## 3 Results and Discussion
### Thermogravimetric Analysis (TGA)
The peak at 371 \({}^{\circ}\)C is connected with the degradation of free HET because a similar peak is observed in the thermogram of free HET (see Figure S2k). The difference in the degradation temperature for gliadin-HET and gliadin-HEDG complexes indicates that HET and HEDG may interact with gliadins through different OH groups. In the case of NAR and NARG, a few peaks are observed. Gliadin-NAR thermograms show two peaks at ca. 330 and 358 \({}^{\circ}\)C, whereas peaks at 322, 335, and 364 \({}^{\circ}\)C are present on the gliadin-NARG thermograms. None of these peaks can be assigned to free NAR or NARG (see Figure S2i.j). The presence of the peak at ca. 330 \({}^{\circ}\)C indicates that NAR and HEDG interact with gliadins in a similar way (see Figure 1c,f). Similarly, RUTG and NARG can form chemical bonds with gliadins through the same OH group (see Figure 1b,d). An analysis of the RUTG and NARG structure shows that they can interact through two hydroxyl groups located in the ring B at position 4' or in the ring A at position 5. In the case of NAR and HEDG, a possible place of interaction is localized in the ring A at position 5. These results suggest that the peak at 322 \({}^{\circ}\)C can be connected with gliadin-QUE/RUTG/NARG interactions through the OH group localized in ring B at position 4'. In contrast, the degradation of chemical bonds formed between the OH group in the ring A at position 5 and gliadins can be observed at ca. 330 \({}^{\circ}\)C for gliadin-NAR, NARG, and HEDG. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Polyphenol** & **Polyphenol** & **Weight Loss** & \multicolumn{2}{c}{**Total (\({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Total (\({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Total (\({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Polyphenol**} & \multicolumn{2}{c}{**Weight**} & \multicolumn{2}{c}{**Total (\({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Total (\({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Total (\({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Total (\({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Total (\({}^{\circ}\)C)**} \\  & **Content** & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** \\ \hline glia\_control & 0 & 68.7 (2.4) \({}^{\rm d}\)\({}^{\rm e}\) & 69 (1) \({}^{\rm b}\)\({}^{\rm c}\) & 310 (3) \({}^{\rm c}\) & glu\_control & 0 & 70.8 (2.1) \({}^{\rm d}\)\({}^{\rm s}\) & 72 (2) \({}^{\rm b}\) & 301 (3) \({}^{\rm d}\) \\ glia\_QUE & 0.05 & 79.3 (1.6) \({}^{\rm d}\)\({}^{\rm s}\) & 76 (1) \({}^{\rm d}\)\({}^{\rm s}\) & 310 (2) \({}^{\rm c}\) & glu\_QUE & 0.05 & 75.6 (2.8) \({}^{\rm d}\)\({}^{\rm s}\) & 69 (3) \({}^{\rm b}\) & 301 (3) \({}^{\rm d}\) \\  & 0.1 & 72.4 (1.1) \({}^{\rm d}\)\({}^{\rm s}\) & 69 (1) \({}^{\rm b}\)\({}^{\rm c}\) & 319 (2) \({}^{\rm d}\) & & & & & & & & \\  & 0.2 & 75.4 (1.9) \({}^{\rm f}\)\({}^{\rm d}\) & 67 (2) \({}^{\rm b}\)\({}^{\rm c}\) & 319 (1) \({}^{\rm d}\)\({}^{\rm s}\) & & & & & & & & \\  & 100 & 48.5 (2.5) \({}^{\rm a}\)\({}^{\rm s}\) & 336 (3) \({}^{\rm c}\) & & & & & & & & & \\ glia\_RUTG & 0.05 & 77.4 (1.5) \({}^{\rm b}\)\({}^{\rm d}\) & 67 (2) \({}^{\rm b}\)\({}^{\rm d}\) & 310 (3) \({}^{\rm c}\) & & & & & & & & \\  & 0.1 & 77.3 (1.8) \({}^{\rm b}\)\({}^{\rm d}\) & 59 (2) \({}^{\rm a}\)\({}^{\rm b}\) & 310 (3)The difference thermograms of glutenins modified by flavonoids and their glycosides, presented in Figure 2, are more structured in comparison with gliadins. This may be related to the more complicated structure of glutenins, which are polymeric proteins. Thermograms of glutenin-QUE show only three peaks--two negatives at 263 and 337 \({}^{\circ}\)C, and one positive at 302 \({}^{\circ}\)C. The positive peak is connected with the degradation of unmodified glutenins (see Table 1). A decrease in the intensity of this peak with increasing QUE concentration indicates that QUE forms chemical bonds with the polypeptide chains of glutenins. The peak at 337 \({}^{\circ}\)C can be assigned to free QUE (see Figure S2g).