An efficient approach for the extraction of anthocyanins from Lycium ruthenicum using semi-continuous liquid phase pulsed electrical discharge system

Lycium ruthenicum is regarded as a good source of natural anthocyanins. In this work, we proposed a novel semi-continuous liquid-phase pulsed discharge (LPD) system for the extraction of anthocyanins from Lycium ruthenicum. The optimized conditions for this method were: 20% ethanol concentration, 7 pH value, 8 kV input voltage, 27 mL/min volume flow, and 8 min treatment time. Under these conditions, a maximum anthocyanins recovery rate (95.69%) was obtained. Compared with batch LPD and heat-assisted extraction (HAE), semi-continuous LPD showed higher anthocyanins yield, shorter time, and lower energy consumption. The antioxidant activity of extracts was determined by scavenging ability of DPPH and ABTS radicals and, reducing ability of Fe3+. The results indicated that the antioxidant activity of batch LPD, HAE, and semi-continuous LPD were similar. Besides, the HPLC chromatograms showed that three methods had similar anthocyanins composition. Thus, semi-continuous LPD was an good and promising method for the extraction of natural anthocyanins.