Science Buddies: "Ask an Expert"

I am a mother of a 4th grader. I am helping her with her sience experiment. The experiment is Organic/natural foods vs non organic/processed foods. 8 days ago she started this experiment by putting natural ham and processed ham in two seperate baggies and sealed them.The question is which one will rot first. Her hypothesis was that the natural one would rot first because it was not filled with additive and preservatives. The next day we included macaroni and cheese. We made a popular brand with preservativesand additives and another popular organic barand. This as before was done in a clean environment. Each type had a sample removed and was put into clear glass contairners and covered tightly with plastic wrap. We are not seeing clear results from the ham. I am wondering if it because the baggies a clinging to the ham. Now it is the 8th day of the ham experiment and we have added two more pieces placed on plates and covered with plastic wrap which is not touching the ham. I am hoping I am steering her in the right direction to show accurate results. In her final conclusion we will show the ham pictures throughout each ones entire experiment and compare them against each other on their same days. If the rot at the same rate or it is not clear then I assume she would have to state this in her conclusion including a new hypothesis and ides for future experiments. Are we doing this right?

Hi,
Sounds like you are off to a good start. My first impression after reading what your post is that perhaps not enough time has elapsed for either of the hams to begin rotting (if they do at all). What is always interesting about a science experiment is that no matter what the result, it will still be important. In other words, even if the results do not match the hypothesis that your daughter originally made, that's perfectly fine and the experiment is still valid. You and your daughter can take a look at the ScienceBuddies guide, which is very helpful in giving you a step by step method to completing your experiment.

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

This website may also be helpful for you to help your daughter write about the results of the experiment.

http://www.suite101.com/content/science ... od-a192406

In addition, in terms of your procedure, it seems to be fine, so I think that it is really a matter of time to see whether or not the ham rots or not! Best of luck to you and your daughter.

Ok, that helps. The science experiment, is as I said is organic/natural foods vs non organic/processed foods. We are titling it You are What You Eat. Her hypothesis being that the organic/ natural food is going to decompose faster than one that is non organic/ processed. Hence, the natural ham vs the processed and the regular mac and cheese vs the organic. She is on a natural diet for adhd and understands the effect food has on the body. We began this experiment trying to prove that the non organic/ processed food has more chemical preservatives in it therefore it will last longer and the organic/ natural will not. Hoping to show proof that the processed foods really are worse for you body. I have printed off research for her of what the different preservatives are and what they can do to a persons body. We really were thinking we would see some dramatic results. Which is really interesting that we have not and some great findings for her experiment. Which seems that you cannot see the adverse affects that chemical preservatives have on the body by seeing which will rot faster. But now it seems her experiment really has two parts, trying to prove as stated above and also an experiment that has to do with causes of food decomposition. My new question is should we stick to the original experiment or should we add the new aspect of it and talk about both. They are really two different topics.
Thank you for your guidance!

Hi,

This is a very good project for a fourth grader. The problem you are having with ham is that it has a high sodium chloride content. Look at the composition of the organic and the processed ham from the label. What is the sodium content? Was any sugar used in the curing. Are there any other differences between the two hams?

The high salt content of all hams will inhibit the growth of many microoganisms, however, salt-tolerant organisms will be able to grow eventually. You will probably see some mold colonies start to form on the sample that doesn’t have the plastic touching the surface of the meat within a few days.

Here is a science buddies project that includes some useful background information that your daughter could use in explaining her project and presenting her results.

https://www.sciencebuddies.org/science- ... p016.shtml

Good luck with the project!


Donna Hardy

Donna Hardy,
The link you sent me is great. I do not have enough time to get petri dishes or do the experiment with any accuracy. I will however guide her to state this new experiment in her conclusion. Because her hypothesis is going to be proven down this seems as something she could reccomend for future retesting of preservatives. Whether natural or man made. Thank you for this direction. I wish we had found this in the beginning. It seems a fun and much more accurate way to show results. Our experiment has been great though because what we have learned is that you cannot prove negative effects of preservatives on the body through decomposition of either food. Both natural and man made preservatives do just that, preserve. The negative affects on the body of both types must be shown through other experimentation.

New question. How do I help her create a chart or graph for this project???

Hi,

How are you recording the results? Are you keeping track of the time that it takes for visible microbial growth? Or, perhaps you could estimate the percentage of the food's surface that is covered with microbial growth? In order to present a graph or chart, some data or measurement is needed. If you haven't measured anything, then perhaps you could have your daughter draw a picture of the final results. If you did keep track of the day that growth first appeared, then you could plot sample number on the x axis vs. number of days of the y axis.

Your results and conclusion are great, even though results did not turn out as expected. Perhaps your daughter could plan to continue this project next year, with a different experiment and a different outcome.

Here is the information from the Science Buddies website on data analysis and graphs and conclusions:

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

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



Donna Hardy

Thank you Donna. We have ben taking photos everyday at the same time each day to record what we are seeing. We are using pieces of paper sitting by the item to record what day it is in the picture. We are doing this for all items all days. When we have seen some growth or extention of growth we have taken an up close picture of it also. How would you record this info in a graph. Could you explain this more? We were planning to use the photos to make flip books to clip to her board to show the process over the length of each foods experiment. They will be able to remove the booklet look at the progression and clip it back. There is not enough room on the board to display each picture side by side and still be able to include the other information. So you would enter the day on one axsis and the rate of time on the other. Would a table chart be best for this and have her write what is evident for that day? such as:
ham in baggies
natural preservatives artificial preservatives
day one - no change - no change

then so on and so forth whit all days and all foods? Or is there a better way?
Thanks for all your help. I think we will continue this one next year just because this is something that means alot to us because of her natural adhd diet. i like the experiment link you sent earlier. I will have her site it in the conclusion and i think it wiould be the one we would like to do next time. We are learning alot about atificial preservatives. She and I as well want to educate about the effects on the body. She is trying to help her friends in her class understand why she has to be on a diet not for weight loss but for concentration. It was fitting with the theme for this year. Solving tomorrows problems today.

Hi,

A science project that is of personal interest to a child is the best type of project, and I’m very happy to hear that your daughter is interested in continuing the project in the future. At the end of her conclusion section, she could write one sentence to say what she will do in her next experiment.

For the results section, you want to present a visual summary of the result so the observer can see immediately what has happened. Since you have very detailed photographs and notes on the results, you could graph the time that it took for growth to appear on all of the samples. A simple bar graph would work and I believe 4th graders are supposed to be able to do bar graphs. List the individual samples on the y axis, and plot the numbers of days that it took for visible growth to appear on the surface of the food on the x axis. If this explanation is not clear, please send me your data (list of samples vs. time for first growth to appear) and I’ll show you how to do this.

In addition, with the detailed records that you have kept, your daughter could pick out one day’s results that give a good example of overall results and present a drawing or photograph of each sample type. She would label each drawing/photograph as, for example, “organic macaroni & cheese on day 8, regular macaroni & cheese on day 8, etc.” The collection of 4 figures, 2 for macaroni & cheese, and 2 for ham, would tell the viewer all about the results of the project. Your daughter should also display the complete results in front of the display board, as the science fair judges will appreciate the meticulous details of the results. You are right that displaying all of the results would be confusing to the viewer.

Next year, your daughter can design an experiment with a dependent variable that can be measured. Results are in weight, length, time, or volts are quantitative and can easily be graphed.

Please let me know if you have more questions.


Donna Hardy