EXPERIMENTAL INVESTIGATION 10.3 How can we investigate if fat is present in food?
Equipment Brown paper Dropper
Suggested substances to test Water Bread Milk Vegetable oil
Method 1. Label four pieces of brown paper as follows: ‘Water (control)’, ‘Bread’, ‘Milk’, ‘Vegetable oil’.
2. Add a small drop of water to the piece of paper labelled ‘Water (control)’ and then rub or add small amounts of the food to the appropriately labelled piece of brown paper.
3. Stand all four pieces of paper on the lab bench for approximately 15 minutes.
4. Hold up all four pieces of paper to the light. A positive test for fat will allow light to pass through the paper.
5. Record your results in a table.
SAFETY • Do not eat any of the food being tested.
)Fig. 10.7 Brown paper becomes translucent on contact with fat
j Go to page 26 of your Experimental Investigations Log to write up this investigation.