Self-aggregating properties of inulin in a dilute solution

The creation of functional food products based on inulin-containing vegetable raw materials can provide the population with functional diabetic nutrition. In this regard, investigation of the technological parameters of obtaining inulin from Jerusalem artichoke tubers (Helianthus tuberosus L.) and determination of its quantitative characteristics seem highly relevant. This study aims to determine the qualitative characteristics of inulin obtained from Jerusalem artichoke tubers by both flash extraction and conventional methods. Jerusalem artichoke inulin samples were obtained by the flash extraction method at a high temperature of 105 °C during both shorter and longer periods of time and by the conventional method at a temperature of 75 °C in a neutral medium. The hydrodynamic properties and molecular weight of the samples demonstrated the self-aggregating properties of this biopolymer. Inulin obtained by the flash extraction method consists of two fractions: low-molecular weight inulin and high-molecular weight aggregate represented by a polysaccharide complex. These aggregates can be formed both by inter- and intramolecular interactions of various inulin fractions in the solution. As expected, their isolation using conventional methods appeared impossible: the method of concentration yielded a number of subfractions on the UV membrane and a large amount of aggregated water-insoluble microgel. At the same time, inulin obtained by the conventional method consists of one fraction, although having a high degree of polydispersity. In order to obtain high-quality inulin intended for nutritional and prophylactic purposes, it is preferable to use the flash extraction method over short periods of time.