A method for isolating a soluble plant protein from a plant material on an industrial scale, wherein the method comprises the steps of: i) mechanically disrupting the plant cells of said plant material to obtain a plant juice, wherein before, during, or after the step of disrupting the plant cells an extraction composition comprising at least one of a reducing agent and a divalent ion source is added to said plant material, said plant cells and/or said plant juice, ii) treating the plant juice to cause aggregation of chloroplast membranes, iii) separating said aggregated chloroplast membranes from the soluble plant protein in said treated plant juice by precipitation and/or microfiltration to provide a plant juice supernatant or plant juice permeate comprising the soluble plant protein, iv) subjecting the plant juice supernatant or plant juice permeate obtained in step iii) to ultrafiltration, optionally in diafiltration mode, to provide a soluble plant protein concentrate, preferably comprising 25-50 wt % of protein, wherein said soluble plant protein concentrate is essentially free of salts and phenolic compounds, and v) subjecting the soluble plant protein concentrate to hydrophobic column adsorption to thereby separate in a single column passage the residual chlorophyll, phenolic compounds and off-odors from the soluble plant proteins to provide a column permeate comprising isolated soluble plant protein that is essentially free of chlorophyll and off-odors, and wherein said method further optionally comprises a steps of: vi) drying the said column permeate comprising soluble plant protein to provide a powder of functional plant protein, preferably said drying is performed by lyophilisation or spray drying, and/or (vii) regenerating the hydrophobic adsorption column, wherein the regenerating is preferably accomplished by the use of ethanol as an eluent of column-adsorbed compounds. i) mechanically disrupting the plant cells of said plant material to obtain a plant juice, wherein before, during, or after the step of disrupting the plant cells an extraction composition comprising at least one of a reducing agent and a divalent ion source is added to said plant material, said plant cells and/or said plant juice, ii) treating the plant juice to cause aggregation of chloroplast membranes, iii) separating said aggregated chloroplast membranes from the soluble plant protein in said treated plant juice by precipitation and/or microfiltration to provide a plant juice supernatant or plant juice permeate comprising the soluble plant protein, iv) subjecting the plant juice supernatant or plant juice permeate obtained in step iii) to ultrafiltration, optionally in diafiltration mode, to provide a soluble plant protein concentrate, preferably comprising 25-50 wt % of protein, wherein said soluble plant protein concentrate is essentially free of salts and phenolic compounds, and v) subjecting the soluble plant protein concentrate to hydrophobic column adsorption to thereby separate in a single column passage the residual chlorophyll, phenolic compounds and off-odors from the soluble plant proteins to provide a column permeate comprising isolated soluble plant protein that is essentially free of chlorophyll and off-odors, vi) drying the said column permeate comprising soluble plant protein to provide a powder of functional plant protein, preferably said drying is performed by lyophilisation or spray drying, and/or (vii) regenerating the hydrophobic adsorption column, wherein the regenerating is preferably accomplished by the use of ethanol as an eluent of column-adsorbed compounds.