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Experimental evaluation of toxic resistance of benthic microalgae Thalassiosira excentrica Cleve 1903 (Bacillariophyta) under the copper ions impactVestnik of MSTUWith an increase in anthropogenic pressure on the ecosystem of the coastal zones of the sea, the relevance of assessing the state of plankton and benthos communities also increases. In the course of the study, the dynamics of the number of cells of the clone culture Thalassiosira excentrica Cleve 1903 (Bacillariophyta) has been determined under the influence of CuSO4·5H2O of various concentrations (32–1024 µg·L–1) under the conditions of 10-day experiments. In the control and at a low concentration of Cu2+, the proportion of living cells remains almost unchanged. The threshold concentration of copper ions for the survival of T. excentrica is 128 µg·L–1. At higher concentrations of Cu2+ (256–1024 µg·L–1), a sharp inhibition and death of the culture has been noted already within 1–3 days. The increase in the absolute number of cells at low concentrations of copper (32–64 µg·L–1) is described by the sigmoid response curve of the test-object. The growth values increase by 4–8 times on the 1st–5th day and decrease by 25–30 % by the 10th day. At Cu2+ concentrations of 128–256 µg·L–1, there is no positive increase in the number of cells on days 1–5; on subsequent days, it decreases by 2 times or drops to zero. The intensity of the specific cell growth significantly decreases depending on the increase in the concentration of the toxicant. It has been found that on days 1–5, the specific increase is positive in the range of copper concentrations of 32–128 µg·L–1 and negative – at concentrations of 256 µg·L–1 and higher. In the period of 5–10 days, for all concentrations of the toxicant, the values of the specific increase are negative. The obtained results make it possible to recommend T. excentrica as a promising test object for toxicological experiments.
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Taxocene of polychaeta of the Laspi Bay water area (the Crimea, Black Sea)Vestnik of MSTUThe coastal zone of Laspi Bay (the Crimea, Black Sea) is attractive for the development of recreational activities. It can negatively affect the state of the bay ecosystem and adjacent waters. The aim of this study is to assess the current state of polychaetes inhabiting the loose soils of the littoral and sublittoral areas of Laspi Bay. In 2016–2019 the fauna of polychaetes was studied in the waters of Laspi Bay. Macrozoobenthos were collected on cruises 84, 86, 96, 108 aboard the research vessel Professor Vodyanitsky and in coastal expeditions. 89 samples were taken (19 deep-water, 70 coastal). 45 species of polychaetes were identified. The average abundance of Polychaeta was 2 368 ± 467 ind./m2. The average biomass was 44,128 ± 13,919 g/m2. Terebellides stroemii makes a significant contribution to the formation of these indicators. The ranked series by density index is headed by T. stroemii, Nephtys hombergii and Melinna palmata. The largest abundance of species is noted at a depth of 46 m where the soil is represented by sand and pebbles. The highest number is noted at depths of 93.5–98 m. Prionospio сirrifera makes the main contribution to the total number. The highest biomass is noted at depths of 53.5–58 m. T. stroemii makes the main contribution to the total biomass. In the Laspi Bay waters are recorded characteristic species – P. сirrifera and Micronephthys longicornis. They are found both in shallow waters and at great depths. Rare species found only at one station include 18 polychaete species. The results obtained give an idea of the taxonomic composition of polychaete worms in the waters of Laspi Bay and can be useful for further monitoring of this area.
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Programming of marine engineers' simulator trainingVestnik of MSTUContinuous improvement of the technical equipment of sea vessels is inevitably accompanied by the development and complication of the training base for marine specialists. Simulator training based on a computer model of operating the units of the liquefied natural gas tanker of the Veliky Novgorod type includes interactive computer programs for learning management, created using the e-Tutor computer module included in the simulator delivery set. In the course of systematizing the experience of using specialized programming tools for educational and research activities of students in organizing and conducting simulator training for electrical engineers on computer simulation models of sea vessels, a system of conventional graphic symbols for the elements of the flowchart of the training exercise program has been formed and their description has been given. Training and control exercises include familiarization with the mnemonic diagrams of the integrated marine vessel automation system and assessment of the state of the ship's electrical power system with their help, starting the propulsion electrical installation, providing energy to the operating propulsion electrical installation under load changes, switching on the backup diesel generator unit for parallel operation with the network in normal and emergency modes, acceleration of the vessel to the given speed in accordance with the tasks of the instructor. The advantages of training programming using the e-Tutor computer module are the ability to use the simulator in self-study mode with automated teaching support.
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Features of ensuring high-quality work of modern electrical power systems of unmanned vesselsVestnik of MSTUUnmanned seagoing vessels are increasingly being used. In the paper the dump scow Rabochaya is considered as an example of an unmanned vessel. An extended marine control system, a video surveillance subsystem, a surveillance and search engine are additionally installed on the scow to carry out industrial tasks in unmanned mode. The correct operation of these systems and the whole vessel depends on the high-quality operation of the ship's electrical power system. The aim of the study is to identify abnormal modes of parallel operation of marine diesel generator sets and to develop methods and means for their elimination. The results of the experimental research and mathematical modeling have revealed the existence of power exchange oscillations when the ship generators operating in parallel. Power exchange oscillations can be detected with the help of generator current oscillations. It has been proposed to introduce a unit for eliminating power exchange oscillations (EPEO) into the automatic control system of ship electrical power systems for eliminating such oscillations. An algorithm for the operation of the EPEO unit has been developed, it controls the settings of the rotational speed regulators of diesel-generator sets. The proposed methods and tools reduce the amplitude of power exchange oscillations to an acceptable value, and therefore contribute to the high-quality operation of the ship's electrical power system and control systems in unmanned mode. The results obtained make it possible to ensure reliable and trouble-free operation of any autonomous electrical power system during the operation mode without maintenance personnel.
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Application of the proportional navigation method in solving problems of navigationVestnik of MSTUThe development of methods and algorithms for ship control when maneuvering relative to a moving object and the creation of automated control systems based on these developments is an urgent task of navigation. The most optimal way to implement control of a moving object relative to another moving object is based on using the proportional navigation method. As applied to navigation problems, this method has been studied at the level of describing the kinematics of the movement of two points. The mathematical model provides for a preliminary calculation of the extrapolated ship coordinates. The construction of ship motion trajectories for any given proportionality factor is carried out taking into account the dynamics of the ship and makes it possible to obtain the law of rudder shift, as well as to predict changes in the process of maneuvering such ship parameters as angular velocity and drift angle. The proposed mathematical model can be used for algorithmic and software support for automated ship control systems when maneuvering relative to a moving object.
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Assessment and fishery of shellfish stocks in the Barents and White Seas in 2000–2020Vestnik of MSTUHydrobionts have a high nutritional value and are the most important component of the food supply for the population of Russia. In the course of the study, the characteristics of the stocks and fisheries of the king crab, opilio snow crab, northern shrimp, Icelandic scallop, sea green urchin and other commercial invertebrates in 2000–2020 are presented. The raw material base of the fishery of the king crab and snow crab is used in full; the indices of their commercial biomass are 215 and 430 thousand tons, respectively; development of TAC – more than 90 %. While maintaining the current management strategy, their commercial stocks will be at a stable level or increase. The commercial stock of the northern shrimp in the Barents Sea and adjacent waters is in a satisfactory condition (at the end of 2020 it was estimated at 2.2 million tons); the distribution density of shrimp in the Russian EEZ has halved. The resource base of the Icelandic scallop fishery in the Barents Sea is not exploited due to the depressive state of the stock: the median of commercial biomass is at the level of 200 thousand tons, which is below the boundary biomass target (224 thousand tons). The growth in the catch of the sea urchin is due to the increased interest of fishers in this object. The annual catch of the sea urchin does not exceed 10 % of the recommended one, fishing efforts are unevenly distributed over different parts of the Murman coast. Cucumaria, mussel, trumpeter, shrimp bear cub, clema, euphausiids are caught in small quantities and remain in the category of underutilized fishery objects.
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Investigation of the effect of structure-regulating additives on the properties of minced fish systemsVestnik of MSTUThe search for new effective structure-forming agents of natural origin in order to improve the technology of fish molded products is an urgent scientific and industrial problem. In the course of the study, to obtain minced fish systems, frozen pollock and pink salmon have been used that meet the technical requirements of the current regulatory documentation. Mixtures of cryoconcentrates from seafood, rice and wheat flour, and the enzyme transglutaminase are used as structure-regulating additives. Cryoconcentrates have been made from cucumaria, squid, Pacific herring milt, octopus skin, seaweed, and scallop mantle. The introduction of dry powdered cryoconcentrates of seafood, containing a significant amount of protein substances, has contributed to the binding of water and an increase in the water-retaining capacity of minced pink salmon and pollock. Based on the results of studying the physical, chemical, rheological and organoleptic properties of dispersed minced fish systems, rational amounts of structure-regulating additives have been established: seafood cryoconcentrates – 4.0–5.0 %; transglutaminase – 0.5 %; rice flour – 2.0 %; wheat flour – 1.0–2.0 %. Molded fish products (cutlets, sausages) containing structure-regulating additives had high organoleptic properties after heat treatment. The results of the research should be used in the development of formulations of fish dispersed compositions in the technologies of molded, emulsion and structured products. The established high water-binding capacity of seafood cryoconcentrates justifies the need to study them as natural cryoprotectors in refrigeration technologies.
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Analysis of complex changes in salmon salting by injection using the food additive PRE-LACKSVestnik of MSTUThe paper presents the results of a comprehensive assessment of the quality of delicacy fish products – salmon fillets of weak salt made using the food additive PRE-LACKS (LLC "Vash technologist", St. Petersburg, Russia) and curing by injection. For the first time, the influence of technological factors has been studied (the concentration of a food additive (in the range recommended by the manufacturer from 3 to 5 % with a step of 1 %), as well as the value of the hydromodulus (in the range from 5 to 20 % with a step of 5 %) characterizing the ratio of masses of the fillet introduced into the thickness when injecting brine and a salted fillet piece) on the formation of a complex indicator of the finished product quality. The developed scale for a comprehensive assessment of the quality (K) of lightly salted salmon fillet of injection salting is presented, including the main groups of indicators – organoleptic and rheological, nutritional value and physico-chemical. The scale includes weighting coefficients based on the results of experimental and sensory studies – both group and for each quality indicator taken into account. It has been shown that using the fuzzy logic method made it possible to obtain the values of the selected influencing factors optimized according to the criterion of achieving the maximum value of K (in the range from 0.9 to 1.0 conventional units, corresponding to the category "delicacy product") – the concentration of the food additive and the value of the hydromodulus – 4 and 15 %, respectively. The results of assessing the influence of selected technological factors on the yield of a semi-finished product immediately after salting by injection, on the yield of finished low-salted products (after ripening), on indicators characterizing the completeness of its maturation (buffering, the ratio of the mass fraction of non-protein nitrogen to the mass fraction of total nitrogen, total acidity, mass fraction of amine nitrogen) have been presented. Based on the results of the research, technological recommendations are formulated for salting salmon by injection using the PRE-LACKS food additive to increase the yield of finished products and improve its consumer properties.
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The role of rotifer in water quality improvement in a fishpondVestnik of MSTURotifers are common in fresh and brackish water bodies, in coastal areas of the seas, and can be an effective tool for analyzing the state of the environment. The ability of rotifers to adapt to unfavourable environmental conditions has been considered in the course of studying the species composition of rotifers in a fish pond near Moscow under the conditions of the supply of organic artificial food for fish and changes in the temperature regime of water. During the period of increased temperature of the water (21–25 °C) and decrease in the concentration of dissolved oxygen from the surface to the bottom layers of water from 3.8 to 0.2 mgO2/L in early July, Asplanchna priodonta helvetica, Brachionus angularis angularis and Brachionus calyciflorus dominated in the pond (98–100 % of the abundance and 99–100 % of the biomass of rotifers). During the period of elevated temperatures, the turbidity indices in the upper layer (0.2–0.5 m) were an order of magnitude lower than those in the deeper layers of the reservoir. Bacteria and tiny particles served as food for rotifers. The temperature of 18–25 °C was favourable for the development of B. angularis angularis in the fish pond. At a temperature of 18 °C, its abundance reached 1,500 ind./L (70 % of the abundance of rotifers). In August, when the temperature of the water column decreased from 20 to 18 °C, the biomass of A. priodonta helvetica changed from 0.3 to 9.5 mg/L (99 % of the biomass of rotifers). Polyarthra vulgaris dominated among small rotifers. During the period of low temperatures, the biomass of rotifers increased to 20 mg/L; its basis was A. priodonta helvetica. Rotifers are able to adapt to conditions of high organic input in a wide range of temperatures and participate in the restoration of water quality in a fish pond.
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Bycatch of marine mammals in the Northwest Atlantic during commercial fishery (based on literature materials and observations by the Polar branch of VNIRO in 2013–2020)Vestnik of MSTUThis paper describes one of the most acute problem for both environmental companies and fisheries – bycatch of marine mammals caused by bioresource exploitation in the Northwest Atlantic (NWA). There is no doubt that fishing has some impact on marine mammals, but information on bycatch of marine mammals is needed to understand the extent of the impact of different fishing gears. The paper is based on data from reports of observers of the Polar branch of VNIRO from fishing vessels in the 3LMNO NAFO zone (Newfoundland Island), as well as literary materials. As a result of the analysis, it has been found that small species of marine mammals, such as gray, common, harp seals from the Phocidae family, common dolphin, short-finned pilot whale (Delphinidae family) as well as harbour porpoise from the Phocoenidae family are most often injured by various fishing gears. Toothed whales (sperm whale, bottlenose whale) are the least susceptible to bycatch. Among the baleen whales, humpback whale, northern right whale and minke whale are often the victims of fishing. Gillnets, trawl fishing, and longlines are the greatest threats to small marine mammal species, while baleen whales are most vulnerable to traps, usually to catch ten-legged crustaceans Decapoda. Analysis of the literature has shown that, in general, the stocks of most marine mammal species in the NWA, excluding the northern right whale, are in a stable condition. The manuscript considers measures aimed at reducing bycatch of marine mammals.
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Changes in the smoltification age of Atlantic salmon (Salmo salar L.) of the Yokanga, Kharlovka and Vostochnaya Litsa Rivers (the Murmansk Region)Vestnik of MSTUThroughout the world, in recent decades, there has been a decrease in the abundance of Atlantic salmon, the main reason for which is a decrease in its survival rate during life at sea. Its value has a direct dependence on the length and, accordingly, the age of the smolts. Foreign researchers have found that the nature of long-term changes in the age structure of smolts can vary significantly by region. At the same time, the age of Atlantic salmon in Russian rivers, which account for a significant part of the area of the range of this species, was not considered. In this regard, the analysis of long-term data characterizing the age composition of salmon smolts of some rivers of the Murmansk region has been carried out. It has found been that in the first years of the period 2000–2018, the age structure of Atlantic salmon smolts was transformed in the rivers Yokanga, Kharlovka and Vostochnaya Litsa. As a result, fish at the age of 6 ceased to occur among them, the abundance of fish at the age of 5+ significantly decreased and the abundance of fish in the age groups of 3+ or 4+ significantly increased. The most likely reason for this is the change in the temperature regime of rivers since the mid-1990s, as a result of which the life time in the rivers of juvenile salmon has been reduced. Rejuvenation of the smolt population may have ambiguous consequences for the abundance of adult salmon, which are determined by the cumulative effect of reducing natural mortality at the stage from eggs to smolts, increasing their abundance and reducing their length, and reducing the survival rate during salmon life in the sea.
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Polychaeta fauna in the northeastern Barents SeaVestnik of MSTUThe northeast of the Barents Sea (the area between the Franz Josef Land and Novaya Zemlya archipelagos) is one of the little-studied areas characterized by a complex structure of the hydrological regime, bottom relief and bottom sediment structure. This area is characterized by the predominance of brown soils with a large number of foraminifera shells, which affects the species composition and structure of benthic communities. The species composition and quantitative characteristics of polychaetes in the northeastern part of the Barents Sea were analyzed on the basis of material collected in December 2019 during Murmansk Marine Biological Iinstitution expeditions on the r/v Dalnie Zelentsy. Faunal complexes of polychaetes have been identified in the study area depending on environmental conditions (type of bottom sediments, depth, hydrological conditions). In the areas of marginal troughs, the detritophagus Spiochaetopterus typicus dominates in terms of biomass and abundance, forming abundant settlements on soft silty-sandy, silty-clay soils. Low values of biomass and abundance have been noted on brown silts with a large number of foraminifera, dominated by Laonice cirrata. On the slopes of underwater hills, washed more strongly by bottom currents, on rough sandy soils with low nutrient content, the dominance of Nephtys ciliata has been noted. The species Sphaerodoridium kolchaki sp. n. recently encountered in the Barents Sea has been noted in the study area as well. The obtained data complement information on the species composition of the northeastern part of the Barents Sea and make it possible to trace further changes in the composition and structure of benthic communities.
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About terraces on the shore of the Teriberskaya Bay of the Barents Sea (the Kola Peninsula)Vestnik of MSTUThe paper considers the results of the study of modern terraces on the coast of the Lodeyny Peninsula in the Barents Sea. According to field observations, decoding of space and geodetic maps and volumetric modeling, signs of three terraces have been identified. Two terraces having a rear seam, a cliff, a brow and horizontal platforms have been studied in more detail. The rear seams are located at 7 and 30 m, and the edges at 10 and 40 m above the sea level. The third terrace is confined to the level of 40–60 m, and has not been studied in detail. According to estimates, the first two terraces were formed about 3,300 and 6,000 years ago respectively. The 1st terrace characterizes the period of slow land rise by 10 m, at the speed up to 3 mm/year, which began about 3,300 years ago and continues to the present. It is characterized by a uniform sea retreat of about 15 mm/year. The erosion products of this terrace are common in the lateral zone and represent modern marine sediments, including beaches forming a new terrace. The 2nd terrace characterizes to the dynamics of rapid land rise by 30 m at a speed of about 11 mm/year, which occurred in the period from 6,000 to 3,300 years ago. The erosion products of this terrace are most common on the coast and are found at a distance of 100 m to 2–3 km from the shore. It is assumed that the speed of movement of the coastline during the retreat of the sea was different and reached up to 900 mm/year. According to the authors, preliminary data indicate the instability of the territory and the manifestation of block movements, which may have a negative impact on the development of infrastructure.
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Development of flour confectionery products with reduced sugar contentVestnik of MSTUThe search for equivalent flavoring sugar substitutes of a non-sugar nature is an urgent direction in the development of the technology of flour confectionery products. In the course of research, a gingerbread recipe has been developed with a partial replacement of the prescription sugar with a 15 % solution of sucralose in glycerin, which most closely correspond to the organoleptic characteristics (taste, smell, texture) of traditional flour confectionery products. The results of the organoleptic evaluation of coded prototypes of gingerbread with the involvement of experts have shown that a decrease in sugar concentration by 25 % does not lead to a statistically significant change in organoleptic parameters in comparison with control samples. Substitution of more than 30 % sugar leads to an increase in the plasticity of the dough complicating the operation of the dosing mechanisms; at the same time, the taste of the products changes (these changes are noted during the tasting assessment); their consistency becomes denser. In the process of research, the stability of the quantitative and qualitative properties of gingerbread during storage has been proved. Experimental samples of gingerbread with 25 % reduced sugar content retain all the indicators established by GOST for their storage for 90 days without statistically significant changes. The decomposition of sucralose in the manufacture of the dough is 0.1 %, in the baking process – 2.6 %, during storage for 120 days – 6.7 % (of the loaded product). The developed recipe allows enterprises to expand the range of confectionery products with reduced sugar content.
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Specialized sports nutrition products using protein hydrolysis compositions of collagen-containing fish raw materialsVestnik of MSTUThe development of specialized sports nutrition with components of collagen-containing fish raw materials is due to the shortage of domestic products of this group, the problem of fish waste processing, scientific data on bioactive peptides of marine origin. Low-molecular active peptides and protein-mineral compositions in the form of powder and liquid dietary supplements were obtained from the scales of sardine and sardinella by methods of deep hydrolysis. During the hydrolysis of raw materials, fermentolysis was carried out with the Alcalase 2.5L enzyme, thermohydrolysis – at temperatures of 130–140 °C. The chemical composition of the scales of two fish species, the products of its hydrolysis, and the amino acid composition of its proteins have been studied. The amount of low-molecular-weight peptides in hydrolysates of sardine scales was investigated by various methods of hydrolysis. Rational methods of hydrolysis of scales – enzymatic and enzymatic-thermal – have been substantiated. They make it possible to obtain protein supplements with protein content of 83.9–85.2 % with a proportion of active peptides with a molecular weight of less than 10 kDa 91.7–98.1 %. A technology for obtaining protein supplements from fish scales has been developed, and their amino acid composition has been studied. The presence of irreplaceable and ergogenic amino acids, accompanying nitrogenous compounds, valuable in sports nutrition, was shown in the peptide supplement. An increased content of calcium, phosphorus and magnesium in the protein-mineral dietary supplement being important for the musculoskeletal tissues of an athlete has been established. On the basis of protein supplements in dry and liquid forms with the addition of beekeeping products, the technology of chewing marmalade for sports nutrition has been developed. Bioproduct "Apikolltonus" belongs to the class of gainers with a protein content of 20.5 %, a carbohydrate of 41.6 % with an amino acid value of BCAA (isoleucine : leucine : valine) 2 : 1 : 1.5. A multicomponent bar for sports nutrition has been developed using protein hydrolysates of scales, flaxseed and apple cakes, and pine nuts. The bar is functional in terms of the content of calcium and phosphorus, dietary fiber, flavonoids, and vitamin E. Recommendations for the use of new sports nutrition products are substantiated.
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Application of the linear method of discriminant analysis of reflectance spectra in the near infrared region for the species identification of fish of the Salmonidae familyVestnik of MSTUIt is well known that fish belonging to the Salmonidae family differ in their nutritional value. Anatomical and morphological features of different salmon species have a certain similarity; therefore, representatives of this family are most often falsified. Assortment falsification of products from fish of this family is usually carried out by replacing more valuable species with cheaper ones with a reduced nutritional value. Most often, counterfeiting of Atlantic salmon (salmon) by Far Eastern ones (chum salmon, pink salmon, chinook salmon, coho salmon) is found. Near infrared spectroscopy (NIR) is now increasingly used for identification and authentication of closely related organisms, in some cases being a rapid method replacing genetic analysis. We have obtained diffusion reflectance spectra of NIR radiation for three species of fish from the Northern Basin belonging to the salmon family. The best classification by fish species has been obtained by analyzing the NIR spectra of pre-dried fat-free muscle tissue samples. In case of wet samples, the observed differences are less significant, up to insignificant differences in individual values from neighboring clusters. The possibility of using the method of linear discriminant analysis of the NIR reflection spectra of muscle proteins for the species identification of fish has been shown.
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Investigation of the chemical composition of pumpkin pulp as a basis for soft drinksVestnik of MSTUPumpkin fruits (Cucurbita spp.) have a number of advantages and high technological potential, thanks to almost universal cultivation in a wide range of agro-climatic conditions, the ability to long-term storage, the content of dietary fibers, pectin and other polysaccharides, carotenoids, polyphenolic substances, vitamins, which cause a wide range of physiological orientation. In the process of researching the composition of local cultivars of pumpkin and the world experience of using Cucurbita spp. in the composition of food products, the need to use this ingredient in beverage recipes has been substantiated. The content of dry substances in the pumpkin samples is from 8.18 % ("Gribovskaya") to 11.6 % ("Orange bush"). The maximum sugar content is distinguished by the varieties "Winter Sweet" (6.87 %) and "Orange Bush" (7.40 %). The content of BAS-antioxidants is (without visible difference depending on the growing region): carotenoids from 1.3 mg/100 g in "Gribovskaya" to 2.0 mg/100 g – "Orange bush"; ascorbic acid – 8.7 mg/100 g in "Rossiyanka" to 14.2 mg/100 g – "Orange bush". Today all parts of the pumpkin fruit are used: the bark is a raw material for the production of feed flour and a substrate for the cultivation of lactobacilli, the seeds are traditionally used to produce pumpkin oil and flour, the pulp of the fruit is a raw material for juice-containing products, purees, carotenoid-containing and polysaccharide extracts, pectin, concentrates of first and second dishes, snack products, pasta, bakery, confectionery and meat products, etc.
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Fatty acid composition of yogurt drink based on mare's milkVestnik of MSTUIn accordance with the local climatic conditions and folk traditions in the Republic of Bashkortostan, dairy horse breeding occupies a leading position. Mare's milk is a unique raw material for the production of a wide variety of highly nutritious, complete and easily digestible food products. Scientists recommend mare's milk as a medicinal and dietary product. The paper presents a yogurt recipe developed on the basis of a composition using mare's milk. The composition received patent No 2677219 (Composition…, 2019). It is known that mare's milk fat is rich in polyunsaturated fatty acids, which are of particular physiological importance for the human body. There is a need to ration and ensure a constant intake of polyunsaturated fatty acids of the ω-3 family with food. The purpose of this work is to study the fatty acid composition of yoghurt. To obtain a fermented milk product, milk from Bashkir mares was used as raw material. The production and research of prototypes of yoghurt were carried out on the basis of the Faculty of Food Technologies of the Bashkir State Agrarian University. The determination of the fatty acid composition of the yoghurt sample took place in the accredited testing laboratory centre "Federal Research Centre for Nutrition and Biotechnology" (Moscow). The use of mare's milk allows one to change the fatty acid composition of the finished fermented milk product. Analysis of the fatty acid composition of the sample has showed that it has a high content of oleic, γ-linolenic, α-linolenic and arachidonic acids.
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Production technology and quality assessment of milk shakes for baby food with vitamin complex enrichmentVestnik of MSTUDiversification of dairy products for baby food is a topical trend in the development of the dairy industry. In the process of producing an ultra-heat-treated (UHT) milkshake, milk with a mass fraction of fat 3.5 %, skim milk with a mass fraction of fat 0.5 %, fruit filling "Cherry" and a vitamin premix are used. The technological process of production includes the acceptance of raw materials, assessment of their quality in accordance with regulatory documents; heat treatment of raw milk; preparation of a normalized mixture; adding ingredients. The prepared mixture is sent for deaeration to a flow-through apparatus, then to a homogenizer, where it is subjected to ultra-pasteurization at a temperature of 136 ± 2 °C with a holding time of 4 ± 1 s. The final stage of cocktail production is packaging and intermediate storage. The resulting product was tested in the laboratory for organoleptic and physicochemical indicators. During the experiments, it has been found that the taste, smell, colour, appearance and consistency meet the requirements of state standards. The content of protein, fat, carbohydrates, calcium and titratable acidity are within acceptable values; the content of vitamins A, D3, E, B6 is higher than the minimum values. The research results on safety indicators meet the requirements of technical regulations. Antibiotics, GMO-derived materials and preservatives are not found in the product. The energy value of the baby milk shake is 63.7 kcal (266.6 kJ/100 g of product).
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Analysis of depolymerization of insulating compositions of electric motor windings based on ultrasonic radiationVestnik of MSTUThis work is a continuation of the fundamental study on implementing an innovative method of repairing electric motors using ultrasound. A study of the method of dismantling windings based on ultrasound has been carried out for the purpose of energy efficiency, environmental friendliness and less time spent on the repair cycle of electric motors in terms of removing the stator winding. The investigated dismantling method is optimal for a number of technical issues in comparison with the existing methods for dismantling electric motor windings. In the work, the main focus is on the material of the winding insulation. Lacquer and compound types of insulation of industrial electric motors, which are the main ones everywhere, have been analyzed. The analysis of the impregnating electrical insulating compositions of the stator windings of electric motors and the influence of ultrasound on them during dismantling of the windings of electric motors at different levels of influence of forcing factors: duration and power of ultrasonic action, concentration and temperature of the working solution. The applied mathematical software systems for calculation and modeling guarantee the reliability and rationality of the results of the experiments obtained during the work. A system of equations has been modeled and models of the effect of useful factors relative to each other have been constructed, the results obtained have been optimized and the optimal parameters of both varnish and compound insulation systems have been identified. The optimal parameters of the investigated types of insulation show encouraging results on many important points: duration, energy consumption, environmental friendliness.