High selective purification of Quercetin from Peanut hull using protic deep eutectic mixture based liquid–liquid microextraction

Abstract

A benign and environmentally viable method for extraction of quercetin from peanut peel was accomplished with acid-based protic deep eutectic solvents (pDESs) by microwave-assisted liquid–liquid microextraction. Extraction efficiency for all pDESs was evaluated with analytical standards (Rutin and Quercetin) by total phenolic content assay with highest partition coefficient observed for 4.8 for rutin and 12.7 for quercetin respectively. Treatment of peanut hull by microwave-assisted liquid–liquid microextraction was performed. Central composite design-based response surface methodology was executed for optimizing the recovery of polyphenols providing maximum recovery of 430 µg QE/ g of husk powder at optimal conditions of 8 minutes irradiation for 323 K with powder sample of 35 mg suspended in 650 µl of pDES. The concentrated samples were analyzed for antioxidant content by total flavonoid content assay. The crude fractions collected were subjected to HPLC and the amount of Quercetin recovered was evaluated. Pure fraction thus obtained was confirmed with H1 NMR analysis. The present method which is eco-friendly and highly economic is viable to be scaled up to be industrially.