Hey all, it's been discussed briefly in some places that mushrooms can have their vitamin D2 content increased greatly by exposure to sunlight, or more specifically the UVB in sunlight. This process was covered in detail in by a grad student and professor at Penn State University _http://foodscience.psu.edu/directory/rbb6/VitaminDEnrichment.pdf
In one test, they managed to raise the vitamin D in about 84g of white mushrooms from 0% recommended daily value to over 824%, simply by exposing the mushrooms to 4 pulses from a professional sterilizing machine that pulses UV light. 800% DV is about 3200 IU, and shiitake produced an IU as high as 6400; compare that to most supplements which have an IU of 1000 or 2000 tops.
Four pulses times 0.873 joules/cm2/pulse is equal to 3.492 joules/cm2, so about 3.5 joules/cm2 were needed to raise the vitamin D in mushrooms by a large margin before diminishing returns begin to set in.
Some more forward thinking groups are incorporating this UVB treatment into their products, but anyone can do this at home if they have a decent UVB light. I decided to experiment with this at home by using a UVB light bulb I have (the specific bulb can be seen here: _http://www.exo-terra.com/en/products/reptile_uvb150.php). Its UVB content at 4 inches or 10 cm was listed as approximately 0.115 watts/cm2. Watts being the same as joules/second, dividing the total energy required by this amount (3.5/0.115) gives about 30 seconds exposure required to optimize the vitamin D levels in white mushrooms (that is, if my math was sound). Different UVB lights may require different levels of exposure, which is a trivial adjustment when you get down to things.
I tested this out by chopping up the serving size (84g -- about a handful) on a cutting board until the pieces were no thicker than half an inch, and just shone the UVB light on them closely for about 30-60 seconds. These were added to a frying pan with lard, garlic, ginger, and onions, all of which was of course optional but exceptionally tasty nonetheless.
This could be a good option for people who require a lot of vitamin D due to living in less well-lit climates, and also for those who want to cut down the money spent on vitamin D supplements.
There is a bit of discussion about the differences between vitamin D2 and D3. The vitamin produced in mushrooms by this method is D2, whereas the vitamin produced by UVB's interaction with cholesterol through regular sun exposure is D3. According to the NIH D2 is converted more slowly than D3 into its bioactive form, 1,25 dihydroxyvitamin D.
If this turns out to be true, there is always the option of blasting your butter, lard, or tallow with UVB light instead of your mushrooms to convert the cholesterol into D3
. I haven't seen any studies of people trying this out yet, but I imagine the energy/cm2 exposure required would be similar. It would probably be safer to do with with animal fats that have less mono and polyunsaturates, since those tend to be more vulnerable to denaturement by high energy.
In one test, they managed to raise the vitamin D in about 84g of white mushrooms from 0% recommended daily value to over 824%, simply by exposing the mushrooms to 4 pulses from a professional sterilizing machine that pulses UV light. 800% DV is about 3200 IU, and shiitake produced an IU as high as 6400; compare that to most supplements which have an IU of 1000 or 2000 tops.
Four pulses times 0.873 joules/cm2/pulse is equal to 3.492 joules/cm2, so about 3.5 joules/cm2 were needed to raise the vitamin D in mushrooms by a large margin before diminishing returns begin to set in.
Some more forward thinking groups are incorporating this UVB treatment into their products, but anyone can do this at home if they have a decent UVB light. I decided to experiment with this at home by using a UVB light bulb I have (the specific bulb can be seen here: _http://www.exo-terra.com/en/products/reptile_uvb150.php). Its UVB content at 4 inches or 10 cm was listed as approximately 0.115 watts/cm2. Watts being the same as joules/second, dividing the total energy required by this amount (3.5/0.115) gives about 30 seconds exposure required to optimize the vitamin D levels in white mushrooms (that is, if my math was sound). Different UVB lights may require different levels of exposure, which is a trivial adjustment when you get down to things.
I tested this out by chopping up the serving size (84g -- about a handful) on a cutting board until the pieces were no thicker than half an inch, and just shone the UVB light on them closely for about 30-60 seconds. These were added to a frying pan with lard, garlic, ginger, and onions, all of which was of course optional but exceptionally tasty nonetheless.
This could be a good option for people who require a lot of vitamin D due to living in less well-lit climates, and also for those who want to cut down the money spent on vitamin D supplements.There is a bit of discussion about the differences between vitamin D2 and D3. The vitamin produced in mushrooms by this method is D2, whereas the vitamin produced by UVB's interaction with cholesterol through regular sun exposure is D3. According to the NIH D2 is converted more slowly than D3 into its bioactive form, 1,25 dihydroxyvitamin D.
If this turns out to be true, there is always the option of blasting your butter, lard, or tallow with UVB light instead of your mushrooms to convert the cholesterol into D3
. I haven't seen any studies of people trying this out yet, but I imagine the energy/cm2 exposure required would be similar. It would probably be safer to do with with animal fats that have less mono and polyunsaturates, since those tend to be more vulnerable to denaturement by high energy.
