Testing for the presence of starches composition

To test pertaining to the presence of starches and healthy proteins macromolecules, to introduce the concept of variations in chemical compounds. Hypothesis:

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If biuret is usually blue after a test for protein, it is a bad result mainly because biuret reagent is blue to begin with. When a solution is usually pinkish purple, or purple, then the evaluation for protein is great. The test remedy for starches is yellow brown. In the event that any substance that is yellowish brown once mixed with iodine, then the test for starches is negative.

If the answer turns purple, or a dark purplish black, then the test out for starches is positive. If PADA water, and sucrose will be tested to get proteins employing biuret reagent, then they displays a negative result. To explain, both DI normal water, and sucrose alone will not contain a search for of protein. In addition , deionized water is commonly used in tests as a bad control. In both trials, if the PADA water is usually tested to get a protein or starch, then it will come again as a negative.

If milk solution, and 50 percent egg white solution will be tested for proteins making use of the biuret solution, then there will be positive results because both of these are composed of necessary protein macromolecules. The usage of condensed dairy brings about a much stronger positive result intended for protein than regular refrigerated milk, since condensed milk is higher in protein. If PADA water, onion juice, and sucrose are tested to get starches applying iodine, then simply there will be a poor result for starches. This is because there are no traces of starch during these solutions. On the other hand, if 1% starch option is analyzed for starch using iodine, then there will be a positive result for starch since there may be starch present. Materials and Methods:

Test Tube Tray

4-5 Test Tubes

Copy Pipet

Protective glasses

Deionized Water (DI water)

Evaporated Milk

50% Egg White colored Solution

1% Sucrose Solution

1% Starch

Onion juice


Biuret Reagent


Test out 1 ” Protective glasses were placed on at the beginning of the experiment! Evaluation for healthy proteins molecules- The test tubes were labeled inside the following buy 1-4; DALAM water, Dairy, 50% EW, 1% Sucrose, and kept still inside the test tube rack. 3 drops of each substance was added to the test tubes. Next. 5 drops of Biuret Reagent were added to quality tubes. The test tubes had been mixed simply by shaking them. Results were documented according to the colour of the new solution. Test 2- For quality for starches, 4 clean test pipes were defined as follows: PADA water, 1% starch, red onion juice, and sucrose. 3mL of each compound was added to each test tube. In addition , 5 drops of iodine was added to each of those. A swirling technique utilized to mix the answer. Results were documented according to the colour of each end product. Results:

Stand 1- Test out for Healthy proteins Using Biuret Reagent Material



your five Drops Biuret


2 . 3 Drops Milk

5 Drops Biuret

Pinkish Violet

several. 3 Drops 50% Egg White

5 Drops Biuret


4. three or more Drops 1% Sucrose

5 Drops Biuret

Light Blue

Desk 2- Test out for Starch Using Iodine 1 . 3mL DI Drinking water

five Drops Iodine

Lumination Yellow

2 . 3mL 1% Starch

five Drops Iodine

Light Purple

3. 3mL Onion Drink

your five Drops Iodine

Mild Yellow

4. 3mL Sucrose

5 Drops Iodine

Light Discolored


For the test for necessary protein macromolecules employing biuret reagent the DI water was blue after being combined with 5 Drops of Biuret Reagent, and sucrose started to be light blue, quite a few were identified as adverse tests to get proteins. This kind of result matched the speculation, given that the is a genuine substance, sucrose is a not starch sweets. When dairy, and fifty percent egg light were mixed with the biuret reagent, the perfect solution for milk was pinkish-purple, and the 50% egg white colored became purple, each representing a positive check for necessary protein. These outcome was parallel for the hypothesis as well knowing that both have a significant volume of proteins. One way this test could possibly be further increased is by using whey protein separate mixed in a water remedy rather than condensed milk because though condensed milk is higher in protein attention than regular milk, whey protein separate has most to also sometimes each of the fat processed out of it, departing a purer protein compound! I would hypothesize that whey protein option would show up as a deeper purple rather than just pinkish purple.


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