Food Test : Science

Testing for Simple Sugars- The Benedict's Test

Aim:
I want to find out how to test for simple sugars

Equipment:

• Bunsen Bunner
• Test tube tongs
• Benedict's Solution
• Food Sample
• Test tubes
• Safty Glasses

Method:

1. Place about 2mL of the food sample into the test tube then add 5 drops of Benedict's Solution
2. Gently heat the test tube over a blue flame. DO NOT BOIL!!

Result:

A positive test for a simple sugars results in the Benedict's Solution changing form a Blue colour to a Yellow colour to an Orange/Red colour.

Conclusion:

When you heated the chemicals it went the colours down of the rainbow starting from Blue and went down but normally it would stop at orange but if your lucky and it didn't expold you would get red.

Testing for Complex Sugars- The Iodine Test

Aim:

I want to find out if a simple of food contains complex sugars.

Equipment:

• Test tube
• Food Sample
• Iodine Solution

Method:

1. Place about 2mL of the sample in a test tube.
2. Add 3-5 drops of iodine and mix.

Results:

If complex sugars (i.e starch) are present the iodine solution will change from a brown colour to a blue/black colour.

If the iodine solution does not change colour then no complex sugars are present.

Conclusion:

We used breed for this and indeed it had complex sugars because it turned black.

 Testing for Protein-The Biuret Test

Aim:

To test if a sample of food contains protien.

Equipment:

• Test tube
• Sodium hydroxide( NaOH) 
• Copper sulfate ( CuSO4) 
• Food Sample

Method:

1. Place about 2mL of the sample into a test tube and add 5 drops of sodium hydroxide.
2. Add 5 drops of copper sulfate.
3. Shake the test tube gently from side to side.

Results:

If the solution remains blue, then no protein is present. If the solution changes to a purple colour then protein is present in the sample.

Conclusion:

The liquids chances from to orange/Yellow to Green to Purple, but my group took its time and we got the formula out of place so we ended up using the teachers we got a video of it but it's not family friendly.