OBTAINING AND RHEOLOGICAL PROPERTIES OF PECTIN ISOLATED USING MICROWAVE RADIATION

Abstract

А method has been developed for extracting modified pectin from plant raw materials by using microwave radiation at the stage of washing. The rheological properties of 5.0% aqueous solutions of apple PV obtained by exposure to microwave radiation of various powers: 300, 450 and 600 W, as well as PV obtained by the traditional method at temperatures of 25, 40, 55, 70 °C were investigated. It is shown that the use of microwave radiation makes it possible to improve the method of obtaining pectins with the possibility of increasing the yield of pectin substances and regulating their structure and properties. The rheological properties of concentrated aqueous solutions of pectins obtained by exposure to microwave radiation of various powers have been studied. It is shown, that all the studied systems of PV solutions are non-Newtonian fluids with a pseudoplastic type of viscous flow anomaly, determined by the values of the microwave energy. The values of the apparent activation energies of the viscous flow of solutions, which are an indirect characteristic of the strength of the structures of the system, have been estimated. Information was obtained on the structure and changes in the structure of their concentrated solutions under the action of external forces and temperature in the course of a viscous flow. It is shown that the power values оf microwave radiation are the main factor determining the structure of molecular matrices of pectin substances and the structure of their concentrated aqueous solutions.