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Click to edit project description www.crestawards.org
Page 1 of 2 What’s in a food? In this project, you will test a range of foods to find out if they contain protein, fat, reducing sugar or starch. You will then do an experiment to work out how much energy is in each of the foods. Getting started You should start this project by selecting different types of foods to test – about five should be enough. Carry out an experiment to find out how much energy is in each type of food. To do this you have to burn the food and see how much it heats up water. You should ask your teacher how to set this experiment up. You’ll need a Bunsen burner, a clamp stand, a boiling tube, some water, a thermometer and something to hold the food over the flame (a small nonluminous flame should be okay). Once the food starts to burn take it away from the flame and hold it under the boiling tube of water. When the flame goes out you should re-light the food - you should keep doing this until it no longer lights. Try to do this quickly so that the water in the boiling tube does not cool down while the food is being re-lit. For each type of food, you should have a temperature rise. Find out the temperature change per gram for each food. You could try some of the tests listed on the right. These will tell you if the food has any protein, fat, reducing sugar (such as glucose) and starch. You will need to ask your group leader how to do the food tests – the tests won’t tell you how much of each thing is in the food, just whether or not there is any. Click to edit project description Things to think about How will you keep it a fair test? How much water will you use for each experiment? Will you stir the water as it heats up, if so, how will you do this? How will you record the change in temperature? Remember, the starting temperature of the water may be different. How could you calculate the temperature rise per gram? Useful resources Suitable foods include: cornflakes, rice, carrot, potato, apple, raisin, bread, pasta, crisps Ask your group leader for help running the following tests: Protein content – Biuret test Fat content – Emulsion test Reducing sugar content – Benedict’s test Starch content – Iodine test. Create a table to display the results of all your food tests.
