The traditional approach to obtaining, identifying, and confirming the biological activity of peptides is laborious and timeconsuming. The development of bioinformatics and computer modeling made it possible to carry out a preliminary theoretical assessment of the potential biological activity of peptides. The aim of the study was to carry out theoretical enzymatic hydrolysis in silico of chickpea, rapeseed and hemp proteins, as well as to predict the profile of potential biological activity of the resulting peptides using bioinformatics tools. As a result of the search for the initial amino acid sequences of chickpea, rapeseed and hemp proteins in the UniProtKB database using the keywords “Cicer arietinum”, “Brassica napus”, “Cannabis sativa”, as well as the origin of the protein — “Storage protein”, 5 isoforms of legumin, 3 isoforms of vicilin and 2 isoforms of provicilin were found in chickpea proteins; rapeseed proteins contained 6 isoforms of cruciferin protein and 7 isoforms of napine; hemp proteins contained 3 isoforms of edestin-1 and edestin-2, 2 isoforms of edestin-3 and 1 isoform of albumin. After hydrolysis using the tools of the BIOPEP-UWM database, 10,131 amino acid sequences of chickpea proteins, 7,206 amino acid sequences of rapeseed proteins and 8,479 amino acid sequences of hemp proteins were obtained. As a result of the classification of the obtained peptides according to the predicted value of their biological activity using PeptideRanker, as well as after predicting toxicity, bitterness and allergenicity, 35 biologically active peptides (BAPS) were identified from chickpea proteins, 21 from rapeseed proteins and 22 from hemp proteins. For chickpea proteins, 29 potential ACE inhibitors, 27 DPP IV inhibitors, 6 oncostatic, 4 antioxidant, 4 antifungal and 3 antihypertensive peptides were predicted. For rapeseed, 22 potential DPP IV inhibitors and 20 ACE inhibitors, 5 antifungal peptides, 3 peptides with potential antioxidant effect, 3 with antithrombotic properties, 2 antihypertensive peptides, 2 with oncostatic properties and 1 with antibacterial activity were determined. Potential ACE-inhibiting activity was determined for 16 hemp peptides, 15 are DPP IV inhibitors, 7 have antifungal activity, 5 have antioxidant and oncostatic effects, 4 have antihypertensive properties, 1 has antituberculous effect. In the future, further in vitro and in vivo studies are needed to confirm biological activity, as there is a potential discrepancy between the results of in silico modeling of hydrolysis and prediction of biological activity and the data from experimental studies.

Nutritional support, as a strategy either alternative or complementary to conventional pharmacotherapy, demonstrates significant potential for modulating the pathogenetic mechanisms of neurodegenerative and neuropsychiatric disorders. This review synthesizes current evidence on the role of micronutrients and bioactive compounds in neuroprotection and neuroregulation. It examines the mechanisms of action of vitamins (E, D, K, A, B complex, C), minerals (selenium, zinc, magnesium, iron, copper, iodine, manganese), and polyunsaturated fatty acids in modulating antioxidant defense, synaptic plasticity, neuroinflammation, and neurotransmitter metabolism. Particular emphasis is placed on their capacity to mitigate oxidative stress and excitotoxicity, while concurrently enhancing neurotrophic support (e. g., BDNF, NGF). The significance of nutrient synergy, exemplified by the combination of vitamin B₁₂ and omega-3 fatty acids, for augmenting neuroprotective effects is highlighted. The review discusses the challenges associated with translating findings from preclinical studies into clinical practice, including variability in bioavailability and the necessity for personalized nutritional approaches. Future research should be directed towards developing comprehensive dietary strategies and elucidating the role of gut microbiota in the metabolism of neuroactive compounds.

Lyophilization has been recognized for many years as an effective method for storing collection cultures, bacterial starter cultures, and probiotics. Cryoprotectors are used to protect bacterial cells from stress during freezing and drying, and to increase their survival. The purpose of our study was to evaluate an effect of three freezing regimes before freeze-drying at temperatures of –20, –30, and –55 °C and solutions of two cryoprotectors, sucrose and trehalose, on the survival and preservation of the metabolic activity of mesophilic lactobacilli. The cultures were grown in 10 % skimmed milk, and in experimental versions, a 20 % cryoprotector solution was added to the culture in a 4:1 ratio. To determine an effect of freeze-drying conditions on bacterial survival and metabolic activity, complete two-factor, three-level experiments were developed and conducted. Two strains of the species Lactiplantibacillus plantarum from the VNIIMS collection, which are used in bacterial starter cultures for cheeses, were studied as representative microorganisms of lactobacilli. The results of assessing the viability of bacteria after lyophilization showed that both cryoprotectors increased the survival of cultures under all freezing conditions, but the best survival rates were obtained using trehalose. Strain-dependent effectiveness of lyophilization of the studied strains was established: in strain Lactiplantibacillus plantarum 28, the maximum survival was at a freezing temperature of –30 °C, in strain Lactiplantibacillus plantarum 37 — at a temperature of –55 °C with the addition of cryoprotector trehalose to both strains. Pre-freezing at –20 °C, also with trehalose, was the best method for preserving the metabolic activity of both cultures. It was shown that the greatest effectiveness of sucrose and trehalose as lyoprotectants during freeze-drying for both bacterial strains was found within the same pre-freezing temperature range of –30 °C. The identified strain-dependent effectiveness of lyophilization should be considered when selecting drying regimens for various collection cultures intended for long-term storage and requires an individual approach for each culture. The obtained results can also be used in freeze-drying of bacterial mass for the production of single-species bacterial starter cultures.

The aim of the work was to produce and assess properties of biodegradable antimicrobial films based on potato starch, glycerin and lactic acid as functional additives for food packaging. Films were produced by the casting method from the solution: 2 % (w/v) starch dispersion was gelatinized (70 ± 1 °C, 30 min), glycerin (0.4 %) and lactic acid (1.0 %) were added, the mixture was degased, poured and dried (60 °C, 24 h), and then conditioned (48 h, 23 ± 2 °C). Thickness, mechanical and barrier properties as well as the antimicrobial activity were measured. The antimicrobial activity was determined by the disc diffusion method on the LB nutrient medium with Escherichia coli and Bacillus subtilis as test cultures, 30 µg tetracycline as a positive control and sterile filter paper disc as a negative control (comparison with free lactic acid). The films obtained were optically homogeneous, without macro defects, and had a thickness of 0.09–0.11 mm. Films demonstrated high tensile strength of 74.8 ± 7.4 MPa and elongation of 23.7 ± 4.6 % (n = 10). Water vapor transmission rate was 1290.7 ± 60.8 g · m^–2 · day, vapor permeability coefficient was 2.05 ´ 10^–4 g · m · m^–2 · day^–1 · Pa^–1 (90 % relative humidity of air). With that, in dry conditions (relative humidity of about 0 %), quite low gas permeability in terms of O₂/CO₂ was recorded (lower than the threshold of the calculation of the stationary permeability). Analysis of the antimicrobial activity by the disc diffusion method showed that the films formed inhibition zones (E. coli: 10.67 ± 1.53 mm; B. subtilis: 10.67 ± 0.58 mm) that were comparable with free lactic acid (9.67 ± 0.58 and 12.00 ± 1.00 mm, respectively). The combined results confirm that starch films with lactic acid have high barrier properties (in the dry phase) and antimicrobial activity (upon contact with the moist surface), which make them promising for using as active packaging for chilled meat and dairy products and as a functional layer in multi-layer films.

Diet-related noncommunicable diseases (NCDs) are a major global health problem. One of the main strategies for NCDs prevention is an increase in a range of available food products, including flour confectionery, with the beneficial nutrient profile. In this paper the character of structure formation in foam-like emulsions for muffins was investigated. The properties of emulsions determine quality of finished products. The recipe composition of muffins was modified by reducing added sugar and fat and incorporating whole and skim milk powders and whey powder. The incorporation of these powders caused an increase in the viscosity of emulsions. The emulsion with whole milk powder had the highest viscosity of undisturbed structure (162.8 ± 8.1 Pa · s), which was 4.5 times higher than that in the control sample (36.1 ± 1.8 Pa · s). The main decrease in viscosity of all samples was noticed at low ranges of shear rate (up to g = 3 s–1), that pointed to low structure strength of emulsions. The values of the dynamic yield strength for all emulsions with powdered raw materials exceeded the value in the control sample (22.4 ± 1.1 Pa). This indicated a change in the flow behavior of the modified systems due to the formation of stronger structural properties. In this study, the rheological model of flow for the samples of emulsions with the modified composition and the control sample was determined and mathematical equations of this process were obtained. It was found that the use of dry milk products and whey powder, and the developed techniques ensured the formation of the necessary amount of structure-forming air phase in the food system. Density of the experimental samples changed insignificantly compared to the control (590 ± 5.3 kg/m3) and was higher than this value in the control by 2 % in the emulsion with whole milk powder (600 ± 5.6 kg/m3), by 3 % — with skim milk powder (610 ± 5.5 kg/m3) and by 5 % — with whey powder (620 ± 5.6 kg/m3). The research results form the basis for the development of technology for muffins with the reduced content of the critically important ingredients according to the principles of healthy nutrition.

Biologically active substances (BAS) of plant origin play a key role in the development of functional foods, bio-additives and medicines. Their use, however, is restricted by difficulties in extraction and low stability. This paper is devoted to investigation of the structure, characteristics and biological impact of the main BAS classes — phenolic compounds, among which flavonoids, stilbenes and lignans stand out. Their role as potent antioxidants and anti-inflammatory agents, as well as their effect on the health of the cardiovascular system, is emphasized. The review covers both traditional and modern methods for extraction of biologically active components from plants, such as maceration, distillation, extraction by the Soxhlet method, ultrasound, microwave and supercritical technologies of extraction. The authors describe in detail spectrophotometric methods DPPH, ABTS, as well as fluorescent method ORAC and its improved version ORAC-SIA, intended for the assessment of the total antioxidant capacity of individual compounds and their combination upon the physiologically relevant values of the acidity of the environment. The results of the study demonstrate the dependency of the BAS yield on the solvent type, hydromodule and a degree of comminution of raw materials. Extraction parameters such as temperature, pressure and pH significantly affect the preservation of thermolabile compounds. It has been found that modification of the structure of cyclotides increases the bioavailability of peptide preparations by 1.5–2 times. Analytical methods like ORAC and its modification ORAC-SIA allows for assessing the antioxidant activity of BAS in complex mixtures including food products. Based on the performed analysis, the conclusions were made regarding the need for optimization of “green” extraction methods, development of the standardized protocols of analysis and in-depth study of the interrelation “structure–activity” for targeted design of BAS.

For the production of high-quality sparkling wines it is necessary to use pure yeast culture of Saccharomyces cerevisiae species, which is able to ferment sugars at elevated CO₂ pressure and is characterized by cold and alcohol resistance. Technological properties of the yeast should be preserved regardless of the storage conditions of the culture. The aim of the research was to study the physicochemical and organoleptic properties of sparkling wines produced from white Muscat grapes using yeast strains ‘Sevastopolskaya 23’ (I-525) and ‘Leningradskaya’ (I-307) stored in the collection of microorganisms of winemaking "Magarach" by subcultivation and cryopreservation. The study used generally accepted methods of microbiology and enochemistry of wine. As a result of the studies, no significant influence of the storage conditions of the yeast cultures on their morphological and cultural characteristics was revealed. The strains retained their cell shape and size, unchanged sediment character, strain phenotype, ability to form a ring and spores. No significant differences were found in the process of must fermentation at 26 ± 1 °С using the studied strains. At the same time, fermentation with the strain I-525 was smooth, and with the strain I-307 — stepwise. Stable resistance of the studied yeast strains to changes in some abiotic factors was found. Fermentation of must at a temperature of 15–18 °C with the strain I-525 was much faster (5–21 days) than with I-307. The sparkling wine samples obtained with the yeast strain I-307 were characterized by higher CO₂ pressure (by 9–21 %) and content of bound forms of CO₂ (by 18.5–20.3 %), as well as by the value of the coefficient of sparkling properties (K>100) and better foam stability (more than 60 s). The method of storing yeast cultures by cryopreservation ensures the preservation of their basic morphological, cultural and technological properties at low labor costs, which makes it advisable to use it for long-term storage of microorganisms.

In light of the deteriorating environmental situation, the search for phytogenic resources with radioprotective and antioxidant properties has become increasingly relevant for the food industry. Certain fruit crops are rich sources of biologically active compounds (BACs). The plants of particular interest are those that accumulate these compounds not only in their fruit, but also in other parts such as seeds and leaves. Representatives of the genus Chaenomeles Lindl. may represent a promising crop for agriculture, the food and pharmaceutical industries in Russia. Although Chaenomeles is mainly cultivated for its fruit production, there are other potential applications that are worth noting. This review examines the biological characteristics, breeding, and biochemical composition of different parts of Chaenomeles species. The most suitable species for cultivation in the Russian Federation include C. japonica, C. speciosa, C. × superba, and C. cathayensis. The paper provides an overview of Chaenomeles cultivars developed by major Russian breeding centers, such as the Nikitsky Botanical Gardens — National Scientific Center (NBS-NSC) and Michurinsk State Agrarian University. Both domestic and international studies on the biochemical composition of Chaenomeles fruits, leaves, and seeds are analyzed. The content of major antioxidant compounds (vitamin C and polyphenols), as well as other bioactive substances, in various plant parts is described. According to literature data, the highest vitamin C concentrations are found in the fruits of C. speciosa and С. cathayensis. All parts of the plant contain chlorogenic acid and polyphenols in varying concentrations. Among the studied species, C. japonica and C. speciosa are the most thoroughly investigated, whereas C. cathayensis remains insufficiently studied.

Lactic acid bacteria of the Lactobacillaceae family play a key role in the food, chemical, agricultural, cosmetic and pharmaceutical industries as the main producer of lactic acid. The main success in production of lactic acid is achieved due to introduction of genetic engineering methods and precision fermentation aimed at the control of synthesis of individual optically clean L/D-isomers and utilization of certain components of sugar-containing substrates of nutrient media. At the same time, bacteria Lactobacillaceae have several natural evolutionary advantages that ensure success of their industrial use, including high acid resistance, productivity and safety. Lactobacillus delbrueckii, L. amylovorus, L. acidophilus, Lacticaseibacillus сasei, L. paracasei, Lactiplantibacillus plantarum and some others can be mentioned as the most promising strains — producers of lactic acid in natural conditions. Productivity of strains to a large extend depends on their ability to ferment specific substrates, first of all, different carbohydrate sources. The use of wastes of the food, agricultural and timber industries as substrates for largescale production of lactic acid is of particular scientific and practical interest. This approach makes it possible to significantly reduce expenses on complex nutrient media and cut production costs. The understanding of the main strategies of substrate utilization by various representatives of Lactobacillaceae allows for a more specific choice of a strain. In this review, the main attention is given to the key peculiarities of fermentation of L. сasei, L. delbrueckii, L. plantarum, and L. acidophilus strains with account for their phylogenetic characteristics and metabolic features. The paper examines the central mechanisms of the utilization of carbohydrates, substrate-specific activation of alternative pathways of metabolism, as well as key genes and their patterns associated with lactic acid synthesis. The authors describe the Embden–Meyerhof–Parnas metabolic pathway, pentose phosphate and phosphoketolase pathways, mechanism of carbon catabolite repression and the role of the Leloir pathway. The role of the key enzymes participating in the process of substrate utilization and formation of lactic acid, including lactate dehydrogenase, lactate racemase, aldolase, citrate lyase and others, is demonstrated.

Consumer interest in high-quality food is growing, especially in functional products. Milk and dairy products are high-nutrient sources that are often enriched with additives to enhance their bioactivity. However, dairy products such as yogurt can be prone to defects, including syneresis. The main components of yogurt, including protein (casein and whey), carbohydrates (lactose), milk fat, calcium, and lactic acid, play a crucial role in the formation and stability of the gel structure. Processing factors, such as heat treatment, temperature, and duration of storage, also affect the physical stability of the product. Generally, additives are used to maintain quality and sensory characteristics, but overconsumption of food with synthetic additives can negatively affect health. Therefore, the use of natural ingredients needs to be developed. Purple sweet potato flour is a natural ingredient that can serve as a stabilizer due to its high starch content. Starch has been widely used as a thickener, stabilizer, and gel former. In addition to starch, purple sweet potato flour contains anthocyanins that can increase the added value of the final product. This article aims to examine the potential use of the purple sweet potato as a nutrient-rich natural stabilizer.

Representatives of the genus Lactococcus are one of the key starter microorganisms in the dairy industry. They play a leading role in lactic acid fermentation in the production of fermented dairy products and cheeses. The article presents the results of a differentiated assessment of the enzymatic activity of nine strains of Lactococcus lactis subsp. lactis in milk at a cultivation temperature of (30 ± 1) °C, as well as during cooling and storage at a temperature of (6 ± 1) °C for 21 days. All studied parameters of acid formation (an increase in titratable acidity during fermentation and storage) demonstrated statistically significant differences between the strains (ANOVA, P < 0.05). The most pronounced variability of the strains was observed in their ability to acidify milk during storage: a decrease in the actual acidity over 21 days ranged from 0.19 to 0.49 pH units. This may be due to their genetic differences in enzymatic activity and resistance to low temperatures, which requires further study. The highest activity at (30 ± 1) °C was observed in four strains (663–12, 792–7, 618–5 and 549–1), which increased the titratable acidity of milk by 69–70 °T. Three of these strains (792–7, 618–5, and 549–1) slowly accumulated acid during storage, increasing the acidity by 4.7–7.3 °T over 21 days. Strains 637–4 and 429–6 showed a low fermentation rate at optimal temperature (an increase in acidity was 56.7 and 54.3 °T, respectively), but a high one during storage (an increase in acidity was 18.3 and 16.7 °T, respectively). Cluster analysis by the Ward method and the Euclidean distance metric performed in the R4.3.1 software environment allowed us to divide the studied L. lactis cultures into three groups according to the nature of the enzymatic profile at the temperature of active fermentation and under the storage conditions. The isolated clusters represent various metabolic profiles that determine the potential use of strains in technological processes. The results obtained indicate that for a comprehensive assessment of the acid-forming activity of cultures when selecting them for using in the composition of starter cultures of direct application for fermented dairy products and cheeses, it is necessary to study both the rate of acid formation and the post-enzymatic potential.

This study aimed to develop a nutritionally enhanced strawberry jam by partially replacing sugar with psyllium husk, a functional dietary fiber known for its water-binding and gel-forming capabilities. Three reduced-sugar formulations (Trials 1–3) containing 25 % psyllium husk solution and varying sugar concentrations (12 %, 26 %, and 30 %) were compared to a traditional control jam (66 % Brix). The impact of psyllium inclusion on the physical, chemical, microbiological, and sensory properties of the jams was evaluated. Sensory analysis was performed by a trained panel of 20 consumers using a 9-point hedonic scale to assess appearance, flavor, odor, spreadability, and overall acceptability. Results showed that psyllium-enriched formulations had significantly lower Brix, total carbohydrates, ash content, and estimated caloric values, while fiber content increased up to 1.05 g/100 g. The pH of all samples remained below 3.0, ensuring microbial safety, with total plate counts <1.0 log CFU/g across all treatments. Instrumental color analysis indicated improved lightness and redness in fiber-enriched samples. Among the tested samples, Trial 3 (30 % sugar, 25 % psyllium husk solution) achieved the highest sensory scores and reached a final Brix value of 63 %, making it the most acceptable formulation. These findings demonstrate that psyllium husk can successfully replace part of sugar while enhancing nutritional value, texture, and palatability. The optimized formulation shows promising potential for commercial application in producing healthier, low-calorie fruit preserves.

Squalene is a carbon-containing organic compound of the triterpene series. It is a precursor of many vitamins, hormones and sterols in a body of mammals, plants, fungi and bacteria. The purpose of this scientific literature review was to systematize data on the physicochemical properties of squalene, sources and methods of its production, as well as to reveal the advantages of using squalene in the formulations of modern functional foods and nutrients. Squalene is easily oxidized by molecular oxygen, as a result of which double bonds are converted into an oxidized form by the chain reactions in which Pi-bonds or π-bonds (unsaturated carbon atoms) are broken and active oxygen radicals are attached to them; as a result saturated forms of the molecule are produced. Squalene is especially abundant in vegetable oils of olive, amaranth, palm, as well as in lupine bean and rice germ oils. Squalene is involved in the biosynthesis of phytosterol, cholesterol, and vitamin D; it protects human skin from UV radiation and other oxidative effects, regulates the cardiovascular system, has the ability to capture free radicals and bind toxic compounds and carcinogens. In the case of using exogenous squalene, it is possible to slow down the growth of tumor cells and reduce the negative impact of oxidative stress. This study presents the main physicochemical properties of natural squalene, provides information on various sources and various strategies for obtaining squalene. The article discusses the therapeutic potential of squalene and the prospects for its application in the formulation of modern functional food products and nutrients. This study will contribute to the search process for new research directions in the field of obtaining squalene from plant raw materials, bacteria, fungi, microalgae, and will also serve as a potential for the development of strategies for increasing the stability and bioavailability of squalene, as well as the development of engineering approaches to large-scale production of functional foods and nutrients based on squalene.

The growing demand for improved food safety has fueled significant interest in antimicrobial polymeric coatings for food contact surfaces. This review offers a thorough examination of various antimicrobial coatings, including natural biopolymerbased, synthetic, and hybrid composites, spotlighting their modes of action and effectiveness in combating microbial contamination. It explores key antimicrobial agents such as metal-based compounds, natural antimicrobials, and synthetic chemicals, discussing their unique properties and potential applications. Equally, the review evaluates different testing methods for antimicrobial efficacy and identifies critical performance factors, including environmental conditions, surface properties, and the type of microbial contaminants. The hurdles and limitations of these coatings are also addressed, including concerns about durability, health and environmental impacts, and economic viability. Through detailed case studies, this review synthesizes current knowledge and offers insights into future research, with a particular focus on biodegradable polymers and innovative natural antimicrobials. The findings emphasize the potential of antimicrobial coatings to enhance food safety and inform the development of sustainable food packaging technologies, supporting advancements in health-conscious and environmentally friendly industrial applications.

In modern conditions, assurance of the global and national food security is becoming a high-priority task that requires a complex approach to the development of the agro-industrial complex. The research is devoted to the analysis of the modern trends influencing the achievement of the key sustainable development goals, in particular SDG 2 (Zero Hunger), SDG (Good Health and Well-Being), SDG 9 (Industry, Innovation and Infrastructure) and SDG 13 (Climate Action). The aim of the study was to develop directions of increasing sustainability of food systems, especially in the segment of meat product production through introduction of the sustainable development principles and ESG practices. During the study, the following methods were used: development of a specialized questionnaire to assess the introduction of the ESG principles; expert monitoring of enterprises of the meat industry; analysis of the implementation of the sustainable development goals; assessment of the existing ESG practices. The results of the study include systematization of modern approaches to sustainable development in the meat industry, determination of the current state of introduction of ESG principles at enterprises; detection of the main barriers and challenges in introduction of the sustainable practices; formation of recommendations on an increase in efficiency of implementation of the sustainable development goals. The scientific novelty resides in the complex approach to assessment of food system sustainability with account for special features of the meat industry and current global challenges. Practical significance of the study consists in the opportunity of using the obtained results to improve management decisions in the sphere of sustainable development of meat industry enterprises as well as to develop strategies for enhancing their competitiveness in the conditions of the growing ecological and social responsibility of business. The results of the study can be useful to specialists in the area of food industry, representatives of governing bodies of the agro-industrial complex, researchers and everyone who is interested in the development of sustainable practices in the agro-industrial sector.

Milk proteins are valuable raw materials for obtaining protein hydrolysates and active peptides formed during hydrolysis. Various proteolytic enzymes and bacteria are most often used for hydrolysis. Important parameters for regulating the degree of protein hydrolysis are duration, temperature of hydrolysis and concentration of a biological agent. The aim of the study was to establish optimum parameters for casein hydrolysis with chymotrypsin and bacterial starter of acidophilus bacillus. A three-factor experiment was used to determine optimum conditions for the hydrolysis process. Three factors were varied during the experiment: hydrolysis time (from 6 to 26 h) with a step of 10 h; temperature (from 32 to 42 °C) with a step of 5 °C; starter amount (from 0.5 to 1.5 %) with a step of 0.5 %. The dependent variable was the degree of hydrolysis. The content of total nitrogen in casein was determined by the Kjeldahl method, and that of amine nitrogen was determined by formol titration. The influence of independent variables on the dependent variable was analyzed using MathCAD, where response surfaces were also constructed. For the obtained multiple regression equations, the authors determined the reliability of the equation by the determination coefficient (R2) and Fisher’s criterion (Fkr), and the statistical significance of the parameters of the multiple regression equation by the Student’s criterion (t). Two regression equations were obtained for the process of casein hydrolysis with chymotrypsin and bacterial starter. Determination coefficients were established, confirming the high significance of the models. Response surfaces were constructed showing the dependence of the hydrolysis degree on the hydrolysis parameters. The optimum parameters of hydrolysis with the enzyme chymotrypsin and acidophilus starter were established. For example, when using chymotrypsin with a hydrolysis duration of 21.99 h, a temperature of 43.3 °C, and an enzyme amount of 0.02 %, the hydrolysis degree will be 28.6 % and when using acidophilus starter with a hydrolysis duration of 31.1 h, a temperature of 35.8 °C, and an amount of starter of 1.5 %, the hydrolysis degree will be 17.33 %.) Thus, the results of the multifactorial experiment made it possible to establish the optimum hydrolysis parameters for obtaining casein hydrolysates with chymotrypsin and acidophilus starter.

Ten samples of Atlantic salmon (Salmo salar L.) caught in the Mezen River in the Mezensky District of the Arkhangelsk Region were prepared by the methods traditional for this place: cooking, frying, baking and salting. Methods for fish preparation, utensils and auxiliary materials were chosen based on the data of survey of the local population. The study assessed experimentally an effect of four methods of culinary processing on the concentration of six elements in the fish fillet: mercury (Hg), arsenic (As), lead (Pb), cadmium (Cd), zinc (Zn) and copper (Cu). Analysis of the results of the experiment demonstrates changes in all six elements in the Atlantic salmon fillet upon culinary processing irrespective of the chosen method, although each method affected these indicators in different degrees. As a result of the study, it has been established that the cooking process led to a decrease in the level of mercury and arsenic in Atlantic salmon in the highest degree. This method of fish preparation is also preferable for the maximum preservation of essential elements — zinc and copper. With that, arsenic and lead are drawn into the broth during cooking. It has been shown that it is best to salt Atlantic salmon to reduce a concentration of cadmium. Salting also demonstrated a significant reduction in the levels of mercury in the fish fillet. However, salting also reduces the concentration of essential zinc and copper. Frying and baking demonstrated the similar effect on changes in the levels of cadmium and copper. It has been confirmed that fish preparation at a high temperature (frying, baking) facilitates a decrease in the levels of essential zinc and copper.