## 3 Results and Discussion
### FTIR Spectroscopy  
To further understand the structure of extracted materials from RBF with different temperatures, FTIR spectra of a series of extracted material coded as RBP30, RBP40, RBP50, RBP60, RBP70, and RBP80 were determined, and the results are shown in Figure 6. The spectra revealed that extracted materials from RBF had similar characteristic absorption peaks at 3439, 2931, 2886,1736, 1637, 1380, 1029, 874, and 813 cm\({}^{-1}\), which indicates that the structure did not obviously change with different temperatures. The strong absorptive peak of 3439 cm\({}^{-1}\) between the regions 3500-3100 cm\({}^{-1}\) is characteristic of a carbohydrate ring featuring a hydroxyl stretching vibration, and showed that there were intermolecular and intramolecular hydrogen bonds [5; 27]. The peaks in the region of  
Figure 5: Thermal properties of RBPs.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multicolumn{3}{c}{**TGA**} & \multicolumn{3}{c}{**DSC**} \\ \cline{2-7}  & **First Mass Loss Stage** & \multicolumn{3}{c}{**Second Mass Loss Stage**} & \multicolumn{3}{c}{**Endothermic Peak**} \\ \cline{2-7}  & **Mass Loss (\%)** & **Onset Temperature (\%)** & **DTG (\({}^{\circ}\)C)** & **Mass Loss (\%)** & **Temperature (\({}^{\circ}\)C)** & **Heat Flow (W/g)** \\ \hline RBP30 & -7.80 & 282.5 & 328.3 & -87.60 & 98.42 & -1.750 \\ RBP40 & -6.83 & 281.2 & 328.5 & -80.76 & 99.34 & -1.539 \\ RBP50 & -8.84 & 296.1 & 333.5 & -7  
3000-2800 cm\({}^{-1}\) absorption at about 2927 cm\({}^{-1}\) was assigned to the C-H stretching vibration and about 2886 cm\({}^{-1}\) asymmetrical stretching vibration [28]. The relatively strong absorption peak at 1736 cm\({}^{-1}\) indicated the characteristic C=O groups, and the band at 1637 cm\({}^{-1}\) to bound water [29]. Each particular polysaccharide has a specific band in the 1200-950 cm\({}^{-1}\) region. This represents the fingerprint region for carbohydrates and is dominated by ring vibrations overlapped with stretching vibrations of C-OH side groups and C-O-C glycosidic band vibration [30] RBP displayed absorption at 1145 cm\({}^{-1}\), 1058 cm\({}^{-1}\), and 1027 cm\({}^{-1}\), which was due to pyranose. In the anomeric region (950-700 cm\({}^{-1}\)), the polysaccharide exhibited obvious characteristic adsorption at 812 cm\({}^{-1}\), indicating the glucopyranose units in RBPs [31]. The \(\beta\)-conformer had absorption peaks near 874 cm\({}^{-1}\), and the \(\alpha\)-conformer region was near 812 cm\({}^{-1}\)[8; 32]. The characteristic absorption peaks at 812 cm\({}^{-1}\) and at nearby 874 cm\({}^{-1}\) were observed in the IR spectra of the RBPs, indicating that the sugar units of the polysaccharides were linked not only by \(\alpha\)-glycosidic bond but also \(\beta\)-glycosidic bonds. The characterization of six extracted materials by FTIR showed the typical absorption of polysaccharide.  
According to report, the narrowing of the wave band is due to the ordering of polymers [33]. The narrowing band in the region 3500-3000 cm\({}^{-1}\) was seen for RBP80, RBP70, and RBP40, in that order, indicating ordering of polysaccharide chains due to the changed extraction temperature. RBP40, with the narrowest band in the region, 3500-3000 cm\({}^{-1}\), had the highest degree of crystallinity (Figure 7). These observations are in line with the XRD data, confirming that the aggregation structures were changed by different extraction temperatures.