This 2022 study investigated 12 glucosinolate compounds in 9 broccoli cultivars across seeds, 3-, 11-, and 17-day-old sprouts:

“Broccoli is rich in glucosinolates (GLs) which makes it an excellent source of these nutraceuticals. Composition and concentration of GLs vary among broccoli cultivars and throughout developmental stages of the plant.

9 aliphatic GLs and 3 indole GLs were identified from 9 broccoli cultivars. Aliphatic GLs concentrations decreased with broccoli sprouts and seedling growth for most cultivars. Indole GLs amounts increased after germination and reached the highest level in Stage B 3-day sprouts or C 11-day seedlings, and fell back to a low level in D 17-day seedlings.

Stage B was a stage that sprouts grew with no lights in medium and were about to be transplanted into pots. Stage C was a period that seedlings began to grow a main leaf, while in Stage D they were growing the second main leaf.

Relatively high accumulation of glucoraphanin and glucoerucin in Chunqiujiali seeds suggests that CQJL broccoli seeds could be used for extraction of beneficial aliphatic GLs in nutraceutical industry.”

https://www.mdpi.com/2223-7747/11/12/1563/htm “Variation in Glucosinolate Accumulation among Different Sprout and Seedling Stages of Broccoli (Brassica oleracea var. italica)”

These researchers are probably early in their careers. They may have otherwise measured broccoli sprout compounds like glucosinolate-hydrosolate isothiocyanates and others, as did the cited 3-day-old broccoli sprouts have the optimal yields. As those researchers said:

“From the perspective of comparison methods, broccoli varieties, and germination processes, there is still lack of a systematic comparison of SF yields and other bioactive compounds contents between broccoli seeds and sprouts.”

Glucoraphanin is not sulforaphane highlighted one pitfall in concluding “CQJL broccoli seeds could be used for extraction of beneficial aliphatic GLs in nutraceutical industry.” Selecting broccoli varieties highlighted another, and provided an example of how human-applicable broccoli sprout compound research across different varieties could be done:

“We found a clear difference in selecting functional broccoli by considering only the GSL content or hydrolysates.

• Even if total GSL content and individual GSL content were high, ITC content could not be produced at a high level.
• When GSL content is high, if nitrile formation rate was also high, more nitrile than ITC would be produced.”

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