Food tests

What are the food tests for sugar, starch, protein and fat?

Sugar - Benedict’s

Starch - Iodine

Protein - Biuret’s

Fat - Ethanol

What are the test results for Benedict’s, iodine, Biruet’s and Ethanol

Benedict’s - Turns Red

Iodine - Brown to blue/black

Biuret’s - Turns purple

Ethanol - Turns cloudy

What are the steps for the amylase required practical?

1. -mix starch with amylase at pH4

2. -add a drop of the mixture to the spotting tile with a drop of iodine every 30 seconds

3. -record how long it takes for starch to turn to sugar (iodine no longer turns blue-black)

4. -repeat at different pH values

5. -control variables:

6. same temperature

7. same concentration of solutions

If iodine is blue/black what is still present?

Starch

If iodine is no longer blue/black what is the starch doing?

It is reacting to make sugar

How often is a sample of starch taken?

Every 30 seconds