Impact of microwave-assisted, subcritical water, and HVED extraction on the content of bioactive components of quince leaves (Cydonia oblonga) extracts

Abstract

Native to the regions of west Asia quince (Cydonia oblonga) is a small tree or a shrub which is now spread throughout the world [1]. Application in traditional medicine proved that quince leaves possess significant medicinal properties. Modern medicine states that quince leaves extracts have cardiovascular, antibacterial, antifungal, antidiabetic, and antioxidant activity [2]. In order to enhance the bioactivity of quince leaves extracts, three green extraction techniques were applied. The applied techniques were microwave-assisted extraction (MAE), subcritical water extraction (SWE), and high voltage electric discharge (HVED) extraction. The efficiency of the extraction techniques was determined by analyzing the content of total flavonoids and antioxidative activity of the extracts. MAE was conducted at five different temperatures (40, 60, 80, 100, 120 °C) and two different extraction time (5 and 10 min) using 50% ethanolic solution as solvent. The HVED was conducted at three different frequencies (40, 70, 100 Hz) and three different extraction times (1, 5, 15 min) while five different temperatures were applied for SWE (100, 125, 150, 175, 200 °C). The content of total flavonoids was ranging between 62.67 and 640.71 mg CAT/g DE, while the IC50 value for the DPPH test was in the range from 7.65 to 0.907 µg/mL. The highest activity was achieved by applying HVED extraction at the conditions of 40 Hz and 15 min. By applying these extraction techniques, it was proved that extracts rich in bioactive components with high antioxidative activity can be obtained with the reduced negative impact on the environment.