Том 12 № 3

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  • Документ
    Hydrodynamic and energy parameters of gas-liquid media
    (2018) A. Shevchenko, O. Stepanets, A. Sokolenko, O. Bilyk
    The paper presents the results of studies related to determining the interconnections between hydrodynamic and energy parameters of gas-liquid media. The whole scope of information about them taken together allows evaluating the prospects of searching for new technologies and their improvement. In the studies, phenomenological generalizations of theories that comply with Archimedes’, Henry’s, Pascal’s laws and the superposition principle have been used to determine the driving and resistance factors when circulation circuits of media appear. It is shown that the energy potential of the latter results from the dissolution of the gas phase and the synthesis of the dispersed gas phase during self-organized or forced processes. These two causes are interrelated, but their manifestations are different. The presence of a dispersed gas phase, regardless of the form it appears in, a priori means the presence of a driving factor in the creation of circulation circuits, whereas the presence of a dissolved gas phase is only the root cause of the formation of the dispersed gas phase. In anaerobic processes, gas phase is represented by carbon dioxide, and in aerobic, by air or nitrogen from the composition of air and CO2. The total driving potential of circulation circuits is determined by the gas-holding capacity that, in turn, depends on the intensity of the synthesis of the dispersed gas phase, on the geometry of the media volumes, and on the physical properties of the phases. The gradient by the level of saturation of the liquid phase by the gas phase is determined basing on their physical and chemical properties and by the hydrostatic pressures of the liquid phase. The boundary saturation depends on the gas phase pressure in the supraliquid volume and the hydrostatic pressure. It is shown that a factor that intensifies mass-exchange processes is the relative rate of emergence of the bubbles in the gas phase. Calculation formulae are developed to estimate the gas-holding capacity and driving factors in the form of Archimedes’ buoyant forces. It is pointed out how important circulation circuits are in creating desaturation and saturation zones of media in order to improve the living conditions for microorganisms.
  • Документ
    Edible film-forming coating with CO2-extracts of plants for meat products
    (2018) A. Soletska, K. Nistor, V. Hevryk
    In this work, a film-forming coating for natural semi-finished pork meat has been developed, which has barrier properties against microbial flora and free oxygen radicals. Polysaccharides such as agar, gelatin, cornstarch, and citrus pectin were used as components of a film-forming coating, as well as CO2-extracts of parsley and ginger. It has been found that the most effective is a coating with the following composition: agar – 0.25%, citrus pectin – 0.5%, citric acid – 0.5%, CO2-extract of parsley or CO2-extract of ginger – 0.1%. This coating prolongs the shelf life of natural semi-finished pork meat at a storage temperature (–1…+1)°С for 2 days compared with the traditional technology.Studying the effect of the film-forming coating developed on the organoleptic properties of meat has shown that on the 7th day of storage at a temperature (–1…+1)°С, there were no signs of spoilage like putrid smell, greenish stain, and sliminess that were observed in the samples without coating. The study of the effect of the coating on the microbiological parameters of the meat has shown that the best microbiologcal stability that does not exceed the allowable values after 7 days of storage at a storage temperature  (–1…+1)°C is that of the sample covered with the film-forming coating with a CO2-extract of parsley. The study of the effect of the film-forming coating on the physical and chemical properties of meat has shown that peroxide number of its fat content is lower by 0.007% of iodine, and the acid number of its fat content is 0.39 mg KOH/kg of fat lower compared to the values of these parameters in the meat samples without coating. Besides, during storage, the mass loss in the meat samples covered with the coating developed was about 6 % less, thus reducing drying loss.
  • Документ
    Determination of functional and technological properties of beef based on the analysis of color digital images of muscular tissue samples
    (2018) О. Savinok, N. Azarova, О. Arsiriy, А. Nikolenko
    The paper considers the kinetics of changes in the values of рН and temperature of beef of slaughtered Holstein bull calfs aged 15 months during cold storage. It has been established that the rate of pH decrease during autolytic maturation is greatly influenced by the rate of temperature decrease. This was observed in the two muscles taken as an example – m. Longissimus dorsi and m. Semimembranosus. A method is suggested of analysing digital images of beef muscular tissue samples in the color coordinate space to study the beef’s color characteristics during cold storage. It has been found out that using this method, with second order polynomial fitting, provides a mean-square approximation error of 5.6% on average from the minimum coordinate of the maximum level of the red component of color. This suggests the objectivity of its use to assess the color of the meat. An analytical dependence has been established between the beef color and the term of refrigeration with the use of information technologies. In accordance with it, it has been determined that due to biochemical processes, there takes place intense oxidation of myoglobin, which results in a dark color of the muscle tissue. In the course of time (up to 120 hours of storage), the red color intensity increases. This is accompanied with decomposition of myoglobin forms that have appeared, and with appearance of МbО2. When beef is stored for more than 140 hours, deeper iron oxidation begins, with formation of methyoglobin, and the brightness of the meat decreases. The developed method allows automating registration and processing of images of muscle tissue in real time, increases the productivity of the assessment, and gives an opportunity to obtain reliable objective results about the meat properties during its storage.
  • Документ
    Features of the hemicellulose structure of some species of regional raw materials and products of their enzymatic hydrolysis
    (2018) O. Nikitina, N. Cherno, S. Ozolina
    Nowadays, it is recognized that a lot of polysaccharides are biologically active. It is well known that these biomolecules show the highest level of their activity if they are water-soluble preparations, their molecular weight being 15–25 kDa, and if they preserve the supramolecular structure of carbohydrates. Basing on the fact that β-glucans of mushrooms are characterized by the antitumor, anticoagulant, anti-inflammatory, and immunomodulatory activities, it is important to determine whether regional raw material contains polysaccharides of a similar structure, and to define the conditions for their fragmentation to obtain products with a given molecular weight. The purpose of the work was to characterize the features of the structure of the hemicellulose complex of the Agaricus bisporous and Pleurotus ostreatus and products of their limited enzymatic hydrolysis. To determine the primary structure of hemicellulose polysaccharides, the 1H-NMR spectra of the samples were registered. It has been shown that β-D-(1→3)/β-(1→6)-glucan dominates in the hemicellulose of Pleurotus ostreatus. Among the hemicelluloses in the Agaricus bisporis, the main polysaccharide was galactoglucan. Its main chain consisted of β-D-glucopyranose residues interconnected with (1→3)-glucosidic bonds. The positions of O-6 monosaccharide are joined by the side branches in the form of β-D-glucopyranoses and the terminal residues of β-D-galactopyranoses. The hemicelluloses of Pleurotus ostreatus also contain manogalactan. Complexes of hemicelluloses of both types of mushrooms contain linear α-(1→3)-glucan in small quantities. It has been studied how the molecular-weight distribution of products of limited hydrolysis of hemicelluloses depends on the conditions of their treatment with the enzyme with β-(1→3)-glucanase activity. The maximum accumulation of a fraction with a given molecular weight of 15–25 kDa was observed at a ratio of E:S = 1:45 and treatment time of 21 hours. A specific reaction with congo red has proved there is a triple helical conformation of the main chain of the polysaccharide for this fraction of carbohydrates, so the supramolecular structure of the molecule is preserved.  
  • Документ
    Investigation of the safety grapeseed powder as an alternative to cocoa-powder in a confectionery glaze
    (2018) O. Gorodyska, N. Grevtseva, O. Samokhvalova, O. Savchenko, A. Grygorenko
    The article considers the safety and environmental cleanliness of grapeseed powders compared to the natural and alkalized cocoa powders. The content of heavy metals in the investigated powders has been determined by the atomic adsorption method; radionuclide activity has been determined by the spectrometric method; the presence of mycotoxins B1, T-2-toxin, zearalenone, and deoxynivalenol (vomitoxin) has been determined by thin-layer chromatography; the amount of nitrates has been determined by the ionometric method; contamination of powders with organophosphorous and organochlorine  pesticides has been determined by chromatographic method.  According to the results of experiments, the content of heavy metals in all investigated powders is within the limits of the maximum permissible concentration, whilst powders of grapeseeds are notable for a significantly lower mass content of plumbum, zinc, copper salts. As for the radioactivity of grapeseed powders, the activity of radionuclides is significantly below the permissible level. Presence of aflatoxin В1 has been detected in the alkalized cocoa powder sample, of zearalenone – in the grapeseed powder oilcake sample. Their concentration does not exceed the allowable concentration. Mycotoxines are absent in other samples investigated. Concentration of nitrates in the natural and alkalized cocoa powder samples is by 20–30 times higher than that found in grapeseed powders. The content of organophosphorous and organochlorine  pesticides in all cocoa powder samples and all grapeseed containing powders is below the method’s threshold of detectability. The glaze samples containing the additives investigated have a considerably lower content of heavy metals compared to the reference samples. Glaze with cocoa powder partially replaced with grapeseed powders has high organoleptic quality parameters. During the glazing process, it is applied on the surface of products in thin layers and cools down in small waves. The results obtained prove that domestic raw materials are safe for human health, and confectionery glaze containing grapeseed powders as partial replacement of the cocoa powder has high safety characteristics.