FEATURES OF THE PROCESS OF DEHYDRATION OF FUNCTIONAL VEGETABLE RAW MATERIALS
Authors:   Institute of Engineering Thermophysics of National Academy of Sciences of Ukraine, Ukraine, Petrova Zhanna , Sniezhkin Yurii ,   Institute of Engineering Thermophysics of National Academy of Sciences of Ukraine, Ukraine
Published: February 2021

Given the general trend of energy consumption, which leads to an increase in the amount of energy consumed worldwide, the cost of this energy is constantly increasing and its deficit is growing. Therefore, it is important to solve the problem of creating and large-scale implementation of modern energy-efficient heat technologies that reduce energy. This is especially true for providing the population to food, as an additional complication is that the production and processing of agricultural raw materials occurs in conditions of increased consumption of gas and other energy sources with low coefficient of performance and high losses of raw materials during processing. Food and nutrition play a leading role in everyone's life, no matter how we treat it. Nutrition is a key moment in the life of every living organism. Functional foods have evolved as a separate category and are not always considered as dietary supplements. Functional food products (FFP) are the products influencing a functional condition of an organism for the purpose of its increase - resistance, working capacity, prolongation of life. Although the definitions of functional products are different, they are basically ordinary foods and beverages, but enriched with a functional component - a nutrient that plays a special physiological role in the body, has a positive effect on human health. The purpose of the paper is a theoretical and experimental substantiation of complex and efficient processing of vegetable raw materials, creation of energy-efficient heat technology of agricultural raw materials processing in order to obtain functional products with maximum preservation of biologically active substances. In this work, 4 groups of functional foods were studied (according to the classification of the main plant functional ingredients of Doctor of Technical Sciences Petrova Zh.O.) - these are antioxidants, phytoestrogens, folates, prebiotics. An important point is to increase energy efficiency with maximum preservation of functional ingredients of raw materials. Preliminary preparation of raw materials for drying was developed and researched, optimal dehydration regime parameters were selected, which allow to reduce energy consumption for the process and to keep BAS for each group of functional raw materials at a high level. Since the increase in energy costs for drying is associated with the difficulty of removing moisture from plant material, it was important to investigate changes in the specific heat of evaporation of water from functional compositions. The conducted experimental researches confirmed the theoretical assumption of dependence of specific heat of evaporation of water from parenchymal fabrics of plants on composite components of raw materials. The obtained results allow to state that at correctly picked up compositions they not only stabilize components of native raw materials, but also there is an intensification of drying process with reduction of energy consumption on process. The duration of the drying process of functional raw materials on the experimental convective stand was calculated by the method of Krasnikov V.V. The estimated drying durations of functional raw materials and drying rates are determined. The kinetics of heat exchange was studied with the determination of the specific heat flux density and the Rebinder number, which proves the efficiency of the introduction of step drying regimes.