Science Buddies: "Ask an Expert"

I am allergic to many raw foods, but my allergist told me I may not be allergic when they are cooked. I've tried to research why and I am finding it has something to do with how these foods are related to my birch tree pollen allergy. My body's immune system may be attacking/reacting to the proteins similar to birch pollen that are in the raw foods. It is also related to the denaturation of these proteins when cooked. They change and the same proteins aren't present after cooking so my body doesn't have the same reaction. This is a fascinating concept to me and I really want to do some type of science fair project related these concepts. Is there a way to test the denaturation of proteins in cooked foods? Can you please direct me to a way to conduct this type of test? Is it possible to test protein changes in any of the following foods that I am allergic to: apples, peaches, carrots, celery, hazelnut, peanut, peppers. I'd appreciate your insight so much. Thank you!

Hi proteindenaturation,

Welcome to science buddies! You have an excellent idea for a science fair project; I have observed that projects that are based on a student’s personal experience often make excellent projects, so I definitely encourage you to continue with your idea.

You probably know that proteins are composed of long chains of amino acids and that denaturation involves a change in the 3-dimensional structure of the protein. An allergy is the body’s response to foreign proteins that could be bacterial or virus invasion, but in your case, your immune system is attacking proteins in ordinary foods, so the immune response is not helpful.

For a science project, you need to do a carefully controlled experiment with measurable results. One possibility would be to use egg whites and denature the ovalbumin protein using heat or pH change and measure the results. Raw egg white is a liquid and denatured egg white is a solid, so it should be possible to measure a physical difference in the proteins.

Here is an idea for an allergy-related project idea from this website. You are allergic to so many foods that this would be challenging to do.

https://www.sciencebuddies.org/science- ... p002.shtml

However, before you decide, I recommend doing a literature search and look for research articles related to allergies and protein denaturation. Go to “Google Scholar” on you web browser and enter search terms; the results will be published research references that will include current topics of research, including materials and methods that you could adapt for your project.

Please post back and let me know what ideas you find. Include the link for the reference and ask any questions you might have. I will also look for project ideas and post back later today. Please let me know what grade you are in, whether or not you have had the introduction to chemistry that includes learning about proteins, and when your project is due.

Good luck@

Donna Hardy

Hi,

Here is a review article on food processing and allergenicity. It is a perfect background paper for your topic because it reviews the effect of food processing on the most common food allergens, The authors report the more effective methods of reducing allergenicity, and include a list of subjects that need additional research. I like review articles because they don’t report results of a specific series of experiments, but instead include a summary of what other researchers have discovered. This is a 2015 paper, so is very recent.

http://www.sciencedirect.com/science/ar ... 1515000848

Let me know if you can’t access the article and I will attach a pdf file. Don't worry if you don't understand everything; just read and understand as much as you can.

Please read through this paper and let me know what subject seems interesting to you. This is obviously a vast area of research, so you need to narrow down the investigation. There are several pages of citations, so you can check out more details by looking up the reference papers on interesting topics.

Let me know if you have any questions and what you think you can do for an experiment. I can definitely help with the details if I know what you want to do.

Donna

Donna,
THANK YOU SO MUCH FOR ALL YOUR HELP!!! Wow! I really appreciate your quick and informative response! Thank you for all the information and ideas. I have been reading a lot of online articles and looking for specific project ideas, too. I am an 8th grader and have been introduced to beginning chemistry, but find it very interesting and want to do something awesome! My project is due December 16th. I need to narrow it down and decide on my topic question this week. I found this possible experiment idea to denature different proteins and find out if they do at different temperatures: http://www.education.com/science-fair/a ... -proteins/
I also wondered about using some of the different methods of denaturing egg whites mentioned in this article: http://www.math.unl.edu/~jump/Center1/L ... oteins.pdf Maybe comparing how long it takes for the different methods/which is faster or works best? What do you think? Is it hard to measure what is most effective?
Sounds like the article you attached will be great, too! I'll read it and let you know. I am just not sure which direction to go and what will be the best for collecting measurable data. Thank you!!!

PS> I really liked your suggestion in your first message to me about denaturing egg white protein using heat or pH change and "measuring the results." What "results" are you referring to? I am not sure I understand what you mean by how I am measuring the physical difference in the proteins. What would I be measuring? Thanks!!!

Hi,

Thanks for including your chemistry background and the due date for your project. The first experiment involves measuring the temperature at which 3 different proteins denature; the second experiment uses egg white protein (ovalbumin) and uses 3 different methods (heat, pH, metal ions) to denature the protein. Both of these experiments would meet the requirement of a science experiment because they include an independent variable (different proteins or different methods of denaturing)

The experiment with temperature measurement is slightly better because you will have a number to graph. You can make the experiment more interesting by adding more proteins, perhaps one or more of the proteins that you are allergic to. For the egg white experiment, you need a method for measuring the denaturation. The project guide suggests looking at the protein to see when it turns from clear to white, but this is not an actual measurement. I will look for a way to measure the egg white denaturation.

Here is the project guide from this website. You will see that the project question is near the top of the list. Continue to read more background information so that you will be able to state your project question this week. I recommend reviewing the complete guide so you will have an idea of where you are going with the project.

https://www.sciencebuddies.org/science- ... ndex.shtml

Donna

Hi,

Here's an idea on how to measure protein denaturation. If you put egg white or another clear protein into a test tube and shine a light onto it, the light will be able to pass through the clear protein until it is denatured and turns opaque. Here is a project idea from this website that explains how to make a cell phone spectrophotometer You would need to adapt this to measure the protein denaturation, but it would be an excellent way to measure your results.

https://www.sciencebuddies.org/blog/201 ... nt-hac.php

It probably would not matter what wavelength you used; you would be measuring the amount of light able to pass through the protein.

If you do temperature measurements, you will also need accurate thermometer with a probe that can be immersed in the protein solution.

Donna

Thank you for all your insights. We decided to test 5 separate 2 min trials increasing temperature each trial noting the changes in the protein denaturation. It was an interesting process and we've learned a lot along the way (including discovering that the different proteins within the egg white denature at different temperatures!) We ordered the materials and tried the spectrophotometer you suggested, but couldn't get it to work for our egg white samples. It seems like a great idea for shining through the clear liquids described in the project on the website, but we struggled adapting it for our experiment and couldn't get pictures with high enough quality to use in the software (even with the raw egg white as a baseline) So instead we just took pictures of the light from an overhead source without the diffraction slide shining through each of our different samples to show that light passed through the uncooked portions and not the cooked portions. As the temperature increased the amount of denatured egg increased and light decreased. Sadly, we were hoping the software used with the spectrophotometer would provide the quantifiable number we could measure the AMOUNT of light and have something to graph. Now we are only finding that all our outcomes are only visual observations of the changes in liquid to solid, amount of light that passes through, and color change from clear to white. We need help finding an actual quantifiable measurement that we can graph.... Would there be a way to separate the AMOUNT of cooked/denatured egg from the uncooked for each trial and then we could use weight? That way we can weigh/graph changes in the amount of cooked egg each time? How can we strain the cooked egg from the uncooked in each sample? We have tried several different types of strainers with varying sizes of holes to get a raw egg white to pass through it, but it only seems to allow the watery type protein substance of the egg white through, the more gelled protein won't pass through (even when raw). Can you think of something that would work to separate the cooked from the uncooked portions? Please help! Our project is due Friday. Thank you so much!

Hi,

You have done a lot of work so far; it’s disappointing that the spectrophotometer idea did not work. It seems like you should have the temperature recorded of the point where the egg white turned from clear to white. The change in appearance is an observation, but the temperature is something you could put on a graph.

I don’t think there would be a difference in weight between native and denatured protein, so that probably won’t work.
There would be a difference in viscosity. Here is an idea from this website on measuring viscosity by letting a marble fall through a liquid and measuring the time. The raw egg white would have a measurable viscosity and the denatured egg white would be solid, so the viscosity would be infinite.

https://www.sciencebuddies.org/science- ... ml#summary

Let me know if you have the temperature measurements to graph and also if you decide to try the viscosity test, let me know what happens.

Whatever you do on your write-up, don’t say that your project did not work. You did the excellent background research and you did the experiment 5 times! That’s amazing. Describe the results of your attempts to use the spectrophotometer app and all of the variations you tried. Graph as much data as you can. At the end of your conclusion, include what you would do if you had time to repeat the project.

I hope this helps.

Donna