Vesicle-enhanced liquid-phase pulsed discharge extraction of polyphenols from green tea leaves

A vesicle-enhanced liquid-phase pulsed discharge (V-LPD) was proposed to extract polyphenols from green tea leaves. The optimal extraction conditions obtained by the process optimization were 3% (w/v) dodecyl trimethy lammonium bromide (DTAB)/sodium dodecyl sulfate (SDS) vesicle, 10% (v/v) ethanol/vesicle, 66 mL/g liquid-to-solid ratio, 5 kV discharge voltage, and 2.5 min extraction time. Under these optimal conditions, the polyphenols yield was 124.650 ± 1.197 mg/g, which was observably higher than that by heat reflux extraction (HRE) (108.156 ± 1.437 mg/g) for 45 min and that by ethanol-enhanced LPD (116.123 ± 1.164 mg/g) for 4 min. The energy consumptions of V-LDP and ethanol-enhanced LPD were far lower than that by HRE. Similar chemical constituents were observed by HPLC analysis in three extraction methods, and the extracts obtained by V-LPD had the highest antioxidant capacity. Therefore, the V-LPD is a time-saving and energy-saving method for the extraction of polyphenols.Industrial relevanceGreen tea is considered to be an important source of polyphenols. The potential of V-LPD has been demonstrated as a time-saving and energy-saving alternative using vesicle solvents for the simultaneous cell disruption and strengthening diffusion of polyphenols from green tea leaves. The polyphenols obtained with V-LPD process can be used in an array of pharmaceutical, cosmetic and food applications.