Sustainable Solutions for the Production of New Feed Supplements From Wine Industry Waste

Continuous population growth and the more intensive production of agro-industrial by- products have a significant environmental impact considering that often these wastes are not re-used (Roselli et al., 2024). The aim of the project (Next Generation EU, 2023)is to valorise the hidden potential of these precious secondary raw materials performing extraction with new eco-sustainable methodologies obtaining nutraceuticals, especially phenolic compounds, that can be used to produce food or feed supplements (Roselli et al., 2024). Preliminary extractions on two varieties of grape pomace (Cabernet Sauvignon and Petit Verdot) have been performed to screen seven Deep Eutectic Solvents (DESs) as innovative green extracting media by using hydroalcoholic solutions as reference. Both fresh and dried matrices were evaluated. These extracts were characterized for their phenolic compounds content through HPLC-DAD. In all 36 samples, up to eight out to thirteen phenolic compounds analyzed (gallic acid, coumaric acid, syringic acid, caffeic acid, catechin, rutin, kaempferol galactoside and quercetin) were detected, reaching a maximum concentration of 0.492 μg g-1. The analyses will help us to select the most efficient DES to be used to set up multiple extractions on more grape pomace cultivar after the next vintage with the possibility to compare them. Then, molecular biology studies will be performed with the aim to find a possible correlation between the nutraceutical value of the extracts and variation on selected gene expression. The final step will consist in the formulation of a new feed supplement for animal nutrition.