Science Buddies: "Ask an Expert"

Dear Science Buddies,
Hi, my name is Ashley and I am an 8th grader at Corona Fundamental Intermediate School in southern California.

This year, one of my long term assignments is a Science Fair project and we must choose a scientific question and try to answer it by using the scientific method. As I was browsing on the Internet for topics, I came across your experiment on Science Buddies called, Burining Calories: How Much Energy is Stored in Different Types of Food? While reading this experiment, I thought it very challenging, interesting, and exciting to perform, so I turned it in as my experiment question, but with a few changes.
Instead of using nuts, popcorn, marshmallows, bread, and petfood, I decided I wanted to find the caloric energy of cereals like Froot Loops and Trix. I performed the same exact experiment with 7 sugary breakfast cereals with 10 trials each.
My experiment question is: Which cereal contains the highest amount of caloric chemical energy and nutritional value to sustain optimal cellular oxidation levels in middle school students?
Hypothesis: I think the cereal highest in protein and lowest in sugar will contain the highest amount of caloric chemical energy and nutritional value.
Right now I have collected the information of my 10 trials for my 7 cereals and have run into some confusion. It says that I must calculate the energy released per individual food item (in calories and Calories), and the energy per unit weight of each food item (in calories/gram and Calories/gram). So I must collect these four data for each trial of cereal. But I do not understand how to find the energy per unit weight of each cereal piece? And after collecting these 4 data, how do I calculate the caloric chemical energy?
Also, after I know the energy released per individual food item in calories, do I times it by 1000 to get the energy in Calories?
If you could please e-mail me back as soon as possible to let me know your opinion I would gladly appreciate it.

Thank you very much and Happy New Year,
Ashley

Reread the experimental writeup of the project in the chemistry section of the project ideas guide of this site. How to calculate the the number of calories captured by water from the burning food is explained, with a worked example. The experiment told you to weigh the food sample before and after you burned it. You need to know the weight burned to compute the calories per unit weight ( by dividing the calories generated by the burned weight). Also notice 1Calorie = 1000 calories= 1 kcal, so to get Calories you divide calories by 1000.

This is a good project! Good Luck!

Dear Science Buddies,
Thank you for answering me back. But, instead of using different kinds of foods in my project, I am testing 7 sugary cereals. Do you think my project is a waste of time when I could just look on the cereal boxes for the caloric chemical energy of the 7 cereals? Do you think I should find the caloric chemical energy of sugary and healthy cereals?
Please write me back.

Happy New Year,
***Ashley***

I think it might be interesting to compare the results obtained by your testing with the packaging on the cereal boxes.

If they're the same, or close, it validates your experimental technique. If different you will need to explore why it might be different, especially if it is inconsistent (some results match, some do not).

Dear Science Buddies,

I have collected all my data for my 10 trials for my 10 cereals but am fuzzy on how to calculate the average or even what should be my final number for each of my 10 cereals. In one of your posted experiments, Burning Calories: How Much Energy is Stored in Different Types of Food, it says I must calculate the energy released per individual food item (in calories and Calories) and the energy per unit weight of each food item ( in calories/grams and Calories/grams.) I guess I don't understand what order I should do these in. Should I calculate the amount of heat captured per trial to get the small calories, then divide by the amount of grams burned, then convert the 10 trials to big Calories by dividing by 1000, then average the 10 trials to find the 1 number of big Calories for that type of cereal?

I don't even really understand what my final 10 numbers will be for my 10 cereals. Will the unit of my 10 final numbers be in Calories? Or will there be 4 different final numbers to compare for each cereal? And if so, how would I compare those 4 numbers to each other?
I need an answer as soon as possible.

Thank you,
ashley

As to your first question as far as I can see your procedure for your calculations is correct. You should go ahead and get started with that.

The final ten numbers you obtain (1 averaged number for each of your 10 cereals ) will tell you the average Calories/gram(energy contained in 1 gram of that cereal). Your hypothesis asks which cereal has the greatest chemical energy density(calories/gram) and you'll find that his number you calculate using the previous method is the best for confirming your hypotheses. You could compare the other numbers if you wanted to but due to variations the numbers might not be consistent.

Phi-unit