## 4 Conclusions  
Fundamental and empirical rheological measurements were applied to assess the properties of the soy, lupin, and yeast protein-based emulsions and batters, respectively. The protein-based emulsions exhibited a weak elastic gel-like behavior with moderate frequency dependence on the storage and loss moduli. The stepped flow tests revealed the shear-thinning behavior of the samples. Among all investigated emulsions, the lupin proteins-based one exhibited the highest apparent viscosity over the entirety of the tested shear rate range. The results of the Mixolab test indicated that emulsion addition influences, in a different manner, the thermo-mechanical behavior of the white wheat flour doughs, depending on the protein source. The reduction of the volume fraction of fats added to the dough, when replacing sunflower oil with the soy or lupin proteins emulsion, ensured a better gelatinization of the starch. Higher torque values were registered for the dough prepared with yeast proteins emulsion in all stages of the Mixolab curve. Oil substitution by emulsion resulted in muffins with higher moisture and firmness values. The structure of the muffins was assessed by analyzing the porosity of their cores. All samples exhibited a good ability to retain the CO\({}_{2}\) released during baking, the pore size being slightly higher in the case of the muffins with lower fat content. The chromatic parameters indicated that the samples prepared with protein emulsion have a more vivid \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sensory Attributes**} & \multicolumn{4}{c}{**Muffin Samples**} \\ \cline{2-5}  & **M** & **M1** & **M2** & **M3** \\ \hline Appearance & 8.92 \(\pm\) 0.29  \\ Flavor & 8.92 \(\pm\) 0.29  & 8.75 \(\pm\) 0.45  \\ Taste & 8.58 \(\pm\) 0.52  & 8.50 \(\pm\) 0.52  \\ Color & 8.83 \(\pm\) 0.39  \\ Texture & 8.67 \(\pm\) 0.49  & 8.08 \(\pm\) 0.52  \\ Overall quality & 8.83 \(\pm\) 0.39  & 8.58 \(\pm\) 0.52 [FOOTNOTE:]Footnote : Significant differences among results on the same line, determined by ANOVA and Tukey post hoc test at \(p<\) 0.05, are shown by different superscript lowercase letters.[ENDFOOTNOTE] \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Sensory evaluation data of muffin samples prepared with different types of emulsion (M—control prepared with sunflower oil, M1—muffins prepared with soy protein-based emulsion, M2—muffins prepared with lupin protein-based emulsion, M3—muffins prepared with yeast protein-based emulsion). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Muffin Sample** & **L\({}^{\star}\)** & **a\({}^{\star}\)** & **b\({}^{\star}\)** & **\(\Delta\)E** & **C\({}^{\star}\)** \\ \hline M & 79.35 \(\pm\) 0.45  & 45.05 \(\pm\) 0.17  \\ M1 & 77.48 \(\pm\) 0.24  & 46.26 \(\pm\) 0.11  & 46.34 \(\pm\) 0.11  & -2.71 \(\pm\) 0.13  & 1.82 \(\pm\) 0.09  \\ M3 & 77.23 \(\pm\) 0.09  & 46.53 \(\pm\) 0.08 [FOOTNOTE:]Footnote : Significant differences among results on the same line, determined by ANOVA and Tukey post hoc test at \(p<\) 0.05, are shown by different superscript lowercase letters.[ENDFOOTcolor. In conclusion, the results reported herein confirm that protein-based emulsions considered in this study are sustainable ingredients for obtaining muffins with reduced fat content with acceptable quality characteristics. Conceptualization, I.A. and I.B. ; methodology, L.D., I.V. and L.P.; software, I.A. and L.D. ; validation, I.B., I.V. and L.P.; formal analysis, L.D. and L.P.; investigation, I.B., I.A., L.D., I.V. and L.P.; resources, I.A. ; data curation, I.B. ; writing--original draft preparation, I.A., I.B. and L.P.; writing--review and editing, I.A. and L.D. ; supervision, I.A. All authors have read and agreed to the published version of the manuscript. This work was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS--UEFISCDI, project number PN-III-P1-1.1-TE-2021-0459, within PNCDI III. Not applicable.