Pulsed Electric Field and L. Leaves: A Successful Combination for the Extraction of High Value Added Compounds.

The present study aimed to evaluate the pulsed electric field (PEF)-assisted extraction of phytochemicals from L. leaves. The study parameters included a PEF pulse duration of 10 or 100 μs for 30 min, using different "green" extraction solvents: pure ethanol, pure water, and their mixtures at 25, 50, and 75% concentrations. The resulting extracts were evaluated against reference extracts obtained without PEF. For estimation of the extraction efficiency, the content in total polyphenols, individual polyphenols, and volatile compounds, as well as the resistance to oxidation, were determined. The optimal PEF contribution on the total and individual polyphenols, rosmarinic acid, extractability (up to 73.2% and 403.1% increase, respectively) was obtained by 25% aqueous ethanol solvent using a pulse duration of 100 μs. PEF was proven to also affect the final concentration and composition of volatile compounds of the extracts obtained.