Food Test Methods Flashcards
1
Q
Benedicts regeant method (sugar)
A
Method
- dissolve food in water using pestle + mortar
- add to boiling tube
- add 2cm squared of benedicts
- place in beaker for 2-3 mins
2
Q
Biuret method (protein)
A
Method
- dissolve food in 1cm of water using pestle + mortar
- add to boiling tube
- add 1cm squared of dilute sodium hydroxide
- add 3 drops of copper sulfate
- shake + watch
3
Q
Emulsion method (fat)
A
Method
- cut food into small pieces
- place in boiling tube
- add 2cm squared of ethanol
- shake + leave to settle
- half fill a 2nd test tube with water
- add drops of the solution in 1st test tube to the water
4
Q
Iodine method (starch)
A
Method
- Add several drops of iodine to a solid food or liquid
5
Q
What is the colour change for the emulsion test?
A
Water becomes cloudy at top of tube
6
Q
What is the colour change for the benedicts reagent test?
A
Blue - green - brick red
7
Q
What is the colour change for the iodine test?
A
Orange/yellow - blue/black
8
Q
What is the colour change for he Biuret test?
A
Pale blue - violet
