Peltier Element Research Articles

Heat application in live cell imaging.

Thermal heating of biological samples allows to reversibly manipulate cellular processes with high temporal and spatial resolution. Manifold heating techniques in combination with live-cell imaging were developed, commonly tailored to customized applications. They include Peltier elements and microfluidics for homogenous sample heating as well as infrared lasers and radiation absorption by nanostructures for spot heating. A prerequisite of all techniques is that the induced temperature changes are measured precisely which can be the main challenge considering subcellular structures or multicellular organisms as target regions. This article discusses heating and temperature sensing techniques for live-cell imaging, leading to future applications in cell biology.

Determination of the possibility of using a functional apparatus for the production of multi-component semi-finished products with a high degree of readiness

The object of research is a functional apparatus for the production of paste-like and powdered vegetable semi-finished products. The problem of combined heat and mass exchange treatment of vegetable raw materials are solved by using a functional apparatus for concentration and drying for processing and production complexes, farm lands. The expected effect during the approbation of the device is predicted under the condition of a functional approach combining the processes of concentration and drying with precise control of the temperature regime due to the use of a film-like resistive electronic heater of the radiating type. In the study, the approbation of a functional device for the production of multi-component vegetable semi-finished products of a high degree of readiness, with concentration and drying in the field of infrared heating at a temperature of 50 °C, was performed. Real-time temperature measurement was carried out by an automatic unit based on TRM, which ensured the accuracy of control at each stage. The temperature of the mashed mass during processing increased from 20.3 °С to 23.2 °С, reaching optimal conditions for forming a film with a thickness of 0.5 mm. In the rotary reboiler, the temperature in height varied from 25.7 °C to 50.1 °C, which contributed to the preservation of the properties of thermolabile raw materials. In the lower part of the apparatus, the temperature of the finished product was 49.8 °C, maintaining the necessary temperature regime for drying. The device creates a convective air flow (0.01 m/s) with the help of Peltier elements, which stabilizes the heat exchange at a temperature of 51.3 °C on the technical partition. The practical use of the functional apparatus will allow its use at processing and production complexes and directly at the places of collection of plant raw materials for resource-efficient production of semi-finished products with a high degree of readiness. These semi-finished products can act as independent functional products for people in extreme conditions or as recipe ingredients for the recipes of various food products.

In-plane thermal anisotropy of natural cork and its variability

This study investigates the natural cork thermal anisotropy and its variability using plane slice samples of 1.4 mm thickness, cut along the principal radial, longitudinal, and tangential directions, from bark previously treated for cork stoppers production. Heating was pointwise applied to the rear face using a copper needle coupled to a Peltier element, while an in-plane thermographic technique monitored temperature evolution on the front surfaces using a Flir SC5650 infrared camera. Thermal diffusivity measurements yielded values of 0.172 ± 0.038 mm2/s (radial), 0.161 ± 0.022 mm2/s (longitudinal), and 0.160 ± 0.027 mm2/s (tangential). Additionally, a volumetric heat capacity of 0.25 MJ/(m3·K) was determined using the Hot Disk technique. This information enabled the calculation of thermal conductivity, ranging from 0.033 to 0.048 W/(m·K). Findings align with existing literature, which reports thermal diffusivity between 0.08 and 0.24 mm2/s and thermal conductivity between 0.035 and 0.045 W/(m·K). This study contributes valuable insights into the thermal properties of natural cork and their orientation-dependent variability.

Implementation of Rapid Nucleic Acid Amplification Based on the Super Large Thermoelectric Cooler Rapid Temperature Rise and Fall Heating Module.

In the rapid development of molecular biology, nucleic acid amplification detection technology has received more and more attention. The traditional polymerase chain reaction (PCR) instrument has poor refrigeration performance during its transition from a high temperature to a low temperature in the temperature cycle, resulting in a longer PCR amplification cycle. Peltier element equipped with both heating and cooling functions was used, while the robust adaptive fuzzy proportional integral derivative (PID) algorithm was also utilized as the fundamental temperature control mechanism. The heating and cooling functions were switched through the state machine mode, and the PCR temperature control module was designed to achieve rapid temperature change. Cycle temperature test results showed that the fuzzy PID control algorithm was used to accurately control the temperature and achieve rapid temperature rise and fall (average rising speed = 11 °C/s, average falling speed = 8 °C/s) while preventing temperature overcharging, maintaining temperature stability, and achieving ultra-fast PCR amplification processes (45 temperature cycle time < 19 min). The quantitative results show that different amounts of fluorescence signals can be observed according to the different concentrations of added viral particles, and an analytical detection limit (LoD) as low as 10 copies per μL can be achieved with no false positive in the negative control. The results show that the TEC amplification of nucleic acid has a high detection rate, sensitivity, and stability. This study intended to solve the problem where the existing thermal cycle temperature control technology finds it difficult to meet various new development requirements, such as the rapid, efficient, and miniaturization of PCR.

Integrated system for temperature-controlled fast protein liquid chromatography. IV. Continuous ‘one-column’ ‘low-salt’ hydrophobic interaction chromatography

Systematic development of a temperature-controlled isocratic process for one-column low-salt hydrophobic interaction chromatography (HIC) of proteins employing a travelling cooling zone reactor (TCZR) system, is described. Batch binding and confocal scanning microscopy were employed to define process conditions for temperature-reversible binding of bovine serum albumin (BSA) which were validated in pulse-response temperature switching HIC experiments, before transferring to TCZR-HIC. A thin-walled stainless-steel column mounted with a movable assembly of copper blocks and Peltier elements (travelling cooling zone, TCZ) was used for TCZR-HIC. In pulse-response TCZR-HIC, 12 TCZ movements along the column desorbed 86.3% of the applied BSA monomers in 95.3% purity depleted >6-fold in 2–4 mers and nearly 260-fold in higher molecular weight (HMW) species. For continuous TCZR-HIC, the TCZ was moved 49–58 times during uninterrupted loading of BSA feeds at 0.25, 0.5 or 1 mg·mL-1. Each TCZ movement generated a sharp symmetrical elution peak. In the best case, (condition 1: 0.25 mg·mL-1 BSA; >17 mg BSA applied per mL of bed) the height of TCZ elution peaks approached pseudo-steady midway through the loading phase with no rise in baseline UV280 signal between peaks. Peak composition remained constant averaging 94.4% monomer, 5.6% 2–4 mers and <0.05% HMW. Monomers were recovered in quantitative yield depleted >3.1 fold in 2–4 mers and 92-fold in HMW species cf. the feed (63.6% monomers, 21.8% 2–4 mers, 14.6% HMW). However, increasing the BSA concentration to 1 mg·mL-1 (condition 2) or employing a fouled HIC column with 0.5 mg·mL-1 BSA (condition 3) compromised monomer purification performance.

Determination of the possibilities of using the universal low-temperature rotary apparatus for the production of meat and vegetable products under the conditions of providing uniform heat supply

The object of research is the process of frying a meat-vegetable product in the developed universal low-temperature rotary apparatus. The problem of ensuring the uniformity of the temperature field during low-temperature processing of meat and vegetable products is solved in the developed universal low-temperature rotary apparatus. The expected effect during the approbation of the apparatus is predicted under the condition of eliminating high-temperature intermediate coolants (hot air, etc.) due to the use of a film-like resistive electronic heater of the radiating type. The temperature field is established, which confirms the uniformity of the temperature effect on meat and vegetable products, and a slight deviation within the limits of autonomous exhaust fans is not critical and within the permissible error. Also, the introduction of Peltier elements into the design of the rotary apparatus will allow converting thermal energy into a low-voltage supply voltage (3–6 W) and, already at 20 °C, ensure autonomous operation of fans. The obtained results in the form of practical implementation of the developed apparatus will allow to implement low-temperature processing of meat and vegetable products. This allows to maximally preserve the functional properties of meat raw materials and the physiological properties of vegetable semi-finished products with a high degree of readiness. The practical implementation of the universal low-temperature rotary apparatus from the side of constructive implementation due to the use of functional containers makes it possible to obtain a wide range of assortment of meat products, both in the shell and without the shell. The elimination of high-temperature intermediate heat carriers (hot air, steam, etc.), their technical networks and generating apparatuss ensures energy and metal-intensive resource savings. In addition, the introduction of multicomponent vegetable semi-finished products of a high degree of readiness (powders, pastes, etc.) into the recipes of meat products will lead to a partial replacement of the main recipe components and an increase in the functional properties of the finished products.

Simulation study of heat transfer enhancement for all-solid-state room temperature magnetic refrigeration system

To address issues relating to large thermal resistance and low heat transfer efficiency between and inside magnetocaloric materials (MCM) in all-solid-state room-temperature magnetic refrigeration technology, this study adopted the method of inserting high thermal conductivity materials (HTCM) into MCM and coupling Peltier elements between MCMs to enhance the heat transfer inside MCM and between microcells, thereby improving the refrigeration performance of the system. In doing so, a two-dimensional simulation model was developed using COMSOL Multiphysics software. The cooling performance enhancement effect of the system resulting from heat transfer improvement within MCM and between MCMs was investigated separately. Furthermore, the impacts of various system operating parameters (such as the number of micro-cell divisions, initial operating temperature, heat transfer time, magnetic field strength, Peltier input voltage), different HTCMs and insertion volume ratios on the system’s cooling performance were explored. The simulation results reveal that, in comparison with the original magnetic refrigeration system, the optimized heat transfer time of the system following enhanced heat transfer within the MCM is reduced from 180s to 8s, accompanied by a 115% increase in the maximum temperature span. Furthermore, coupling the Peltier elements elevates the maximum temperature span by 274%.

Peltier element for real-time heat flux detection in fruit cooling under forced air convection

Peltier element for real-time heat flux detection in fruit cooling under forced air convection

SPEED: an integrated, smartphone-operated, handheld digital PCR Device for point-of-care testing

This study elaborates on the design, fabrication, and data analysis details of SPEED, a recently proposed smartphone-based digital polymerase chain reaction (dPCR) device. The dPCR chips incorporate partition diameters ranging from 50 μm to 5 μm, and these partitions are organized into six distinct blocks to facilitate image processing. Due to the superior thermal conductivity of Si and its potential for mass production, the dPCR chips were fabricated on a Si substrate. A temperature control system based on a high-power density Peltier element and a preheating/cooling PCR protocol user interface shortening the thermal cycle time. The optical design employs four 470 nm light-emitting diodes as light sources, with filters and mirrors effectively managing the light emitted during PCR. An algorithm is utilized for image processing and illumination nonuniformity correction including conversion to a monochromatic format, partition identification, skew correction, and the generation of an image correction mask. We validated the device using a range of deoxyribonucleic acid targets, demonstrating its potential applicability across multiple fields. Therefore, we provide guidance and verification of the design and testing of the recently proposed SPEED device.

Polymerase Chain Reaction Microchip and PID Controller Based Thermal Cycler Design

Numerous specific procedures are needed for nucleic acid detection using traditional approaches. Because of the time and instrumentation requirements, poor detection limits, and other factors, they are behind in creating point-of-care (POC) testing. In addition, some of these traditional approaches can be extremely sensitive. Microfluidic technologies are being used to overcome these challenges by enabling the efficient and automatic performance of all analytical stages, such as sample pre-treatment, reactions, separations, and diagnostics in microchannels on a small chip. The use of microfluidics technology in polymerase chain reaction (PCR) technology has resulted in many advantages. PCR microchips and portable thermal cyclers that can be used for POC testing have enabled faster amplification with accurate results. This paper proposes a low-cost, fast enough thermal cycler for POC testing that uses a polymer-glass microchip and an affordable Peltier element to quickly heat samples. A laser cutter was used to build the microchip needed to perform PCR, which was designed using a computer-aided design (CAD) software. The heating and cooling elements employed in the creation of the thermal cycler were Peltier elements, heat sink, centrifugal fan, and CPU fan. A microcontroller and H-Bridge modules were used to control the temperature with the help of proportional-integral-derivative (PID) controller algorithm. After that, the circuit components and PID control algorithm—which was created for temperature control—were combined to create the PCR cycle. The analysis focuses on the heating and cooling performances of suggested thermal cycler.

Abstract TP288: Selective Brain Hypothermia Induced by Thermoelectric Cooling

Background: Stroke or Traumatic Brain Injury (TBI) are leading causes of disability and death in the United States. Hypothermia is a known neuronal protectant. Current hypothermia interventions include intravascular, intranasal, and surface brain cooling technologies but these interventions have not been well utilized clinically. Cooling the brain a few degrees below normothermia (T&lt;36°C) has been shown to yield significant neuroprotective effects. Noninvasive surface cooling methods are most desirable given their less patient complications, provided the desired therapeutic hypothermia effect (T 33-36°C) can be maintained. Method: These investigators propose a novel noninvasive solid state technology that employs addressable Peltier thermoelectric cooling elements to generate hypothermia. ThermoPelt’s closed-looped microcontroller design provides the ability to address individual Peltier elements to selectively reduce the temperature of localized regions of the brain, thus allowing precision therapeutic hypothermic conditions to be realized. Results: Assessment of ThermoPelt performance was accomplished with use of virtual prototype (engineering mathematical model representations of the brain) and early, in vitro experimental physical prototype testing. Preliminary results obtained from virtual and physical prototype tests verify ThermoPelt feasibility to achieve hypothermic conditions. Conclusion: In this new method of generating hypothermia, the preliminary findings demonstrate that our noninvasive ThermoPelt technology is capable of reducing brain temperature at controlled rates to selectively target specific head and neck regions.

ПРЕОБРАЗОВАНИЕ ТЕПЛОВОЙ ЭНЕРГИИ В ЭЛЕКТРИЧЕСТВО: ПОТЕНЦИАЛ И ЭФФЕКТИВНОСТЬ ТЕРМОЭЛЕКТРИЧЕСКИХ ГЕНЕРАТОРОВ НА ОСНОВЕ ЭЛЕМЕНТОВ ПЕЛЬТЬЕ

Relevance Energy extraction using thermoelectric generators powered by Peltier elements through the application of both natural and engineered heat sources, aiming to create a new green method for clean energy production. Aim of research This study delves into the literature analysis to identify the factors that influence the accuracy of energy conversion, and aims to investigate the performance of Peltier elements while learning the principles of heat transfer, creating optimal conditions for the operation of a thermoelectric generator based on them. During the experiments, by adapting the process conditions, a process transfer function is formed, which aims to improve the energy generation efficiency. The aim of the study is to analyze the efficiency of thermoelectric generators based on Peltier cells. Research methods Physical foundations of thermoelectricity, development of a mathematical model. Results The study analyzed that the simulation revealed the presence of temperature gradients in regions with thermal waters of the mountain mass, and a mathematical model of the process was developed.

Моделирование и идентификация элемента Пельтье TEC1-12706 для применения в малообъемных биореакторах искусственного ЖКТ рыб

The bioreactor of a static mini-model of the artificial gastrointestinal tract of fish will provide modeling of processes in the gastrointestinal tract of industrially grown fish (carp, trout, and sturgeon). The study aimed to determine the thermodynamic processes occurring in the bioreactor and the possibility of using the thermoelectric converter TEC1‑12706 in the temperature control system of the bioreactor. The temperature in a bioreactor with a volume of up to 200 ml should vary from 45 to 14℃, the accuracy of maintaining the temperature is 0.1℃. As a result, a mathematical model was obtained with an adjustment according to the identified system parameters, which makes it possible to evaluate thermodynamic processes in the bioreactor, select hardware and create its general mathematical model. The parameters of the Peltier element were identified using a prototype layout measuring the temperature of the cold side of the converter, the hot radiator, the environment, the temperature of the liquid in the reactor, and the current consumed. The operation of the real system took place at an external temperature of 28.31℃; all physical drives were in the temperature equilibrium and under the same initial conditions. A comparison of temperature changes in the real system and the mathematical model obtained as a result of identifying the parameters of the Peltier element showed a non-perfect match of values, but the nature of the temperature change is identical. The following conclusions have been drawn: in the mathematical model, it is necessary to take into account additional drives and flows describing non-ideal conditions of experimental data, for example, thermal reflection of the working surface of the table and partial reflection of air flows. One third of the maximum converter power is sufficient to reduce the temperature of the filled bioreactor by 2 to 3℃. Thus, the thermoelectric converter TEC1‑12706 can be used in an in vitro modeling system of the gastrointestinal tract of fish.

Экономическая эффективность использования полупроводникового охлаждения компьютерной техники

An assessment of the economic efficiency of creating a semiconductor cooling system for computer equipment has been carried out. The proposed solution is a more advanced version of the liquid cooling system of a personal computer (PC) using a Peltier element. Compared with existing analogues, the proposed project has a number of competitive advantages: high performance of the system, which has a reserve of power for more advanced new computer equipment on the market, combined with a low price. The economic effect of the transition from water cooling systems to combined cooling systems, including both liquid and semiconductor cooling elements, is studied. The economic justification of the transition to thermoelectric cooling systems for PCs and servers within the framework of the real project “PC semiconductor cooling System” is carried out, its novelty is described, prospects for commercialization are considered, market analysis and segmentation are carried out, as well as the calculation of planned economic indicators. The results of calculating the criteria for the economic efficiency of an investment project are presented: net discounted income and internal rate of return. The approaches used can be used to assess and justify the investment attractiveness of scientific projects.

Improving the reactor for thickening organic plant-based polycomponent semi-finished products with high degree of readiness

The object of this study is the process of thickening organic polycomponent compositions based on Jerusalem artichoke, apples, pumpkin, cranberry, and dogwood to produce high-level semi-finished products employing the proposed equipment and technological solutions implemented in a unified reactor. Conventional thickening devices have a steam heat supply system, which leads to overheating of certain layers of raw materials and prevents the mobile properties of the apparatus under the conditions of significant execution of organic properties of raw materials. The introduction of apratur-technological solutions could provide the competitive advantage of the reactors by heating the film-like emitting electric heater using a mixing device with a heating surface. Increasing the total area of heat exchange to 1.24 m2 (prototype – 0.98 m2). There is a decrease in specific heat consumption by 20 %, specific metal capacity by 47 %, and the duration of the process by 30 %. We have determined rheological properties in the thickening of the organic polycomponent composition of the paste at a temperature of 55 °C and a shift rate within 3.0…4.5 s-1, effective viscosity is in the range of 22...3.5 Pa·s. In this case, the kinetics of boiling in an improved reactor are by 27 % smaller than that in the basic structure R-P-150m. According to organoleptic indicators, the composition "B" has a pleasant harmonious taste of all components. The results of the studies are relevant for practical implementation in the temperature range from 35 °C to 55 °C. The hardware and technological solutions form the competitiveness of mobile reactors for the thickening of plant semi-finished products under conditions of elimination of the steam component and an increase in the surface of the heat exchange of the mixing device. Providing preference in operating duration with the simultaneous use of Peltier elements to convert secondary heat to the autonomous work of exhaust fans in the motor compartment

(Invited) Estimating OCP-Temperature Dynamics for Determining Lithium-Ion Battery Entropy Coefficients

The open-circuit potential (OCP) of a li-ion cell is a function of both state-of-charge and temperature. Characterising its dependence on temperature is important for thermal simulations as the derivative of the OCP with temperature acts as a reversible heat source term in the model. Known as the entropy coefficient, this derivative is a thermodynamic quantity that varies over the cell’s state-of-charge (SoC). The potentiometric approach [1] is widely used to characterise the entropy coefficient for a given SoC. This involves applying step changes in the temperature and allowing the cell OCP to reach (or approach) a steady-state value, which can take several hours (>8 hours), for a given SoC of interest.Robust techniques are required that can significantly reduce the experimental time and quantify the entropy coefficient over the full SoC window, leading to higher fidelity battery thermal models. In this work, the dynamics between the OCP and cell temperature are exploited via system identification techniques to derive the entropy coefficient. This is achieved by estimating the underlying kernel function between the cell OCP and temperature dynamics. The kernel function is a non-parametric estimate of the dynamics from which the entropy coefficient can be determined.In this work temperature signals are designed with multiple frequency components and applied to a cell via Peltier elements. The corresponding OCP response is then analysed, in the frequency domain, to estimate the kernel function. Unlike the potentiometric method, which drives the battery to steady-state and necessitates long experimental durations, the kernel function can be estimated under transients, facilitating faster characterisation. The figure demonstrates comparable results of the entropy coefficient, over the full SoC interval, when estimated via the kernel function and the potentiometric approach. The approach, compared to the potentiometric method, however, brings around a two to three times reduction in experimental time per SoC and gives insight into the OCP and temperature dynamics. The signal design, kernel estimation and entropy coefficient estimation procedures are detailed in this talk. Schmidt, J. P., Weber, A., et al., Electrochimica Acta 2014, 137, 311-319. DOI 10.1016/j.electacta.2014.05.153 Figure 1

A 3D-printed oscillatory polymerase chain reaction system using a single heater

Nucleic acid amplification is a process that arises in all organisms. Polymerase chain reaction (PCR) is a standard laboratory nucleic acids amplification technology in vitro widely used in medical detection and biometric-related research. This device represents the first demonstration of 3D-printed oscillatory thermocycling within a portable PCR device. This study uses a single Peltier element to create the three temperature regions required for PCR. The overall control system uses an Arduino microcontroller with the advantages of easy development, abundant resources, and easy access to device software design. The sample-driving system integrated with the 3D printed object and the laser-cut acrylic component to achieve the linear reciprocating motion of the sample is conducive to the realisation of the portable design of the device. After system optimisation, the reaction tube moves from the denaturation zone to the aluminum block for cooling, and it moves to the groove of the denaturation zone from the annealing zone to accelerate the sample temperature rise. The time duration reduces from 180 s to 85 s to complete one thermal cycle. Combining the 5 mm instead of 3 mm thickness of the acrylic material and the configuration of the acrylic end exposed in the air creates a more significant temperature difference from 25 °C to 40 °C. Using this oscillatory PCR device, we successfully amplified a 219 bp PCR product of turmeric DNA after 30 thermal cycles within 50 min. The developed PCR device will cost less than $300 USD in our work. Compared with previous works, the cost of this research device is relatively low, and the total volume of the device is quite small. This work should be interesting to persons involved in diagnosing the infectious diseases of viruses and bacteria and identifying the fake healthy food in the low-cost bioreaction chambers in fields and remote areas.

Development of a Thermal Cycler for a Low-Cost Real-Time PCR Application

With the COVID 19 pandemic and the rise of polymerase chain reaction (PCR) testing in its wake, affordable large-scale testing became necessary. A thermal cycler for PCR has been developed that is affordable, fast, and accurate. The thermocycler must follow a specific temperature profile consisting of three different temperature levels. To ensure the success of any PCR, the tempering elements must accurately follow the tempering profile and be stable heat sources to maintain any given temperature. A control mechanism is required to approximate this prescribed temperature behavior. The basis for this is a Proportional-Integral-Differential (PID) controller, whose functionality is ensured by a feedback mechanism consisting of a temperature sensor. The PID controller provides precise attainment and maintenance of the temperature levels. A high performance Peltier element is used to heat and cool the PCR system. This is controlled by a programmable power supply and, in combination with a heat dissipation system, achieves heating and cooling powers in excess of 200 W. In addition, different design variants of the thermal cycler were created and their temperature behavior was simulated. These were then implemented, tested and the PID controller tuned accordingly. These tests help to find the best design for the thermal cycler with the optimal heat distribution.

Experimental study about the impact of open cell aluminium foam (OCAF) insertion in salt-based phase change material (PCM) for electronics thermal management

Thermal management of electronic components is a critical task in a harsh thermal environment. Spacecraft and satellites' electronics are susceptible to highly intermittent heating and cooling thermal conditions, which imposes challenges for robust thermal management system design. Phase change materials (PCM) are a promising solution for overcoming these challenges and enhancing thermal control performance. The lower PCM thermal conductivity and PCM supercooling limit PCM utilisation in electronic thermal control systems. The present study aims to provide solutions for enhancing the heat transfer within the PCM, boosting the PCM thermal conductivity, and diminishing the PCM supercooling. The open-cell aluminium foam (OCAF) was adopted for boosting the heat transfer within the PCM. A thermal management module (TMM) integrated with a salt-based PCM/OCAF composite was developed for electronics thermal management. The TMM was tested under intermittent thermal conditions of heating and cooling. An electric heater and Peltier cooler were affixed to the TMM for the heating and cooling process, respectively. Three levels of heat fluxes were adopted: 700, 1000, and 1400 W/m2. The heating process lasted one hour; then, the TMM was cooled by the Peltier element to the initial temperature. The research novelty covers the gap in understanding how OCAF affects salt-based PCM supercooling when subjected to varying heating loads during intermittent cycles. The outcomes reported a remarkable improvement in thermal management efficiency. The PCM-based TMM reduced the highest temperature by about 20.4 %, 21.6 %, and 23 % at the three heating levels. The OCAF diminished the PCM supercooling curiously. The reduction in PCM supercooling was 43.5 % compared to the 100 % PCM case obtained at the heat flux of 1400 W/m2.

Improving a technique for making fried meat chopped semi-finished products in functionally closed environments with the addition of blended dried semi-finished product

The object of this study is the production process of chopped meat semi-finished products with the addition of blended dried semi-finished products based on Jerusalem artichoke, pumpkin, and zucchini to the recipe, followed by frying in functionally closed environments. A technique for the production of dried semi-finished products based on Jerusalem artichoke, pumpkin, and zucchini is proposed for use in the recipes of fried minced meat products to substitute bread. The water absorption of bread (at 23 min.) was compared at 11.3 cm3 and 12 cm3 for the dried mixture, which is 6.1 % higher. A comparative analysis of the chemical composition confirms a much higher content in the dried blend: 6 times more potassium, 4 times more calcium, and 31 times more dietary fiber. Also, the blend is characterized by a low fat content of 0.13 g and the presence of vitamins C, A, etc. Frying of chopped meat semi-finished products is proposed in functionally closed environments (FCE) with artificial cooling based on a heat exchanger with cold water and Peltier elements. The process is carried out at a temperature of 150...160 °C for 300 seconds. It was found that during 30 s of frying the test samples in FCE, the pressure is equal to 9ˑ103 Pa, during 90 s – 28ˑ103 Pa, at 120 s – 35ˑ103 Pa, at 210 s – 40ˑ103 Pa, and at 300 s – 42∙103 Pa, respectively, which makes it possible to predict the process. The dynamics of frying chopped meat products in FCE with artificial cooling on the basis of a heat exchanger with cold water and Peltier elements for the 1st period of loss are about 52.6·10-3 %/s, for the 2nd it is virtually unchanged. The maximum difference in changes in the fat medium is on 120...150 seconds of frying and actually reaches 12.0 % of the total fat content. At the end of the frying process, the total content of fatty medium is about 5.3 %, thereby confirming the effectiveness of using artificial cooling