Investigation of properties of sunflower and rapeseed oils obtained by the soxhlet and microwave extraction methods

Saabunud / Received 01.02.2022 ; Aktsepteeritud / Accepted 15.04.2022 ; Avaldatud veebis / Published online 15.04.2022 ; Vastutav autor / Corresponding author: Valentyna Bandura ; [email protected] main purpose of the study was to evaluate the possibility of replacing hexane, which is traditionally used for the extraction of vegetable oils, with ethanol as a safer solvent when extracting oil from sunflower meals and rapeseed in the microwave field. Thus, the influence of the solvent type on physicochemical characteristics of oil and the low-fat meal was studied. The main indicators of the composition and quality of sunflower and rapeseed extraction oil were studied. The quality of oil and ways of its use in food products are mostly determined by its fatty acid composition. Analysis of the fatty acid composition of the oil was performed by the method of gas chromatography using a column HP-88 100 m* 0.25 mm*0.20 µm. The possibility of using oil in food was established by conducting pilot laboratory studies and investigating changes in physicochemical parameters during storage. The extraction by the Soxhlet method (hexane as a solvent) was compared with the method of extraction of raw materials in a microwave field (ethyl alcohol as a solvent). Studies of physicochemical parameters indicate the degree of oil oxidation (determination of peroxide and anisidine values). The peroxide value is an indicator of the content of primary oxidation products. The peroxide value of the oil obtained by the method of Soxhlet extraction (hexane as a solvent) was 5.0 (½O mmol) kg–1 . The peroxide value of the oil obtained by extraction in a microwave field (ethyl alcohol as a solvent) was 3.8 (½O mmol) kg–1 . The anisidine value is an indicator of the content of aldehydes in vegetable oils (secondary oxidation products). The anisidine value of the oil obtained by the method of Soxhlet extraction (hexane as a solvent) was 0.3 s.u. The anisidine value of oil obtained by extraction in a microwave field (ethyl alcohol as a solvent) was 0.2 s.u. Comparing the data of peroxide and anisidine values, it can be argued that the oil obtained by extraction of raw materials in a microwave field (ethyl alcohol as a solvent) had the best indicators. The acid value is one of the main qualitative indicators that characterize the degree of oil freshness. The acid value of the oil obtained by the method of Soxhlet extraction (hexane as a solvent) was 3.1 (mg KOH) g –1 . The acid number of the oil obtained by extraction in a microwave field (ethyl alcohol as a solvent) was 2.1 (mg KOH) g –1 . A comparison of the acid values of oils extracted from the raw material by different extraction methods shows that the oil obtained by the method of extraction of raw materials in a microwave field using ethyl alcohol as a solvent has the best acid value. Studies have shown that the oil, which was obtained by extraction of raw materials in a microwave field using ethyl alcohol as a solvent, had the best resistance to oxidation during storage (three months)

Application of the differential scanning calorimetry method in the study of the tomato fruits drying process

Saabunud / Received 18.05.2020 ; Aktsepteeritud / Accepted 14.07.2020 ; Avaldatud veebis / Published online 14.07.2020 ; Vastutav autor / Corresponding author: Ihor Kupchuk e-mail: [email protected] changes in the process of heating fresh fruit, sundried fruits and powder obtained from the dried tomato fruits were studied by differential scanning calorimetry method application. The kinetics of the shredded fruits in the dryer proves the prospects for using convective drying, which is performed for 295 minutes. The kinetic coefficients of drying and critical moisture content in the crushed fruits of tomato were determined. The kinetic coefficients were determined by the graphicalanalytical method: a = 0.839, ln(α) = 1.3 and α (1 s–1 ) = 0.262. It was determined that the critical maximum moisture content for drying the shredded fruits of tomatoes is 1.503% mm–1 , after what the process of combustion of vegetable tissue begins. The application of the differential scanning calorimetry (DSC) method allowed the fuller study of the mechanism of drying the fruits of tomato in different condition: fresh, sundried and dried. It was determined that the greatest amount of energy is consumed to remove free moisture (1,993 J g–1 ) from the fresh tomatoes. At the same time, when being cooled, crystallization in plant tissue occurs with the release of energy in the amount of 0.03922 J g –1 . When drying the previously sun-dried tomatoes the process of moisture removal and the partial decomposition of the compounds that are unstable to temperature is completed. At the same time, at the 129.61 °C temperature in the powder obtained from the fruits of tomatoes, melting of carbohydrates and other compounds occurred. Thus, this confirms the need to observe the normalized value of the mass fraction of moisture in the powders in the process of their packaging, storage and use. The basic technological system of production of powder from dried fruits of tomatoes is offered

Case study: Dynamics of sunflower seed movement in the vibrating tray of the infrared dryer and its influence on the drying process

Saabunud / Received 03.06.2021 ; Aktsepteeritud / Accepted 21.09.2021 ; Avaldatud veebis / Published online 21.09.2021 ; Vastutav autor / Corresponding author: Valentyna Bandura [email protected] of researches on the study of the material particle movement on the vibrating surface of the container machine intended for seed drying in the infrared field is carried out. Comparison of traditional devices for dehydration of raw materials with energy supply of infrared irradiation is performed. It is shown that current tendencies of the development of heat and mass transfer equipment are connected with the use of electromagnetic generators of infrared energy. The purpose of the work is to study the process of movement of sunflower seeds on a vibrating tray dryer. To achieve this goal, a dynamic scheme of the vibrating tray has been proposed and theoretical and experimental studies of the process of grain movement have been carried out. It has been established that when the speed of drive electric motors increases from 950 to 970 rotations per minute, the speed of vibro-transportation increases as well, but when reaching a certain value of speed, under a further increase in speed, the speed of vibro-transportation decreases. Experimental studies have allowed to specify the design parameters of vibrating trays and select rational parameters of the technological process of drying, namely the oscillation frequency of the vibrating tray, which is f = 100 s–1

USING OF THE WAVE TECHNOLOGIES IN INTENSIFICATION PROCESSES OF HEAT AND MASS TRANSFER

The advantages of wave technologies in comparison with traditional thermal technologies are considered. The aim of research is using of innovative wave technologies to intensify the processes of heat and mass transfer in the processes of dehydration and extraction, while reducing energy costs. A classification of the mechanisms of intensification of heat and mass transfer processes is proposed. Technical methods for intensifying heat and mass transfer during the processing of plant raw materials using technologies for targeted delivery of energy are developed. Samples of equipment are presented that implement technologies of directed energy action and innovative products obtained at these facilities. The results of experimental studies of drying in the microwave and infrared fields are shown

Теоретичне обґрунтування та ідентифікація процесів тепломасообміну у вібраційній сушарці з ІЧ-енергопідведенням

The paper contains theoretical substantiation of the processes of radiation-convective heat and mass transfer between all the defining objects inside the vibration dryer with IR energy supply. The presented equations, developed on the basis of the heat and material balance, describe the basic dynamic characteristics of the drying mode for oil-bearing grain material in a continuously operating IR dryer.Since there is no exact analytic solution of the presented mathematical model shaped as a system of differential equations with partial derivatives, the authors propose an approximate solution. The latter allows identifying the dependences between the distribution of temperature and moisture content of grain and oil-containing materials along the length of the dryer for any moment of time.The numerical solution of the reduced mathematical model is possible only with the presence of certain interconnected kinetic coefficients. The kinetic coefficients can not be found experimentally by direct measurements; therefore, the article proposes a method to overcome these difficulties. The presented approximate analytical solution of the synthesized mathematical model, with the use of the method of inverse problems, has allowed determining sets of coefficients by the results of the experimental identification of dehydration. In the future, experimentally identified parametric complexes of the model can be used in the analysis of the drying process for approximate solutions or for further exact numerical solution.Experimental studies of dehydration of grain material have proved that when the power of an IR source is increased from 400 to 500 W, the time for drying from the initial moisture content of 11 % to 8.75 % decreases from 9 to 7 minutes. It is determined that the Rebinder effect characterizing the dampness and thermal properties of the material decreases with a decrease in the moisture content from 0.04 at 11 % to 0.01 at 9 %. This is interesting from the practical point of view as the obtained results and the developed mathematical model can be used for increasing the energy efficiency of the processes of thermal drying in typical facilities that prepare oil-bearing grain materials for their processing.Теоретически обоснованы процессы радиационно-конвективного тепломассообмена между всеми определяющими объектами внутри вибрационной сушилки с ИК-энергопводом. На основе теплового и материального балансов определены уравнения, описывающие основные динамические характеристики режима сушки маслосодержащего зернового материала в непрерывно действующей ИК-сушилке.В связи с тем, что точного аналитического решения представленной математической модели в виде системы дифференциальных уравнений в частных производных не существует, предложено приближенное решение. Оно позволяет идентифицировать зависимости распределения температуры и влагосодержания зернового и маслосодержащего материала по длине сушилки для любого момента времени.Численное решение приведенной математической модели возможно только при наличии определенных взаимосвязанных кинетических коэффициентов. Кинетические коэффициенты экспериментально прямыми измерениями найти невозможно, поэтому в статье предложен метод преодоления этих трудностей. На основе представленного приближенного аналитического решения синтезированной математической модели, с использованием метода обратных задач, определяются комплексы коэффициентов по результатам экспериментальной идентификации процесса обезвоживания. В дальнейшем экспериментально идентифицированные параметрические комплексы модели можно использовать при анализе процесса сушки на приближенных решениях или для дальнейшего точного численного решения.На основе экспериментальных исследований обезвоживания зерноматериала установлено, что при увеличении мощности ИК-источника от 400 до 500Вт время сушки с начальной влажности материала 11 % до 8,75 % уменьшается с 9 до 7 минут. Определено, что критерий Ребиндера, характеризующий влаготепловые характеристики материала, уменьшается при уменьшении его влажности из величины 0,04 при 11 % до 0,01 при 9 %. Это интересно с практической точки зрения и дает возможность использовать полученные результаты и математическую модель при энергетическом совершенствовании реализации процессов термической сушки в типичных объектах подготовки к переработке маслосодержащего зерноматериалаТеоретично обґрунтовано процеси радіаційно-конвективного тепломасообміну між усіма визначальними об’єктами всередині вібраційної сушарки з ІЧ-енергопідведенням. На основі теплового і матеріального балансів визначено рівняння, які описують основні динамічні характеристики режиму сушіння олієвмісного зернового матеріалу в безперервно діючій ІЧ-сущарці. У зв’язку з тим, що точного аналітичного розв’язку представленої математичної моделі у вигляді системи диференціальних рівнянь у частинних похідних не існує. Запропоноване наближене рішення дозволяє ідентифікувати залежності розподілу температури і вологовмісту зернового та олієвмісного матеріалу за довжиною сушарки для будь-якого моменту часу.Чисельний розв’язок наведеної математичної моделі можливий лише при наявності визначених взаємопов’язаних кінетичних коефіцієнтів. Кінетичні коефіцієнти експериментально прямими вимірами знайти не можливо, тому у статті запропоновано метод подолання цих труднощів. На основі представленого наближеного аналітичного розв’язку синтезованої математичної моделі, з використанням методу обернених задач визначаються комплекси коефіцієнтів за результатами експериментальної ідентифікації процесу зневоднення. В подальшому експериментально ідентифіковані параметричні комплекси моделі можливо використовувати при аналізі процесу сушіння на наближених розв’язках або для подальшого точного чисельного розв’язку.На основі експериментальних досліджень зневоднення зерноматеріалу встановлено, що при збільшенні потужності ІЧ-джерела від 400 до 500Вт час сушіння з початкової вологості матеріалу 11 % до 8,75 % зменшується з 9 до 7 хвилин. Визначено, що критерій Ребіндера, який характеризує вологотеплові характеристики матеріалу, зменшується при зменшенні його вологості з величини 0,04 при 11 % до 0,01 при 9 %. Це є цікавим з практичної точки зору і дає можливість використовувати отримані результати і математичну модель при енергетичному удосконаленні реалізації процесів термічного сушіння в типових об’єктах підготовки до переробки олієвмісних зерноматеріалі

Research of Wheat Drying in a Microwave and Combined Filter-microwave Dryer

The aim of the conducted study is to determine kinetics of the complex effect of microwave energy supply and filter drying of the process of water release from the wheat layer. There is offered a combination of MW and filter drying. A special feature of this combination must be its more effectiveness and high speed of water elimination from surface layers of wet seeds and, as a result, the productivity increase of the drying way, decrease of specific energy consumption.There was determined the influence of the specific load of the material, radiator power on processes of microwave and filter-microwave drying of wheat seeds. There were compared microwave, filter-microwave and convective drying of seeds by parameters of specific energy consumption, drying speed.The specific energy consumption at microwave drying of seeds was 4 MJ/kg, at filter-microwave drying 3.8 MJ/kg that is lower than existent convective dryers. The speed of microwave drying changes from 0,5 to 3 %/min, filter-microwave – from 0.3 to 0.7 %/min. The speed is at the level of standard convective dryers.The conducted studies allow to recommend a new combined way of FMW drying of seeds with low energy consumption.Revealed features of heating and drying are possible to be used at developing industrial dryers.The base of experimental data is possible to be used for optimizing and determining effective conditions of MW and FMW drying

RESEARCH OF WHEAT DRYING IN A MICROWAVE AND COMBINED FILTER-MICROWAVE DRYER

The aim of the conducted study is to determine kinetics of the complex effect of microwave energy supply and filter drying of the process of water release from the wheat layer. There is offered a combination of MW and filter drying. A special feature of this combination must be its more effectiveness and high speed of water elimination from surface layers of wet seeds and, as a result, the productivity increase of the drying way, decrease of specific energy consumption. There was determined the influence of the specific load of the material, radiator power on processes of microwave and filter-microwave drying of wheat seeds. There were compared microwave, filter-microwave and convective drying of seeds by parameters of specific energy consumption, drying speed. The specific energy consumption at microwave drying of seeds was 4 MJ/kg, at filter-microwave drying 3.8 MJ/kg that is lower than existent convective dryers. The speed of microwave drying changes from 0,5 to 3 %/min, filter-microwave – from 0.3 to 0.7 %/min. The speed is at the level of standard convective dryers. The conducted studies allow to recommend a new combined way of FMW drying of seeds with low energy consumption. Revealed features of heating and drying are possible to be used at developing industrial dryers. The base of experimental data is possible to be used for optimizing and determining effective conditions of MW and FMW drying

Розробка хвильових технологій інтенсифікації процесів тепломасопереносу

The study has proved that in order to improve the heat technologies of food production, innovative principles of energy supply are needed. The hypotheses of using wave technologies for targeted delivery of energy to elements of food raw materials are proposed. Classification of the mechanisms of heat and mass transfer intensification in food processing technologies is given. Thermophysical models of the vibrational and barodiffusion mechanisms are presented. The possibilities of a combined action of these two mechanisms are determined. It is shown that vibrational and electromagnetic fields can significantly intensify the processes of heat and mass transfer. Mechanisms, effects and mathematical models of barodiffusion and the action of vibrational fields are justified.The method of “dimensional analysis” has determined the numbers of wave similarity: modified numbers of Reynolds, Péclet, and Stanton. New numbers of similarity are proposed: the number of energy action and the dimensionless complex that takes into account the ratio of inertial forces caused by vibration and movement of the conveyor belt. On the basis of these numbers, similarities are generalized in the criterial form of a database of experimental data on extraction and drying. The methodological novelty in the processing of these experiments is the use of an effective mass transfer coefficient that takes into account the total effect of diffusion and inertial flows of liquid from the solid phase.The experiments were carried out to dry sunflower seeds in a vibration dryer. The results of drying wheat seeds and peas on the belt with electromagnetic energy sources are shown in the form of dependency graphs and mathematical models based on the database of the experimental data. The drying speed achieved was 0.4 %/min on the vibrating dryer; on the IR belt dryer, this parameter was 0.75 %/min when drying peas and 1.75 %/min when drying sludge and seeds of sunflower.The results of the complex experimental research on coffee extraction in a microwave extractor are presented in the paper. The evaluation of the completeness of extraction of extractive substances under the action of the microwave field showed the results, on average, 15 % higher than by the standard thermal method. The prospects of the combined action of the electromagnetic and vibrational fields are shown on the basis of the results for optimizing the microwave extractor.Предложены технологии адресной доставки энергии для интенсификации тепломассопереноса при переработке пищевого сырья. В основе предложенных гипотез – волновые технологии комбинированного электромагнитного и вибрационного действия. Обоснованы механизмы, эффекты и математические модели бародиффузии и действия вибрационных полей. Предложены числа волнового подобия, на основе которых обобщены базы экспериментальных данных по экстрагированию и сушке. Приведены результаты оптимизации микроволнового экстрактораЗапропоновано технології адресної доставки енергії для інтенсифікації тепломасопереносу при переробці харчової сировини. У основі запропонованих гіпотез – хвильові технології комбінованої електромагнітної і вібраційної дії. Обгрунтовано механізми, ефекти і математичні моделі бародіффузіі і дії вібраційних полів. Запропоновано числа хвильової подібності, на основі яких узагальнені бази експериментальних даних по екстрагуванню і сушінню. Наведено результати оптимізації мікрохвильового екстрактор

Innowacyjne metody suszenia nasion rzepaku energią mikrofalową

Rape is an important oil crop with a wide range of uses. Harvested rapeseed must be cleaned and dried before processing. The process of drying rapeseed as a small-seeded crop has its own specifics. One of the new drying methods is the use of microwave radiation, the disadvantage of which is uneven heating of the product. The purpose of this work was to study the modes of drying rapeseed by electromagnetic radiation in the ultra-high frequency range in combination with filtration. The indicators of the intensity of oilseed drying by infrared irradiation on the experimental stand were determined. The analysis of the conducted studies showed that the temperature of seeds at the maximum microwave power rises in general 1.5 to 1.8 times faster than at half the power. The higher the seed moisture content is, the higher the rate of temperature increase. After each blowing cycle, which lasted for five seconds, the temperature of the rapeseeds was set higher than the previous temperature, and after increasing the blowing time up to fifteen seconds, the temperature decreased by 8–12°C and cyclically stabilized. The applications of microwave drying represented in the paper are environmentally friendly, since the seeds do not come into direct contact with the products of gas combustion, which deteriorate its quality due to the possible penetration of carcinogenic components into the products. Experimental data was taken into account when developing the design of a small-sized grain dryer for farms, in which the drying process takes place without heating the air as a heat carrier.Rzepak jest ważną rośliną oleistą o szerokim zakresie zastosowań. Zebrany musi zostać oczyszczony i wysuszony przed przetworzeniem. Proces suszenia rzepaku, jako rośliny o małych nasionach, ma swoją specyfikę. Jedną z nowych metod suszenia jest wykorzystanie promieniowania mikrofalowego, którego wadą jest nierównomierne ogrzewanie produktu. Celem postawionym w niniejszej pracy było zbadanie sposobów suszenia nasion rzepaku za pomocą promieniowania elektromagnetycznego w zakresie ultrawysokich częstotliwości w połączeniu z filtracją. Określono wskaźniki intensywności suszenia nasion oleistych za pomocą promieniowania podczerwonego na stanowisku doświadczalnym. Analiza przeprowadzonych doświadczeń wykazała, że temperatura nasion przy maksymalnej mocy mikrofalowej wzrasta ogólnie od 1,5 do 1,8 razy szybciej niż przy połowie mocy. Im wyższa wilgotność nasion, tym większe tempo wzrostu temperatury. Po każdym cyklu nadmuchu, który trwał pięć sekund, temperatura nasion rzepaku była wyższa niż poprzednia, a po zwiększeniu czasu przedmuchiwania do piętnastu sekund, temperatura spadała o 8–12°C i cyklicznie stabilizowała się. Przedstawione w artykule zastosowania suszenia mikrofalowego są przyjazne dla środowiska, ponieważ nasiona nie wchodzą w bezpośredni kontakt z produktami spalania gazu, które pogarszają ich jakość ze względu na możliwe przenikanie składników rakotwórczych do produktów. Dane eksperymentalne zostały wzięte pod uwagę przy opracowywaniu projektu małej suszarki do ziarna dla gospodarstw rolnych, w której proces suszenia odbywa się bez podgrzewania powietrza jako nośnika ciepła

Визначення оптимальних коефіцієнтів трансформації трансформаторів електроенергетичних систем в умовах неповноти інформації про значення діагностичних параметрів

On the base of damage rate analysis of power transformers and methods of EES modes control, the necessity of using the results of on-line diagnostics of LTC transformers not only for determinations of the expediency of further operation or equipment repair but also for calculation of optimal transformation coefficients (with account of the suggested RRCT) for their application in the process of modes control has been proved.The mathematical model of RRCT is developed to by applying the methods of neural-fuzzy modeling, this model, taking into account both current and retrospective values of diagnostic parameters enables to study the impact of diagnostic parameters of RRCT and determine its current value, which is necessary for automatic and automated reliable and optimal control of EES modes.The improved method of determination of optimal control actions, realized by the LTC transformers by means of comparative analysis of the results of calculation of EES modes with quasi-resistances of the circuit branches, enables to select the transformer and calculate transformation ratios that provide minimal losses of active power, minimal amount of LTC switching.The error of RRCT determination by means of the developed mathematical fuzzy model as compared with the training sample of the model and the opinion of independent experts does not exceed the error of the devices, measuring diagnostic parameters.Such results are explained by complex usage of probability theory methods, neuro-fuzzy modeling and modern software Matlab.Such peculiarity of the suggested method of determining optimal control actions by LTC transformers, as the account of RRCT, in the process of EES mode control provides such advantages as reduction of the damage rate of the equipment, reduction of active power losses in EES. The peculiarities of the method of determining optimal control actions by LTC transformers, with the account of their technical state, open up the prospects of development and introduction of modern microprocessor-based systems of optimal automatic control of LTC transformers in EES.Usage of quasi-resistors of circuit branches, which, unlike the transformers, used for calculation of nominal resistances of the lines, take into account the state of the transformers and possible losses of utility companies due to the possible damages, enables to calculate the EES mode in case of transformers transformation ratio change and by means of comparison of calculated power losses, select the most efficient transformer.Further progress of the given research includes the development of mathematical models of other kinds of high voltage equipment involved in the process of ESS modes control, damage of which is possible.Путем анализа повреждаемости силовых трансформаторов и методов управления режимами электроэнергетических систем (ЭЭС) доказана целесообразность использования результатов оперативного диагностирования трансформаторов с РПН при оптимальном управлении режимами. Приведена нечеткая модель коэффициента остаточного ресурса трансформатора. Рассмотрен метод определения оптимальных управляющих воздействий трансформаторами с РПН, с учетом их технического состоянияПутем анализа повреждаемости силовых трансформаторов и методов управления режимами электроэнергетических систем (ЭЭС) доказана целесообразность использования результатов оперативного диагностирования трансформаторов с РПН при оптимальном управлении режимами. Приведена нечеткая модель коэффициента остаточного ресурса трансформатора. Рассмотрен метод определения оптимальных управляющих воздействий трансформаторами с РПН, с учетом их технического состоянияШляхом аналізу пошкоджуваності силових трансформаторів та методів керування режимами електроенергетичних систем (ЕЕС) доведена доцільність використання результатів оперативного діагностування трансформаторів з РПН під час оптимального керування режимами. Приведена нечітка модель коефіцієнта залишкового ресурсу трансформатора. Розглянутий метод визначення оптимальних керуючих впливів трансформаторами з РПН, з врахуванням їх технічного стан