The expediency and prospects of using secondary fish raw materials from silver carp in the structuring agents technology have been substantiated. The combination of secondary fish raw materials and seaweed with different mechanisms of gelation has a targeted effect on the organoleptic, structural-mechanical, and physicochemical properties of food products. Accordingly, the expediency of adding the Black Sea alga cystoseira (2%) to optimize the mineral composition of the structuring agents and increase their jelly-making properties was established. Using experimental studies and multicriteria optimization, the optimal ratio of secondary fish raw materials – 40%; water – 60% and rational heat treatment – 150 min, at a temperature of 85 – 100 °C has been determined. An analysis and comparison of various preservation methods have confirmed the expediency of using the freeze-drying method of drying fish broths for the production of structuring agents, which allows to preserve of the original properties of the product, biologically active substances, reduce the mass of the dried product and increase the shelf life of the structuring agents. The optimal storage conditions have been determined – the ready-made structuring agents were packed in three-layer paper kraft bags and stored in a cool dry place at a temperature of 22 ±2 °C and relative humidity of no more than 70% for 12 months. It was found that the physical and chemical indicators of the structuring agents depend on the features of the structure, amino acid composition of fish collagen. The presence of the overwhelming number of high-molecular-weight molecules in the composition of the structuring agents and the preservation of the native structure determine high indicators of dynamic viscosity, dissolution time, and strength. As a result of the research, it was revealed that the high protein content largely depends on the amount of collagen in the secondary fish raw material, which has a positive effect on the gelling properties of the product being created.
Keywords: secondary raw material; silver carp; structuring agent; physical indicator; chemical indicator; biological value
INTRODUCTION
The natural and climatic conditions and significant resource potential of Ukraine contribute to the development of fisheries in their freshwater reservoirs. The production of commercial fish in domestic aquaculture farms is 23 thousand tons, of which 60% is silver carp (State Statistics Service of Ukraine, 2020).
Accordingly, an important task of fish processing enterprises in Ukraine is to ensure and increase the efficiency of using the resource potential of the domestic fishery complex, possibly under the condition of rational use of fish from own water reservoirs of the country (Makarenko et al., 2021).
One of the main ways of efficient use of fish resources is the processing of secondary fish raw materials left after their processing. About a third of secondary fish raw materials from silver carp are heads, bones, and fins, which are a valuable source of proteins, primarily collagen, and are widely used in the food industry (Mushtruk et al., 2020).
A promising direction in the processing of collagen-containing secondary fish raw materials from silver carp is the production of structuring agents. Monitoring of modern trends in the market for structuring agents testifies to their limited assortment based on domestic raw materials, the most common of which is gelatin. However, due to massive cases of cattle diseases, the use of collagen of animal origin is dangerous (Suchenko et al., 2017).
A great contribution to the solution of the problem of complex fish processing and production of structuring agents were made by scientists Kaklyugin and Belousova (2017), Nikiforova (2020), Antipova et al. (2019), Andreev and Morozov (2020), Kao et al. (2014), Makarov et al. (2019) and Postnov et al. (2018).
However, there are no conceptual developments in the direction of the study of consumer properties of structuring agents based on secondary fish raw materials from the most common object of aquaculture in Ukraine – silver carp, which determines the relevance and practical importance of scientific research.
Scientific Hypothesis
The hypothesis of the research work was based on the assumption that the combination of protein (heads, bones, fins of silver carp) and polysaccharide (cystoseira alga) structuring agents improves the organoleptic characteristics of food products, increases the water-holding capacity, and allows to create products with a predictable complex of consumer properties. According to the results obtained, it was confirmed that the combination of structuring agents of various natures makes it possible to more accurately regulate the consistency of the product, purposefully affects the structural-mechanical and physicochemical properties of food products through the use of raw materials with various mechanisms of gelation.
MATERIAL AND METHODOLOGYSamples
Research of structuring agents for control and experimental samples (packed edible gelatin, grade P-7, manufactured by the Lysychansk Gelatin Plant; structuring agents based on secondary fish raw materials; structuring agents based on secondary fish raw materials with the addition of the Black Sea algae cystoseira) were carried out using the following raw materials: heads, bones, and fins of freshwater herbivorous fish – silver carp (Arictichthys nobolis Rich, two-year-old, autumn catch, weight 2 – 2,5 kg ), grown in the Irkliivskyi herbivorous fish hatchery according to DSTU 2284 (2010) (Figure 1); algae cystoseira, which is sold in the form of a dry powder following GOST 31413 (2010); drinking water following DSTU 7525 (2014).
Silver carp.
Chemicals
Calcium chloride, CaCl2. (AGROZONE Ukraine).
Hydrochloric acid, HCl (grade A, analytical grade, LLC “Khimlaborreaktyv” Ukraine).
Sodium hydroxide, NaOH (grade A, analytical grade, LLC “Khimlaborreaktyv” Ukraine).
Sulfuric acid, H2SO4 (grade A, chemically pure, LLC “Khimlaborreaktyv” Ukraine).
Animals and Biological Material
The studies used variegated silver carp weighing 2 – 2.5 kg, 50 – 60 cm long, autumn catch, which was grown at the Irkliivskyi fish farm of herbivorous fish. Conducted studies of the structural and morphological composition of experimental groups (heads, internal organs, carcasses, fillets, scales, fins, bones), calculated the proportion of edible and inedible parts.
Gas chromatograph (“Kupol-55”, “Shimadzu Corporation” Japan).
Program viscometer (Brookfield LVDV-II+PRO USA), pH meter HI8314 HANNA (“SPECTRO LAB” Ukraine).
Laboratory Methods
The study of the chemical composition of the structuring agents was carried out according to the following methods: mass fraction of moisture by drying a sample of the product to constant mass at a temperature of 100 – 105 °C according to DSTU 8029 (2015); mass fraction of ash – by the gravimetric method, after mineralization of the sample weight in a muffle furnace at a temperature of 500 – 600 °С following DSTU 8718 (2017); mass fraction of lipids by the Soxhlet method, which consists in the fact that fat is weighed after its extraction with a solvent from a dry sample weight in a Soxhlet apparatus, based on the determination of the change in the mass of the sample after extraction of fat with a solvent following DSTU 8718 (2017); mass fraction of protein by determination of total nitrogen by the Kjeldahl method, based on the ability of the organic material of the product sample to be oxidized with concentrated sulfuric acid in the presence of a catalyst following DSTU 8030 (2015).
The amino acid composition of proteins was determined by ion-exchange liquid column chromatography on an automatic amino acid analyzer T 339 using an LG ANB cation exchange resin (Sorochan and Shtemenko, 2005).
The mineral composition was determined by inductive plasma atomic emission spectrometry according to DSTU ISO 11885 (2005).
The study of physical and chemical indicators was carried out according to the following methods: transparency – according to own patented method (Patent No. 73282, 2012) on a universal computing device; strength – by the method of establishing the maximum load required for the destruction of the gelatin surface following GOST 11293 (2017); melting temperature by defining the temperature at which the gelatin turns into a liquid state following GOST 11293 (2017); dissolution time by the method of establishing the duration of complete dissolution according to GOST 25183.3 (1982); dynamic viscosity by the method of determining the viscosity of a solution at certain temperatures and a decrease in viscosity after determining the holding time on a capillary viscometer according to GOST 25183.4 (1982); active acidity by determining the pH of a solution of a certain concentration at a certain temperature with using a pH meter according to GOST 11293 (2017).
Description of the Experiment
Sample preparation: Fish raw materials (heads, bones, fins) of silver carp were washed in clean running water at a temperature not exceeding 15 – 20 °С; while mucus, blood, and other residues were removed simultaneously with washing. Washing was carried out until the water was clear. The quality of washing was monitored visually. The washed fish raw material was crushed and subjected to heat treatment. Next, the fish raw material is fed to the shredder "Volgar 5 U", where it is ground to a homogeneous mass. In the process of mixing, all the raw materials are thoroughly mixed for further loading into the boiler cooker of the required portion. The experimentally established optimal ratio of fish waste and water was 1:1.5; heat treatment was 2.5 hours at a temperature of 85 – 100 °C. At the initial stage of heat treatment, cystoseira was added in the form of a dry powder (2%). To reduce the mass fraction of moisture, the fish broth was subjected to freeze-drying at a temperature of (50 – 70 °C). The ready-structuring agents were packed in three-layer paper kraft bags and stored in a cool dry place at a temperature of 22 ±2 °C and relative humidity of no more than 70% for 12 months. A control sample, structuring agents based on secondary fish raw materials were sent for analysis; structuring agents based on secondary fish raw materials and cystoseira. Then, an average sample was taken from each unit, which was characterized by its general chemical composition, mineral content, the amino acid composition of proteins, and physicochemical parameters.
Number of samples analyzed: Three types of structuring agents were used in the study of the samples: control – gelatin of animal origin and two samples based on secondary fish raw materials of silver carp and addition of cystoseira.
Number of repeated analyses: The study was repeated 5 times, and the experimental data were processed using the methods of mathematical statistics.
Number of experiment replication: Each study was carried out five times, the number of samples was three, resulting in fifteen repeated analyzes (Figure 2).
Structuring agents.
Statistical Analysis
The statistical analysis data were produced by Microsoft excel and Statistica 15. The accuracy of the obtained experimental data was determined using the Student’s test for a confidence probability of ≤0.05 based on the number of parallel determinations at least 5. Linear programming problems were solved using the MS Excel spreadsheet processor “Search for a solution” setting (Excel Solver).
RESULTS AND DISCUSSION
Structuring agents experimental samples were evaluated according to the following physicochemical parameters: dissolution time, active acidity, dynamic viscosity, gelatin strength, gelatin melting point, solution transparency (Table 1). Previous studies have established the effectiveness of the use of fish collagen in comparison with collagen of animal origin in terms of the main physicochemical parameters (Mezenova, 2017;Hanani, 2016). Research shows that dissolution time is one of the important quality criteria for structuring agents (Andreev and Morozov, 2020;Kao, 2020). It is known that the degree of solubility of the structuring agents depends on many factors: the size of the granules, the type of raw materials used, temperature, etc.
Physical and chemical quality indicators of structuring agents.
Indicators
Control
Structuring agents based on
secondary fish raw materials
secondary fish raw materials and cystoseira
Dissolution time, min.
12 ±0.6
5 ±0.2
6 ±0.3
Dynamic viscosity, mPa·s-1
16 ±0.8
17 ±0.7
18 ±0.9
Gelatine strength, H
10 ±0.5
10 ±0.5
11 ±0.5
Solution transparency,%
28 ±1.4
32 ±1.6
30 ±1.5
Melting temperature of gelatine, °C
27 ±1.3
30 ±1.5
31 ±1.5
Active acidity, pH
5.5 ±0.2
6 ±0.3
6 ±0.3
Note: (n = 5, p ≤0.05).
However, first of all, dissolution is associated with the hydration of proteins, that is, the binding of water molecules to proteins. Scientists associate this phenomenon with the structural features of collagen in various fish species (Shokina et al., 2020;Bredikhina and Zarubin, 2019). Protein, like any hydrophilic high molecular weight compound, swells, and then the protein molecules begin to gradually transfer into solution.
When swelling, water molecules penetrate the protein and bind to its polar groups. A dense network of polypeptide chains is delimited. Further absorption of water leads to the separation of protein molecules from the total mass and dissolution. This is the process of electrostatic binding of water molecules to the polar groups of side radicals of acidic amino acids with a negative charge and basic amino acids with a positive charge. However, swelling does not always lead to rapid dissolution, for example, animal collagen, unlike fish collagen, can remain in a swollen form, having absorbed a large amount of water. Similar statements were highlighted in the works of scientists (Mezenova et al., 2018;Zarubin, 2018;Palamarchuk et al., 2020). This can explain almost twice as fast the dissolution time of research structuring agents based on secondary fish raw materials – 5 minutes and cystoseira – 6 minutes, compared to the control – 12 minutes. The solubility of animal collagen is hampered by structural features – cross-links between polypeptide chains. A paradoxical phenomenon is observed: the protein contains many anionic or cationic groups, and its solubility in water is relatively low (Vorobiev and Nizhnikova, 2017;Dzyuba and Zemlyakova, 2019). It was noted that the melting point of the control sample is the lowest (27 °C), of the structuring agents based on secondary fish raw materials (30 °C), and structuring agents based on secondary fish raw materials and cystoseira (31 °C). Scientists have proven that the lowered melting temperature of fish gelatin-based on scales of various fish species (by 4 °C compared to the minimum normalized value for gelatin of animal origin) is due to the peculiarities of the amino acid composition of the raw material (Yakubova and Bekesheva, 2018a;Abdelhedi et al., 2019;Palamarchuk et al., 2019).
The transparency of the structuring agent solution characterizes the degree of their contamination with mechanical impurities. It was found that the value of the transparency index of new structuring agents is higher than that of control. During storage, the transparency of all samples ranged from 27 – 30%. Accordingly, high transparency indicates their high quality. The predecessors (Yakubova and Bekesheva, 2018b) noted that the transparency index of a 5% solution of fish gelatin exceeds the traditional standard values by more than 17.0%, which confirms its high organoleptic properties as a food consistency regulator.
Dynamic viscosity is one of the main characteristics of structuring agents. According to this indicator, all product samples are within acceptable limits (16 – 18 mPa.s-1). Scientists noted the higher values of viscosity indicators of fish structuring agents (by more than 18%), compared with animal gelatin (Bekesheva, 2019). However, it is worth noting that the results of the prototypes of Structuring agents based on secondary fish raw materials are the most optimal compared to the control and Structuring agents based on secondary fish raw materials and cystoseira. It has been proven that in the manufacture of any product with a gelatin structure, it is advisable to use structuring agents with medium viscosity, since structure formers with high viscosity can render the created product too rigid and elastic consistency, respectively, structuring agents with low viscosity, on the contrary, do not provide the required strength of the product.
In works (Nikolaev et al., 2016;Zarubin and Bredikhinа, 2016), the effectiveness of combining protein-polysaccharide structuring agents to obtain the required structure of a food product is confirmed.
An indicator of the quality of the structuring agents is the strength of the gelatin, which directly depends on the pH of the medium. The greatest strength is observed in the range from 5 to 7 pH.
The nutritional value of the structuring agents was examined by their chemical composition, namely, the content of proteins, fats, and minerals (Table 2).
Chemical composition of structuring agents.
Content, %
Control (gelatine)
Structuring agents based on
secondary fish raw materials
secondary fish raw materials and cystoseira
Moisture
14.0 ±0.7
15.0 ±0.7
15.0 ±0.7
Protein
83.0 ±4.1
82.0 ±4.1
82.0 ±4.1
Fat
1.5 ±0.07
1.4 ±0.07
1.1 ±0.05
Minerals
1.4 ±0.07
1.3 ±0.06
1.6 ±0.09
Note: (n = 5, p ≤0.05).
So, the high content of proteins (82%) and minerals characterizes the degree of the biological value of natural structuring agents. It should be noted that the structuring agents based on secondary fish raw materials and cystoseira contain a greater amount of minerals (1.6%) compared to the structuring agents without cystoseira (1.3%). Accordingly, the addition of cystoseira made it possible to rationalize the mineral composition of the product, since cystoseira contains a complete complex of mineral elements.
In the works (Kao, 2017;Baidalinova and Lyapustina, 2018;Zheplinska et al., 2019) it is indicated that the amount of protein in the research fish gelatin is within the range (87.36 – 91%), which confirms the rather high biological value of the product.
One of the important quality criteria for structuring agents is their biological value, which is largely determined by the content and balance of amino acids, especially essential ones (Holembovska et al., 2021;Nesterenko et al., 2020). Characteristics of the amino acid composition are shown in Figure 3.
Analysis of the amino acid composition of protein structuring agents.
During studies of the amino acid composition of proteins, the structuring agents, the highest content of such amino acids was noted: glycine, alanine, proline, aspartic and glutamic acids. These amino acids form a repetitive sequence in the polypeptide chain, resulting in the helical structure of collagen. Accordingly, the high content of glycine 162.7 – 176.4 mg.100g-1 and glutamic acid 142.1 – 153.1 mg.100g-1 in research structuring agents is a characteristic feature of the amino acid composition of fish collagen. Amino acids such as histidine, isoleucine, valine are found in a smaller amount, which is due to the smaller number of cross-links. Experimental studies of the amino acid composition of fish gelatin (Antipova et al., 2019) showed that it is almost identical to the animal. However, animal gelatin lacks tyrosine and cystine.
It was also found that fish gelatin has a lower content of hydroxyproline, but almost 2.5 times more proline (Antipova and Storublevtsev, 2016). An objective assessment of the biological value of proteins was determined by a set of indicators: amino acid rate, KRAS, utilitarian coefficient. Amino acid rate of structuring agent proteins was determined following the FAO/WHO scale (Table 3). The biological value of protein compositions depends on the content of essential amino acids in them and their ratio in the product and the idealized model (Karpenko, 2019). So, the dominant amino acids are lysine, threonine, phenylalanine, and tyrosine, the limiting ones are valine and isoleucine.
Amino acid rate of protein of structuring agents.
Amino acid, %
Amino acid content according to the FAO/WHO scale
Control
Structuring agents based on
secondary fish raw materials
secondary fish raw materials and cystoseira
Valine
50
45
47
49
Isoleucine
40
29
32
34
Leucine
70
50
71
74
Lysine
55
72
101
105
Methionine + Cystine
35
34
78
83
Threonine
40
50
93
87
Phenylalanine + Tyrosine
60
38
70
71
To assess the degree of protein utilization, the coefficient of difference of the amino acid rate was calculated. KRAS of the control sample is 16.4%, of the research ones is 37.8 – 38.2%.
The biological value of the reference protein is 100%. In experimental samples, biological value is 61.8% (structuring agents based on secondary fish raw materials) and 62.2% (structuring agents based on secondary fish raw materials and cystoseira), control ones – 83.6%. The value of the utilitarian coefficient of the amino acid composition of the experimental samples (0.618 – 0.836) indicates a high balance of amino acids relative to the standard.
Thus, the qualitative composition of structuring agent proteins based on secondary fish raw materials from silver carp indicates the expediency of their effective use in the food industry.
One of the important indicators of the nutritional value of structuring agents is the content of the main macro- and microelements in their composition (Table 4).
Mineral composition of structuring agents, mg.100g-1.
Mineral element
Control
Structuring agents based on
secondary fish raw materials
secondary fish raw materials and cystoseira
Potassium
7.94 ±0.31
98.0 ±4.1
90.45 ±4.2
Calcium
343.0 ±10.61
68.1 ±3.32
69.3 ±3.46
Iron
0.91 ±0.04
1.09 ±0.05
1.02 ±0.05
Chlorine
454.0 ±22.49
545.7 ±27.16
475.6 ±23.70
Selenium
-
-
6.24 ± 0.28
Bromine
2.78 ±0.13
3.37 ±0.16
5.01 ±0.24
Phosphorus
300 ±10.12
120 ±5.6
170 ±8.1
Zirconium
0.10 ±0.004
0.05 ±0.002
0.16 ±0.008
Sulfur
2.1 ±0.10
2.8 ±0.14
4.98 ±0.24
Note: (n = 5, p ≤0.05).
Analyzing the quantitative composition of macro- and microelements of research structuring agents in comparison with the control, an increase in the level of potassium, iron, sulfur, bromine, chlorine should be noted. Experimental samples of structuring agents, in comparison with the control, contain a significant amount of potassium necessary for the human body, which ensures the normal activity of the cardiovascular system. The potassium content in structuring agents based on secondary fish raw materials is 98.0 mg.100g-1, in the sample from cystoseira – 90.45 mg.100g-1, which exceeds the value of the control sample by 113.94%.
An increased amount of iron 1.2 times in experimental samples compared to the control will contribute to a positive effect on the protective functions of the body, since iron is involved in respiration, hematopoiesis, immunobiological and redox reactions, and a sufficient amount of calcium (68.1 – 69.3 mg.100g-1) will improve its assimilation by the human body.
In terms of sulfur content, the dominant is structuring agents sample based on secondary fish raw materials and cystoseira – 4.98 mg.100g-1, because sulfur is used in the human body to neutralize many toxic products formed during metabolism.
A distinctive feature of the studied samples of the structuring agents with cystoseira is a significant bromine content, which is 5.01 mg.100g-1 which is almost twice as much as in the control – 2.78 mg.100g-1, and selenium – 6.24 mg.100g-1. The enrichment of the mineral composition of the structuring agents with bromine and selenium can be explained by their sufficient content in cystoseira.
The results of the study show that the addition of seaweed – cystoseira to the structuring agents contributes to the optimization and enrichment of their mineral composition in comparison with the structuring agents without cystoseira and the control sample.
CONCLUSIONS
It was found that structuring agents based on secondary fish raw materials are characterized by a high protein content (82%), which has a positive effect on the jelly-making properties of the structuring agents. The dominant amino acids are glycine, proline, alanine, aspartic and glutamic acids. The value of the utilitarian coefficient of the amino acid composition of the new structure-formers is within the range (0.61 – 0.83), which indicates a high degree of assimilation of their proteins by the human body.
It has been proven that the addition of cystoseira to the structuring agents based on secondary fish raw materials increases the content of Bromine (5.01 mg.100g-1) compared to the control (2.78 mg.100g-1) and Selenium (6.24 mg.100g-1).
Confirmed a high degree of jelly-making properties of structuring agents, characterized by a complex of indicators of viscosity (16 – 18 mPa.s-1), strength (10 – 11 H), melting point (27 – 31 °C), and solubility (5 – 6 minutes).
It was found that the addition of cystoseira to the structure-forming agents promotes optimization and enrichment of their mineral composition in comparison with the structure-forming agents without cystoseira and the control sample.
Acknowledgments:
We express our gratitude to Professor Olena Sydorenko.
This study did not receive external funding.
The authors have no conflicts of interest.
This article does not contain any research that would require ethical statements.
AbdelhediО.JridiaM.NasriaR.MorabL.ToldrábF.NasriaM.2019 Rheological and structural properties of Hemiramphus far skin gelatin: Potential use as an active fish coating agent.Food Hydrocolloids8733134110.1016/j.foodhyd.2018.08.005AndreevM.MorozovI.2020 Influence of structuring agents of various nature on the rheological properties of gelatin food products based on secondary fish raw materials.KSTU News578998AntipovaL.AkimbaiD.StorublevtsevS.2019 Fish gelatin in the technology of specialized food products.Science, nutrition and health98102AntipovaL.StorublevtsevS.2016 Comparative properties of collagen proteins of fish and animal origin.VGU Bulletin, series: chemistry. biology. pharmacy43741BaidalinovaL.LyapustinaE.2018 Isolation of natural protein structuring agents from collagen-containing secondary fish raw materials.Scientific journal “KSTU News”514560BekeshevaA. A.2019Development of technology and commodity assessment of sweet jellied dishes using fish gelatin : dissertation theses. Yekaterinburg, Russia : Astrakhan State Technical University181BredikhinaO.ZarubinN.2019 Development of an integrated technology for processing organic waste from fish processing enterprises into collagen-containing hydrolysates for food purposes.VNIRO Works17610912110.36038/2307-3497-2019-176-109-121DSTU 22842010Live fish. General technical requirements.DSTU 75252014Drinking water. Quality control requirements and methods.DSTU 80292015Fish and fish products. Methods for determining moisture.DSTU 80302015Fish and fish products. Methods for the determination of protein substances.DSTU 87182017Fish and fish products. Methods for the determination of ash and mineral impurities.DSTU ISO 118852005Water quality. Determination of 33 elements by inductively coupled plasma atomic emission spectrometry. DzyubaN.ZemlyakovaO.2019 Review of modern methods of obtaining collagen hydrolysate from aquatic organisms.Scientific notes of V.I. Vernadsky TNU. Series: technical sciences303747910.32838/2663-5941/2019.3-2/14GOST 112932017Gelatin. Technical requirements.GOST 25183.3. 82Photographic gelatin. Method for determining dissolution duration.GOST 25183.4. 82Photographic gelatin. Method for determining viscosity and viscosity drop.GOST 314132010Algae, sea grasses and their products. Acceptance rules and sampling methods.HananiZ. А. N.2016Gelatin. In Smithers, G. Encyclopedia of Food and Health, Reference Module in Food Science. Amsterdam, Netherland : Elsevier, р. 191-195. ISBN 978-0-08-100596-5.10.1016/B978-0-12-384947-2.00347-0HolembovskaN.TyshchenkoL.SlobodyanyukN.IsraelianV.KryzhovaY.IvaniutaA.PylypchukO.MenchynskaA.ShtondaO.NosevychD.2021 The use of aromatic root vegetables in technology of freshwater fish preserves.Potravinarstvo Slovak Journal of Food Sciences15129630510.5219/1581IPOSR2012Industrial Property Office of Ukraine. Method for determining the transparency (turbidity) of gelatin products. Patent holders: Sydorenko, O., Ivanyuta, A., Romanenko R. Patent No.73282, 2012-25-09.KaklyuginY.BelousovaS.2017 Features of technology and equipment for complex processing of fish raw materials.Scientific works of KubGTU5272280KaoT.2017 Physicochemical properties of gelatin from scales of the yellow-finned crucian carp Acanthopagrus latus (Sparus latus).Young scientist9143122125KaoT.2020 Fish skin as a source of edible gelatin.Young scientist323224749KaoT.NguyenT.NguyenV.2014 Some aspects of the technology of obtaining gelatin from collagen-containing secondary fish resources.BSU Work912332KarpenkoY. V.2019Development of a technology of a balanced biological value of culinary jellied products from small-eyed grenadier : dissertation theses. Vladivostok, Russia : Moscow State University of Food Production, 156 p.MakarenkoA.MushtrukM.Rudyk-LeuskaN.KononenkoI.ShevchenkoP.KhyzhniakM.MartseniukN.GlebovaJ.BazaevaA.KhalturinM.2021 The study of the variability of morphobiological indicators of different size and weight groups of hybrid silver carp (Hypophthalmichthys spp) as a promising direction of development of the fish processing industry.Potravinarstvo Slovak Journal of Food Sciences15118119110.5219/1537MakarovA.MaksimenkoY.AleksanyanI.DyachenkoE.2019 Development of rational drying regimes in the production of gelatin based on fish processing waste.Technologies of the food and processing industry of the agro-industrial complex - healthy food products2285663MezenovaN. Y.2017Development of a technology for a bioproduct for sports nutrition using biomodified collagen-containing fish raw materials : dissertation theses. Moscow, Russia : Kaliningrad State Technical University, 223 p.MezenovaO.VolkovV.HoelingA.MerzelT.GrimmT.MezenovaY.2018 Comparative assessment of hydrolysis methods for the production of protein products from collagen-containing fish raw materials and assessment of their quality.Scientific journal “KSTU News”49126144MushtrukM.VasylivV.SlobodaniukN.MukoidR.DeviatkoO.2020Improvement of the Production Technology of Liquid Biofuel from Technical Fats and Oils. In Ivanov, V., Trojanowska, J., Machado, J., Liaposhchenko, O., Zajac, J., Pavlenko, I., Edl, M., Perakovic, D. Advances in Design, Simulation and Manufacturing IІI. Switzerland : Springer International Publishing, p. 377-386. ISBN 21954364-21954356.10.1007/978-3-030-50491-5_36NesterenkoN.OrlovaN.MotuzkaY.IvanyutaА.MenchynskaA.2020 Biological value of protein of quick-frozen semi-finished products from cultivated mushrooms.International Journal of Food Science and Biotechnology.548993NikiforovaA.2020 Review of methods for the rational processing of fish waste.Comprehensive research in the fishery industry: materials of the VI International Scientific and Technical Conference of Students, Postgraduates and Young Scientists. Vladivostok263267NikolaevD.DubrovinS.KuranovaL.2016 Testing of the device “Food Checker” in the study of the rheological properties of a structured fish product, made with the use of gelatin.AGTU Bulletin, Series. Fishery4139144PalamarchukI.MushtrukM.SuchenkoV.DudchenkoV.KoretsL.LitvinenkoA.DeviatkoO.UliankoS.SlobodyanyukN.2020 Modelling of the process of vybromechanical activation of plant raw material hydrolysis for pectin extraction. Potravinarstvo Slovak Journal of Food Sciences14123924610.5219/1305PalamarchukI.MushtrukM.VasylivV.ZheplinskaM.2019 Substantiation of regime parameters of vibrating conveyor infrared dryers.Potravinarstvo Slovak Journal of Food Sciences13175175810.5219/1184PostnovG.ChervonyiM.MaksymenkoA.GulyiO. Omelchenko.ApanasenkoA.2018 Prospects for the use of technology for deep processing of pond fish.Equipment and technologies for food production2596510.33274/2079-4827-2018-37-2-59-65ShokinaY.KuchinaY.NovozhilovM.PopovM.ShokinG.2020 Study of the rheological properties of gels based on broth made from stellate ray cartilage (Raja radiata) in the technology of natural fish culinary products - jellied fish, in jelly, fish gelatins and brawn.MGTU Bulletin23330231210.21443/1560-9278-2020-23-3-302-312SorochanO.ShtemenkoN.2005Methods of analysis of amino acids : scientific and methodological manual. Dnepropetrovsk, p. 60.State Statistics Service of Ukraine2017Available at: http: //www.ukrstat.gov.ua/operativ/operativ2017/rg/rg_u/arh_dvbr_reg_u.html.SuchenkoY.SuchenkoV.MushtrukM.VasulivV.BoykoY.2017 Changing the quality of ground meat for sausage products in the process of grinding.Eastern European Journal of Enterprise Technologies411566310.15587/1729-4061.2017.108876VorobievV.NizhnikovaE.2017 Research and application of fish scales in various industries.News of the Kaliningrad State Technical University45147159YakubovaO.BekeshevaA.2018a Substantiation of regulated indicators of the quality of edible fish gelatin.Food Industry34606510.29141/2500-1922-2018-3-4-7YakubovaO.BekeshevaA.2018b Scientific substantiation of the physical properties of fish gelatin.AGTU Bulletin: Series. Fishery2018313214010.24143/2073-5529-2017-3-132-140ZarubinN. Y.2018Development of product technology using a composition based on collagen hydrolysate from fish skin and plant components : dissertation theses. Moscow, Russia : Moscow State University of Food Production, 193 p.ZarubinN.BredikhinaO.SemenovG.KrasnovaI.2016 Production of dry high-quality fish hydrolysates using vacuum freeze drying.AGTU Bulletin, Series: Fishery3138144ZheplinskaM.MushtrukM.VasylivV.DeviatkoO.2019 Investigation of the process of production of crafted beer with spicy and aromatic raw materials.Potravinarstvo Slovak Journal of Food Sciences13180681410.5219/1183