Use of Ion-Exchange Resins for Cleaning Inulin Containing Syrups from Chicory Roots
The studies were performed to determine the effectiveness of ion-exchange purification of syrup from chicory using Purolite resins (USA). The quality of purification was evaluated by the volume of the purified syrup per volume of crude resin in terms of the pH value for the cation exchanger not higher than 3.5 units and for the anion exchanger not lower than 4.0 units. In the work, we used the extract from dry chips of Yaroslavsky chicory variety. After diffusion, we derived a solution, the colon" of which varied from yellow to brown. It was characterized by high chromaticity (8-14 AU). The mass fraction of protein was 6.86%; the mass fraction of ash was 3.14%. For purification, the extract was subject to ion-exchange without pretreatment with OU-B activated carbon. Since double ion-exchange did not provide the mass fraction of protein and colour of syrup required for the production of inulin, it was additionally purified with activated carbon at a dose of 4%. Further, it was purified by a two-stage scheme (cation exchanger + anion exchanger + cation exchanger + anion exchanger) at a temperature of 20-35 C and at a flow rate of 1.0-2.5 syrup volumes per one volume of resin per hour. After this treatment, the content of impurities in the syrup decreased by dozens of times (the content of protein decreased to a level of not more than 0.5%; the content of ashes decreased to a level of not more than 0.2%); chromaticity did not exceed 0.4 AU. Ion-exchange of the extract from dry chicory chips on Macronet MN 150 adsorbent reduced chromaticity by more than 50% and completely removed the bitter taste.