Comparison of different methods for the removal of natural deep eutectic solvents after gas-expanded liquids extraction of bioactive compounds from orange by-products

• NADES under gas expanded extraction conditions tested. • All cleaning processes provided extract without NADES with different profiles and bioactivity. • Activated charcoal-based purification provided the richest extracts in bioactive compounds. • Acetone as antisolvent is the most effective procedure to eliminate NADES from biomass. • NADES-free bioactive natural extracts are obtained from orange by-products. This study investigates the extraction and purification of bioactive compounds from citrus biomass using gas-expanded natural deep eutectic solvents (NADES), focusing on their neuroprotective potential. After the extraction, different cleaning techniques, including solid-phase extraction (SPE) with C18 stationary phase, activated charcoal purification, and antisolvent methods, were evaluated to study their efficiency in removing the NADES and recovering the extracted bioactive compounds efficiently. The use of ethanol combined with activated charcoal provided the extracts with the highest recovery of bioactive compounds including flavonoids (quercitrin, narirutin, hesperidin), limonoids (limonin, tangeretin), and terpenes (limonene, α-terpineol, α-terpinolene). This extract also had the highest neuroprotective activity. On the other hand, the removal of NADES from the residue of the gas-expanded NADES extraction was also evaluated. The use of acetone as an antisolvent was shown to be the most effective procedure to eliminate NADES from this biomass. Its use allowed recovering the most important components as well as a better recovery of other bioactive compounds, such as carotenoids. Thus, this work demonstrates the usefulness of the studied approaches to obtain a NADES-free extract from a new gas-expanded NADES process maintaining its bioactive potential and composition