Glycerol-based NADES for bioactive compound extraction from Prunus spinosa L. fruit: formulation, characterization, and application

Abstract

The objective of this study was to synthesize and evaluate three innovative Natural Deep Eutectic Solvents (NaDES) for their potential in extracting bioactive compounds from blackthorn (Prunus spinosa L.). The NaDES solutions were synthesized by combining glycerol as a hydrogen bond acceptor with fructose to form N1, sucrose to form N2, and tartaric acid to form N3. The characterization involved pH, viscosity, and conductivity measurements, stability evaluations, and Fourier-transform infrared spectroscopy, with extraction efficiency compared against conventional 70% ethanol solvent. Evaluation criteria included total phenolic content, total flavonoid content, and antioxidant activity using the DPPH method. The characterization revealed significant variations in pH, viscosity, conductivity, and chemical structure, directly influenced by the type of hydrogen bond donor employed. Furthermore, TPC was highest in N1, reaching 9.28 mg GAE/g DW, followed by N3, N2, and 70% ethanol. Flavonoid yield peaked in N3 (3.26 mg CE/g DW), followed by N2, N1 and 70% ethanol. The hydroethanolic extract exhibited the highest antioxidant activity at 87.89%. LC-DAD analysis supported these quantification results. These findings underscore the potential of glycerol-based NaDES as a green, non-toxic alternative for extracting bioactive compounds positioning them as promising candidates for future applications in the food, cosmetics, and pharmaceutical industries.