## 4 Discussion
### FTIR and NMR Spectra of Dandelion Inulin  
The observed bands in the FT-IR spectra of the dandelion inulin are typical for inulin. The bands at 817 cm\({}^{-1}\) in both spectra prove the presence of \(\beta\)-D-fructose residues linked to 1\(\rightarrow\)2 glycoside bonds. The IR spectra of the dandelion inulin exhibit absorption bands characteristic of inulin-type glucofructans and are consistent with a report by [PERSON] et al. [10], who identified the band at 937 cm\({}^{-1}\) as characteristic of a furanose ring. The absorption bands at about 874 cm\({}^{-1}\) and 819 cm\({}^{-1}\) are characteristic of 2-ketoses in furanose form and confirm the CH\({}_{2}\) ring vibration of \(\beta\)-anomer and the presence of 2-ketofuranose [10; 14; 25; 42; 43]. Moreover, [PERSON] et al. [18] also reported that 934 cm\({}^{-1}\) is typical for fructofuranosyl group, while [PERSON] et al. [3] demonstrated that a band at 874 cm\({}^{-1}\) is typical for \(\beta\)-glycoside bonds. In addition, the bands observed in the dandelion inulin spectra coincide with the chicory inulin Raftiline used as a reference and are consistent with FT-IR data for inulin-type frtactu [10; 14; 15; 16; 44]. The bands present in the IR spectrum are close to the reported 818, 874, and 937 cm\({}^{-1}\) for inulin, indicating the presence of a \(\beta\)-(2\(\rightarrow\)1) glycosidic bond [42; 43; 44].  
Moreover, the NMR spectra additionally confirm the linear structure of inulin-type frtactu, and the reported chemical shifts are consistent with previous reports for dandelion inulin [6; 7; 10]. Additionally, the NMR spectra of dandelion were compared with those of the chicory inulin Raftiline HPX used as a reference (Figure 5e,f). The results confirm the structure of inulin. In the \({}^{1}\)H NMR spectra of dandelion inulin, only one anomeric shift was found at 5.3-5.4 ppm due to the \({}^{1}\)H of a glucose unit with low intensity, in comparison with the protons from the fructose unit with high-intensity shifts. However, in the \({}^{13}\)C NMR spectra of dandelion inulin, only shifts typical for carbons from the fructose unit were found. The chemical shift at 103 ppm in the \({}^{13}\)C spectra was due to the C-2 of \(\rightarrow\)1)-\(\beta\)-D-Fruf-(2\(\rightarrow\) ). In addition, the chemical shifts for glucose carbons were not observed in dandelion inulin, while they were found in the \({}^{13}\)C NMR spectra of the chicory inulin used as a reference (Figure 5f). The absence of signals for a glucose unit in the \({}^{13}\)C NMR spectra has also been reported for inulin-type fructans isolated from stevia, agave, and echinacea, due to its very small amount in the sample [14; 36; 44]. This observation has been reported in all studies with inulin with a low degree of polymerization [44]. The reported chemical shifts for the fructose unit are consistent with other data for inulin-type fructans [3; 10; 14; 26; 44]. The results presented from the NMR studies confirm the linear chemical structure of inulin isolated from dandelion roots, composed of one terminal glucose unit and fructofuranosyl units linked by \(\beta\)2\(\rightarrow\)1. The type of extraction did not cause a significant effect on the structure of inulin, and only the molecular mass and degree of polymerization decreased when a high temperature and long extraction time were applied, especially during classical extraction.