Antioxidant extraction and bioactivity preservation from winery by-products by Natural Deep Eutectic Solvents (NaDES)

In recent times, the feasibility of sourcing the bioactivity and health-promoting activity of anthocyanins, flavanols, stilbenes and phenolic acids from viticulture and winery by-products was explored. In particular, pomace, wine lees, and pruning stalks attracted a great deal of interest among scientists, technologists, and businesses. Traditional solid-liquid extraction methods employ hazardous solvents, such as hydrocarbons, alcohols and chloro-alkanes. As an attempt to convey compliance to the pillars of Green Chemistry, the possibility to choose innovative eco-friendly solvents was evaluated. Furthermore, this approach could preserve the activity of the bioactive compounds for possible applications in food, pharmaceutical, cosmetic and phytosanitary domains. In this work, natural deep eutectic solvents (NaDES) were used to investigate Solid-Liquid Extraction of phenolic species from Merlot marc. Two different operating temperatures were tested and the influence of biomass grinding was investigated. Experimental results show that both kinetic and final anthocyanins extraction efficiency are positively affected by biomass grinding and by temperature increase.