chemical element of carbohydrate
carbon, hydrogen, and oxygen
chemical elements of fats
carbon, hydrogen, and oxygen
chemical elements of protein
carbon, hydrogen, oxygen, and nitrogen
large molecule=starch, glycogen and cellulose
small molecules=?
glucose
large molecule=protein
smaller molecules=?
amino acid
large molecule=fats and oil
smaller molecule=?
trygliceride
test for starch?
iodine solution
test for reducing sugars
benedict solution
test for proteins
biuret test
test for fats and oils
ethanol emulsion
method for iodine solution
place sample of food in spotting tile
number each food sample
add 2 drop of iodine
record colour
results of iodine solution
Blue-black → starch present ✔️
Brown/orange (no change) → no starch ✔️
method for reducing sugars test
add 2cm3 of benedict to food sample in a boiling tube
place tube in boiling water
leave for 3-4 min
record result
results of benedict solution
-Blue → no reducing sugar ❌
-Green → yellow → orange → brick-red → increasing concentration ✔️
test for protein method
place sample of food in test tube
number the tube
add 2cm3(20 drop)of biuret
record color of reagent
test for fats method
add 2cm3 ethanol to food sample
shake tube for 10 sec
pour sample slowly into tube of distilled water
record result
protein results
-Purple/lilac ✔️ → protein present
-Blue (no change) ❌ → no protein
ethanol emulsion results
-Milky/cloudy white ✔️ → lipid present
-Clear (no change) ❌ → no lipid
