ФИЗИКО-ХИМИЧЕСКИЕ СВОЙСТВА И ТЕПЛОФИЗИЧЕСКИЕ ХАРАКТЕРИСТИКИ ЭКСТРАКТОВ ЛИСТЬЕВ БЕРЕЗЫ ПОВИСЛОЙ (BETULA PENDULA)

Abstract

The use of additives of natural origin in food production, can improve their nutritional value, give them the necessary properties and increase their competitiveness in the market. The interest in food products containing natural substances is widespread. Birch has been known for its healing properties for a long time and modern studies of itsextracts’properties open new boundaries for its use in the food industry. The use of birch biomass is not appropriate in terms of customer demand. The method of extraction has justified the removing nutrients from plant material. However, the extracts have low concentrations of nutrients affecting their useful properties. Among other methods of concentration there can be distinguished evaporation under a vacuum, as a way to maintain more useful properties of extractives. The receipt of concentrated extract on an industrial scale is difficult due to the lack of data on the physicochemical and thermal properties of birchleaves extract which is necessary for a design and manufacturing equipment, including evaporators. The work contains the research results of the effects of temperature and the concentration of dry matter on the physicochemical properties (density, viscosity, surface tension) and thermal characteristics (thermal conductivity, specific heat) of birch leaves’ extract produced using the most widespread research methods in experimental practice. The received data areanalyzed and presented in the form of diagrams which help to trace discovered dependences. As a result of statistical processing of the experimental data we have got multiple regression equations describing the change of physicochemical properties and thermal characteristics of the extracts in a wide range of temperatures and dry matter content.