Subcritical Water Extraction of Allelochemical Compounds from Mucuna Beans

Abstract

This work aims to obtain allelochemical compounds from mucuna beans by applying subcritical water extraction (SWE). The influence of the water flow rate (solvent to beans ratio), temperature, and static time applied during extraction was evaluated in the removal of compounds of interest, with pressure fixed at 10 MPa. The application of water flow of 1 mL min^–1 (22.5 mL g^–1) provided greater removal of L-Dopa and total phenolic compounds (TPC). The temperature (120 °C) increased the extraction of L-Dopa, TPC, and total flavonoids (TF), providing greater antioxidant activity (AA). Furthermore, 20 min of static time preceding dynamic extraction promoted a percentage increase of ∼41.2% and ∼61.5% in the extraction of L-Dopa and TPC, respectively. In the profiled compounds, phenolic acids, flavonoids, and anthocyanins were the phytochemicals identified. The extract obtained under ideal conditions allowed a mass yield of ∼58.1 wt %, with active potential evaluated by levels of L-Dopa, TPC, and TF, as well as AA, validating the high antioxidant activity and suggesting allelopathic potential of the extract.

This study explores the obtaining of phytochemical compounds such as phenolic, flavonoids, and L-Dopa, which promote antioxidant activity with bioherbicidal potential from mucuna beans, through an extractive process using water under subcritical conditions.