Ionic liquid-based negative pressure cavitation-assisted extraction of three main flavonoids from the pigeonpea roots and its pilot-scale application

A new method, Ionic liquid-based negative pressure cavitation-assisted extraction (ILs-NPCE) was investigated to extract three main flavonoids genistin, genistein and apigenin from pigeonpea roots. The influential parameters of the ILs-NPCE were optimized by the single factor and the BBD (Box-Behnken design) experiments. [C8mim]Br was used as the experiment ionic liquid, the optimal conditions were: temperature 74 °C, negative pressure −0.07 MPa, liquid/solid ratio 20:1 mL/g, concentration 0.53 M and extraction time 15 min. The maximum extraction yields of genistin, genistein and apigenin were 0.482 ± 0.008, 0.496 ± 0.017 and 0.291 ± 0.015 mg/g, respectively. The extraction kinetics were also studied under the optimized conditions and it indicated that the ILs-NPCE showed much more advantages such as higher extraction yields, shorter time and more environmental friendly process than other methods. Moreover, this extraction method was also applied with pilot-scale extraction and their yields were 0.477 ± 0.013, 0.480 ± 0.014 and 0.271 ± 0.021 mg/g, respectively. Thus, it was indicated that the developed ILs-NPCE method could be an alternative method for natural compounds extraction in industry.

► The kinetics of ILs-NPCE process was investigated for the first time.
► ILs-NPCE method was effective and environmental friendly.
► The ILs-NPCE was successfully scaled up to pilot-scale.
► The ILs-NPCE could be a potential method for industrial production.