This 2023 clinical trial with broccoli sprout powder investigated ways of improving blood plasma measurements:
“Quantifying sulforaphane (SFN) and its thiol metabolites in biological samples using liquid chromatography-tandem mass spectrometry is complicated by SFN’s electrophilic nature and the facile dissociation of SFN-thiol conjugates. We used the alkylating agent iodoacetamide (IAA) to both release SFN from protein thiols and force the dissociation of SFN metabolites.
After 15 min of incubation, approximately 90% of the SFN was recovered. After 2 hours of incubation, SFN loss to thiol conjugation was significant, with approximately 30% recovered. The percentage of SFN lost in this manner in human plasma upon protein precipitation would likely be greater than the loss we observed in fetal bovine serum (FBS), as free thiols in human plasma are approximately 6 times higher than in FBS.
Subjects were 12 healthy, young (19–30 y), men (n = 4), and women (n = 8). They consumed three EnduraCell capsules with water.
Per the manufacturer, each capsule contained 700 mg of 100% whole broccoli sprout powder, including active myrosinase and 21 mg of glucoraphanin, which upon full conversion to SFN would yield ∼8 mg, equaling ∼24 mg of SFN total per three-capsule dose. We note that full conversion to SFN, even with active myrosinase in the supplement, is not expected.
SFN concentrations in plasma increased for all subjects, with the highest being 193 nM for subject 4 one hour post consumption. Asterisks for the 2 and 3 hour time points indicate a p-value of <0.05, comparing that time point to the previous time point for that participant.
This thiol-blocking method increased SFN percent recovery from FBS from 32 to 94 ± 5%. Applying the method to clinical samples, SFN concentrations were on average 6 times greater than when IAA was omitted.”
https://pubs.acs.org/doi/10.1021/acs.jafc.3c01367 “Bioavailable Sulforaphane Quantitation in Plasma by LC–MS/MS Is Enhanced by Blocking Thiols”
I didn’t highlight subject bioavailability statistics or researcher generalizations. Someday, researchers will be interested and forward-thinking enough about their field to plan ahead and investigate likely occurrences such as:
- What caused Subjects 3 and 4 to have much higher responses than Subjects 2 and 6?
- What caused Subjects 5 and 11 to have their highest sulforaphane levels at their 3-hour points, whereas 3-hour points were most other subjects’ lowest levels?
And, of course, what was the actual sulforaphane intake by researcher measurements vs. relying on manufacturer statements? Especially when researcher lab equipment was available to measure that.
This study’s proof of concept demonstrated a 10% sulforaphane loss after 15 minutes, and a 68% loss after two hours. Applying their finding to home sprouting, I wouldn’t expect any advance preparation method of broccoli sprouts or seeds to adequately address sulforaphane degradation.
I’d suggest microwaving up to 60°C (140°F) and/or grinding and/or blending broccoli sprouts and seeds just before eating to optimize your sulforaphane intake. Also, taking the very reactive sulforaphane by itself to optimize your results.
Surface Your Real Self 
Thank you for your excellent reply. I am really grateful for your article referral. I went to the article you referred to and will need to reread it to be sure I am clear. Your conclusions about home sprouting needs look to be valid and this article would indicate an extreme and unfortunate conclusion for my question. Before ceding to the probability of your comment of the need to “Microwave or grind or blend sprouts and seeds just before eating” I would like to make sure my comprehension of the article is complete. What they pointed out was that the testing system for the measurement of ST (they use STN) though its metabolites and compounds has been limited by the fact that ST is very reactive and some of the reactions make investigations difficult because of the difficulty in what happens to ST and the reversibility of some of those ST containing compounds. However, in another place you pointed out that the ST in seeds is indeed associated with water (which is what the microwaves react with) and I am trying to ascertain if the process of heating/microwaving and grinding the seeds might have some point at which a patient preparing tea might find some technique to expedite and simplify the efforts they would have to go through to convert broccoli seed to tea. As mentioned, this is personal for me since my son is suffering from early onset PD.
It would be nice to see the same study done with broccoli sprouts instead of a supplement. I would assume that the digestian and conversion to SFN in the gut would produce a more steady rise in plasma due to digestion when compared to a supplement. Anyway, I’m thinking it might be an idea to spread out the consumption of sprouts throughout the day?
Sure! There are many animal studies we can safely take clues from. But they won’t ever be replicated in humans because there’s no way to make money on it, and they’d last too long.
Take the Eat broccoli sprouts every day study, for example. All the rats did was eat regular chow that had cooked broccoli in it for 14 days. Using the maximum lifespan approach, one rat day is 32.2 human days. 14 rat days would be 451 human days.