Methods of isolating and physiochemical properties of inulin ractions with different chain lenghts from chicory plants

Native inulin extracted from chicory root consists of chains of fructose units by β (2→1) bonds with different degrees of polymerization. Inulin composition and its functional properties depends on genetic characteristics, growth environmental conditions, harvesting time, as well as the method of extraction the processes applied after extraction. "Short-chain" inulin, is more soluble and sweeter, so it can be used as sugar replacer, while "long-chain" inulin, commonly used as a fat substitute, is less soluble, more viscous and thermally stable. In this research, for isolating different structural fractions of inulin, root of chicory strain of Orchies was used. The Effect of different treatments including ethanol solvent to syrup ratio (2:1 and 10:1), crystallization and precipitation of aqueous solution in -20°C, and ultrafiltration using 4 kilo-dalton UF cut off on the degree of polymerization, yield of extraction and physicochemical properties of the compounds were compared. The results showed that ethanol with higher concentration resulted in more precipitation of inulin. Inulin participated by 2:1 E/S ratio had the highest degree of polymerization (66) and the least reduced sugar (1.2%) compared to those from other methods of fractionation. Inulin participated by ultrafiltration of permeate fraction had the lowest degree of polymerization (16) and highest reduced sugar (5.31%) compared to those from other methods of fractionation.