A brassica vegetable tablet contains at least 50 .mu.g of sulforaphane and a maximum of 50 .mu.g of sulforaphane-nitrile. A process for producing a brassica vegetable product includes inactivating endogenous myrosinase enzyme in a brassica vegetable and thereafter blending the vegetable with exogenous myrosinase enzyme. The preferred process may include steam blanching as the method of inactivating the endogenous myrosinase enzyme. The preferred process may also include horseradish root as the source of exogenous myrosinase enzyme.