Food supplies energy for all animals—without it we could not live. The quantity of energy stored in food is of great interest to humans. The energy your body needs for running, talking, and thinking comes from the foods you eat. Not all foods contain the same amount of energy, nor are all foods equally nutritious for you. An average person should consume a minimum of 2,000 kilocalories per day. That is equivalent to 8,360 kilojoules. Calories and joules are both units of energy. We will use joules in this lab since it is the accepted SI metric standard.
You can determine energy content of food by burning a portion of it and capturing the heat released to a known amount of water. This technique is called calorimetry. The energy content of the food is the amount of heat produced by the combustion of 1 gram of a substance. It is measured in kilojoules per gram (kJ/g).
In this experiment, you will
- Measure temperature changes.
- Monitor the energy given off by food as it burns.
- Determine and compare the energy content of different foods.