The article is devoted to the analysis of scientific publications on the problem of accumulation and removal of mineral nitrogen (nitrate, ammonium, nitrite) in the conditions of the westernmost region of Russia. The article presents the stages of research development over the past 76 years (1949–2025). It has been found that interest in this issue is stipulated by the applied problems in the field of agrochemistry, agroecology, geoecology, and hydrology. Most of the in-depth research with a largescale coverage of the territory and an integrated approach was carried out at the end of the twentieth century in connection with the active development of the environmental field in science. The priority of a systematic approach in the organization of regional work belongs to the Center of agrochemical service "Kaliningrad". This allowed us to determine the level of nitrate nitrogen losses, which is significantly higher than in other regions of the zone of sod-podzolic soils of the European part of Russia. The reasons are the humid climate of the territory and drainage reclamation to improve the water-air regime of waterlogged soils. At the beginning of the 21st century, the relevance and demand for information on the migration of mineral nitrogen increased due to the introduction of intensive agricultural technologies and climate change. The lack of primary information on the impact of fertilizer volumes and the intensity of mineral nitrogen removal in the "soil – perched water / groundwater / drainage waters – drainage channel" on various types of agricultural land may cause errors in the modeling results. Currently, there is a need for systematic fundamental and applied regional research on the agrogeochemistry of mineral nitrogen due to its high mobility and physiological role for living components of ecosystems.

Currently, the study of the effect of eutrophication on the food preferences of fish is one of the foundations for understanding the processes of transformation of food chains in aquatic ecosystems. Ichthyocenoses play a key role in the dynamics of water body productivity. Changes in their qualitative and quantitative characteristics bear a significant influence on primary production and eutrophication of ecosystems. Vendace, as a plankton feeder, demonstrates high plasticity of the food spectrum, which reflects the environmental changes. In the context of increasing anthropogenic load and climate change, the study of vendace diet allows to assess the state of the ichthyocenosis and the rate of eutrophication of the lake. The ecosystem of lake Vishtynetskoye has undergone significant changes in the past few years, which is reflected not only in the state of the biota, but also affects the trophic relationships in it. Vendace of lake Vishtynetskoye, being valuable species, as in other water bodies of its range, sharply reacts to these changes, including a change in the food spectrum. At the same time, being mass plankton feeder, it can affect eutrophication processes and it can  be used as one of the objects in environmental biomanipulation. The food spectrum studies were conducted in summer 2022. The main components of vendace diet are cladocerans and copepods, as well as representatives of the zoobenthic community. The results showed that the diet of vendace is quite stable, but changeable due to some changes in temperature conditions and anthropogenic factors. These changes reflect transformations in the lake ecosystem associated with an increase in the flow of allochthonous substances and a change in the biochemical activity of the biota.

Involvement of the society in an active lifestyle and sports has led to an increased need for specialized sports nutrition. This market segment has long been dependent on imported supplies. The relevance of developing a domestic product is substantiated by a review of the range of modern sports nutrition. The purpose of this study was to substantiate the use of functional food additives from fruits and vegetables, unsuitable for food use due to external defects, in the technology of a drink intended for athletes in speed-strength sports. Additives of the VITUMIN series have obtained by fermentation of apples, oranges, bananas of low quality with subsequent sublimation of the water-soluble fraction of the fermentalizate. The components of the dry drink mix recipe (VITUMIN additive, whey protein concentrate, silicon dioxide, xanthan gum, sunflower lecithin) have been selected to ensure stabilization of the mixture in dry form and the formation of an emulsion consistency in diluted form. The optimal content of the main components of a protein-carbohydrate drink – the VITUMIN additive and whey protein – has been determined using mathematical modeling. The paper decribes the technological process of manufacturing a drink called BioCarb. The organoleptic properties of the drink in dry and dissolved form are characterized. The chemical composition of the product has been studied: protein content is 27.7%, carbohydrates are 54.4%. The energy and nutritional value of the drink has been determined, its functionality in terms of vitamin content (B₁, B₂, C, PP, P), and minerals (Na, K, Ca, Mg, P, Fe) has been found. Athletes are recommended to consume 190 g of the drink diluted in water or milk once during the training period and twice during the competition period. The quality and technological process of manufacturing the product are regulated in the developed technical documentation (TU and TI). 

This article reveals the importance of developing food products for people with gluten intolerance, whose number, according to various estimates, is up to 3% of the world's population. The  process of designing a recipe for gluten-free shortbread biscuits "Osenniy tsvetok" with a partial replacement of rice flour with carrot pomace powder, pumpkin pomace powder, pumpkin peel powder and lupine flour is described. Partial replacement of powdered sugar with dry milk whey (DMW) is proposed in order to compensate for the deficiency of complete animal proteins in the biscuit. The recipe of the experimental product is supplemented by replacing butter with sunflower oil, that eliminates the presence of saturated fatty acids and their trans isomers. The dosages of functional components have been determined using mathematical modeling methods: 5.1% carrot pomace powder, 4.8% pumpkin pomace powder, 5.4% pumpkin peel powder, 5.4% lupine flour, 44.0% DMW. Dough pieces have been formed by depositing and baked at 190–200 °C for 10–15 minutes. The organoleptic analysis data characterize the "Osenniy tsvetok" biscuits as products of predominantly regular shape, with pleasant color, smell and taste. Based on the calculated and experimental data on the chemical composition of the biscuit, it has been found that the product is enriched with dietary fiber (13.8% of the daily value), vitamin B₂ (14.5%), beta-carotene (15.3%) and vitamin E (56.7%), while it has an improved ratio of animal and vegetable protein (55:50) and its increased biological value (65.4%). It has also been found that individual physicochemical indicators of biscuit quality comply with the requirements of regulatory documentation. 

Vegetarianism, i.e. refusal of animal products, has become one of the popular types of nutrition lately. Animal products contain vitamins, micro- and macroelements necessary for maintaining the normal functioning of the human body. Vegetarians do not receive them due to the refusal to consume "animal" products. In particular, supporters of this type of nutrition suffer from the so-called "protein starvation". Nevertheless, the increase in demand for plant foods poses the challenge for researchers to create new products with increased nutritional value, as well as to expand their range on the market. Literature data on the chemical composition of some plant crops have been studied. The use of soybeans as the main raw material has been justified, since among other legumes they have the maximum protein yield and are most often used to isolate vegetable protein. The article proposes an improved recipe for tofu cheese, which will increase the range of vegetable cheese on the market for vegetarians, as well as those fasting and people with lactose intolerance. The coagulation process of the latter to obtain a protein product has been studied. The conditions of thermal acid coagulation have been analyzed using citric, acetic and lactic acids as an example to obtain cheese with positive organoleptic properties. The chemical composition of soybeans has been studied for the content of mass fraction of moisture, protein, fat, minerals and iron. A recipe for canned vegetables with tofu has been proposed, which is characterized by an increased content of calcium, iron and fiber. The article demonstrates a possibility of increasing the range of vegetarian products on the market and creating a functional food product. 

The paper presents scientifically substantiated solutions to expand the range of fish culinary products for preventive purposes. The culinary products have been produced on the basis of such fish raw material as pollock, which is the basis of catch in Russia, according to the studied statistical data. The preventive effect on the gastrointestinal tract has been achieved through the use of biologically active additive – zosterin – in concentrations from 1 to 8%, depending on the type of product. Zosterin is polygalactouronan of sea grass Zostera marina, collected in the Far East region of Russia and produced in the Moscow region. Functional properties of zosterin as a structure-forming agent of fish mince used in the production of fish culinary products such as nuggets and muffins have been substantiated. This additive will improve the moisture-holding capacity, and therefore the juiciness of minced meat, as well as the formability of products. In addition, it will increase the stability of products during transportation, as zosterin affects the strength of the product. As a result of the collected data on the study of organoleptic, physicochemical and rheological parameters the following types of products have been proposed: fish nuggets, cooked with the addition of 3% zosterin and gluten-free fish muffins with the ratio of fish and other ingredients, equal to 1:1, and with a concentration of zosterin 5%. The developed types of products can be a source of dietary fiber (content of dietary fiber not less than 3 g per 100 g for solid food products according to the requirements of the Technical Regulations), which will positively affect the normalization of the gastrointestinal tract. 

The relevance of the study is stipulated by the need to obtain reliable information on the mooring pull for fishing vessels, as well as for transport vessels involved in towing fishing boats both in the coastal zone and inland waters of the Russian Federation. The current state of the small fishing fleet is characterized by the presence of obsolete vessels that require constant repair and modernization. One of the key characteristics that determine the efficiency of a fishing vessel is its mooring pull, which affects the maneuverability and safety of the vessel in confined spaces. However, it should be noted that it is not always possible to accurately determine the mooring pull of a small vessel based solely on mathematical dependencies. This is due to the fact that the mathematical models include empirical coefficients obtained not for the entire range of characteristics of various types of fishing vessels, their engines and types of propellers. This circumstance significantly limits the possibilities of using the mathematical apparatus to justify the traction on the mooring lines of a small fishing vessel. The article presents approximate dependencies of the traction on the mooring lines for a small fishing vessel, which allows improving the accuracy of calculations and increasing the reliability of fleet operation. This technique can serve as a basis for further research in the field of optimizing the characteristics of the small fishing fleet and its renewal, which, in turn, will contribute to improving the overall efficiency of fisheries in the country.