Biochemical indicators, quality and safety of domestic and wild pig slaughter products

Animal husbandry is one of the important branches of agricultural production, which plays an important role in the formation of food security of Ukraine and providing the population with important types of food. The correct methodical approach to the inspection of organs and tissues of slaughtered animals allows to avoid errors in the diagnosis of various diseases, in the sanitary assessment of slaughter products, to prevent meat losses and the release of food products that are dangerous for humans. Analyzing the requirements of the modern market and the priority directions for the development of trade relations between the countries of the European Union for our country, it should be noted that the responsibility for the export and import of products of animal origin and the control of the production of high-quality and safe products is entrusted to the specialist of the state veterinary service. Organoleptic analysis of slaughter products is an important component of inspection. In addition, it should be noted that determining the degree of freshness of meat for a long time was carried out only with the help of the organoleptic method. It has been proven that organoleptic indicators provide comprehensive information for determining the good quality of meat. The quality of meat or its nutritional value refers to the chemical composition of the fleshy part, which includes muscle, fat and connective tissue. The chemical composition, energy value, digestibility, taste, culinary and other properties of meat depend on the ratio of these tissues. The quality of meat is influenced by the breed of animals, sex, age, fatness, the nature of fattening, conditions of transportation and pre-slaughter aging, methods of stunning, degree of exsanguination, etc. The article presents materials related to the inspection of animal slaughter products in the Zhytomyr region (agro-food market in the city of Olevsk). The study was carried out as part of the research work of the department of normal and pathological morphology, hygiene and expertise “Monitoring the content of toxic substances in drinking water, feed and their impact on the body of cattle and the quality and safety of products”, state registration number – 0120U101318. The purpose of the study is to inspect the slaughter products of domestic and wild pigs in the agro-food market of the Zhytomyr region. The task of the work was to determine the organoleptic, physico-chemical and microbiological indicators of slaughter products of domestic and wild pigs. The testing laboratory of veterinary and sanitary examination in the market carries out significant work on the inspection of animal slaughter products, which ensures the release of good-quality products for the population. As a result of the inspection of the slaughter products of domestic and wild pigs, it was established that all meat samples according to organoleptic parameters corresponded to the parameters of fresh high-quality meat, the reaction to peroxidase was positive, the pH of the meat ranged from 5.9 to 6.1. No trichinella was detected during trichinoscopy of pork samples. Veterinary and sanitary examination of livestock products on the markets is carried out only by veterinary medicine specialists of state laboratories or other state institutions of veterinary medicine. The laboratory carries out mandatory quality and safety control of all controlled products sold, including food products of animal origin intended for human consumption. In this regard, it is important to carry out inspection, sanitary evaluation of slaughter products of slaughter animals and determination of morphological characteristics of meat of domestic and wild pigs.


Introduction
The logic, which is based on common sense and the economic laws of civilized farming, convincingly shows that the problem of providing the population and the food industry with meat is practically impossible to solve without the inten-sive development of all branches of animal husbandry and, especially, pig farming (Martyshuk et al., 2019;2020;Maksym et al., 2020).The level of its development is decisive in ensuring the country's food security (Susharnik, 2021;Shevchenko, 2021;Khalak et al., 2021).Indicators of production and consumption of livestock products are the main fac-Citation: Furman, S. V., Sokulskyi, I. M., Lisohurska, D. V., Lisohurska, O. V., & Gutyj, B. V. (2024).Biochemical indicators, quality and safety of domestic and wild pig slaughter products.Ukrainian Journal of Veterinary and Agricultural Sciences, 7(2), 28-35.tors in determining the population's standard of living.The livestock industry is the primary source of supply of highquality food products, and its products are raw materials for the processing industry (Heraymovich et al., 2019;Hunich et al., 2021;Mykhalko et al., 2023;Povod et al., 2024).
Pig farming is one of the essential areas of agribusiness, taking the third place in the livestock industry of Ukraine in terms of product value, second only to dairy and poultry farming (Maksym et al., 2022;Povod et al., 2023;Mykhalko et al., 2024).Even though some nations and even regions of the world do not consume pork for religious and other reasons, its share in the total production of meat is about 90 million tons, that is, 39.6 %, while chicken -27.1 %, meat -24.2 %, lamb and goat meat -4.7 % and 4.4 % -for all other types of animals and poultry (Izhboldina et al., 2021).
The priority for the development of this industry is given due to such fundamental biological and economic characteristics of pigs as multifertility, omnivorousness, and economical use of feed (Mykhalko, 2021).As established by special studies, 20 % of the total energy of feed consumed by animals of various species and poultry is transformed into food for humans with pork, 15 % with cow's milk, 7 % with chicken eggs, and 5 % with poultry meat, beef, and lamb -4 % (Zbarsky & Shpak, 2016;Kopytets, 2018).
Following the Law of Ukraine "On Veterinary Medicine", veterinary and sanitary examination of livestock products and raw materials of animal and plant origin is carried out as a mandatory state veterinary control in places where trade in animals, products, and raw materials of animal and plant origin is organized (Bogatko et al., 2017;Zakon Ukrainy, 2023;Zakon Ukrainy, 2024).The purpose of veterinary-sanitary examination as one of the numerous fields of practical activity of veterinary medicine specialists is to confirm the safety of products of animal origin, reproductive material, biological products, and substances, including the analysis of production technology, and to prevent human diseases from zoonoses and other diseases when consuming food, and also in the prevention of livestock and poultry diseases spread through animal feed (Sybirna et al., 2016;Gorobei et al., 2018).The veterinary and sanitary examination is carried out following the Laws of Ukraine "On Veterinary Medicine", "On Basic Principles and Requirements for the Safety and Quality of Food Products" (Zakon Ukrainy, 2023;Zakon Ukrainy, 2024).All types of animals that enter meat processing plants as raw materials for obtaining meat and slaughter products are called slaughter animals.Healthy domestic animals and poultry are allowed for slaughter.Slaughter of sick animals or those suspected of having infectious diseases is permitted in cases provided for by the rules of pre-slaughter veterinary inspection of animals and veterinary and sanitary examination of meat (Gorobei et al., 2018).
During storage, meat and meat products are exposed to environmental factors, which leads to undesirable changes in the product's chemical composition for the consumer.Most often, changes occur under the action of microorganism enzymes.Thus, mesophilic aerobic and facultatively anaerobic microflora will prevail in unrefrigerated meat and products.At the same time, during their storage in a cooled state, coldloving microflora will dominate, and it will cause technological defects and affect sanitary and hygienic indicators (Salata, 2017).The organoleptic method for determining the freshness of meat is the main one.It includes determining the appearance, smell, color, and consistency of muscle tissue, the state of fat, bone marrow, tendons, and joints.This method also includes the study of broth when cooking meat (smell, taste, aroma, transparency) (Kitaeva, 2021).
Nutrition is the most essential need of the human body, and satisfaction largely determines a person's health and quality of life.Meat and meat products are among the most critical food products (Kausar et al., 2019;Albuquerque et al., 2022).However, at the same time, the quantity and value of livestock products may deteriorate due to production and storage technology violations.Farm animals are exposed to several infectious and non-infectious diseases, which significantly leads to a deterioration in the quality of meat (Stetsiv & Stetsiv, 2019).
The quality of meat or its nutritional value refers to the chemical composition of the fleshy part, which includes muscle, fat, and connective tissue.The chemical composition, energy value, digestibility, taste, culinary, and other properties of meat depend on the ratio of these tissues.The quality of meat depends not only on organoleptic and biochemical indicators but also on the chemical composition of meat, which is affected by the breed, sex, age, fattening of animals, health status before slaughter (Koval, 2012), as well as conditions of transportation and pre-slaughter holding, methods of stunning, degree of exsanguination, etc (Oleksiienko et al., 2020).
The nutritional value of meat primarily depends on its morphological and chemical composition, degree of digestibility (Joo et al., 2013).The reserve of food products for humans is the meat of wild hunting and industrial animals (Listrat et al., 2016;Geiker et al., 2021).Depending on the species of wild animals, their meat differs in organoleptic characteristics, morphological and chemical composition, taste, and culinary qualities (Badis et al., 2014;Czarniecka-Skubina et al., 2022).In contrast to the meat of domestic animals, game meat contains more mineral salts and vitamins and less fat: it is deposited on the viscera and subcutaneous tissues, and in muscle tissue, as a rule, it is absent.At the same time, game meat is richer in nitrogenous substances, mainly proteins.Unlike adults, the meat of young animals has less fat and more loose connective tissue.Fat in wild animals is deposited under the skin, in the pelvic cavity, in the lumbar region, near the kidneys, and only in case of high fatness -in other body parts.Some animals have little of it (elk, hare), and such meat is considered lean, while others have significant deposits (bear, reindeer, wild boar).Deposits between muscle bundles and muscles occur very rarely; therefore, on cross-section, the muscles are homogeneous, and there is no marbling of the meat (Gill, 2007;Avramenko, 2017;Alikord et al., 2018).
In most wild animals, the meat has a red color immediately after removing the skin.However, after 3-4 hours, it darkens as a result of oxidation of myoglobin by air oxygen and takes on a bluish or blue-violet shade (Kasprzyk et al., 2019;Macháčková et al., 2021).The meat of wild rams and goats (gazelles, mouflons, arharids, etc.) is dark red, finegrained, thin-fibered, moderately juicy or tough (depending on age).Adipose tissue is deposited between muscle fibers in a rather thin layer (Murariu et al., 2023).Moose meat is dark red, and the muscles on dissection are coarse-fibered, uniform in color, and covered with dense, well-developed fascia without layers of fat.Fat is deposited in the form of small areas in the area of sternum, lower back, and in the pelvic cavity (Yakubchak et al., 2012;Shtyk et al., 2013).Deer meat is pale red or intense red with a bluish tint.Mus-cle fibers are thin, tender, and fine-grained on dissection.Fat layers between muscle fibers are rarely found.Adipose tissue of white color, dense consistency (Kim et al., 2017;Lee et al., 2020).The meat of the saiga is bright red and quickly darkens in the air.Coarse-fibered muscles without layers of fat.There are small deposits of fat in saiga carcasses.The color of the meat and the degree of exsanguination depend on the method of harvesting saigas.The meat of the wild boar is light red, sometimes dark red, complex, and dense.The muscles of adult males are coarse-fibered, and the meat has a specific smell and often an unpleasant taste.In one-year-old young animals, the muscles are thin; the meat is tender, fragrant, and juicy.Fat is deposited, as a rule, under the skin, in the area of the kidneys, and rarely -between muscle fibers (Rudy, 2010;Avramenko & Nagorna, 2017;Ciobanu et al., 2022).The fat of different animal species differs in consistency, melting point, and color.The consistency of fat and its melting point depend on its chemical composition.The more unsaturated fatty acids, particularly stearic, in the fat, the higher its melting point and the more complex the consistency.The melting point of different types of animal fats is different.Therefore, taking into account other indicators, it is possible to determine the species belonging to carcasses and their parts (Yakubchak et al., 2012;Zakon Ukrainy, 2023).
The work aimed to inspect pig slaughter products at the agro-food market in the Zhytomyr region.

Materials and methods
The study was carried out as part of the research work of the Department of Normal and Pathological Morphology, hygiene, and Expertise: "Monitoring the content of toxic substances in drinking water and feed and their impact on the body of cattle and the quality and safety of products", state registration number № 0120U101318.
The material for the study was the slaughter products of domestic pigs (Domestic pig -Sus scrofa domestica) and wild pigs (Wild pig, or wild boar -Sus scrofa L.).To study the quality and safety of slaughter products, 6 carcasses of each group of animals were used.Domestic pigs were kept in personal farms of the Olevsky town and Olevsky district.Wild pigs were raised in the village's conditions of the State Enterprise "Forestry".Bilokorovychi Olevsky district, Zhytomyr region.
Pre-slaughter inspection veterinary-sanitary examination of animal carcasses and slaughter products were carried out following the "Rules of pre-slaughter veterinary examination of animals and veterinary-sanitary examination of meat and meat products".Organoleptic tests (color, smell, consistency of meat, condition of tendons, fat) were carried out to determine the degree of freshness of meat.
Organoleptic studies involve determining the appearance and color of the meat, the surface of the carcass, the condition of the muscles on the cut, consistency, smell, the presence, and condition of fat and tendons, as well as the quality of the broth.Organoleptic tests were carried out in daylight and at room temperature.When inspecting the carcass's surface, the presence or absence of a drying crust was determined.It should be pale pink or pale red.Attention was paid to the color, consistency, and smell of meat from the surface and on the cut, the presence of blood clots, and contamination.
Determination of meat consistency was carried out by pressing on the surface of any part of the carcass with a finger and observing the speed of filling of the formed hole: if it is immediately leveled -fresh meat, after one minutequestionable, if not leveled -poor quality.Samples of meat and internal organs were taken from the superficial and deep layers.Smears-imprints were made from the samples on glass slides.Smears-imprints were dried in the air, then carefully fixed over the flame of vodka and stained by Gram, bacterioscopy was carried out.

Results and discussion
A scientific procedure for inspecting carcasses and internal organs was followed to carry out the inspection.The carcass must be presented with the head and internal organs for inspection.All slaughter products were examined following the "Rules of veterinary examination of slaughter animals and veterinary and sanitary examination of meat and meat products" (2002).
The veterinary and sanitary examination of pig slaughter products was generally carried out, starting with the head and internal organs since they are the most likely objects of infection.Lymph nodes that collect lymph from these organs can most quickly have pathological changes that will be detected by an expert.
During the general examination of the carcass, attention was paid to the degree of exsanguination, subcutaneous tissue, pleura, peritoneum, and condition of muscles and joints.The presence of edema, tumors, abscesses, and hemorrhages was excluded.One also need to pay attention to the degree of bleeding of the carcass, it can be: good, satisfactory, bad and very bad.To determine the degree of exsanguination, it is necessary to cut the muscle tissue and attach a piece of filter paper to the cut.
The lumbar, cervical, scapula-ulnar (anconeus), pelvic limb, and diaphragm muscles were cut and examined to investigate cysticercosis.Samples of muscles from the legs of the diaphragm, intercostals, masticatory, and hypoglossal muscles were necessary for testing for trichinellosis.To test for trichinellosis, both legs of the diaphragm, located under the spine at the level of the last thoracic vertebra, closer to the tendinous part of the intercostal muscles, the masseter, and the hyoid muscle, were taken from each carcass.Muscle sections are prepared, for which small pieces of muscle tissue the size of an oat grain are cut with bent scissors along the muscle fibers.
When comparing the humerus of wild and domestic pigs, an aboveblock hole was established at the distal end of these bones of wild pigs, which is not found in domestic pigs.Slaughter products of domestic and wild boars were subject to mandatory testing for trichinellosis.
Microbiological studies of animal slaughter products are carried out in case of suspicion of infectious diseases, poisoning, diseases of the gastrointestinal tract, respiratory organs, the presence of inflammatory processes in organs and tissues, abscesses, multiple wounds, and bone fractures, in case of questionable degree of freshness of meat, removal of intestines later than two hours from the moment of slaughter, as well as meat obtained from long-term pursuit of wounded and driven animals.If necessary, biochemical studies are carried out.
The procedure for using meat and other slaughter products was determined based on the results of microbiological and biochemical studies.
Tuberculosis, mycobacteriosis, pseudotuberculosis, pasteurellosis, etc., are diagnosed in animals during the postslaughter veterinary and sanitary examination.Invasive diseases can also occur in wild animals.Trichinellosis can affect all types of carnivorous and omnivorous animals.
Trichinella was not detected in any of the pork samples.The veterinary-sanitary evaluation of meat and internal organs of wild animals for various diseases of infectious and invasive etiology does not differ from the sanitary evaluation of slaughter products of domestic animals.No infectious diseases were detected during the research period.
Meat and meat products contain complete animal fat proteins, necessary mineral salts, and many vitamins.Animal meat contains all the substances required for the growth and development of the body and the maintenance of its vital activity.The nutritional value of meatdepends on its morphological and chemical composition, degree of digestibility, and organoleptic indicators (Koval, 2012;Terlouw et al., 2021).
Table 1 shows that all meat samples, according to organoleptic indicators, correspond to the indicators of freshquality meat.However, slaughter products derived from domestic and wild animals are somewhat different.The meat obtained from animals raised on private farms of the population was pink with a dark shade.The meat obtained from wild pigs grown at the State Enterprise "Forestry" was red.

Table 1
Organoleptic indicators of slaughter products of domestic and wild pigs (М ± m, n = 6) The surface of the joints is smooth and shiny.Tendons are elastic, dense Transparency and aroma of the broth Transparent, fragrant fat on the surface in the form of large drops Transparent, fragrant, fat on the surface in the form of large and small drops It should be noted that the meat of wild pigs had the most pronounced smell.This meat gave a broth with a faint aroma.The surface of the meat is red or pinkish-red in color, the drying crust is weakly expressed, and the fat is soft and partially colored in pink.Muscles on the section are red; they leave a slightly moist spot on the filter paper.When cut, the meat is dense and springy; the hole formed when pressing with a finger is quickly leveled.The smell is specific, characteristic of fresh meatwith a slightly sour smell.Fat condition: color -pale pink; soft, elastic; does not have the scent of salting or bitterness.Transparency and aroma of the broth: transparent, aromatic, fat on the surface in fine drops.
Therefore, according to organoleptic indicators, meat obtained from domestic and wild animals corresponded to fresh meat.
As a result of the organoleptic evaluation of the meat of domestic pigs, it was determined that the carcasses obtained from the slaughter of healthy animals differ among themselves in terms of quality indicators.Therefore, two groups of carcasses with different organoleptic indicators were determined.The first group -NOR pork had the best organoleptic indicators: the surface is covered with a pink crust, the muscles are pink, slightly moist, do not leave a wet spot on the filter paper, and the fat is soft and white.The meat is dense and tender when cut, and when pressed with a finger, the pit immediately fills up.The smell is specific, characteristic of fresh meatwith a faint sour smell.The broth has good taste properties, is aromatic, is specific for this type of meat, and has fat balls of the same size that are evenly distributed on the surface of the broth.Organoleptic indicators of pork of the second group (PSE), obtained from animals of different age groups, differed from high-quality meat (NOR) by a less elastic consistency, the cut surface was soft, significantly moistened (exudative), the color was pale pink, the crust dried in formed slowly during the ripening process.The fat is shiny, slightly softened, white-yellow in color, and crumbles when crushed.The tendons and joints of the limbs are hard, white, less shiny, the synovium is transparent.The following changes were observed in the organoleptic indicators of the broth from such meat: less aromatic, cloudy, fat balls unevenly distributed on the surface of the broth.
Under the terms of Ukraine's membership in the WTO, new market regulation systems are being created, which should meet European requirements for the quality and safety of food products as much as possible.The research of chemical and microscopic indicators of the meat of domestic and wild pigs was based on the methods of research on the difference in the chemical composition of the meat of healthy and diseased animals (Novhorodska, 2016).In the meat of healthy animals, in the process of biochemical ripening, most physicochemical parameters change within 6-24 hours after slaughtering the animals.During the ripening of the meat of sick animals, changes in physico-chemical parameters do not coincide after slaughter.In cases where we had a suspicion that the meat was obtained from an ill or slaughtered animal in a state of agony, we used biochemical research methods: we determined the pH, carried out a reaction with copper sulfate, and a peroxidase reaction (Table 2).For physical and chemical studies, meat samples were taken from the superficial and deep layers of muscles weighing up to 200 g.

Table 2
Biochemical and microscopic parameters of pig meat (М ± m, n = 6) Name of the indicator Domestic pigs Wild pigs Reaction with copper sulfate, number of samples "+"; "±"; "-" --рН 5.7 ± 0.5 5.5 ± 0.7 Peroxidase reaction, number of samples "+"; "±"; "-" + + Microscopy of smears-imprints, the number of microorganisms in the field of view of the microscope 9.3 ± 0.8 12.2 ± 0.6 Note: (-) -negative reaction; (+) -positive reaction; (±) -doubtful In the meat of healthy animals, in the process of biochemical ripening, most of the physicochemical parameters change within 6-24 hours after the slaughter of the animals, and autolytic processes of tissue component decay take place.The authors noted that the processes of decay in muscle tissue lead to significant changes in the optical-geometric properties of its surface and near-surface layers (Shchebentovska, 2014).During the ripening of the meat of diseased animals, the change in physical and chemical parameters during the same time after slaughter does not pass (Brewer & Novakofski, 2008).The indicator of the mass fraction of moisture is important since a large amount of moisture in meat contributes to the reproduction of microorganisms and rapid spoilage (Bogatko et al., 2017).As can be seen from the table, the reaction with copper sulfate in all samples was adverse.The peroxidase reaction was positive.This indicates that the meat is obtained from a healthy animal.The pH of meat depends on many factors, including the autolysis process.Autolytics are the process of disintegration of tissue components under the influence of enzymes contained in them, which begins in the tissues of the animal immediately after slaughter (Huang et al., 2021).In addition, the meat's pH affects the carcasses' ripening process.According to research results Shebanin P. ( 2016) it was noted that the pH index of pig meat of all groups and weight conditions was 5.40-5.44units.Such results of studies of the active acidity of the muscle tissue of the experimental animals prove that no violations of the ripening process of the carcasses were detected.
After the animal's life has ended, the composition and properties of tissues, primarily muscle, change significantly.Due to the cessation of oxygen supply and suspension of synthesis processes, the metabolism of substances and energy in tissues is disorganized.As a result, reverse life processes become irreversible and flow in one direction -decay.Postmortem changes in muscle tissue are related to the activity of enzymes since enzymes are not inactivated when the animal dies (Strashynskiy et al., 2019).Specific autolytic transformations in muscle tissue occur following the characteristics of metabolism, concentration, and localization of enzymes (George et al., 2016;Kaimbayeva et al., 2020).Depending on the composition of the tissue and the concentration of hydrolase, the degree of destructive transformations of components is different for different types of muscle tissue.Autolytic transformations of meat are based on changes in the carbohydrate system, the ATP resynthesis system, and the state of myofibrillar proteins that are part of the contraction system (Paska et al., 2017;Balan et al., 2020).
Changes in meat caused by autolytic processes occur in meat technology in various ways of processing, for example, during cooling and storage of chilled beef, freezing and cold storage, thawing, salting, grinding, etc.The nature and depth of autolytic changes in meat affect its quality and nutritional value.Our research determined that the pH values corresponded to fresh meat (Table 2).The analysis of organoleptic research data shows that the meat of domestic and wild pigs corresponds to the indicators of good quality meat.Meat from domestic pigs: the color is characteristic of pork (from pink to pale red); the smell is characteristic of pork; the consistency is elastic (the pit is leveled in the first 1-3 seconds after pressing with a finger); subcutaneous fat is white, unchanged; tendons are shiny, dense, elastic.The cooking test in all cases confirmed the meat's excellent quality (the broth is transparent, with drops of fat on the surface).The meat of wild pigs: color -red; the smell and consistency are characteristic of pork; subcutaneous fat is pale pink, unchanged; tendons are shiny, dense, and elastic.The cooking test in all cases corresponds to good quality meat.

Conclusions
Summarizing the research results, it was established that all samples, according to organoleptic indicators, corresponded to the indicators of fresh, high-quality meat, the reaction with 5 % sulfuric acid in the broth -in all samples, the broth is transparent; The pH of the meat ranged from 5.5 to 5.7; the peroxidase reaction was positive.An anatomical comparison of the humerus of wild and domestic pigs revealed the presence of a supra-block opening at the distal end of these bones of wild pigs, which is not found in domestic pigs.
Prospects for further research.Further research will determine the content of heavy metals and radionuclides in the meat of domestic and wild pigs.