Extraction of Polyphenolic Antioxidants from Red Grape Pomace and Olive Leaves: Process Optimization Using a Tailor-Made Tertiary Deep Eutectic Solvent

In the framework of introducing green strategies for food processing, industrial orientation has shifted towards replacement conventional petroleum-based solvents with alternative eco-friendly ones. On this basis, objective study was to synthesize a novel, tertiary, food-grade deep eutectic solvent, composed glycerol, citric acid, and L-proline (GL-CA-Pro), test it as solvent extraction polyphenols from agri-food waste biomass. After an initial screening on various common residual materials (apple peels, lemon orange red grape pomace, olive leaves), evidence emerged that indicated GL-CA-Pro more effective than other DESs commonly used polyphenol extraction. Furthermore, extracts pomace (RGP) leaves (OLL) were shown contain higher level total increased antioxidant activity. Process optimization those two response surface methodology revealed major difference pertained time. addition, both materials, provide yields (53.25 42.48 mg gallic acid equivalents per g dry mass, respectively) compared water 60% aqueous ethanol. However, chromatographic analyses OLL suggested ethanol suitable some principal polyphenolic constituents. The RGP extract produced exhibited significantly stronger effects hydroethanolic extracts, but outcome diversified. It concluded is very efficient polyphenols, its efficiency regarding comparable