Science Buddies: "Ask an Expert"

Hello, my science fair project is lowering cholesterol in food (egg yolk) using enzymes found in mushrooms (shiitake) to convert the cholesterol to vitamin D. I found this experiment at www.us.edu/CSSF/Current/Projects/S0528.pdf. I need to measure the amount of cholesterol in the egg yolks at various points in the experiment, but am not sure how exactly to measure the concentration of cholesterol. Since the research I have found states that mushrooms, using enzymes tyrosinase and isozymes, convert ergosterol to vitamin D, I was hoping to measure vitamin D levels in the egg yolk also. What do I need to do this? Any help is greatly appreciated. Thank you!

you can buy a cholesterol level counter

Number 1: May i point out that i asked about that in one of the forums.

Number 2: If you read the thread, I tried this project and i failed miserably because the results came back the same before and after sunlight exposure so im not sure if you want to continue with this project. I'm just warning you, but you might figure out what i did wrong soooo good luck and please tell me what your results end up being!

Number 3: If you want to know i used a CardioChek cholesterol machine and i bought the test strips online (I don't think they're in store). Both items are pretty expensive though. I also used a UV light because the temperature outside can affect the reaction that occurs. The original guy who did this project used the same machine and test strips so i don't know how he got his results because i tried again and again. I think it is because egg yolks have a lot of cholesterol in the whole yolk but on the test strip only a small amount of the yolk goes on the strip so the cholesterol is less. Or maybe not! That's what i think. I wanted the sample to have a full day of sunlight or UV light in my case so i measured it before sunrise and after sunset. I hope this helps and good luck!

Please tell me if it works cause i'd love to know what i did wrong!

Hi there,

I tried to answer Number10XD's question in another thread, but I am not sure what is going on with that cholesterol meter: https://www.sciencebuddies.org/science- ... 835#p49835

If you have access to a high school laboratory you might be able to do the classic Libermann Burchard test: http://en.wikipedia.org/wiki/Liebermann ... chard_test

Alternatively you could try to have samples tested by a food laboratory, here is just one example: http://www.foodtestinglab.com/food-testing-sample.htm

Cheers,
Colin

A slideshow about the Liebermann-Burchard test: http://sdamiati.kau.edu.sa/Files/001108 ... _Mlab9.pps

Thank you for the slideshow link. It was very helpful.

Number10XD wrote:Number 1: May i point out that i asked about that in one of the forums.

Number 2: If you read the thread, I tried this project and i failed miserably because the results came back the same before and after sunlight exposure so im not sure if you want to continue with this project. I'm just warning you, but you might figure out what i did wrong soooo good luck and please tell me what your results end up being!

Number 3: If you want to know i used a CardioChek cholesterol machine and i bought the test strips online (I don't think they're in store). Both items are pretty expensive though. I also used a UV light because the temperature outside can affect the reaction that occurs. The original guy who did this project used the same machine and test strips so i don't know how he got his results because i tried again and again. I think it is because egg yolks have a lot of cholesterol in the whole yolk but on the test strip only a small amount of the yolk goes on the strip so the cholesterol is less. Or maybe not! That's what i think. I wanted the sample to have a full day of sunlight or UV light in my case so i measured it before sunrise and after sunset. I hope this helps and good luck!

Please tell me if it works cause i'd love to know what i did wrong!

Thank you for the information. Can you refer me to the original experiment that used a cholesterol meter? I remember coming across that one, but cannot find it anymore. Any help is appreciated. It is helpful to read other people's experiences.

SandbaggerOne wrote:A slideshow about the Liebermann-Burchard test: http://sdamiati.kau.edu.sa/Files/001108 ... _Mlab9.pps

thank you very much. This slideshow was very helpful. I am getting all the materials needed to conduct y experiment using the Lieberman-Buchard test as outlined in the slideshow. I have tried to read other articles on this method, but they were much more complicated and harder to understand.
I have one question though, the slideshow says to add 10ml of alcohol-aceton solvent in the centrifuge step of the process. I haven't been able to find out what type of alcohol (isopropyl, denatured or benzyl), and what the proportion of alcohol to acetone should be.
Any help you can give me on this area would be greatly appreciated.
Thanks so much!

1:1 ethanol to acetone mixture.

See also here, scroll down 1 page: https://books.google.com/books?id=Ws570 ... um&f=false

Thank you!