**4. Materials and Methods**

#### *4.1. Materials*

The research was conducted on 650 white wheat (*Triticum aestivum*) flour (WWF) type from the 2019 harvest, provided by Dizing S.R.L. (Brusturi, Neamt, Romania). Wheat flour chemical components reported to dry matter were: lipids content of 1.11 ± 0.03%, protein content of 14.41 ± 0.21%, carbohydrates 81.26 ± 0.16%, ash content of 0.60 ± 0.05%, moisture of 14.01 ± 0.16%, total polyphenols content of 105.59 ± 4.42 µg GAE/g. The falling number was 404 ± 1.73 s, wet gluten content was 29.75 ± 0.15%, dry gluten was

10.04 ± 0.13%, gluten deformation index was 6.17 ± 0.29 mm and the water absorption capacity was 59.54 ± 0.31%. Grape pomace from the Fetească Regală variety was provided by Ias,i Research and Development Center for Viticulture and Vinification and was dried in a convection oven at 50 ◦C for 18 h. Grape peels were manually separated, ground and sieved to obtain the particle size of <180 µm. Grape peels contained 2.50 ± 0.19% lipids, 9.85 ± 0.05% proteins, 25.25 ± 0.05% fibers, 55.73 ± 0.20% carbohydrates, 4.47 ± 0.03% ash, 8.00 ± 0.08% moisture and 1448.69 ± 15.39 µg GAE/g polyphenols, 0.40 ± 0.01% pectin reported to dry matter (dm) and a water absorption capacity of 271.10 ± 4.34%. Wheat flour was sieved before mixing in order to achieve a particle size of <300 µm. Composite flours were mixed for 15 min in a Yucebas Y21 machine (Izmir, Turkey).
