A method and apparatus for increased yields of water-soluble polyphenols from plant seeds is provided. The method includes inducing seed germination within a selected range of temperatures. The method also includes inducing germination in an atmosphere having elevated carbon oxygen concentration and/or a reduced concentration of oxygen. The method further includes exposing the seeds to light and extracting water-soluble polyphenols with an aqueous solution without adding an organic solvent such as alcohol.
