Sulforaphane is an isothiocyanate that can be obtained from cruciferous vegetables such as broccoli. There are nearly 1000 studies since the year 2000 with sulforaphane in the study title on PubMed, and the frequency of publication is increasing as science is finding that this molecule has nearly miraculous properties in upregulating the antioxidant defense system - via the NRF2 pathway - as well as suppressing inflammation.
Sulforaphane is formed when an enzyme named myrosinase acts on a stable precursor named glucoraphanin. Typically this reaction happens when the plant membrane is destroyed - by example from chewing - and the enzyme and substrate are mixed. While glucoraphanin and the end product sulforaphane are very stable under heat, the enzyme myrosinase is very fragile and is rapidly destroyed at temperatures above around 70 centigrade. In the plant, there is a complication because there is a competitor protein named the epithiospecifier protein (ESP) that produces a useless nitrile form of sulforaphane in competition with myrosinase. There is at least one 2003 study that shows you can destroy ESP and maximize myrosinase activity by heating broccoli sprouts to under 70C. Once the ESP is neutralized, then the reaction between myrosinase and glucoraphanin can proceed at a high rate. The key sulforaphane production rate graph from that study is attached.
The interest in sulforaphane is growing so rapidly and appears to be so well-deserved, that I wanted to start a thread here to try to determine what would be an optimal way to "brew" glucoraphanin and myrosinase to maximize the output of sulforaphane in solution prior to ingesting it, if you start from a supplement rather than from broccoli sprouts. For my own case, I find broccoli sprouts too time-consuming, and I hate the taste. I end up becoming a kind of farmer and spending time on things that do not add flavor for me. There are commercial supplements like Jarrow Broccomax and Nutramax Avmacol that have already removed the ESP and contain just the myrosinase and glucoraphanin.
I want to see if we can identify an optimal brewing procedure for these supplement powders. Studies by Avmacol indicate that the bioabsorption of sulforaphane when you are ingesting the precursors in their tablet averages (with great variation) around 35%. Bioabsorption of sulforaphane is much higher at around 70%, and with less variation. If we brew the precursors of sulforaphane at an optimal temperature, prior to ingesting, we also dramatically increase the production of sulforaphane. This creates a virtuous cycle where we can increase sulforaphane dramatically, but then amplify our gains by absorbing the already-higher amounts of sulforaphane at twice the level of the precursors. So what is that optimal temperature? Do we have a chemist in the house who can look at the studies I list below and above and help us figure out an optimal procedure?
This 2016 study neutralizes ESP then determines the optimal brewing procedure is 38 centigrade for three hours. The problem I see in those graphs is that they never tested a temperature above 38C, so how can we know the optimal temperature? The key sulforaphane production curve from that study is also attached.
No one is going to babysit a temperature controlled bath for three hours to create sulforaphane. This is as cumbersome as raising broccoli sprouts. So if we could produce 80% as much sulforaphane in 10 minutes at 65 centigrade - just for an example - that would be a big win and would give us a good combination of convenience and output. The problem is I do not see any study testing above about 40C. In comparing the sulforaphane production rates at a temperature around 65C in the 2003 study to the production rates 38C temperature in the 2016 study, does anyone here see a case to "brew" Avmacol at temperatures around 65C instead of 38C, to maximize the amount of sulforaphane you can produce in a shorter period of time?
Part of my misunderstanding here may be that the 2003 study is using the 10-minute procedure as a way to neutralize ESP only. If you read their experimental procedure in section 3.4 it says "Homogenates intended for quantification of sulforaphane and sulforaphane nitrile were allowed to incubate at room temperature for 8 h prior to extraction and centrifugation as described above." That suggests that this 2003 study actually used an eight hour brewing time, after first disabling ESP.
In any case, if anyone can find even one study where sulforaphane production is studied at temperatures above 40 centigrade, that would be very helpful. If anyone has access to an analytical lab and wants to play around with this, that would also be a very desirable thing in helping people to maximize their consumption of sulforaphane from supplements.
Attached Files
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Antioxidant_Sulforaphane-Production-Temperatures.jpg 97.82KB
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Antioxidant_Sulforaphane-Production-Temperatures-Without-ESP.jpg 94.04KB
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