Grape skin and seed flours as functional ingredients of pizza: Potential and drawbacks related to nutritional, physicochemical and sensory attributes

As a consequence of the increase in consumer demand for added-value foods, the purpose of this study was to develop pizza bases, exploiting the techno-functional properties of oenological flours. Fortified pizza bases were obtained by replacing wheat flour with 15, 20, and 25% of skin flour (GS) and skin/seed flour (GM). The replacement with GS and GM allowed to increase the content of anthocyanins and phenolic compounds and the antioxidant activity, especially when the mix of grape skin and seeds was used. The addition of GS and GM at the highest percentages, allowed to obtain "high fiber content" pizza bases by reaching more than 6 g of dietary fiber/100 g. At the highest substitution levels, significant differences were found depending on GM and GS addition both for hardness (13.93 vs 22.75) and chewiness (9.73 vs 18.19). The analysis of volatile compounds (VOCs), instead, showed that the addition of grape flours reduced the presence of pyrazine and increased the concentration of esters, acids, ketones, and aldehydes, known for their significant sensory impact. The sensory evaluation was in line with the results of VOCs, highlighting the perception of must, acid, and pungent, as well as with the physicochemical analysis.