Food tests starch, glucose

Question 1

Starch method

Answer 1

1. Obtain a small amount of the solution or food
2. Add 2/3 drops of dilute iodine solution (orange)
3. If it turns blue,black then starch is present

Question 2

starch key word

Answer 2

DIMPLE TILE

Question 3

glucose method

Answer 3

soluble in water
1. take 2cm3 of the liquid and put in test tube
2. add 2cm3 of Benedicts solution (blue) to the test tube and shake gently
3. place in hot water bath for 2 minutes
4. if a red orange ppt forms then glucose is present
5. green = less glucose
darker the red, = the more glucose

Question 4

glucose key word

Answer 4

HEAT

Question 5

lipids method

Answer 5

1. pour 1cm3 of ethanol into a test tube containing the food sample
2. shake test tube
3. transfer the ethanol to a fresh test tube and add 1cm3 water
4. If a cloudy white emulsion forms, fat is present

Question 6

protein method

Answer 6

1. pipette 2cm3 solution into a test tube
2. add biurette solution
3. if the solution goes purple, protein is present

Question 7

protein key word

Answer 7

PURPLE PROTEIN