food tests

Question 1

describe the test for lipids

Answer 1

-dissolve the sample in ethanol
-add distilled water
-white emulsion should form

Question 2

describe the test for proteins

Answer 2

-add buriet
-solution will turn blue to lilac

Question 3

describe the test for starch

Answer 3

add iodine
positive result solution will turn from orange to blue black

Question 4

describe the test for reducing sugars

Answer 4

-add bendicts
-heat in water bath
-positive test solution will turn from blue to green yellow orange or brick red

Question 5

describe the test for non reducing sugars

Answer 5

-do usual benedict test and solution will remain blue
-add acid and boil
-cool the solution then add an alkali to neutralise
-add benedicts reagent and heat again
-a postive would be blue to orange or red

Question 6

what is a non reducing sugar

Answer 6

sucrose