**4. Conclusions**

Based on the literature data, the acetylation of rice proteins with acetic anhydride, which was used in the presented work, is one of the most effective chemical methods for improving some functional properties without negatively affecting a change in chemical composition. However, it is still difficult to find an explanation for the relationship between the structure of the modified proteins and their function. The acetylation of a commercial rice protein preparation using a dose of 0.4 mL of acetic anhydride/g of protein improved the WBC and emulsifying properties at pH 8, which extends the possibilities of using the modified rice samples in the processing of meat, fish, and plant products, as well as in finely ground meat products, coffee whiteners, milk, or frozen desserts.

**Supplementary Materials:** The following supporting information can be downloaded at: https://www. mdpi.com/article/10.3390/molecules28020770/s1. Table S1: Amino acid composition, Table S2: Foam stability results.

**Author Contributions:** Conceptualization, J.M.; methodology, J.M., K.W., M.Z.-D. and A.Z.; software, S.W.; validation, J.M., K.W., M.Z.-D. and A.Z.; formal analysis, J.M., K.W., M.Z.-D. and A.Z.; investigation, J.M., resources, J.M.; data curation, A.K.; writing—original draft preparation, J.M.; writing—review and editing, A.K.; visualization, J.M., supervision, A.K.; project administration, A.K.; funding acquisition, A.K. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was financially supported by the National Science Centre of Poland (2019/03/X/N29/01823). The APC/BPC was financed/co-financed by the Wroclaw University of Environmental and Life Sciences.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data are contained within the article and Supplementary Materials.

**Acknowledgments:** J.M. would like to thank Przemysław Łukasz Kowalczewski for his help with editing the manuscript (Pozna ´n University of Life Sciences).

**Conflicts of Interest:** The authors declare no conflict of interest.

**Sample Availability:** Samples of the compounds are available from the Authors.
