Science Buddies: "Ask an Expert"

Hi, for my science fair idea, I found online that you could test if your probiotic capsules contained live cultures by pouring the capsule's powder into milk at room temperature, and if the milk curdles, clumps, or firms, it contains live cultures. http://kblog.lunchboxbunch.com/2009/03/ ... ve-at.html (this is the website I used)
So going off this, my question for my science fair idea is if the temperature at which the experiment is conducted affects the probiotics effectiveness in making the milk curdle, clump, or firm. Since the body temperature changes throughout a person's life, for example when they are sick, pregnant, exercising, etc, will the probiotic be affected by the change in temperature. I would test 4 different situations where I would conduct my milk and probiotic capsule experiment; room temperature, average body temperature, fever temperature, and pregnancy body temperature. My hypothesis is that the higher the temperature the milk is left to curdle in, the less effective the probiotic will be and will not curdle, clump, or firm the milk as much compared to the room temperature test sample.

I do have some concerns for this idea.

Will the change in temperature be too slight of a difference to even notice a change in the milk and is there a more accurate way to test my different samples for the effectiveness of the probiotics instead of basing my conclusions off just the appearance of the different test samples?

Also I am a little concerned about testing the samples at different temperatures because I want the tests to be fair, however I think my option would be to use an oven at home to simulate the different temperatures or try to find an incubator at my school. Any suggestions would be much appreciated on how I can keep my experiment as fair as possible.

Thank you so much for your time in reading my post!

Hello!

This is a fantastic idea for a project! Noticing changes in the appearance of milk is the easiest way to determine if your live cultures are effective at a particular temperature. This is the quickest way to test if the live cultures are active at the temperatures that you plan to test, and would be the easiest indicator of the temperature's effect on probiotic effectiveness.

Your first concern is valid. The temperature change from room temperature to average body temperature is large enough to possibly see a difference, but I'm not sure if the change in pregnancy body temperature from normal body temperature will be. I think that during pregnancy, some women tend to have slightly higher body temperature, but only by a degree or two.

If you have access to incubators at your school, this would be the best option in my opinion. This allows you to control the temperature more precisely. However, an oven can work as well.

Let me know if something I said was confusing, or if you have any more questions!

-Surya

Thank you for your response! I will definitely try to see if there are incubators available at my school. Instead of doing different body temperatures, should I do a different temperature test? Possibly a cooler temperature? I was thinking maybe a freezer or refrigerator temperature. I heard that most probiotic companies tell you to store their probiotics in a cold area so the live cultures don't die. Could I test all sorts of probiotic situations in different temperatures and analyze the affect of different temperatures on probiotics?
Thank you so much for your help!

Hi there!

Your project sounds really cool. If you don't have access to an incubator at your school, I found this link on Sciencebuddies that will help you make one at home. https://www.sciencebuddies.org/science- ... ubator.pdf

And testing different temperatures (cold, warm, hot) is a great idea with different probiotics. It will definitely help to make your project unique and complete because like you said its suggested to store in the fridge.

Good luck, let us know if you have other questions and keep us posted!
Nikki

Hi!
I will definitely be using the at home incubator.
Thank you for your help! I will keep you posted.

Hi!

I have completed my trials of my probiotic samples. For my project I am having trouble figuring out the best way to display my data. If I were to make a graph, I have several trials and for each trial i took pictures at 0, 12, and 24 hours. I have 2 different brands I used for the experiment, and I had one of each brand at each temp: fridge temp, room temp, and body temp. I am having trouble trying to display my data. I tried to make a graph, but my data and results are based off the appearance and texture of the samples, and are not numerical values. Instead of using numbers, should I use pictures to display my results instead? What would be the best way to display my qualitative data?

Thanks for all your help!

Ally

Hi Ally,

What you could do is convert some of your qualitative data to numerical values. For example, you could define a scale for appearance/texture (say 0 for normal looking milk, 10 for curdled/green milk). For each brand, you can plot the rating for texture against the time point. This way, you can display all of your data on a graph (all three time points together for each brand on the x-axis and the values for appearance on the y-axis). Additionally, you can paste pictures representing images of different ratings on your scale with a description in words for the ratings. For example, you can put a picture of what would be a "5" on your presentation, with a word description, just to give an illustration.

Let us know if you have further questions. Best of luck!

-Pharma