Science Buddies: "Ask an Expert"

Hello I am interested in doing this science fair project but im not quite sure how to do it!

https://www.usc.edu/CSSF/Current/Projects/S0528.pdf

In this project ground mushroom gill and egg yolk is combined and put out in the sunlight while the control is kept in the dark. Then the samples are measured for cholesterol before and after to see whether the cholesterol decreased which it is supposed to because the cholesterol is converted to Vitamin D during the mushroom enzyme reaction that happens.
But if i am to do it i want to do other foods that are high in cholesterol too (like butter or whole milk).

How to measure the cholesterol and how much of the mushroom gill i should put in are the things that i am stuck on.

Can somebody please help me because i am stuck!

Thank you!

Can someone please give me advice on how to do this project. I HAVE TO FINISH WRITING A RESEARCH PLAN AND RESEARCH NOTES BEFORE BREAK BECAUSE I AM VERY BEHIND! So please can anyone help me because i can't change my project and im really stressed out right now!

Hi,

That’s a very interesting project! I did not know that shiitake mushrooms had medicinal as well as culinary uses.

Do you have any more details about this project other than the pdf in the link? I was wondering where the person got the ground shiitake. I have seen the dried mushrooms in the grocery store so I would buy those to try first. An electric coffee bean grinder would be perfect for making shiitake powder, otherwise a blender should also work or a mortar and pestle if you have one.

The other question I have is how they tested for cholesterol. I know there are home test strips you can buy in the pharmacy, but there are several different brands. They were designed to measure cholesterol and triglycerides in a drop of blood, however, and I wonder how well they work with egg yolk. I would suggest that you do some reading on cholesterol testing before you go shopping.

There are a couple of other variables that are not described in the project procedure. One is the length of time that the egg yolk-shiitake mixture is exposed to sunlight. Is it minutes or hours? You may have to do some time experiments to determine this. The other variable is temperature. The rate of an enzyme reaction increases with temperature. I would try to keep the temperature fairly constant and at about 25C (77F) for good enzyme reaction. This could be a problem in December and January when the outside temperature may be quite cold depending on where you live.

You could try doing the experiment indoors using an artificial light source but it would have to be a full-spectrum lamp that mimics sunlight, especially in the ultraviolet wavelengths because that is apparently what stimulates the reaction. Window glass absorbs most UV radiation so you cannot put the egg yolk-shiitake mixtures in a sunny window as you might think and still get the enzyme reaction to occur.

I hope this gives you enough information to get started. Repost to this same thread as you have more questions and we will try to help you do this project. I am very curious to know how well the shiitake can reduce cholesterol in food.

Good luck!

Sybee

Thank you so much!

I sadly do not have any more details about the project nor can i find any more online. This isn't a common project at all and that's one of the main reasons i'm nervous to do it! I'm not sure where he got the mushrooms but i think i might try to find some online or in an Asian grocery store.

I looked into testing for cholesterol and i might just buy one of the devices because most home test strips don't come with a lot of strips and i need to do 5 trials.

Do you think one of these lamps would work?
- http://www.staples.com/V-Light-Full-Spe ... o-top-link
- http://www.amazon.com/Sunlight-Natural- ... B003DRBOJ8

Again thank you sooooooo much!!!!

You are welcome! Hopefully we can help you with this project so you can get it going.

One thing I just thought about was that the project pdf did not specify whether to use fresh shiitakes. I have seen dried shiitakes in a couple of different grocery stores but I don’t recall if they had fresh. If you have a nearby Asian market, they might have fresh ones; just make sure you are getting the right thing. In my experience sometimes the labels are not in English.

The project pdf also said to use ground up mushroom gills so you would have to dissect out the gills to use for your experiments. I don’t know what would be the best way to grind up fresh mushroom tissue. I would think you might need to add a little water to it to make a slurry.

You had also asked about how much to test. The project pdf said equal amounts of ground shiitake and egg yolk. You would only need a drop to do the cholesterol test so you don’t need much. A teaspoon of each would probably be enough.

Some enzymes can lose activity fairly quickly once they are exposed to light and air so I would grind up the gills just before you are ready to add them to the egg yolk and start the irradiation.

Now about those ‘full spectrum’ lamps—what you need is light that contains the UVB portion of the spectrum and I don’t know whether these lamps do. I do know that PetsMart sells a lamp for lizards and other reptiles that produces the UVB that they need: http://www.petsmart.com/reptile/bulbs-l ... tid-500036 This would be your best bet, I think, to reproduce sunlight in your experiments.

I hope I have answered all your questions. Maybe the other experts can add their suggestions. This is a particularly challenging project but I think it is also an especially interesting one. I wonder if any other mushrooms would work besides shiitakes. You could compare with the plain old white button mushrooms from the grocery store or with portabellas.

Good luck!

Sybee

Thank you! Thank you! Thank you!

For now i am finally prepared to do my project thanks to you!

You are most welcome! Just remember, if you have any questions at all, don't hesitate to ask. It's better to take a few minutes to check something with us than assume you are right only to find out later you overlooked a key point. My lab-mates have saved me more than once from some error i just wasn't seeing.

Good luck!

Sybee

Okay thank you!

I'm stuck on one more thing...Sorry if i'm asking too many questions!

I have called many Asian markets where i live and no one sells fresh shiitake mushrooms. They only sell dry and some sell frozen.

So i was wondering would frozen work? I don't think i can use dried cause the gills wouldn't be fresh.

Or could i use another type of mushroom like Portobello???

Thank you!

Hi,

You can't ask too many questions! It's better to check with other people when you aren't sure of something. We certainly don't know everything but we can at least tell you where to look for more information.

You could test several different species of mushroom but you have to include shiitakes because the reaction appears to be specific for them. Frozen mushrooms should work ok. Just don't thaw them until you are ready to make the gill extract and start the experiment. If you want to make the project more interesting, why don't you also get some dried shiitakes and try them. You said you didn't think they would work, but you don't know that. A scientist doesn't assume things are true or false. He tests them by doing experiments to find out the answer.

Good luck!

Sybee

THANK YOU SO MUCH!!!!

I did my project and it didn't work. I used a cardiochek cholesterol machine to measure the cholesterol before and after the UV light exposure and the results both times came back as <100...I honestly don't know what to do now. I measure it multiple times and the results came back as the same thing. This project was expensive and it didn't even work. Can you please help me figure out a solution because i can't find how to fix this or do anything and i'm stuck and hopeless. Thank you.

PS: I am searching for another project in case there isn't any solution but can you please help me?

Umm can someone please help me because i am literally super super behind right now! Im so sorry if i sound desperate or demanding...I'm just really stressed and worried...So if anyone can please help me i would really appreciate it!

Hi there,

It may be that as this device was designed to detect cholesterol in blood it does not work well on egg yolks (I'm not sure how the test works so it is difficult to speculate why it is not working here). 1 reason could be that cholesterol in the blood is part of a larger structure that includes various proteins, including one called apolipoprotein: http://en.wikipedia.org/wiki/Apolipoprotein The most common forms of these complexes are called LDL and HDL for Low and High-density lipoproteins respectively. The form present in egg yolks could be incompatible with the chemistry of the test.

http://en.wikipedia.org/wiki/Low-densit ... #Structure
http://en.wikipedia.org/wiki/High-density_lipoprotein

It looks like this device can measure total cholesterol, HDL, or triglycerides. Are you certain you had the device in total cholesterol mode? I see from reading about the device that it and the strips must be above 68 F temperature. Was everything warm enough? Also, the strips have expiration dates. Can you double check that the strips have not expired? Finally, even though you got a very low reading, I wonder if dilution of the sample would actually result in a better reading? An average egg yolk has about 180 mg cholesterol and is about 20-30mL in volume, lets say 25. That would translate to a concentration of 720 mg/dL, well above your reading of less than 100 mg/dL. (1 deciliter is 100 mL). Perhaps diluting the sample 1:1 or 1:2 in water would give a more accurate reading. If so, you would then multiply the reading by the dilution factor (2 for 1:1 or 3 for 1:2).

Finally, have you considered contacting the company to see if someone there would be nice enough to help, perhaps someone on their technical staff could tell you if it even should work on eggs?
http://www.ptsdiagnostics.com/contact-us.html

Hope this helps,
Colin

Hello and thank you so much for replying! Yep that is what it thought too and since the amount of cholesterol in the whole egg is a lot i think a small sample of it isn't enough.

I am sure the device was in cholesterol mode and the results were in mg. Yes i had the house at above 70 F. The strips were not expired when i did the project, but now they are. The thing is the test strip has a very small hole where you put whatever you are testing in so how would the dilution work?

I actually forgot about calling them but i will!

Thank you so much for your help!!!!

Hi there. The meter measures cholesterol concentration, not total amount, so that is not the problem. However, the meter requires a minimum volume in order to do a proper reading. I am not sure how you added the sample to the strips. How much sample did you add to the strip and how did you add it? To dilute the sample you would need to take a fixed volume of the yolk (say 1 tablespoon), and add 1 or 2 volumes (e.g. tablespoons) of water. Then mix, do the reading, and multiply the reading by the dilution factor. It could be that the straight yolk does not flow well into the strip.

Cheers,
Colin

Hey. I added the sample using a pipette and i filled the circle that is on the test strip for the sample. Okay so dilution should work orrrr...?

I honestly don't know if diluting the sample will help. It is counter-intuitive that it will, but I was slightly concerned that the very viscous egg yolk was not wetting the strip properly or flowing into the sample orifice in the strip, and that diluting the sample would allow it to flow into the sample hole more easily. Other than that I don't have any other suggestions (other than testing blood!). Does the meter come with any solution for testing the unit and strips, something that should give a positive reading? In the other thread where another person asked about this project I suggested that he or she look into the classic chemistry test used to detect cholesterol, or else try a food testing lab: https://www.sciencebuddies.org/science- ... 28&t=14078

-Colin

Okay thank you i think i might think of the other options or think of changing my project and saving this one for next year.

But thank you soooooo much!!!