Investigation of ion exchange resin process parameters for producing high-purity inulin from Jerusalem artichoke (<i>Helianthus tuberosus</i> L.) powder

Abstract This research aimed to investigate the effects of ion exchange resin (IER) process parameters, including resin type, sequence, contact time, extract concentration, and temperature, on the production of high-purity inulin from Jerusalem artichoke (JA) powder. Three IER types were evaluated: strongly acidic cation resin in calcium (Ca) and hydrogen (H) forms, and weakly basic anion resin in hydroxide (OH) form. Inulin extract at 2 °Brix was treated using single, double, and triple resin sequences with 2-min contact time. Triple sequences (H-OH-Ca and Ca-H-OH) effectively balanced pH and removed total sugars, reducing sugars, protein, and ash better than single or double sequences. The H-OH-Ca sequence yielded the highest purity (79.68%), which increased to 80.67% when extending contact time to 6 min, reducing protein and ash to 0.14% and 0.004%, respectively. Using 5 °Brix extract and 35 °C temperature further improved purity to 89.09% with 71.12% recovery. Fourier transform infrared (FT-IR) confirmed structural similarity to commercial inulin (90.38% match), while 1H nuclear magnetic resonance (NMR) indicated a degree of polymerisation of 10.76. These results demonstrate that optimised IER processing can produce high-purity inulin from JA powder with structural and functional properties comparable to commercial inulin.