The interaction between proteins and salts in aqueous solutions represents a compelling scientific problem in both biophysical and medical research. One manifestation of the interaction in the bovine serum albumin (BSA)-NaCl-H2O system is the formation of ordered patterns upon droplet drying. In our experiments, the topographic features of the deposited particles as well as their elemental composition were studied using optical microscopy and scanning electron microscopy (SEM). In this work, we experimentally investigated the stepwise change in the characteristic structures of the precipitate with an increase in the BSA concentration from 0.005 to 35 mg/mL. The formation of discrete BSA-NaCl ring deposits near the droplet edge and around crystallization centers in the interior at BSA concentrations of 0.05-1 mg/mL proved particularly interesting. We demonstrated the sequence of ring structure formation: the process primarily begins with the formation of BSA aggregates arranged in sectors around the circumference, which in turn serve as nucleation sites for NaCl crystallization. We propose a qualitative conceptual-phenomenological interpretation of the observed experimental effects. Concentration-dependent patterns in the emergence and development of other patterns (such as spikes, fractal structures, and chrysanthemum-like formations) were established. These results expand our understanding of protein behavior in aqueous-salt solutions. This can be used in medical diagnostics as biomarkers. The characteristic patterns presented in the work can serve as a useful experimental basis for further studies of the impact of physicochemical factors on proteins and other biopolymers.

The two-year research involving laboratory and field studies supported by Geant4 computer simulation is aimed at determining the optimal parameters of 1 MeV accelerated electrons and 80 keV X-ray pre-planting irradiation of wheat seeds in order to find the optimal dose range which increases the crop yield while making wheat plants more resistant to fungal diseases caused by species of the genus Septoria. During the laboratory studies we measured the germination rate and biometric properties of plants, as well as the type, number, and average diameter of fungi found in the irradiated and non-irradiated seeds after irradiation with electrons and X-rays with the dose range 2-1000 Gy. Following the laboratory studies showing that the doses exceeding 30 Gy decreased the germination rate of wheat, field studies evaluated the impact of pre-planting irradiation with the doses in the range of 5-30 Gy on the wheat productivity and the rate of fungal diseases in wheat plants grown from irradiated and non-irradiated seeds. It has been found that the dose range 5-15 Gy is more preferable for pre-planting wheat irradiation, both for e-beam and X-rays, since it increases the crop yield while making wheat plants more resistant to fungal diseases caused by species of the genus Septoria. The X-ray dose of 15 Gy is found to be the most effective since it increased the yield up to 40% and also suppressed the Septoria glume blotch up to 40%. Since seed irradiation requires a particularly delicate approach given that the goal of irradiation is not only to reduce the rate of fungal diseases in the plants but also to increase the crop yield without detriment to the soil and the plant itself, consistency of dose uniformity across the seeds during pre-planting irradiation ensures the high reliability and repeatability of the irradiation effect. Our approach to irradiation planning with the use of Geant4 computer simulation allows us to precisely estimate the dose distribution in individual seeds and the distribution of radiation-chemical yield of radicals occurring as result of radiolysis in order to predict the effect of pre-planting irradiation and select the optimal irradiation parameters for maximizing the yield and crop quality.

Electron beam irradiation, extensively used for suppressing a wide range of pathogens contaminating food products, pharmaceuticals and biological raw materials, inevitably damages the surrounding proteins, stripping the product of its essential nutritional and functional properties. This issue can be addressed by adjusting the electron beam irradiation dose, bearing in mind the concentration of proteins in the product since it can affect the rate of radiation-induced modifications in proteins. The study investigates the impact of 7.5 MeV electron-beam irradiation on modifications in bovine serum albumin (BSA) molecules in 0.9% NaCl solution in the concentration range of 0.5-70 mg/mL, encompassing a wide range of protein concentrations in food products, pharmaceuticals and biological raw materials. Conformational changes and aggregation of BSA were evaluated using UV-Vis spectrophotometry at λ = 350 nm. Peptide bond rupture in protein native structures was assessed by performing HPLC-MS/MS analysis after trypsin hydrolysis using three selected peptides located in different domains of the BSA amino acid sequence. It was found that the rate of radiation-induced modifications increased with an increase in the irradiation dose but decreased markedly as BSA concentration increased. While at the BSA concentration of 0.5 mg/mL over 87% of BSA molecules underwent peptide bond rupture under irradiation with a dose of 5 kGy, a two-fold increase in the BSA concentration and irradiation dose enabled bond rupture in only 20% of BSA molecules. Our experimental approach resulting in the development of the dose and concentration model allows us to quantify the degree of radiation-induced protein modifications depending on the irradiation dose and protein concentration in food products, pharmaceuticals and biological raw materials.

During the development of food radiation processing protocols, one of the aims is to find an optimal dose range for a specific type of product in which pathogenic microflora are inhibited while biochemical and organoleptic properties are not disturbed. When various food products are exposed to ionizing radiation, volatile organic compounds (VOCs) are formed. Depending on the radiation dose, the list of VOCs and their content change, so they could be considered marker compounds for the description of irradiation-related processes. This work proposes a universal way to study and compare the profile of volatile compounds in products of animal and plant origin using GC-MS in combination with various data representation techniques, including unsupervised machine learning methods. The VOC profiles of beef, chicken, turkey, fish, and potatoes were examined.

This study investigates the impact of 1 MeV electron beam and 80 keV X-ray irradiation on the decomposition rate and radiation–chemical yield of 1-hexanol in aqueous saline solution to develop a comprehensive approach to determining reliable volatile organic compound markers for food irradiation. A 50 mg/L 1-hexanol solution was irradiated with the doses ranging from 100 to 8000 Gy at various dose rates ranging from 0.2 to 10 Gy/s to assess the impact of irradiation parameters on the decomposition rate and radiation–chemical yield of volatile compounds typically found in food. GC–MS analysis revealed a non-linear decrease in 1-hexanol concentration with increasing dose, accompanied by the formation of aldehydes, ketones, and secondary alcohols. Among these products, hexanal was detected at the lowest applied dose and exhibited dose-dependent behavior that correlated strongly with 1-hexanol degradation. Density functional theory calculations identified the most probable pathways for the formation of hexanol decomposition products, involving direct ionization, radical reactions, and oxidation. A mathematical model proposed in the study describes dose-dependent transformations of 1-hexanol into hexanal, enabling quantitative estimation of the degradation extent of hexanol. The findings suggest that hexanal can serve as a quantitative marker for hexanol degradation, supporting the development of rapid “dose range” determination methods for food irradiation that ensure microbial safety while minimizing undesirable oxidation of proteins, fats, and carbohydrates.

Oxidation of lipids and proteins occurs in food products with a high concentration of fat and water such as chilled meat and fish under the action of ionizing radiation, which leads to the formation of volatile organic compounds (VOCs) in the product and appearance of specific smell and taste. During storage, various biochemical processes occur in processed chilled products which also result in a change in the concentration of VOCs that affect the organoleptic properties of the product. The accumulation of volatile compounds identified in beef samples both immediately after radiation processing and within four days after irradiation is studied by gas chromatography–mass spectrometry to determine the effective dose range for the radiation processing of beef. Monitoring of the concentration of VOCs in samples of chilled beef meat irradiated with accelerated electrons with the energy of 1 MeV in a dose range of 0.25 to 5 kGy reveals explicit dependences of the concentrations of certain alcohols, aldehydes, and alkanes on the absorbed dose and storage time. The proposed mathematical model that describes the dependences of the concentrations of VOCs identified immediately after irradiation in beef samples on the irradiation dose is based on the simultaneous occurrence of two competing processes: decomposition of compounds due to their oxidation and accumulation due to the oxidation of other compounds after exposure to ionizing radiation. It is found on the basis of the results of the study that the effective dose range of radiation processing is 250 to 1000 Gy.

Catalase serves as a crucial component of the antioxidant defense system by catalyzing the decomposition of hydrogen peroxide into water and molecular oxygen. This study investigated the effects of 1 MeV accelerated electron irradiation on catalase activity in model solutions at doses of 100 Gy and 1000 Gy. Enzyme activity was assessed using two complementary methods: spectrophotometric analysis and the oxygen bubble method. The experimental results demonstrated dose-dependent inhibition of catalase activity, indicating that substantial radiation-induced structural modifications may occur in the enzyme molecule as a result of irradiation. To understand the relationship between the irradiation dose and the catalase inhibition, calibration curves plotting the dependencies of hydrogen peroxide decomposition rate and the delayed appearance of oxygen bubbles after adding hydrogen peroxide to catalase saline solution on the catalase concentration showed a 1.5-fold reduction in catalase activity at 100 Gy and a 40-fold decrease at 1000 Gy. Based on these findings, we propose a novel biodosimetry approach utilizing the oxygen bubble formation delay time as an express assessment tool for detecting high radiation doses absorbed by biological objects, for example, food products. The results obtained in the study have important implications for evaluating radiation effects on biological systems, in particular catalase-containing food products, offering potential applications in radiation safety monitoring and food quality control.

Background: Recently, extensive use of antibiotics has increased the amount of antibiotic residues in the natural water environment. Methods: This study presents an experimental investigation into the degradation of penicillins, tetracyclines, streptomycin and chloramphenicol in aqueous solutions when exposed to 1 MeV accelerated electrons with doses of 0.1, 1, 3 and 7 kGy using HPLC-HRMS analysis. Results: It was found that electron beam irradiation with a dose of 7 kGy ensures 98-99% removal of antibiotics, with the initial concentrations ranging from 15 mg/L to 30 mg/L depending on the class of antibiotic. The mathematical model proposed in the study, which estimates the dose dependencies of the relative concentrations of antibiotics and their degradation products in aqueous solutions, reveals different decomposition rates of antibiotics of different classes due to the different radiosensitivities of antibiotics. It has been found that tetracycline has a considerably higher radiation-chemical yield compared to the other antibiotics when exposed to accelerated electrons. Conclusions: Using density functional theory in combination with the mathematical model, we have developed a novel approach to establishing a quantitative irradiation marker of antibiotic degradation as a result of irradiation, which involves finding the degradation product whose formation requires a minimum number of ionization events. Using such an approach, it is possible to establish the extent of antibiotic degradation in water after irradiation with different doses and find the optimal irradiation doses for industrial water treatment.

The objective of this study is to develop a universally applicable approach for establishing the optimal dose range for the irradiation of plant and animal products. The approach involves the use of the optimization function for establishing the optimal irradiation dose range for each category of plant and animal product to maximize the suppression of targeted pathogens while preserving the surrounding molecules and biological structures. The proposed function implies that pathogens found in the product can be efficiently suppressed provided that irradiation is performed with the following criteria in mind: a high irradiation dose uniformity, a high probability of irradiation hitting pathogens and controlled heterogeneity of radiobiological sensitivity of pathogens. This study compares the optimal dose ranges for animal and plant products using beef tenderloin and seed potato tubers as examples. In a series of experiments, our team traced the dose dependencies of myoglobin oxidation in beef and the amount of potential damage to albumin’s native structure. The behavior patterns of myoglobin derivatives and the amount of potential damage to albumin found in this study determined the optimal dose range, which appeared to be wider for beef irradiation compared to that for seed potato tubers, as they do not require uniform irradiation of the entire volume since targeted phytopathogens are predominantly found within the surface layers of the tubers. The use of proprietary methods involving spectrophotometry and high-performance liquid chromatography–mass spectrometry provides a novel perspective on the quantitative assessment of the myoglobin oxidation level and the potential damage to albumin’s native structure.

Radiation treatment of food makes it possible to solve some issues of the food industry, including suppression of pathogenic microbial contamination, retention of the nutritional value of the product, and increase in its shelf life. This treatment method in combination with highly sensitive methods of gas chromatography–mass spectrometry makes it possible to reveal biochemical markers of irradiation treatment in meat products with moderate fat content, such as chicken and turkey. This work describes the experimental results of the dependences of the content of volatile organic compounds in chilled chicken meat treated with 1 MeV accelerated electrons with the doses from 250 Gy to 20 kGy in two weeks of storage. The content of volatile organic compounds in irradiated and reference food samples has been determined on days 0, 1, 4, 6, 8, 11, and 13 after irradiation treatment. Similar behavior pattern of aldehydes identified in treated poultry meat, namely, hexanal, heptanal, and pentanal, has been determined in two weeks of product storage. An increase in the aldehyde concentration has been detected in samples treated with doses from 500 Gy to 10 kGy on days 1–4 after irradiation. It has been revealed that, with an increase in the irradiation dose the period of aldehyde accumulation in irradiated meat is displaced toward a shorter period of product storage. Thus, aldehydes can be considered as potential markers of irradiation treatment of chicken meat in the first four days after irradiation.

A method is proposed for the high-performance liquid chromatography–mass spectrometry quantification of the effect of an ionizing radiation dose on the structural characteristics of bovine serum albumin (BSA) in an aqueous solution by identifying unique peptides of the protein domain structures. BSA with an initial concentration of 500 mg/L in the physiological solution is irradiated with an accelerated electron beam with the maximum energy of 1 MeV and an average beam current of 1 pA at a dose rate of 18.5 Gy/s. The dose absorbed in the sample volume is estimated with a Fricke (ferrous sulfate) dosimeter. After irradiation of the BSA solution at doses of 0.3, 0.6, 1, 8, and 20 kGy, the structural integrity of the protein native form is analyzed and the protein content is quantified. To do this, the compounds with a mass of more than 30 kDa are removed by centrifugation, and then, BSA is subjected to enzymatic hydrolysis with addition of the trypsin solution, and the resulting peptides with a mass of more than 10 kDa are repeatedly removed. The samples obtained are examined by high-performance liquid chromatography–mass spectrometry. After that, the content of intact protein molecules is estimated by determining the concentrations of unique peptides corresponding to each of the three domains formed from the BSA amino acid sequence. Using the developed technique, a change in the natural conformation of the investigated protein (its denaturation) in water samples induced by ionizing radiation at a dose ranging from 0.3 to 20 kGy is established, on average, for 71

This study focuses on the behavior of volatile organic compounds in beef after irradiation with 1 MeV accelerated electrons with doses ranging from 0.25 kGy to 5 kGy to find reliable dose-dependent markers that could be used for establishing an effective dose range for beef irradiation. GC/MS analysis revealed that immediately after irradiation, the chemical yield and accumulation rate of lipid oxidation-derived aldehydes was higher than that of protein oxidation-derived aldehydes. The nonlinear dose-dependent relationship of the concentration of volatile organic compounds was explained using a mathematical model based on the simultaneous occurrence of two competing processes: decomposition of volatile compounds due to direct and indirect action of accelerated electrons, and accumulation of volatile compounds due to decomposition of other compounds and biomacromolecules. A four-day monitoring of the beef samples stored at 4 °C showed that lipid oxidation-derived aldehydes, protein oxidation-derived aldehydes and alkanes as well as alcohol ethanol as an indicator of bacterial activity were dose-dependent markers of biochemical processes occurring in the irradiated beef samples during storage: oxidative processes during direct and indirect action of irradiation, oxidation due to the action of reactive oxygen species, which are always present in the product during storage, and microbial–enzymatic processes. According to the mathematical model of the change in the concentrations of lipid oxidation-derived aldehydes over time in the beef samples irradiated with different doses, it was found that doses ranging from 0.25 kGy to 1 kGy proved to be most effective for beef irradiation with accelerated electrons, since this dose range decreases the bacterial content without considerable irreversible changes in chemical composition of chilled beef during storage.

This study focuses on the impact of pre-planting irradiation of seed potatoes on the phenophases of the root crop and proliferation of fungus Rhizoctonia solani on the new crop tubers. A two-year monitoring of seed potatoes after irradiation shows that treatment of tubers with 30–40 Gy decreases the spread of fungal infection on the surface of the tubers. It was found that low-energy electrons used in the experiment are the most effective irradiation treatment since they penetrate in the upper layers of potato tubers affected by the fungus.

The need to develop safe methods for radiation processing of food products to improve their quality and extend their shelf life stimulates new scientific research aimed at increasing their effectiveness. Oxidation of lipids and proteins occurred under the impact of ionizing radiation in products with a high fat and water content, such as chilled meat and fish products, leads to the formation of volatile organic compounds in the product thus giving it a specific smell and taste. During storage, biochemical processes associated with microbial enzymatic activity and auto-oxidation develop in processed refrigerated products. These processes also modify the volatile organic compounds, which affect the organoleptic properties of the product. The method of gas chromatography-mass spectrometry was used to study the behavior of volatile compounds identified in irradiated beef samples both immediately after irradiation and four days later to determine the effective dose range for the radiation processing of beef. Monitoring of the content of volatile compounds in beef samples irradiated by 1-MeV electrons within a dose range from 0.25 to 5 kGy showed that the content of certain alcohols, aldehydes, and alkanes exhibited pronounced dose- and time-dependent character. The developed mathematical model describes the dependence of the concentration of volatile compounds identified immediately after irradiation in beef samples on the irradiation dose. The model is based on the simultaneous occurrence of two competing processes: the decomposition of compounds due to their oxidation and accumulation due to oxidation of other compounds after exposure to ionizing radiation. The results obtained revealed that the effective dosage range of radiation treatment lies between 250 and 1000 Gy.

The study suggests an algorithm for estimating the depth dose distribution in the material irradiated with an accelerated electron beam, based on the absorbed dose distribution data in the reference material, such as aluminum or water. It was shown that a margin of error in the measured absorbed dose distributions as well as the choice of the materials have an impact on the accuracy of reconstruction of the dose distributions in the materials.

Radiation treatment of food products carried out to increase their shelf life can result in chemical transformations initiated by free radicals. Volatile compounds (alcohols, aldehydes, ketones, etc.) formed, in particular, as a result of lipid oxidation, impair the organoleptic properties of products. Method of gas chromatography-mass spectrometry (GC-MS) makes it possible to identify the fact of food processing by detection of volatile marker compounds: in the case of meat products, the existing standard brings under regulation detection of 2-alkylcyclobutanones, however, the products with a reduced fat content, such as turkey and chicken, require an alternative marker. The results of GC-MS study revealed the dependence of microbiological parameters and the content of various volatile organic substances in chilled turkey meat on the dose of electron radiation. It is shown that the total amount of alcohols, ketones and aldehydes (11 compounds) decreases exponentially with an increase in the absorbed dose. An increase in the radiation dose leads to a higher content of carbonyl compounds (aldehydes and acetone), which results in a specific taste and smell of the irradiated products. At the same time, the acetone concentration increases linearly with the absorbed dose, which makes it possible to use acetone as a potential marker of the degree of irradiation of low-fat meat products. Irradiation in the “working” doses (0.5–1 kGy) significantly suppresses the pathogenic microflora and keeps the organoleptic properties of the product.

The research explores a wide range of applications for electron accelerators in industrial irradiation processing. It also compares the physical properties of electron beams, dose ranges, and methods used for irradiation of polymers, medical items, transplantology objects, pharmaceuticals, and foods. Moreover, the study discusses the depth dose non-uniformity in objects irradiated with accelerated electrons. The research also highlights the dependency of geometry, density, and chemical composition of the object on the dose distribution. Another focus of the study is computer simulation of electron irradiation method, encompassing all physical and technical parameters to assess the dose distribution throughout the irradiated objects, since without knowing the precise electron beam spectrum, it is impossible to accurately reconstruct the dose distribution throughout the objects. Considering that the beam spectrum cannot always be identified, especially for industrial accelerators, the study presents algorithm for reconstructing the dose distribution in irradiated objects. The final part of the research provides methods for increasing the dose uniformity throughout objects irradiated with electron beams.

The necessity of developing safe methods of processing food products which improve the quality and extend their shelf life entails further scientific research aimed at increasing the efficiency of radiation processing of food products. Ionizing radiation causes lipid peroxidation in the items with a high fat and water content, such as chilled meat and fish products, which leads to formation of organic volatile compounds that render the food the specific flavor and smell. Gas chromatography-mass spectrometry is a technique that provides identification of chemical changes that actually occur in the product after irradiation. Experimental data on the content of organic volatile compounds in chilled turkey and salmon meat samples exposed to irradiation with 1 MeV accelerated electrons in the dose range from 0.25 to 2 kGy revealed both common and different trends in the behavior of dose dependences of alcohol, aldehyde and ketone contents in various types of chilled products. A proposed mathematical model based on the possibility of simultaneous occurrence of two competing processes, i.e., the decomposition of compounds due to their oxidation and the accumulation of compounds due to oxidation of other compounds after exposure to ionizing radiation match a dose dependent character of experimental data.

This study focuses on the influence of pre-planting irradiation on the development, health, and yield of seed potatoes infected with Rhizoctonia solani. The research was prompted by the need to ensure crop security and sustainability in the modern-day environment, which calls into question the future sufficiency of crop yields. Considering that the focus has shifted to non-chemical methods of crop treatment at all plant development stages in response to more stringent regulations governing potato production, it is particularly important to refine physics-based methods to suppress fungal diseases caused by Rhizoctonia solani. Irradiation of tubers with 20–150 Gy inhibited the potato development phases and the doses exceeding 150 Gy completely suppressed the potato sprouting. Doses ranging from 20 Gy to 100 Gy decreased the quantity of large tubers by 10–20% on average while the number of medium and small tubers increased by 5–15% and 3–10%, respectively. Irradiation of seed potatoes also decreased the sclerotia and non-sclerotia forms of diseases caused by Rhizoctonia solani in the harvested tubers. It was found that 1 MeV electron irradiation with doses ranging from 20 Gy to 30 Gy is the most efficient for the pre-planting treatment of seed potatoes since the penetration of low-energy accelerated electrons into the upper layers of potato tubers ensures the suppression of diseases caused by Rhizoctonia solani by at least 10% from the value of non-irradiated samples and prevents the reduction of total yield allowing for a maximum of 25% loss.