Cooking methods such as microwaving do not synthesize or increase the baseline quantity of glucoraphanin or sulforaphane in broccoli.
"You do not increase the levels of either sulforaphane or glucoraphanin by a cooking method whatsoever. You may enhance it, you may its destruction, you may its loss or limit its loss." (said at 1:10:14)
The claim that cooking methods cannot increase the levels or yield of sulforaphane in broccoli is contradicted by food science literature. In raw broccoli, the heat-sensitive epithiospecifier protein (ESP) preferentially directs glucoraphanin hydrolysis toward an inactive byproduct (sulforaphane nitrile) rather than sulforaphane. Controlled thermal processing—such as mild steaming (1–3 minutes) or mild microwave heating (50–60°C)—selectively inactivates ESP while preserving myrosinase activity, which significantly increases sulforaphane formation and yield compared to raw, untreated broccoli. Additionally, mild microwave heating has been shown to increase measurable glucoraphanin and sulforaphane yields compared to raw controls.
- contradicts: Impact of thermal processing on sulforaphane yield from broccoli ( Brassica oleracea L. ss… (Journal of agricultural and food chemistry 2012)
"A myrosinase cofactor directs hydrolysis away from the formation of bioactive sulforaphane and toward an inactive product, sulforaphane nitrile. The cofactor is more heat sensitive than myrosinase, presenting an opportunity to preferentially direct hydrolysis toward sulforaphane formation through regulation of thermal processing... Boiling and microwave heating caused an initial loss of nitrile, with a concomitant increase in sulforaphane, followed by loss of sulforaphane, all within 1 min. In contrast, steaming enhanced sulforaphane yield between 1.0 and 3.0 min in all but Brigadier." (abstract, results, passage verified)
pubmedfull study (doi) - contradicts: Microwave cooking increases sulforaphane level in broccoli. (Food science & nutrition 2020)
"Both microwaving and mild heating increased the GLR and SFR levels in broccoli compared to the raw samples (without any treatment). In particular, SFR level was significantly low under 40°C and dramatically increased from 40 to 60°C, but nothing was detected at 70°C. Compared with conventional heating, microwave heating increased the GLR and SFR yield by about 80% at 50 and 60°C." (abstract, results, passage verified)
pubmedfull study (doi)