Studies of water bodies near MSW landfills are usually limited to hydrochemical parameters. However, since hydrochemical parameters are subject to frequent variability, and the negative effects of MSW landfills can occur over a long period of time, it is necessary to use the most "constant" indicators. It is proposed to expand the list of the studied parameters at the expense of hydrobiological ones, since hydrobionts are good bioindicators of the environment, and the use of various indices makes it possible to more accurately determine the nature and consequences of pollution by filtration waters of MSW landfills of water bodies. The article presents the results of a qualitative and quantitative study of zooplankton and zoobenthos from three water bodies (one background and two likely to be adversely affected) as part of the environmental monitoring of the impact of the Kaliningrad MSW landfill on aquatic ecosystems. The qualitative composition of zooplankton and zoobenthos revealed typical representatives for this area, mostly eutrophic organisms. An assessment of the contamination of the studied water bodies has also been carried out using the Pantle-Bucca method of indicator organisms modified by Sladechek, which is quite simple and often used in application. The calculations have made it possible to identify the state of aquatic ecosystems, in which water bodies retain high species diversity and biomass of zooplankton and zoobenthos. The studied water bodies, according to the gradation, can be characterized as "medium pollution". The most "polluted" is the nearest water body to the MSW landfill (a second-hand pond 400 m from the landfill), which is essentially a "buffer zone" between the MSW landfill and the Kaliningrad Bay. 

The Pechora River is one of the largest rivers in the European part of Russia. It plays an important role in maintaining ichthyofauna biodiversity. Being highly sensitive to the quality of habitat conditions, whitefish species are subject to severe negative effects with an increase in anthropogenic pressure on aquatic ecosystems from the resource industry, as well as selective trapping during fishing. The purpose of this study is to assess the spawning part of the whitefish (Coregonus lavaretus L.) population in the lower reaches of the Pechora River in the autumn of 2024 with an analysis of the influence of some abiotic factors on its reproduction. The biological parameters of 106 whitefish individuals have been analyzed, including the size and age structure, sexual composition, and stages of gonad maturity. In catches, the predominance of males (67%) over females (33%) has been established, as well as the dominance of individuals by age 5+ – 6+ years (78,2%). High water temperatures (up to 12,2 °C in September) are a factor affecting spawning time, as evidenced by the predominance of fish with stage III gonad maturity (53%). However, correlation analysis has not revealed a significant relationship between water temperature and catch rates (R² = 0,04). Catches per effort in 2024 amounted to 0,88 specimens/alloy, which is lower than the average for the last 3 years (2,07 specimens/alloy), however, the catch per effort, expressed in kg per alloy, remains stable (0,46 kg/alloy) and remains at the level of the average annual value of 0,45 kg/alloy. The data obtained confirms the need for further monitoring to assess the state of the whitefish population under anthropogenic influence. 

Lake Vishtynetskoye is the largest and deepest lake in the Kaliningrad region, and it is a part of the Vishtynetsky Nature Park. According to the hydrochemical indicators, the lake is classified as oligotrophic with some mesotrophic characteristics in the coastal areas. The purpose of our study was to determine the species composition of the heterotrophic microbial communities in Lake Vishtynetskoe and to identify the physiological groups of bacteria involved in the transformation of organic compounds. The material of the research was heterotrophic bacterioplankton from Lake Vishtynetsky in June 2022-2023. During the study period, the average number of heterotrophic bacteria did not exceed 0,7× 10³ CFU/ml, which is typical for oligotrophic water bodies. No clear differences in the number of heterotrophs between the years of the study were found. Changes in the number of heterotrophs at the sampling stations, with the highest microbial number in the shallow, well-heated areas of the lake and the lowest in the deep-water zones were revealed. We also found a similar pattern of fluctuations in the number of heterotrophs depending on the water temperature at the observation stations. In the microbial communities of Lake Vishtynetsky, there are species of bacteria that actively ferment carbohydrates, break down proteins, and reduce nitrates to form molecular nitrogen. The abundance of bacteria that decompose a wide range of carbohydrates and the polyatomic alcohol mannitol is significant. Rod shape bacteria as Aeromonas, Enterobacter, Bacillus, Pseudomonas, coccus bacteria as Staphylococcus, Sarcina were in water microflora. The uniformity of the microbial community structure and its biochemical activity indicate the self-purification processes in Lake Vishtynetskoe.

The article presents a biochemical analysis of cage aquaculture of rainbow trout contained in the Angara River that has been carried out for the first time. The tested individuals were kept in cages on the Angara River, within the city of Irkutsk, at a temperature of 12-15. We received the feed Appens GROWER EF in the amount of 2% of the fish weight. Determination of the LC content in extracts of the lipid fraction of fish tissues (white muscles) have been performed by gas chromatography with mass spectrometric and flame ionization detection methods. The interrelationships of the feed composition and the physiological and biochemical processes of growth and development of trout aquaculture have been revealed. Lipids of white muscles of mature Parasalmo mykiss individuals kept in cages of the coastal pelagic river have been studied. Docosahexaenoic and oleic acids dominated in the total lipids in the muscles of the studied individuals. The role of w-3 and w-6 fatty acids in the body of fish and their ratio has been discussed. The article considers the value of consuming rainbow trout as a source of polyunsaturated acids. A high content of physiologically significant ω-3 polyunsaturated fatty acids has been found in the muscles of rainbow trout from the Angara River cage aquaculture. It is indicated that it is better to use fish meat as full-fledged food than its fat. The data obtained characterize the fish studied as a high-quality aquaculture product containing a high percentage of essential fatty acids against the background of a good adaptation of fish to the conditions of their maintenance, including feed.

The structural and mechanical characteristics of minced fish washed with an electrically activated sodium chloride solution after its enrichment with preemulsified krill oil have been determined using penetration and organoleptic methods. Comparative data are presented on carotenoid losses during heat treatment of molded food products from washed minced fish for krill oil emulsions based on sodium caseinate (CE), lecithin (LE) and their composition (CLE). The study of samples after cooking has showed that as a result of heat treatment, a decrease in carotenoid losses is observed in all samples, with the best effect achieved for CE. The highest value of the yield stress (YS) before freezing has been noted for semi-finished products made from minced fish washed with an electrically activated solution with the addition of CE (6950 Pa), however, a rather crumbly consistency has been noted. The best ratio of rheological and organoleptic characteristics before freezing has been observed in washed minced fish with the addition of CLE, while the YS of minced fish washed with an electrically activated solution is 5000 Pa, which is more than 2 times higher than the same indicator in samples of unwashed minced fish (2350 Pa). After defrosting, the use of CLE allowed maintaining the required level of organoleptic characteristics of raw products: plasticity and the absence of a crumbly structure. It has been suggested that sodium caseinate apparently promotes the formation of stable, fairly viscous emulsion structures in which the protein shells of oil droplets themselves are capable of copolymerizing or mechanically intertwining with the main myosin protein network. 

Mayonnaise products are in great demand among the Russian population, and the mayonnaise market has been showing steady growth over the past decade. In accordance with current trends in healthy eating, consumers are asking for low-calorie products enriched with healthy nutrients. Since mayonnaise and mayonnaise sauces contain a large amount of oil, the main direction of developing healthy food products is to change the fatty acid composition of sauces and ensure a balance of fatty acids by increasing the omega-3 content. For these purposes, fish oil can be used, introduced as a substitute for traditional vegetable oils. The aim of the work was to develop a cardioprotective emulsion sauce with a balanced fatty acid composition, stabilized with plant components. Using the mathematical modeling method, the recipe for the sauce has been optimized, optimal dosages of vegetable components (carrot puree and blackcurrant puree) have been established in its composition. Carrot puree in the amount of 10.4 % by weight of the finished product and blackcurrant puree 16.7% ensure the stability of the emulsion based on sunflower oil and fish oil and the favorable flavor and aromatic properties of the sauce. The organoleptic and physico-chemical quality parameters of the sauce have been described, which is a homogeneous sour cream-like product of purple color, with a distinct fish and berry-vegetable flavor and odor. The developed product contains 43.72% fat, which corresponds to the fat content of products in the category of mayonnaise sauces. During 30 days, there has been no increase in the amount of yeast, molds, and E. coli bacteria in the product, and QMAFAnM has not exceeded 15 CFU/g. The sauce is characterized by a lower calorie content in comparison with classic mayonnaise, it is a source of cardioprotective components: omega-3 fatty acids, lecithin. 

The use of food additives of various functionality is currently one of the main strategies of the confectionery industry, while during the heat treatment of the raw mass, substances undergo structural transformations of various nature. The study of such transformations allows for the targeted regulation of the parameters of technological processes, and therefore, this paper presents the results of studies of polymorphic transformations of D-mannitol (food additive E421) during thermostating at a temperature of 180 °C in a time interval of up to 3 hours using UV-electronic and IR-vibrational spectroscopy. Analysis of the vibrational spectra shows the presence of the initial commercial D-mannitol preparation in the form of the most thermodynamically favorable β-modification, whereas all the thermostatted solid phases are represented by α-modifications. The latter is reliably confirmed by the study of the IR spectral profiles of both the mid-frequency (900–1800 cm^-1) and high-frequency (2800–3000 cm^-1) regions. At the same time, the absence of intensive bands in the region of 1650–1800 cm¹ should be noted, which indicates the suppression of the processes of oxidative destruction of mannitol. The study of the dynamics of changes in solid phases melting points and profiles of their electronic spectra in the ultraviolet region shows an extremum   (174 °C) and a pronounced maximum at 260 nm for a sample that was thermostatted for 1.5 hours. It can be assumed that under these experimental conditions, chemical processes may occur in parallel with phase transitions, possibly involving dehydration and cyclization. These results are expected to serve as the basis for the development of a thermo-processing technology for polyols to produce combined food additives based on them under the conditions of elevated temperatures.

The article considers the issue of the correctness of the calculation of the bending of a rectangular rigid isotropic plate with a clamped perimeter under the action of a centrally applied concentrated force. It is shown that various sources devoted to the analysis of this calculation scheme offer different formulas for determining the maximum deflection at the plate center and the maximum value of the specific bending moment at the center of the long edge of the plate. Moreover, conventionally, the reference literature offers two types of calculation formulas for determining each of these quantities. A search has been conducted for various works and articles devoted to the issue considered in the article. Several sources have been found in which the sequence of solving the bending of these plates can be disclosed in detail, but these sources are deposited. An analysis of the dimensions of the calculation formulas and auxiliary calculation coefficients has been performed. Calculations have been performed for three different plates with a change in the aspect ratio. The correct calculation formula is selected based on a comparative analysis of the calculation results with the calculation of plates by the finite element method in the Fidesys software package. Within the framework of the considered calculation schemes, the error in determining the maximum deflection and the maximum value of the specific bending moment along the long side of the plate according to one group of formulas does not exceed 5 %, while according to another group of formulas, the calculation error reaches 75 %. The error in applying the calculation formulas for plate materials with a Poisson's ratio different from 0.3 has been determined.