Biology Foodtests

[abcde]

AOA!
Can anyone kindly provide notes for all food tests in the syllabus below(detailed)?

 

[Nibz]

1-Benedict's test for Reducing Sugar: It allows us to detect the presence of reducing sugar (e.g glucose) in a solution.
** Di-saccharides such as Sucrose are non-reducing sugars and will not react in BENEDICT'S SOLUTION***
Copper (II) Sulfate is present in this solution, which turns REDDISH BROWN when a reducing sugar is present.
- The final color of the solution depends on how much precipitate was formed and therfore the color gives an indication of how much REDUCING SUGAR was present.
positive result for this test is : a REDDISH BROWN color whereas a negative result shows a BLUE solution (unchanged)

2- Test for Starch
When Iodine is added to any substance containing starch, there will be a BLUE-BLACK color, indicating the presence of starch!
Positive result: BLUE-BLACK
Negative result: BROWN COLOR (Unchanged)

3- BIURET'S Test for Protein: This is made up of SODIUM HYDROXIDE and Copper (II) Sulfate. The Blue color of the solution changes to a VIOLET, if protein is present.
Postive Result: VIOLET
Negative: BLUE

4- ETHANOL EMULSION TEST:
Here you add ethanol to a small amount of oil (containing fats, of course). Then after adding water, if a WHITE (MILK-LIKE) emulsion forms, this will indicate the presence of fats.

 

[UxaiR]

 

[UxaiR]

Although" Nibz " have Explained them very nicely
just wanted to add this file
Hope it Helped

 

[abcde]

Both helped. Thank you for the effort!