This 2020 review explored sulforaphane stability and formation:
“Sulforaphane (SF) is beneficial to our health since it can reduce incidence of a number of tumors, induce cell cycle arrest and apoptosis in multiple experimental models. However, since neither SF nor myrosinase is thermostable, it is essential to increase stability of SF and/or enhance conversion of glucoraphanin (GRP) to SF by myrosinase to maximize SF therapeutic benefits.
- Since little or no water is needed for microwaving and stir-frying, and broccoli is not immersed in water during steaming, SF content in broccoli florets is higher in these processes compared to that in boiled florets.
- Thermostability of Brassicaceae myrosinase varies across different species and cultivars, as well as the plant organ. For example, myrosinase in broccoli florets are more thermosensitive compared to that in sprouts, likely due to the presence of a seed-specific myrosinase.
- GRP in cooked broccoli can be hydrolyzed by intestinal microbiota to SF, sulforaphane nitrile, and/or other isothiocyanates and nitriles, although the decomposition rate is very low. However, continuous feeding of rats or mice with broccoli increased myrosinase-like activities in colon and cecum contents.
Mild heating (40-60 °C) by microwave increased SF content in broccoli. High-power microwave heating with temperature control at 60 °C could retain higher bioavailability.
Continuous broccoli ingestion enhances myrosinase-like activity of gut microbiota. Regardless of differences in endogenous amounts of glucosinolates and myrosinase across multiple broccoli varieties, moderate microwaving ensures optimum SF availability.”
https://www.sciencedirect.com/science/article/abs/pii/S0308814620326339 “Approaches for enhancing the stability and formation of sulforaphane” (not freely available)
Several studies previously curated were referenced, including:
- Microwave broccoli seeds to create sulforaphane;
- Microwave broccoli to increase sulforaphane levels;
- Enhancing sulforaphane content.
Why wait around for approval or citation or social validation of research? When Study 2 showed microwaving increased sulforaphane and glucoraphanin content this time last year, I followed the evidence and acted accordingly.
Researchers who deny microwaving’s beneficial effects on broccoli compounds up to 60° C can publish contrary findings, or keep their biased opinions to themselves. See Increase broccoli compound amounts with thermosonication for further evidence.