Sorption characteristics of pectin isolated from Jerusalem Artichoke tubers (Helianthus tuberosus L.)

Introduction. The aim of the present study is the isolation of pectin from Jerusalem artichoke tubers (Helianthus tuberosus L.) and the analysis of its sorption characteristics Materials and methods. Research was carried out on the pectin content of the tubers of Jerusalem artichoke plants cultivated in Bulgaria. The polyuronide content (PUC) was determined via the McCready method. The static gravimetric method was used for analysis of the sorption characteristics of pectins. Results and discussion. The polysaccharide was extracted. The isolated pectins were analyzed in physical terms: the equilibrium sorption isotherms, belonging to type II in Brunauer's classification, were obtained experimentally. The entire isotherm length demonstrated statistically significant hysteresis. The Henderson and Chung-Pfost models provided adequate isotherm description. The pectin content of the three Jerusalem artichoke samples is 14.8, 9.2 and 11.9 % a.d.m., respectively. The monomolecular moisture content of pectin was within the 7.42 - 7.92% dry basis range, its corresponding water activity value - within the 0.14 - 0.16 range. Conclusion. The results of research are advisable for use in develop of functional food ingredient which is used pectin as a gelling agent and a stabilizer.