Optimization of green extraction of high‐value components from Eugenia uniflora leaves: Thermal stability and in‐vitro biological activity

Abstract Deep eutectic solvents (DES) were evaluated as a sustainable route to obtain bioactive compounds from Eugenia uniflora L. leaves (EUL). Completely randomized experimental designs determined the process conditions. The DES composed of cholinium chloride as hydrogen bond acceptor (HBA) and lactic acid, glycerol, or 1,2‐propanediol as hydrogen bond donor (HBD) showed the best extraction capacity. The better conditions were 150 min, 65°C, and a solid:liquid ratio of 1:30. The major constituents of the extracts, quantified by high‐performance liquid chromatography (HPLC), were naringin and caffeic acid. Moreover, the DES promoted a preservative effect on the EUL extracts against thermal treatments. All extracts exhibited high antioxidant and antiglycation activities and iron‐chelating potential. Moreover, when lactic acid was the HBD, the extracts showed considerable antibacterial activity. Therefore, it was effectively proposed as an effective and green route to obtain extracts with potential applications in the food, cosmetic, and pharmaceutical industries.