Food tests (practical)

What is the first step in preparing a food sample for testing?

• Mix with water.

• Filter with funnel and filter paper.

• Grind up food samples using pestle and mortar.

• Heat the sample.

After grinding the food samples, what is the next step in the preparation process?

• Heat the sample.

• Mix with water.

• Add salt.

• Dry the sample.

What is the final step in preparing a food sample for testing?

• Mix with water.

• Grind up food samples using pestle and mortar.

• Filter with funnel and filter paper.

• Boil the sample.

How can you test for the presence of starch in a sample?

• Add Benedict's solution and heat

• Add iodine solution and look for a color change

• Add biuret solution and look for a color change

• Add silver nitrate and look for a precipitate

How can you test for the presence of starch in a sample?

• Add vinegar to the sample.

• Add iodine solution to the sample.

• Add salt to the sample.

• Add sugar to the sample.

What color change indicates the presence of starch when iodine is added?

• Red to green

• Yellow to purple

• Brown to blue-black

• Orange to pink

Describe how you would test for the presence of a reducing sugar in a sample.

• Use Benedict's solution and heat the sample; a color change to orange indicates reducing sugars.

• Add iodine solution; a blue-black color indicates reducing sugars.

• Use Biuret reagent; a purple color indicates reducing sugars.

• Add silver nitrate; a white precipitate indicates reducing sugars.

What reagent is used to test for the presence of a reducing sugar in a sample?

• Benedict's reagent

• Iodine solution

• Biuret reagent

• Silver nitrate

What is the next step after adding Benedict's reagent to a sample when testing for reducing sugars?

• Cool the test tube in ice

• Boil the test tube in a hot water bath

• Shake the test tube vigorously

• Add hydrochloric acid

What color change indicates the presence of a reducing sugar when using Benedict's test?

• Blue to green

• Blue to brick red

• Blue to yellow

• Blue to purple