Microwave-Assisted Extraction of Prunus cerasus L. Peels: Citric Acid-Based Deep Eutectic Solvents

Abstract

In the present study, waste by-products of one of the most popular fruit juices in the World has been valorized for its high-added value ingredients. Peels of sour cherry (Prunus cerasus L.) have been extracted by deep eutectic solvent (DES)-based microwave-assisted extraction method (MAE). DES system contained citric acid as hydrogen bond acceptor (HBA) and ethylene glycol as hydrogen bond donor (HBD) (1/4, molar ratio). In order to optimize the MAE system Central Composite Design (CCD) of Response Surface Method (RSM) has been used. The measured variables were the yields of total phenolic content (TPC), total anthocyanins (TA), and cyanidin-3-glucoside. Optimum conditions were determined as 0.1 g of peel and a 50 % (v/v) water contribution to the DES for the maximum recovery of TPC (16.85 mg-GAE/g-FP), TA (3.39 mg-cyn-3-glu/g-FP) and cyanidin-3-glucoside (mg/g-FP) in the MAE of sour cherry peels. The relationship between the responses was also established.