Extraction of polyphenols from bigarade (Citrus aurantium L.) leaves using water bath and ultrasound

Abstract

Thanks to their bioactive compounds, plant by-products such as bigarade leaves gained importance due to their potential capability to reduce disease risk factors caused specifically by oxidative stress and aging. The lack of convenient extraction techniques and the excessive amounts of organic solvents and energy use by conventional extraction called attention to the need of reinforcing and emphasizing the trend of "green chemistry". In this study, ultrasound-assisted extraction (UAE) and conventional water bath (WB) extraction of total phenolic compounds (TPC) from Citrus aurantium leaves were investigated along with the corresponding antiradical activity. The effects of extraction time, temperature, solid-liquid ratio and solvents (water, ethanol and methanol) were studied using both extraction techniques. The optimized extraction parameters were as follows: for the water bath, 2 hours, 60°C, solvent water at 1:40 solid-liquid ratio. For the ultrasound: 25 minutes, 45°C, 75% ethanol and 1:50 solid-liquid ratio. Under these optimal conditions, the obtained yield of TPCs was improved by about 30% using UAE compared to WB, without impairing the antiradical activity. The outcomes of this study indicate that UAE is beneficial and a more cost efficient technique of extraction of bioactive compounds from bigarade leaves.