Science Buddies: "Ask an Expert"

When I asked her again, she now says the diet option would be okay, but I would have to make up a diet that would work for a pescatarian... I'm so confused.

Hi,

It's important to follow the rules of a science fair. When working with humans, it's necessary to sign an informed consent form. You can find more information on the science buddies website under, science fair project guide>science fair project guide additional resources>scientific review committee>working with humans. Normally, you need to submit the form and get permission to do human projects in advance. I had not heard of science fairs that absolute prohibit working with humans, but I suppose this is possible. Or, perhaps your teacher thinks it is too late to submit the necessary paperwork.

But it's OK, you can still do the other half of the project. You can ask the question "do non-dairy product provide equivalent calcium as dairy food sources?" or "Can pescetarians obtain sufficient calcium from non-dairy milk sources?" You can do the survey on product labels and gather information on the quantity of calcium per serving. For the non-dairy milk sources, also note the source of calcium, e.g. calcium phosphate, calcium sulfate, calcium chloride, etc. If you look at enough product labels, you will have lots of data to analyze. You will need to look at the background literature to get more information about the solubility/availability of the calcium from different calcium salts, but this will add more substance and interest to your project.

Donna Hardy

I think I will do comparing the solubility of calcium salts used in dairy and nondair products. I am now researching what calcium salts are in soy milk. and what caclium salts are in skim milk. I will then change the ammount to find out how soluble the soy milk and skim milk are. Does that make sense? And could I find this data on the product label? My teacher has these rules(that I have understood from what she has told me) They have calcium salts at the school. No human subjects (the late paperwork makes sense but I'm not sure). It has to be an actualy experiment (which I was confused on because last year we were allowed to do research projects, but maybe its the paperwork again or something). I am sorry for my ignorance, and all this confusion between me and my science teacher, but thank you over and over and over again for all the help you have given me.

Hi,

That's great if you can do the diet survey. You are a pescetarian, so after you fill out the informed consent form, all you have to do is write down all the food and drink that you consume for a few days, and try to estimate the quantity. I would not recommend making up a diet; just eat what you normally would eat. Then use the following website to check the calcium content of all the foods you have consumed:

http--www.nal.usda.gov-fnic-foodcomp-Data-SR1 ... 17w301.pdf

You can add up the mg of calcium to get your daily total.

I would not recommend making up a diet; just eat what you normally would eat. That would be real data. You are going to answer the question, "do pescetarians consume enough calcium in their diet?" and the answer will be either yes or no; with science fair projects, there's no right answer, so it's OK if you don't consume 1000 mg of calcium. If it turns out that you consume less than 1000 mg per day, then you will have to discuss this in your conclusion section, and perhaps suggest changes that would bring your daily diet up to the 1000 mg total. It will be a great science fair project either way.

Please do double check with your teacher again.

Donna Hardy

Hi,

This is a little confusing, but I do understand now. Your science fair requires doing a lab experiment, so the ideas we have discussed don't really qualify, although otherwise, they would be good projects. I think that's what your teacher has been trying to communicate with you.

Can you check to see if you have the calcium, EDTA, and eriochrome black T available? How about a centrifuge? Please confirm what lab resources you have available.

Or do you have 2-3 pescetarian and 2-3 dairy-consuming friends available. Doing a diet survey and compiling calcium results would qualify as an experiment if you did this with a number of individuals. Although this type of project takes time; if your project is due on January 22, I don't think you will have time for this option. And you would still have the problem of the informed consent forms. When do you have to turn in your board?

Donna Hardy

Hi,

Another method of measuring calcium ions in solution is by using a calcium specific electrode with a pH meter. I checked one source and it cost $180 for the electrode, and you would have to have a pH meter to use it. Ask your teacher if she knows where you might have access to this type of electrode, which might be found in a hospital or research lab. You would want to compare the calcium ions in dairy and non-dairy milks. This would be a great lab project if you could find the equipment to borrow.

If your school doesn't have the reagents for the colorimetric calcium assay, and if you can't find a pH meter with a calcium electrode to use, you will probably not be able to do an experimental project on this topic this year. The only option for a calcium project would be if you could get permission to do the survey/research project. You can save this project for next year's science fair, but for this year, you will need to switch to a different project. Let me know if you need to do this.

Donna Hardy

I will email my teacher about the equipment, and if she doesn't have it, then I will probably just end up doing something simple from the website. And I do happen to have 2 vegetarian friends (who eat dairy) but no friends who only have nondairy, but maybe next year. Thank you for all your help, over and over again.

Hi,

I'm sorry this is not working out and I'm sorry my suggestions did not help you get this project done for this year. Good luck to you and do let us know at science buddies if there's anything else we can do to help.

Donna Hardy

Umm... this is just a clarification My school has a pH meter but not a calcium specific electrode. What reagents do need for the colorimetric assay? would have to use the meter at school, but it only measures pH. This is the general response my teacher gave me, this means I should choose another project right?

Hi,

Regular pH electrodes don't work; you need to calcium-specific electrode for your pH meter for calcium analysis. Here is the reference the colorimetric assay:

http://faculty.ccri.edu/aahughes/GenChe ... ration.pdf

Check with your teacher to see if EDTA, calcium carbonate, 12 M HCl, and Eriochrome Black T are available from your school. If not, then you definitely need to select a different project. I don't know how well this test works with milk because it's designed for water samples.

Donna Hardy