No de novo sulforaphane biosynthesis in broccoli seedlings

► The plant metabolite sulforaphane has been identified for its anticarcinogenic properties. ► Broccoli contains high amounts of sulforaphane in the form of precursor glucoraphanin. ► The highest concentration of glucoraphanin/sulforaphane is found in young broccoli seedlings. ► Glucoraphanin/sulforaphane in seedlings exclusively originates from seed reserves. ► Consumption of young seedlings contributes to a higher intake of protective glucosinolates.