In order to determine the optimal technological parameters for obtaining stevia leaf sweet extract, the dependence of the extractives' yield on the temperature and extraction process duration was investigated. A mathematical model has been built that makes it possible to determine and predict the extraction process at different technological parameters in order to effectively obtain extractive substances. The expediency of using whey from the production of fermented milk cheese as an extractant for obtaining stevia extract has been substantiated. It was experimentally established and mathematically confirmed that the use of whey makes it possible to increase the yield of extractives by 12.1 %, as opposed to the use of an aqueous solution. In order to intensify the extraction process, it is proposed to use a rotary-pulse apparatus. It was found that the application of a rotary-pulse apparatus makes it possible to increase the yield of extractive substances from sweet grass by 0.1–0.4 % compared to maceration. The optimal technological parameters for obtaining stevia extract have been determined: hydro module, 1:15; extractant, whey; extraction temperature, 85±5 °С; process duration, 20–25 min. The use of graphic and mathematical modeling in the environments "Mathcad" and "Statistica" helped construct 3D-graphic models to illustrate the dependence of the degree of extraction of extractive substances from dry stevia leaves on the technological parameters for obtaining extracts. The improved technology of obtaining stevia leaf sweet extract will significantly expand the range of "healthy foods" through the partial or complete replacement of sugar. The production of such dietary products will have a social effect and economic attractiveness for food industry enterprises

The prospects for the use of a plant raw material – stevia as a natural sweetener for obtaining sweet extracts have been substantiated. Literary research has been conducted on the expediency of carrying out preparatory operations of stevia-raw material in order to intensify mass exchange processes during extraction; their necessity has been theoretically justified. A number of studies have been conducted with the aim of intensifying the process of extracting the dry mass of stevia leaves. Preliminary preparation of stevia was carried out – crushing (using a laboratory crusher – A1-DM2R) and subsequent sieving to the average size of the leaf fraction – 3.9±0.1 mm. It is proposed to use whey from the production of sour milk cheese to obtain sweet extracts of stevia for their further use in the food industry. It has been established, that the highest efficiency of the extraction process of the prepared dry stevia leaf mass is achieved with a hydromodule – 1:15. Carrying out the process under these conditions allows to achieve the highest degree of extraction of extractive substances – 29.9. The results of the experimental studies, obtained and presented in the article, can be used to carry out further physicochemical analyzes of the quality of the obtained stevia extracts and the possibility of combining them with a milk base to obtain a dietary range of food products

The advantages and disadvantages of Arduino controllers in relation to refrigeration automation systems are considered. An example of using the Arduino controller for creating an automation and monitoring system for a nonstandard laboratory refrigeration unit is presented. Arduino is a computing hardware platform for affordable design, the main components of which are the microcontroller board with input and output elements, as well as the Processing / Wiring programming environment in a programming language similar to C, C ++. Arduino can be used to create standalone interactive objects, connect to the software that is used on your computer. The main advantage of using Arduino-based controllers is the availability of information about the microcontroller card, the specification of the elements, the software. Information is freely accessible and can be used by developers in any field. Microcontroller boards have a special structure, due to which, if necessary, it can be expanded by adding new components to the device. Thus, the presented platform allows to improve or change the operation of the automation system of the refrigeration unit, depending on the requirements of the consumer of the cold. The presented variant of automation of refrigeration systems gives an opportunity to come up with a new approach to the design of refrigeration units. During the development of the automation system, a modular algorithm for controlling and protecting the refrigeration unit was created in all its variants, the necessary peripheral equipment and signal receivers were selected. It is shown that the value ratio -functionality of these devices significantly exceeds the similar indicators of the world's leading manufacturers of refrigeration automation systems.

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