Grape pomace flour: A functional and sustainable ingredient for gluten-free pasta

Grape pomace (GP), a winemaking by-product rich in polyphenols and anthocyanins, was used as a functional ingredient to enhance the nutritional and functional properties of gluten-free pasta. Grape pomace flour (GPF), from red grape varieties, was characterized for its moisture content (2.13 ± 0.41 g/100 g), total polyphenols (1773.52 ± 207.24 mg GAE/100 g), anthocyanins (72.38 ± 16.18 mg/100 g), pH (3.59 ± 0.02), titratable acidity (12.32 ± 0.45 g/100 g), fibre (64.1 ± 5.02 g/100 g), water binding capacity (420.38 ± 15.75 g/100 g), and oil binding capacity (340.63 ± 57.97 g/100 g). Gluten-free fettuccine was formulated with 0%, 5%, and 10% GPF, and the cooking, chemical, and physical properties of both fresh and dried pasta were evaluated. The incorporation of GPF significantly affected the pasta's functional properties and nutritional profile. The optimal cooking time increased from approximatively 5 min for control samples (0% GPF) to about 7 min for pasta containing 10% GPF. Enriching gluten free pasta with GPF significantly increased the content of bioactive compounds. Total polyphenol content increased from three to sixfold compared to the control sample, depending on the level of GPF added and the drying process. Furthermore, anthocyanin content increased up to 88.05 ± 4.14 mg/kg in fresh gluten free pasta samples, however, the drying process induced degradation of these pigments up to 29%. The results showed that fortifying gluten-free pasta with grape pomace flour improves its nutritional and functional properties and promotes circular gastronomy practices through the valorisation of agri-food by-products and their sustainable reintroduction into the food system.