Frequency and wave type effects on extractability of oleuropein from olive leaves by moderate electric field assisted extraction

The moderate electrical field (MEF) process was used to reduce the process time (t) of oleuropein extraction from olive leaves. MEF process was performed with methanol-water (4:1 v/v) with sine wave-SN and square wave-SQ at 30 V/cm with different frequencies (1, 1000, and 2000 Hz). The conventional extraction (CE) method was performed for 8 h in methanol-water (4:1 v/v) mixture at 40 °C. The effects of MEF conditions on t, effective electrical conductivity (EEC), cell disintegration (Zc) and extraction performance coefficient (EPC) were determined. SN provided desired extraction yield in a shorter time than SQ (p