Preparation of porous silica nanocomposites from montmorillonite using sol-gel approach | Author : Dmytro Doroshenko, Igor Pylypenko, Borys Kornilovych, Irina Subbota | Abstract | Full Text | Abstract :The object of research is montmorillonite, which due to its properties and structure shows high sorption characteristics. However, the significant barrier to its use in industrial water purification technologies is the tendency of montmorillonite to be self-dispersed in aqueous solutions on elementary structural layers and to form stable suspensions. It creates difficulties with separating the solid and liquid phases after the sorption process. The authors used the sol-gel method for the synthesis of nanocomposite materials based on montmorillonite using tetraethoxysilane as a gelling agent. The synthesis involves the hydrolysis reaction of tetraethoxysilane and the subsequent polycondensation of silica molecules with hydroxyl groups of montmorillonite. The obtained samples inherit good sorption properties from a layered mineral and a solid frame structure from silica. Such a structure of synthesized nanocomposites is ensured by the presence of siloxane bonds, which help to bound together the elementary particles of montmorillonite. This, in turn, improves the water resistance of samples. Based on the results of rheological studies, it has been shown that the basic processes of the structure formation in the initial water-alcohol suspensions of the hydrolysis products of tetraethoxysilane and montmorillonite occur at a concentration of 1 % silica, which is due to the colloidal and chemical properties of the investigated systems. It has been shown that the treatment of montmorillonite with tetraethoxysilane hydrolysis products leads to the formation of a material with lower ability to swell and with better separation of liquid and solid phases. The optimum content of silica in the sample, which is in the range of 0.1 to 14 %, makes it possible to reduce the optical density of solutions by 2.5 times compared with the original montmorillonite. It has been shown that the synthesized materials retain a sufficiently high sorption capacity to remove the cationic dye methylene blue (up to 158 mg/g), which rises with increasing clay mineral content. And has been having a higher selectivity (up to 3.4 dm3/mg). |
| Substantiation of proposals on the use of insulating apparatus in the liquidation of emergencies with the release of hazardous chemicals | Author : Pavlo Borodych, Natalya Deyneko, Pavlo Kovalev, Victor Streletc, Roman Shevchenko | Abstract | Full Text | Abstract :In work, the technical possibilities of using personal respiratory protective equipment are considered as an object of research. Such funds are used in fire and rescue units, during emergency rescue operations related to the liquidation of emergency situations with the release of hazardous chemicals. It is shown that one of the most problematic places for the participation of personnel of fire-rescue units is the contradiction between the protective properties of personal protective equipment and the danger that may be in the organization of the release of a hazardous substance. This applies to the personnel of firefighting and rescue units, which are the first to start carrying out appropriate rescue operations. As a result, even with the full implementation of existing regulatory requirements, work in isolating devices can be dangerous for the rescuer.
At the heart of the chosen approach to the solution of the task in view lay the assessment of the possibility to provide such a general protection factor of the insulating device in the assembly with the front part, which will exceed the coefficient of toxic environmental hazard. The study used an analytical definition of the requirements for the testing of compressed air equipment equipped with helmet-masks. It showed that rescuers can work at the epicenter of an accident with the release of hazardous chemicals, if in checking the tightness with the help of devices when creating a test vacuum of 2000 Pa, the rate of the decrease in vacuum will not exceed 32 Pa/min. However, experimental verification of the obtained theoretical results allows to state that the fire and rescue unit will not be able to achieve this requirement. Increasing the test dilution to a level that exceeds 1000 Pa is accompanied by a significant increase in the suction in the system «insulating apparatus – respiratory organs».
It has been proven by experience that protection devices are provided with compressed air, equipped with pulmonary automatic devices, which create an overpressure air in the UMS. In this case, the threaded connection of the insulating device with the front part must not be used. This allows to recommend the use of compressed air devices equipped with pulmonary automatic devices as a basic set of isolating apparatuses, creating air overpressure in the UMS
Exceptions are subdivisions, in the area of operational departure of which there are facilities on which there is a large number of hazardous chemicals with a toxic hazard coefficient of more than 2,3·105. In this case, they should be completed with complexes of personal protective equipment of ampoule type. |
| Analysis of dynamics of man-made fires in conditions of urbanization in Ukraine | Author : Kateryna Vasiutinska, Sergey Barbashev | Abstract | Full Text | Abstract :Research subject is the dynamics of manifestations of fires of man-made origin in urban settlements in relation to the demographic changes in urbanization processes in the period 1997–2017. The problem cause of increase of urbanization is global climatic changes which is initiates fires. Those fires are one of the most dangerous events with large numbers of victims and significant material losses.
The methodology for studying the dynamics of manifestations of emergencies of man-made origin has never considered relationship between the rate of urbanization in Ukraine over the past 20 years and demographic changes.
The study uses a statistically-analytical and functional method for estimating the number of fires. The study shows a high degree of correlation between the decrease in the number of fires and the reduction in population density with a slow pace of urbanization over the last 20 years. The basis for the positive dynamics of the manifestations of fires is the objective conditions of the technogenic-urban environment and the subjective factors associated with the human factor.
It is shown that the demographic factor affects the growth of the risk of human deaths on one side and the number of fires of man-made origin is reduced on the other side, in case of urbanization on the level of up to 67 %. Next level up of urbanization leads to a sharp increase in the number of emergencies. At the same time, the tendency to reduce the risk of death from fires with a decrease in population density and an increase in the level of urbanization above 67 %.
The effect of reducing the vulnerability of the urban population, except demographic factor, is related of providing cities with significant human, technical and material resources.
Due to the revealed correlations of demographic and urban factors with the dynamics of the manifestation of fires, we are able to develop measures to monitor, prevent and eliminate the consequences of fires in populated areas. A risk-based fire-fighting strategy is applicable to protect people and property in areas of high population density. |
| Research of fatty acid composition of tomato seeds | Author : Olga Benderska, ?lexandr Bessarab, Vitaliy Shutyuk | Abstract | Full Text | Abstract :The object of research is secondary products of tomato processing, namely, tomato seeds of technical and biological maturation. One of the most problematic places in the tomato processing industry is the formation of a large amount (up to 30 % of the total mass of tomatoes) of waste containing a large amount of proteins, lipids, carbohydrates, minerals and biologically active compounds. The solution of the problem of recycling of secondary tomato resources becomes possible provided that they are determined by their chemical composition and biological value and the selection of technological parameters for further processing.
During the studies, the chemical composition of tomato seeds was analyzed and it was found that tomato seeds are an excellent source of carotenoids, proteins, sugars, fibers, waxes and oils. At the same time, the seeds of the technical stage of maturity differ from the biologically mature seeds with high content of proteins – by 0.81 %, fiber – 0.4 % and sugars – by 0.21 %. The obtained results of the analysis of the fatty acid composition of tomato seeds of technical and biological maturity allowed to establish that among the fatty acids in the analyzed samples contained 47.72 % polyunsaturated tomato seeds of technical maturity and 50.96 % – biological maturity. There are no trans isomers, and the ratio between the unsaturated omega-3 and the omega-6 acids in the seed corresponds to the latest recommendations for nutrition of the population in accordance with the principles of enthusiasm.
The obtained results of the analysis of the chemical composition of the secondary tomato raw material have shown that the issue of improving the technologies of complex processing of tomatoes, which will provide high economic and social effects, remains an important issue. Thanks to the use of semolina food products from tomato seeds, it becomes possible to obtain foods that have high levels of essential amino acids, salts and water soluble proteins, carbohydrates and lipids that are represented by poly unsaturated fatty acids. |
| Development of the technology of mushroom sauce with functional ingredients | Author : Irina Kublinskaya | Abstract | Full Text | Abstract :The object of research is mushroom powders of champignons (Agaricus campestris), reishi (Ganoderma lucidum), shiitake (Lentinula edodes) and technology mushroom sauce with a thickener.
In Ukraine, the consumption of cultivated mushrooms, namely mushrooms, shiitake and reishi is growing more and more, as evidenced by the growing volumes of mushroom cultivation by Ukrainian farms. The scientific literature does not adequately cover the issue of effective technologies for obtaining mushroom powder-like semi-finished products and finished products from them for restaurants. The use of mushroom powders from shiitake, reishi and champignons mushrooms to prepare mushroom sauces leads to an increase in the number of essential amino acids, B vitamins, PP, extractives in the finished product. As a result, biological value improves, organoleptic quality parameters of mushroom sauces improve. This will increase the popularity of mushroom sauces among modern consumers of restaurants.
In the course of research the assortment of sauce products of high biological value and the specifics of physiological influence of shiitake, reishi and champignons mushrooms on the human body have been analyzed. A scientifically-determined technology of sauce of mushroom of increased biological value with functional ingredients – mushroom powders of champignons mushrooms, reishi, and shiitake has been developed.
The optimization of the recipe of the newly created product has been optimized and the optimum prescription composition of the mushroom sauce with mushroom powders with a ratio of mushroom powders in the recipe composition of 1:1:2 (shiitake:reishi:champignon mushrooms) has been proposed. The structural and mechanical properties of an innovative sauce were compared and compared with the control sample of mushroom sauce prepared according to the traditional technology. So, at a shear rate of 200 s-1, the viscosity of the developed sauce is 0.38 Pa·s, whereas the viscosity of the mushroom sauce prepared according to the traditional technology is 0.3 Pa·s.
It is established that mushroom sauce with mushroom powders has high biological value, optimal rheological and organoleptic quality indices.
The developed sauce with mushroom powders will enable to expand the assortment of sauce products of high biological value on vegetable raw materials for restaurants. The introduction of innovative technology will significantly save the time of production of own production sauces and financial costs, since the developed technology involves the production of mushroom powders from non-conformal mushroom raw materials. |
| Development of a complex bakery improver «Freshness SMS Super» to extend the freshness of wheat bread | Author : Tetyana Vasylchenko, Olena Bilyk, Oksana Kochubei-Lytvynenko, Natalia Breus, Yulia Bondarenko | Abstract | Full Text | Abstract :The object of research is wheat bread, one of the biggest drawbacks of which is staling during storage. The intensity of the processes in the finished product, which determine the staling, depend on the quality of the raw materials, in particular, the baking properties of the flour.
The solution to the problem of prolonging the freshness of wheat bread is possible using non-traditional raw materials, food additives and complex bakery improvers.
During the development of the complex bakery improver «Freshness SMS Super», dry whey enriched with Mn and Mg was selected as a functional basis, the technology of which was developed by scientists of the National University of Food Technologies (Kiev, Ukraine). The active part of the improver includes carboxymethyl cellulose, emulsifier, enzyme preparation of amylolytic action with maltogenic amylase, ascorbic acid, maltodextrin, apple pectin.
Based on the Sheffe’s centrifugal plan, we obtained graphical models that predict the optimal dosage of a complex bakery improver «Freshness SMS Super» in the case of processing flour with various baking properties. According to the graphical models it is found that in the case of using medium-strength flour that has a normal gas-tongue ability and water-repellent capacity in the range of 59-61 %, the optimal dosage of the complex bakery improver « Freshness SMS Super» is 1.5 % of the weight of flour.
It is established that when using a complex bakery improver «Freshness SMS Super» the products become harder. This is due to the fact that the recipe for a complex bakery improver includes moisture-retaining food additives that, during the storage of bakery products, release moisture more slowly than biopolymers of flour. Also in the composition of the improver is an enzyme preparation with maltogenic a-amylase, which slows the process of starch retrogradation, reducing the loss of moisture by starch.
Thanks to the use of the complex bakery improver Freshness SMS Super, bakery products keep freshness up to 72 hours of storage unpacked regardless of the baking properties of the flour. |
| Justification for use of two-component mixtures for cooking wheat bread | Author : Olena Kalashnyk, Olha Barabolia, Olena Mykhailova, Svitlana Pisarenko, Olha Yudicheva, Svetlana Moroz, Gabriella Birta, Alina Tkachenko, Olena Kyrychenko, Nadiya Gnitiy | Abstract | Full Text | Abstract :The object of research is wheat bread. One of the most problematic places is the need to correct the food ration of the population in order to enrich traditional food with vital nutrients. Taking into account that bread refers to the products that are in the daily diet of the majority of the population, improving its nutritional value helps to improve the diet as a whole. Improving the nutritional value of bread can be achieved by adding alternative types of flour – corn, oatmeal, spring wheat flour.
In the course of research, the modeling of formulations was used by the method of tasting evaluation. 9 formulations of bread based on two-component flour mixtures with the addition of corn, oats, buckwheat and spring wheat flour were developed (7.5 % and 15 %).
The obtained samples were examined for compliance with organoleptic and physicochemical parameters, as well as safety indices. According to the physicochemical indicators of quality (humidity and acidity), all the samples corresponded to the Ukrainian normative documentation, the safety indicators also did not exceed the permissible limits. The best organoleptic properties were bread, in the composition of the recipe which was added wheat flour in the amount of 7.5 % and 15 %. A high number of points received bread from a mixture of wheat and oat flour (7.5 %). Samples with the addition of corn and buckwheat flour differed in organoleptic properties. This is due to the fact that different types of flour in different ways affect the taste characteristics of the finished product.
The received results of researches testify to expediency of application of two-component mixtures of flour. It is expected to improve the amino acid composition of the product, reduce energy value due to the chemical composition of flour used in new formulations.
Thanks to this, it is possible to obtain bread for functional and dietary purposes. In comparison with similar known formulations, the developed samples provide the following advantages: improvement of nutritional value, improvement of organoleptic properties of the product. |
|
|