More accurately, Brassica vegetables contain
myrosinase, which helps break down glucosinolates
like glucoraphanin into usable forms of isothiocyanates including sulforaphane.
Check out this video, I think you'll find the answer here: https://nutritionfacts.org/video/second-strategy-to-cooking-broccoli/ The video is summarized here: Adding
myrosinase enzymes in the form of even a pinch of mustard powder to cooked cruciferous (cabbage - family) vegetables
like kale, collards or Brussels sprouts can offer anti-cancer sulforaphane levels comparable to raw, removing the necessity to pre-chop for maximum health benefits.