The science of nutrition and healthy eating
The science of nutrition and healthy eating

This free course is available to start right now. Review the full course description and key learning outcomes and create an account and enrol if you want a free statement of participation.

Free course

The science of nutrition and healthy eating

1.2 How many kilocalories in a peanut?

If you can do the following experiment, you should get a rough idea about how many kilocalories there are in a peanut.

This experiment involves burning a peanut, so you need to take the appropriate precautions. If necessary, ask someone to help you. It is probably best done outside on a calm day because quite a lot of smoke might be produced. If you cannot do this experiment, you might still be able to follow the ideas and try the calculations.

Activity 1 Measuring energy in food

Allow approximately 45 minutes.

Equipment and materials

  • a peanut – ideally the fresh ones you can buy in their shells or for feeding to birds. These work much better than salted peanuts
  • a cork
  • a sewing needle
  • some aluminium foil
  • an old metal tablespoon
  • some water
  • a lighter or matches.


Download this video clip.Video player: Please note this video has no audio.
Skip transcript: Please note this video has no audio.

Transcript: Please note this video has no audio.

Push a needle into a cork
Mount a peanut
Fill a tablespoon with water
Ignite the peanut
Heat the water
End transcript: Please note this video has no audio.
Copy this transcript to the clipboard
Print this transcript
Please note this video has no audio.
Interactive feature not available in single page view (see it in standard view).
  1. Push the eye of the sewing needle carefully into the end of the cork, and spike the peanut onto the sharp end. This will allow you to hold the peanut while it burns, so you don’t burn your fingers.
  2. Place some aluminium foil underneath where you will burn the peanut, so that bits falling off the peanut won’t cause any damage.
  3. Fill the tablespoon with water and set it to one side. This is the equivalent of the jacket of water around the bomb calorimeter.
  4. Use a lighter or a match to set the peanut alight. This may take a few attempts.
  5. Once the peanut is burning steadily, hold the spoonful of water over it. Watch carefully to see if you can get the water hot enough for it to boil.

Remember that everything will get hot once your peanut is alight. Please be careful!

So, can you use a peanut to boil your tablespoon of water?


Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus