Science Buddies: "Ask an Expert"

Hi! I am trying to help my daughter with her science fair project and am having issues. While I understand that some experiments will fail.. I strongly believe that I should be able to get SOME type of reaction and am not. I am hoping someone can help

So we are trying to figure out what dog food creates the most gas. We purchased 4 different varieties... some more natural than others. We ground up each of the 4 foods separated to a fine grain. I then made a HCL mixture from Muriatric acid/water, tested it with a pH strip so that it was a 1 pH. Each test tube than got equal amounts (2 tbsp) each of dogfood and HCL. We shook it for 30 seconds, put a balloon on the top, making sure the air was all out and added them to a hot water bath.We let them sit overnight. Nothing. The liquid is almost completely absorbed in the lower quality foods.. but I am having a hard time that no gas was released..

any ideas?? Or am I going about this all wrong???

Thanks so much in advance for any help and ideas!!

Nicole

Hi Nicole,

This is a really cool project idea, and I don't want you to get discouraged. You did a great job mimicking stomach acid, and you should definitely note the difference in liquid absorption among the foods. That is a result that you were not originally testing, but it's something your daughter can use!

I think the problem is that gas is not usually produced by a reaction between the food and stomach acid. Instead, the gas that causes flatulence is produced by bacteria in the intestinal tract, when those bacteria break down foods that our digestive enzymes cannot. Here are a couple sites describing this for dogs, but it's basically the same in humans:
http://www.sixwise.com/newsletters/2010 ... ulence.htm
http://www.petwave.com/Dogs/Dog-Health- ... rview.aspx

If you do not have time to do any more experiments, it is perfectly okay for your daughter to describe the results you did get with the liquid absorption. If you have time to do a little more experimentation, you could try comparing the dry weight of the foods before and after exposure to the acid. That might help you decide how much would be broken down in the stomach, and thus how much is left for the bacteria in the intestines.

I hope that helps you get thinking. Please post again (in this same thread) if you have more questions.

Heather