## 4 Conclusions  
The analysis of the TGA parameters of both gluten proteins (gliadin and glutenin) showed that they do not differ in weight loss, while gliadins show a higher degradation temperature. This difference can be related to the structure of the proteins examined, especially the type and number of disulfide bridges formed by these proteins. The addition of flavonoids/glyosides caused changes in the thermal parameters of gliadin. The presence of these compounds led to an increase in the weight loss. The weight loss values increase depending on the structure and size of the compound used. The greatest increase in weight loss was observed for quercetin, rutin, and naringenin, which are characterized by the smallest spatial size. Glutenin mass loss does not change in the presence of the tested polyphenols. On this basis, it was concluded that glutenins are responsible for the thermal stability of the gluten network. The difference in TGA thermograms showed that quercetin can interact with gliadin through OH groups located in different positions, while rutin and hesperidin form chemical bonds with gliadin proteins through precisely defined OH groups due to the presence of the glycosidic part. Hesperetin and hesperidin can interact with gliadin through different OH groups. Naringin and hesperidin interact with gliadin in a similar way. Rutin and naringin can form chemical bonds with gliadin through the same OH group. Additionally, detailed analysis of the difference TGA thermograms shows that quercetin, rutin, and naringin interact with gliadins through the OH group located at the B ring in the 4' position. Similar behavior of rutin, naringin and naringenin, and hesperidin was observed as a result of the analysis of the difference TGA thermograms of glutenin. Difference thermograms of quercetin-modified glutenins show that these flavonoids form chemical bonds with the polypeptide chains of glutenins. It was found that quercetin, due to its unbranched structure, can attach to the glutenin network and stabilize it. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15137303/s1](https://www.mdpi.com/article/10.3390/app15137303/s1)]([https://www.mdpi.com/article/10.3390/app15137303/s1](https://www.mdpi.com/article/10.3390/app15137303/s1)). Figure S1: Structure of flavonoids and their glycosides: quercetin (QUE), rutin (RUTG), naringenin (NAR), naringin (NARG), hesperetin (HET), hesperidin (HEDG); Figure S2: Thermogravimetric profiles (left) and derivative thermogravimetric profiles (right) of gliadins (glia_control), gliadins modified by flavonoids and glycosides and pure flavonoids and their glycosides; Figure S3: Thermogravimetric profiles (left) and derivative thermogravimetric profiles (right) of glutenins (control), glutenins modified by flavonoids and glycosides and pure flavonoids and their glycosides; Figure S4: DSC thermograms of gliadins modified by flavonoids: (a) quercetin (QUE), (c) naringenin (NAR), (e) hesperidin (HET) and their glycosides: (b) rutin (RUTG), (d) naringin (NARG), (f) hesperidin (HEDG); Figure S5: DSC thermograms of glutenins modified by flavonoids: (a) quercetin (QUE), (c) naringenin (NAR), (e) hesperetin (HET) and their glycosides: (b) rutin (RUTG), (d) naringin (NARG), (f) hesperidin (HEDG). Conceptualization, M.K. and A.N. ; methodology, M.K., A.Z.W., and A.N. ; formal analysis, M.K. ; investigation, M.K. and K.H.M. ; writing--original draft preparation, M.K. and A.N. ; writing--review and editing, A.Z.W. and A.N. ; visualization, M.K. ; supervision, A.N. ; funding acquisition, M.K. All authors have read and agreed to the published version of the manuscript. This research was funded by the NATIONAL SCIENCE CENTER, POLAND, grant number 2019/33/N/NZ9/02345. Not applicable. The raw data supporting the conclusions of this article will be made available by the authors on request. Analyses were performed in the Centre of Synthesis and Analysis BioNan-of-Techno of the University of Bialystok.