Please. Help on food spoiling experiment

[Dannard]

I need help figuring out how to conduct an experiment using agar gel to find out how temperature can affect the rate at which different food spoils.

Thanks a lot. Please reply ASAP

[matthewmulanax]

Could you provide some details as to what you want to demonstrate or prove?

What will be growing on the agar?

Answers to these questions will help the experts guide you.

Matthew W. Mulanax

[rai_91]

Similar to what Matthew asked, what exactly is your topic statement and your hypothesis? Did you do any background information on this topic?

[donnahardy2]

Hi Rai,

If you are thinking about doing a project on food spoilage, you should check out the information on Microbiology from the Science Buddies Website:

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

Click on the section about agar and inoculating microorganisms, and be sure and review the safety information about working with bacteria. The various sections under the 'Microbiology," heading will give you all of the information you need to grow bacteria from food samples.

It sounds like you are planning a project on the fascinating topic of food microbiology. In case, you haven't finalized your question and hypothesis yet, here is a website that lists several possible topics of investigation:

http://en.wikipedia.org/wiki/Food_microbiology.

We do want you to have a successful project, so let us know more about the details of your project if you need any more help.


Donna Hardy

[Dannard]

ok well I did some research on like what causes the spoiling food (different types of bacteria and molds), and I wondered how the temperature in the refrigerator keeps them from growing.

and I was wondering what kind of experiment I should do to prove this. I also wanted to use different factors besides temperature and see how they affect the preservation of the food.

thanks

[donnahardy2]

Hi,

Temperature has a significant effect on the growth of microorganisms, and bacteria will grow faster at higher temperatures. For example, many bacteria are able to double in number every 24 hours at 4 degrees Centigrade, but can double every 20-30 minutes at a warm 37 degrees Centigrade. The taste and smell of the food will start to change when the bacteria reach about 10 to the 7th (10,000,000) bacteria/ml or gram of food If a food sample starts with 100 microorganisms per ml or gram, what would the time difference be before spoilage becomes apparent at the two temperatures?

For a science project, I think that you should focus on one variable and not try to do too much. For example, you could work on the problem of how best to transport potato salad on a warm summer day, and compare bacterial growth at different temperatures. Or, perhaps you could test frozen foods that are not stored according to directions, and perhaps thawed and then reheated later. If I were going to do this project, I would probably do an experiment and find out how long it is safe to leave wet cat food out before discarding it. However, you should select a project that you are interested in. What made you decide to choose this topic? Other variables that you could consider besides temperature would be pH, addition of preservatives, oxygen levels, and salt concentration.

The next step will be to state your problem, and then your hypothesis. You would then design a controlled experiment that will test your hypothesis. For your experiment, all of the conditions of the experiment would be identical, except for one independent variable, such as temperature. You could then count the bacteria in the food samples over time to see what the effect the variable has on the numbers of bacteria (your dependent variable).

So, what problem are you interested in solving?

Donna Hardy