Biochemical food test methods Flashcards
What is the test for reducing sugars
Benedict’s test
What is the name of the reagent for testing reducing sugars
Benedict’s solution
Does the test for reducing sugars require heat
Yes
When testing reducing sugars what colour shows a negative result
Blue
When testing reducing sugars, what colour shows a positive result
Red
When testing for starch, what is the name of the reagent
Iodine
When testing for starch what indicates a positive result
Solution changes from orange to blue/black
When testing for non-reducing sugars, what must you confirm first
That it isn’t a reducing sugar by doing benedict’s test
After a negative Benedict’s result when testing non-reducing sugars, what is the next step
To add acid and boil- usually HCl
When testing for non-reducing sugars, what is the step after adding HCl
To add an alkali- NaHCO3
When testing for non-reducing sugars, what happens after adding the alkali
Add Benedict’s reagent and heat again and view the colour change
What is the test for proteins
Biuret
What is the name of the reagent when testing for proteins
Biuret
What is a positive result during the biuret test for proteins
Solution turns from blue to purple
What is the test for lipids
The emulsion test
