The present invention relates to a process for producing glucosinolates, particularly glucoraphanin, from cruciferous plants. More particularly, a method is provided for producing glucosinolates from agricultural by-products and waste. The general method comprises providing a mixture of glucosinolate-containing plant material and liquid, heating the mixture to inactivate enzymes in the plant material, contacting the heat inactivated mixture with an anion exchange membrane whereby at least a portion of the glucosinolates are extracted from the liquid and absorbed onto the anion exchange membrane, and releasing the glucosinolates from the anion exchange membrane. Preferably, the extraction and release steps are repeated at least once. The glucosinolates produce by the method of the invention may be incorporated into a variety of food products, pharmaceuticals, and health supplements.