A 2024 study evaluated genetic makeups of 29 broccoli varieties for their sulforaphane-producing capability:

“Sulforaphane (SFN) is one of the most important bioactive compounds in cruciferous vegetables, and is derived from glucosinolates (GSLs [glucoraphanin]). GSLs are hydrolyzed by myrosinases to produce SFN.

However, SFN is not a unique hydrolysate of GSLs. Another enzyme, named epithiospecifier protein (ESP), hydrolyzes GSLs to produce undesirable nitrile components, resulting in a low SFN yield.

Fresh 7-day-old seedlings of 15 broccoli cultivars with a high SFN content did not fully correspond to those with a high GSL content. Seven out of the fifteen broccoli cultivars, such as C2, C8, C12, C21, C22, C28, and C33, produced high SFN, but their GSL content were not particularly remarkable.

Extracted SFN yield from the curds (the curd of broccoli refers to its edible part, which is the entire flower head) was about 70% of that from the seedlings. Nevertheless, in consideration of the obviously higher biomass and lower cost of curds compared to seedlings, these results confirmed that the extraction method established here could also efficiently extract high SFN from broccoli curds and was more feasible for the large-scale extraction of SFN.

Decreased ESP activity can lead to increased SFN formation in broccoli. Broccoli cultivars with strong GSL biosynthetic ability, high myrosinase, and low ESP enzymatic activity are the preferred materials for SFN production.”

https://www.mdpi.com/2218-273X/14/3/352 “Sulforaphane-Enriched Extracts from Broccoli Exhibit Antimicrobial Activity against Plant Pathogens, Promising a Natural Antimicrobial Agent for Crop Protection”

I haven’t seen a broccoli variety suitable for home sprouting advertised for its combined high glucoraphanin biosynthetic ability, high myrosinase enzyme activity, and low epithiospecifier protein enzyme activity genetic profile. Seems like a marketing opportunity. I use a narrow temperature band to suppress ESP activity but not suppress myrosinase activity of 3-day-old sprouts.