Flashcards in B2.1.2 - Food Tests Deck (14)
Which solution do we use to test for sugars?
Which solution do we use to test for starch?
What colour is Benedict's solution when it contains no simple sugars?
What colour is iodine solution when there is no starch present?
What colour is iodine solution in the presence of starch?
How do we prepare a food sample?
1. Crush the food with a pestle and mortar.
2. Add a few drops of distilled water and mix well.
What is distilled water?
Pure water (it contains no other chemicals)
How do you test for starch?
1. Add a few drops of iodine solution to a food sample.
2. If solution turns blue/black starch is present.
How can you test for SOLID lipids?
1. Rube the piece of food on filter paper.
2. Hold paper to light source.
3. If paper turns translucent - lipids are present.
What does translucent mean?
How can you test for lipid in a food solution (LIQUID)
1. Add a few drops of ethanol to the food solution.
2. Shake tube and leave for 1 minute.
3. Pour ethanol into a tube of water.
4. If solution turns cloudy - lipids are present.
How do you test for simple sugars?
1. Add a few drops of Benedict's solution to the food sample.
2. Heat the test tube in a water bath.
3. If the solution turns orange/red the food contains simple sugars.
How do you test for protein?
1. Add a few drops of copper sulfate to food solution.
2. Add a few drops of sodium hydroxide.
3. If solution turns purple - proteins are present.