Separation and purification of sulforaphane (1-isothiocyanato-4-(methylsulfinyl) butane) from broccoli seeds by consecutive steps of adsorption-desorption-bleaching

Sulforaphane has received attention in recent years due to its biological properties; it is found in broccoli seeds but must be released by enzymatic action from its precursor molecule. In this study, a novel process to purification of sulforaphane from broccoli seeds is described. The procedure is divided in three consecutive steps: 1) hydrolysis and extraction, 2) adsorption/desorption of crude extract, and 3) bleaching step. The adsorption capacity (65-74 mg/g) and sulforaphane recovery (67-79%) were consistent in the adsorption/desorption step, which is important because it is possible to obtain up to 40% of sulforaphane content. Maximum bleaching was reached at 15-20 min, increasing the purity of sulforaphane considerably. It is possible to obtain 90% of bleaching and good recoveries. Purified sulforaphane from broccoli seed extracts was identified by mass spectrometry. Infrared and ultraviolet spectroscopy confirms the presence of sulforaphane in each step as well its separation and purification.