2.8. HPLC Analysis of Inulin

Inulin was quantified by HPLC analysis following the analytical method reported by Zutela and Sambucetti [34]. The chromatographic equipment consisted of an Agilent 1260 HPLC (Agilent Technologies, Santa Clara, CA, USA) equipped with a refractive index detector and an Aminex HPX-87C (Bio-Rad Laboratories S.r.l., Segrate, Italy) anion exchange column. The mobile phase was ultrapure water (MilliQ^®, Merk Millipore, Burlington, MA, USA) at 85 °C at a flux rate of 0.6 mL min⁻¹ and an injection volume of 20 µL. Pure inulin from chicory (Sigma–Aldrich, St. Louis, MO, USA) was used as an external standard for calibration. A calibration range between 0.5 and 5 mg mL⁻¹ was set for inulin quantification.