Zusammenfassung der Ressource
Biology: Food Tests
- Lipid
- Mix with ethanol. Pour
mixture into water.
- If present: cloudy, white
emulsion will form at
top of water.
- Reducing Sugars
- Heat sample with
Benedict's solution (alkaline
copper sulfate).
- If present: colour
change from blue
to orange-red.
- Non-Reducing
Sugars
- Make sure there are
no reducing sugars
in sample first.
- Boil in hydrochloric acid
(HCl). Cool it and neutralise
it by adding sodium
carbonate or sodium
hydrogrencarbonate.
- Carry out reducing
sugar test again.
- If present: will give a
positive result in
reducing sugar test.
- Starch
- Add a solution of
iodine
- If present: changes
colour from yellow-brown
to blue-black.
- Protein
- Add biuret reagent
of sodium hydroxide
and copper sulfate.
- If present: colour
change from light blue
to lilac.