Inulin Determination by an Improved HPLC-ELSD Method

Abstract

Since inulin utilization as a sugar or fat replacer, texture modifer, and emulsifer is increasing in the food industry, there is a need for its determination for food control and labeling. This study reports the development and validation of an advanced high-performance liquid chromatographic method with evaporative light-scattering detection (HPLC-ELSD) method for inulin quantifcation, with optimized extraction conditions (1:10 w/v solid-to-solvent ratio, 1 h/80 °C in a water bath continued with 30 min ultrasonication for the extraction step, and precipitation during the night with four volumes of acetone). The rapid HPLC-ELSD analysis (16 min) has been performed by isocratic elution with water as a mobile phase and optimized detector parameters (temperature of evaporator 80 °C, temperature of nebuliser 80 °C, gas fow rate 1.3 standard liters per minute, detector gain 1). The method was validated in terms of limits of detection and quantifcation, intra- and inter-day precision and accuracy, and recovery. The proposed method was carried out using a cation exchange (Ag+) column for the frst time for the inulin determination, avoiding the hydrolysis step in order to simplify and accelerate the quantifcation.