food tests Flashcards
1
Q
glucose
A
- 1 ml of glucose solution
- 2 ml of Benedict’s solution
- place in boiling water for 3-5 minutes
2
Q
no glucose
A
turquoise
3
Q
has glucose
A
bright orange
4
Q
little glucose
A
greenish
5
Q
starch
A
place a small drop of iodine solution (initial colour brown) if it changes to black/blue starch is present if not it’s absent
6
Q
lipids
A
grind food sample with ethanol decant, put out the liquid portion mix with water
if solution is cloudy - lipids are present
solution is clear - no lipids
7
Q
ether test (fat)
A
grind food sample with ether, pour liquid onto filter paper and leave it to evaporate
if fatty stain = means lipids are present
no stain = no lipids are present
8
Q
proteins
A
place protein solution into test tube add a few drops of biuret reagent
protein present = purple
no protein = stays the same (blue colour)
