Ultrasound-assisted extraction, quantification and characterization of inulin from agave, chicory and Jerusalem artichoke

This study investigated the extraction, quantification and characterization of inulin obtained from agave (Agave americana) leaves, chicory (Cichorium intybus) roots and Jerusalem artichoke (Helianthus tuberosus) tubers. Ultrasound-assisted extraction (UAE) was employed under varying solid-to-liquid ratios (1:3–1:6) and ultrasonic frequencies (30–60 kHz), while maintaining a constant extraction time of 35 min and a temperature of 40 °C. Proximate and mineral profiling revealed agave to be richer in moisture and fat, chicory in protein and ash, and Jerusalem artichoke in fiber, with potassium and calcium were the dominant minerals across all sources. Inulin extraction efficiency increased significantly at a solid-to-liquid ratio (1:6) and an ultrasonic frequency (60 kHz). Among the tested samples, Jerusalem artichoke exhibited the highest inulin content (93.53 ± 3.81%), followed by chicory (90.39 ± 2.96%) and agave (78.99 ± 3.08%). Physicochemical and techno-functional evaluation showed that agave inulin contained high dry matter (92.86%), relatively high oil-holding capacity (3.27 g/g) and moderate solubility (74.32 g/L). Chicory inulin exhibited maximum solubility (114.66 g/L) with moderate dry matter (91.48%) and lower water-holding capacity (1.68 g/g). Jerusalem artichoke inulin presented the highest dry matter (94.89%) along with superior water-holding capacity (5.40 g/g) and comparartively lower solubility (4.76 g/L). Fourier Transform Infrared (FTIR) spectroscopy of inulin confirmed the presence of alcohol and glycosidic ether groups while X-ray diffraction (XRD) patterns displayed broad amorphous halos with semi-crystalline features varying by source. In conclusion, Jerusalem artichoke proved to be the most promising source of inulin, demonstrating higher extraction efficiency and favorable techno-functional and structural properties for food and nutraceutical applications.