A method for improving a cell biomass includes de-ashing the cell biomass by applying pulsed electric field (PEF)- or constant electric field (CEF)-treatment to the cell biomass in a solvent, optionally under pressure higher than the ambient pressure, to thereby extract an ash fraction from the cell biomass into the solvent.

A method for improving a cell biomass includes de-ashing the cell biomass by applying pulsed electric field (PEF)- or constant electric field (CEF)-treatment to the cell biomass in a solvent, optionally under pressure higher than the ambient pressure, to thereby extract an ash fraction from the cell biomass into the solvent.

A method is for the extraction of a phytochemical, e.g., peptide or protein, or a chemical element from a macroalgae, by applying pulsed electric field (PEF)- or continuous electric field (CEF)-treatment to the macroalgae in a solvent, under pressure higher than the ambient pressure. A device and system carry out this method.