Food Tests Flashcards

1️⃣ Familiarise yourself with the flashcards:

  • Look through all the flashcards to see what’s on both sides.
  • Make sure you understand the information on each card. If something’s unclear, click the link to the revision notes at the bottom of the page for more details.

2️⃣ Test yourself:

  • Look at the question or prompt on each card and try to remember the answer before flipping it over.
  • Check the answer and make a note of any cards you find challenging and need to go over more.

3️⃣ Consistently Review and Practice:

  • Use spaced repetition: spend more time on the cards you struggle with and go over them more often.
  • Regularly review all the flashcards to help you better understand and retain the information over time.

Note: We may include questions that have multiple correct answers. It’s useful to remember specific examples to understand these concepts better.

What are the initial steps for preparing a food sample for testing?

1. Break up the food using a mortar and pestle.
2. Place the crushed food in a beaker with distilled water.
3. Stir until some food dissolves.
4. Filter the solution using a funnel and filter paper.

What is the Benedict’s test used for and how do you perform it?

The Benedict’s test detects reducing sugars.

Add the test sample to Benedict’s solution in a test tube, heat it in a water bath at 80°C for 5 minutes, and observe the colour change (blue to green, yellow-orange or brick red).

What does the Iodine test detect and how do you perform it?

The Iodine test detects starch.

Add a few drops of iodine solution to the test sample in a test tube and observe the colour change. A deep blue/black colour indicates the presence of starch.

What does the Biuret test detect and how do you perform it?

The Biuret test detects proteins.

Add an equal volume of sodium hydroxide (NaOH) to the test sample, then add two drops of copper sulfate (CuSO4) solution. Stir and observe the color change from blue to purple if proteins are present.

What is the Emulsion test used for and how do you perform it?

The Emulsion test detects lipids.

Mix the test sample with ethanol, then add an equal volume of distilled water. A white cloudy emulsion indicates the presence of lipids.

What indicates a positive result in the Benedict’s test for reducing sugars?

A positive result in the Benedict’s test is indicated by a colour change from blue to green, yellow-orange or brick red, depending on the concentration of reducing sugars.

You’ve used 10 of your 10 free revision notes for the month

Sign up to get unlimited access to revision notes, quizzes, audio lessons and more

Sign up