food tests Flashcards
1
Q
Lipids test
A
emulsion test
add ethanol then shake
add to water
milky emulsion will form
2
Q
proteins
A
biuret test
add sodium hydroxide solution
add copper (II) sulfate solution
purple=positive
blue=negative
3
Q
starch
A
add iodine dissolved in potassium iodide solution
4
Q
sugars (reducing)
A
benedicts test
add benedict’s reagent to sample
heat in a water bath that’s been brought to a boil
positive forms a coloured precipitate
green,yellow,orange,brick-red
5
Q
Non-reducing sugars
A
add dilute hydrochloric acid
neutralise it with sodium hydrocarbonate
add benedict’s reagent to sample
heat in a water bath that’s been brought to a boil
positive forms a coloured precipitate
green,yellow,orange,brick-red
