Assessment of Efficient Deep Eutectic Solvent-Based Extraction, Activity, and Environmental Impacts of Naringin.

Abstract

Naringin, a bioactive flavonoid found in citrus peels-a common byproduct of fruit processing-is typically extracted using volatile organic solvents, which raises issues about operational safety and environmental sustainability. This study integrated quantum chemical calculations with experimental approaches to conduct high‑throughput screening of deep eutectic solvents (DESs) for naringin extraction from pummelo peel. Among 72 DESs, calculated infinite dilution activity coefficients indicated the solvation capacity, whereas σ-profiles examined potential hydrogen-bonding and hydrophobic interactions. The subsequent extraction experiment identified the DES consisting of tetrabutylammonium bromide/propylene glycol (TEABr/PG, 1:2 molar ratio) exhibiting the highest naringin yield among the nine DESs re-evaluated. Single-factor experiments coupled with response surface methodology systematically optimized the parameters to a liquid-to-solid ratio of 10 mL/g, 30% water content, 40 °C, and 0.5 h. The naringin yield attained 141.31 mg/g under these mild conditions, significantly surpassing yields obtained with conventional methanol or ethanol. Beyond yield, the extract also showed potent antioxidant activity, particularly in ABTS radical scavenging, and notable antibacterial effects against E. coli and S. aureus. Importantly, the sustainability of the optimized process was evaluated using the Modified Green Analytical Procedure Index (MoGAPI). The TEABr/PG-based method achieved a greenness score of 78, outperforming ethanol (76) and methanol (72), demonstrating a win-win outcome between extraction efficiency and environmental sustainability. By combining high‑throughput solvent screening with systematic process optimization, this work not only establishes an efficient naringin extraction process but also offers a framework for evaluating both process performance and greenness, supporting citrus peel valorization within a bio‑circular economy.