machines and mechanisms. Tribologicalstudieswerecarried out to determine the run-in path of fluoropolymers PTFE Powder101 and PTFE Powder 161, which is 250–400 m during frictional interaction with steel. The maximum load limit (up to 0.8 MPa) at which products made of the studied materials retain their performance was determined.

JUSTIFICATION OF THE TECHNOLOGY OF FUNCTIONAL SOY YOGURT

Larysa V. Bal-Prylypko — 2025-04-15

Today, in the context of promoting a healthy lifestyle, there is a growing interest among the Ukrainian population in functional food products that are alternative to dairy products, in particular, fermented drinks – yogurts, made from soy products. At the same time, such products use food additives of synthetic origin against the background of a wide range of non-traditional raw materials and ingredients of natural origin. The aim of the work is to substantiate the use of blueberries, stevioside and dihydroquercetin in soy yogurt to obtain a finished functional product. It was found that blueberries in the form of puree are characterized by high nutritional and biological value, and dihydroquercetin has the highest antioxidant activity compared to other antioxidants. The content of blueberry puree in the experimental samples varied within 14.0–18.0 %, stevioside was added in an amount of 0.01 %. According to organoleptic quality indicators, it was found that the experimental sample with a content of blueberry puree of 16.0 % is characterized by the most pleasant taste and smell and was selected for further research. The use of 16.0 % blueberry puree made it possible to increase the mass fractions of carbohydrates and dietary fiber compared to the control by 0.92 % and 0.27 %, respectively. In terms of vitamin and mineral composition, a significant increase in the content of vitamin C in the experimental sample with a content of blueberry puree of 16.0 % was observed – by 2.75 mg, potassium – by 54 mg, iron – by 0.23 mg and magnesium – by 8.0 mg. The possibility of using soy suspension, stevioside, blueberry puree, and dihydroquercetin in soy yogurt to obtain a finished functional product has been proven.

SUBCRITICAL EXTRACTION OF BIOLOGICALLY ACTIVE SUBSTANCES FROM WHEAT BRAN

Valerii A. Sukmanov — 2025-04-15

Wheat bran (WB) is the main by-product in the grain processing industry and contains a large number of biologically active substances, which, unfortunately, are not used in the food industry today. The work is devoted to the study of the process of subcritical water extraction of WB. The aim of the study is to determine and scientifically substantiate the rational values of the parameters of subcritical extraction of biologically active substances from wheat bran: sugars, protein, phenols, and antioxidant properties. Methods. Liquid extracts were obtained on a laboratory installation based on a high-pressure reactor when varying the parameters in the following ranges: temperature – 140–180 °С; time – 3–18 min; fraction size – 0.25±0.05; 0.50±0.08 and 0.75±0.1 mm, hydraulic modulus – 1 : 10,
1 : 15, 1 : 20, 1 : 25 and pressure 5 MPa. Results. Empirical dependences of a number of indicators of subcritical wheat bran extracts on the parameters of the extraction process were experimentally obtained and their optimal values were determined: temperature, duration, hydraulic modulus, raw material fraction size and pressure. The influence of the extraction process parameters on the studied target substances was investigated; the values of the parameters were established (hydraulic modulus 1 : 20, PV fraction size 0.5 mm, pressure 5 MPa, temperature - 170 °С, extraction duration 12.0–14.9 min. depending on the target substance), at which the maximum values of the indicated indicators are achieved: sugar content – 317.9 mg/g CP; protein – 184.2 mg/g CP; total polyphenol content – 31.2 mg/g of CP and radical scavenging activity – 0.162 mmol/g of CP. Conclusions. The results obtained can be used to improve the technology for obtaining biologically active substances from PV using the subcritical water extraction method for further use in the food industry.

SYNTHESIS AND CHARACTERIZATION OF SILICATE GLASS FROM ALTERNATIVE RAW MATERIALS USING HYDROTHERMAL CHARGE

Nataliia V. Zhdaniuk — 2025-04-15

Aim. To study the possibility of expanding the raw material base of glass production due to the use of high-silica raw materials – diatomite and perlite. Thus, the introduction of the main component of silicate glass SiO₂ occurs due to amorphous silica contained in rocks. Methods. The batch was prepared by hydrothermal method. Autoclave processing of rocks and silica was carried out for 4 hours at a temperature of 170 °С and a pressure of 0.5 MPa. NaOH was used as an alkaline agent. The molar ratio of SiO₂ to NaOH was equal to 2. The SiO₂–Na₂O–PbO system and the glass composition in mole fractions were selected for the studies: SiO₂ – 52.4 %; Na₂O – 26.2 %; PbO – 21.4 %. The composition point lies on the liquidus isotherm of about 800 °C. The glass synthesis was carried out at a temperature of 1100 °C. Results. The study of the kinetics of glass making showed that when using hydrothermal making batches based on rocks, the stage of obtaining conditioned glass mass occurs at significantly lower temperatures than in the case of glass making from traditional batches and is at least 100 °С. Thus, it can be argued that the use of hydrothermal batches will reduce energy costs at the glass making stage. DTA results confirmed that the physicochemical activity of batches using amorphous silica is lower than for batches made using crystalline silica. X-ray confirmed that all glass samples welded at a temperature of 1000 °С are characterized by high X-ray amorphousness, which indicates the completion of glass formation processes. A visual assessment of the processes of silicate and glass formation showed that the boiling temperature of model glass based on hydrthermal batches is 110–120 °С lower than for glass made on the basis of traditional batches. Conclusions. Thus, it can be argued that the use of alternative raw materials, diatomite and perlite, will allow obtaining silicate glass. And the use of the hydrothermal method for obtaining the charge allows for a reduction in energy consumption during the glassmaking stage.

SPECTROPHOTOMETRIC AUTHENTICATION IMAGES OF HOPS ESSENTIAL OILS

Vladislav V. Liubchenko — 2025-04-15

Hop essential oils are natural, useful substances enriched with biologically active terpene complex. They possess attractive nutritional and energy-stimulating properties and can positively affect the immune-supporting functions. However, they are at risk of falsification, necessitating the development of competent identification methodologies. This research aimed to create methodological, analytical, and informational bases for hop oils to study the possibility of their identification and control against falsification by spectrophotometry. Essential oils of bitter and aromatic hop types were analyzed. The quality and safety parameters of the oils met regulatory requirements. The optical density spectra of hop oil were evaluated and compared in the light absorption wavelength range from 190 nm to 900 nm. It has been established that the identification spectrophotometric images of optical density, when a light beam is transmitted through hop oil samples, discretely, with a wavelength step of 0.05–1 nm, form peaks of total terpene absorption in the ranges of 350–620 nm. These are the main criteria for the formation of spectrophotometric databases of hop oils. Spectrophotometric images and pilot authentication models were developed for high-quality samples of bitter and aromatic hop oils. These findings contribute to the organoleptic authentication of hop oil spectrograms to prevent falsification.

AGITATION LEACHING OF URANIUM FROM THE MICHURINSK DEPOSIT

Oleg V. Kozhura — 2025-04-15

This research is dedicated to the investigation of agitation leaching of uranium ore from the Michurinsk deposit at 75 °C and atmospheric pressure, with the addition of ferric sulfate as a uranium oxidant in the composition of oxidized titanium white waste acid from titanium dioxide pigment production. It has been demonstrated that ferrous sulfate in titanium white waste acid solutions is quantitatively oxidized by oxygen to ferric sulfate in a gas-liquid reactor with mechanical agitation, using nitrogen compound-based catalysts within a time frame acceptable for the technological process. Replacing up to 40 % of sulfuric acid in uranium acid leaching solutions with oxidized titanium white waste acid allows for an increase in uranium extraction from 76 % to 88% at an Sol : Liq ratio of 1 : 1 and a total acid consumption of 90 kg/t of ore. The maximum uranium extraction corresponds to a leach filtrate concentration ratio of C(Fe³⁺)/C(Fe²⁺) ≥ 1. The use of counter-current agitation leaching in multiple stages can further enhance uranium extraction from refractory ore to above 90 %. However, substituting more than 40 % of sulfuric acid with oxidized titanium white waste acid leads to a decrease in uranium extraction due to the negative impact of impurities present in the waste acid. Increasing the consumption of sulfuric acid doped with oxidized titanium white waste acid to 110 kg/t of ore does not result in further uranium extraction improvement. The addition of oxidized titanium white waste acid in agitation leaching ensures a high level of uranium extraction from refractory ores. A final conclusion regarding the feasibility of implementing this approach in uranium concentrate production requires further investigation into the impact of impurities introduced with titanium white waste acid on other stages of the technological process.