food tests

Question 1

what does benedict’s reagent test for

Answer 1

sugars

Question 2

what does a positive test for sugar look like

Answer 2

the sample will turn from blue to green/yellow for moderate sugars and brick red if high sugar

Question 3

what does iodine test for

Answer 3

starch

Question 4

what does a positive test for starch look like

Answer 4

the sample will turn from brown to black

Question 5

what does biuret solution test for

Answer 5

protein

Question 6

what does a positive test for protein look like

Answer 6

the sample turns from blue to purple

Question 7

what does the sudan 3 test test for

Answer 7

lipids

Question 8

what does a positive test for lipids look like

Answer 8

top layer will turn bright red

Question 9

how do u prepare a food sample

Answer 9

1- break food up with a pestle and mortar
2- transfer into a beaker and add distilled water
3- stir mixture to help dissolve food
4- filter solution using a funnel lined with filter paper to remove solid food

Question 10

how do u test for sugar

Answer 10

1- add 5cm of food sample to test tube
2- prepare a water bath and set to 75 degrees
3- add about 10 drops of benedict’s reagent to test tube
4-place the test tube in the water bath using a test tube holder and leave for 5 minutes

Question 11

how do you test for iodine

Answer 11

1-add 5cm of food sample and a few drops of iodine solution to a test tube and shake

Question 12

how do you test for protein

Answer 12

1-2cm of your food sample and 2cm of biurets solution to a test tube and shake

Question 13

how do u test for lipids

Answer 13

1- add 5cm of your food sample and 3 drops of sudan 111 stain solution to the test tube and shake
FOOD SAMPLE DOES NOT NEED TO BE FILTERED