**4. Conclusions**

The incorporation of RPC flour and the replacement of margarine by rapeseed oil into the formulation of WF-based biscuits resulted in a nutritionally enhanced product with a higher amount of antioxidants. Moreover, the UAE of ingredients used for dough preparation produced higher recoveries of total antioxidants in comparison with the conventional extraction.

A higher percentage of RPC in the formula increased the antioxidant potential of the proposed biscuits. However, these biscuits had lower sensory scores for color, odor, texture, flavor, overall acceptability, and purchase intent.

The estimated parameters, RPC content, and SAFA content affected the DPPH results, and sensory characteristics of the baked biscuits. However, the amount of RPC flour had a greater positive effect on the antioxidant potential of biscuits than the fat type used for dough preparation. Nevertheless, the added level of RPC was a more negatively effective independent variable on the sensory properties of the biscuits studied.

The good agreement between the predicted values and experimental results verified the validity of the proposed models and the optimal ingredient amounts for the baking of biscuits incorporating by-products of rapeseed oil industry.

**Author Contributions:** Conceptualization, A.S.-C., S.P. and M.M.; Data curation, A.S.-C., S.P. and M.M.; Formal analysis, S.P. and M.M.; Investigation, A.S.-C., S.P. and M.M.; Methodology, A.S.-C., S.P. and M.M.; Supervision, A.S.-C.; Visualization, A.S.-C., S.P. and M.M.; Writing—original draft, A.S.-C., S.P. and M.M.; Writing—review & editing, A.S.-C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

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

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Acknowledgments:** The authors would like to thank Angelika Gawro ´nska for analysis of antioxidant capacity.

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

#### **References**

