Process development for producing high-purity inulin powder from Jerusalem artichokes through hot water extraction, purification, and drying

This study aims to optimize the production of inulin powder from Jerusalem artichoke tubers through hot water extraction, ion exchange purification, and drying. A full factorial design was employed to investigate the effects of extraction temperature (60, 70, and 80 °C) and time (20, 40, and 60 min) on inulin content. The optimal condition was identified as 60 °C for 20 minutes, yielding an inulin content of 56.84%. Extraction temperature significantly influenced extraction efficiency. Structural integrity of the extract was verified using synchrotron radiation-based Fourier transform infrared spectroscopy. Purification via strong acid cation and weak base anion exchange resins reduced conductivity (from 7.24 to 0.75 mS/cm) and improved decolorization efficiency to 50.96%, resulting in a purer extract. Both freeze drying and spray drying produced high-purity inulin powders (80.46% and 76.77%, respectively). The spray-dried powder exhibited lower water activity, higher bulk and tapped densities, greater whiteness, and reduced hygroscopicity, indicating improved storage stability. Essentially, hot water extraction under optimal conditions, followed by ion exchange purification and spray drying, presents an operationally viable method for producing high-quality inulin powder with desirable physicochemical and functional properties for food applications. • Hot water extraction preserves inulin and maintains desirable extract quality. • Ion exchange purification reduces conductivity and improves decolorization. • Spray drying produces stable inulin powder with compact form and high whiteness.