Technological and design solutions for combined microwave-ultrasonic inulin extraction

Abstract

The article discusses a promising method for extracting inulin from plant raw materials. The aim of the work is to develop and scientifically substantiate the method, operating parameters and design solutions for microwave-ultrasonic extraction of inulin from various raw materials. Traditional methods of inulin production are characterized by high energy intensity, duration and risk of thermal degradation of the target product. A scheme is proposed that combines microwave exposure (frequency 2450 MHz) and ultrasonic exposure (frequency 22 kHz, intensity 50 W/cm2) to the extraction mixture in a single recirculation circuit. Microwave exposure provides rapid volumetric heating of intracellular moisture and loosening of plant tissues, while ultrasonic cavitation intensifies the destruction of cellular structures and, as a result, mass transfer processes. A machine and hardware scheme of the method has been developed, including the stages of raw material preparation, combined extraction, filtration, clarification, concentration and drying. The optimal process parameters have been experimentally substantiated: a 1:4-1:8 hydraulic module, a temperature of 338-348 K, a cycle duration of 20-40 minutes, and a circulation rate of 20-30 volumes/hour. The combined method reduced the extraction time by 1.5 times compared to known methods while maintaining a high inulin yield (up to 95-98%). The finished product meets the requirements of the regulatory documentation for physico-chemical (humidity 4-6%, inulin content ≥ 95%, ash content < 0.2%) and microbiological parameters. The proposed method ensures the preservation of the molecular weight and prebiotic activity of inulin. The proposed solutions are scalable, patent-protected, and adaptable for processing various types of inulin-containing raw materials.