Physicochemical, Functional, and Antibacterial Properties of Inulin-Type Fructans Isolated from Dandelion (<i>Taraxacum officinale</i>) Roots by “Green” Extraction Techniques

Abstract

The current study aims for the isolation and physicochemical characterization of inulin from defatted dandelion roots using green extraction techniques, including microwave extraction (MAE) and ultrasound-assisted extraction (UAE). The structure and degree of polymerization of inulin were elucidated by chromatographic techniques, as well as by FTIR and NMR spectroscopies. The color characteristics, water- and oil-holding capacity, solubility, swelling properties, wettability, angle of repose, flowability, and cohesiveness of dandelion inulin were evaluated. Moreover, the antioxidant and antibacterial potential of dandelion inulin were revealed. The results were compared with the conventional extraction and inulin from chicory. Dandelion inulin was evaluated as a powder substance with a degree of polymerization (DP) of 17–24. The highest yield (20%) was obtained by classical extraction; however, UAE and MAE demonstrated the highest purity. FT-IR and NMR spectra revealed that dandelion inulin is glucofructan with a molecular weight of 2.7–3.2 kDa that consists mainly of fructosyl units β-(2→1) linked to one α-D-glucose unit UAE was evaluated as the most perspective technique for the simultaneous extraction of inulin from dandelion roots, with the highest average DP 24 and high purity (82%), molecular mass, total fructose content, swelling index, and oil-holding capacity. Dandelion inulin exhibited intermediate cohesiveness, fair flowability, and moderate antimicrobial activity against Listeria monocytogenes 863 and Bacillus subtilis 6633. The physicochemical and functional properties of dandelion inulin reveal its future potential as an additive in food, cosmetic, and pharmaceutics formulations as a texture modifier, a fat replacer, and a drug carrier.

Keywords

• dandelion roots
• inulin
• microwave and ultrasonic extractions
• FT-IR spectra
• NMR spectroscopy
• functional properties