Food Testing

Testing for simple sugars

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

Equipment:

• Bunsen burner
• Test tube tongs
• Benedicts Solution
• Food sample
• Test tubes
• Safety Glasses

Method:

1. Place about 2mL of food sample into a test tube then add 5 drops of Benedict's solution.
2. Heat the test tube over a blue flame. (DO NOT LET BOIL!!!)

Results:

A positive test for a simple sugar result in the Benedict's Solution changing from a blue colour to an orange colour to a red/brown colour.

Conclusion:

The orange juice reacted with Benedict's Solution, therefor orange juice must contain simple sugar.

Photos:

Testing for Complex Sugars (Iodine Test)

Aim:

I want to find out how to test for complex sugars

Equipment:

• Iodine solution
• Food sample
• Test tube

Method:

1. Place 2mL of the food sample into a test tube.
2. Add 3-5 drops of iodine

Results

If complex sugars are present, the iodine solution will change from a brown colour to a black colour.

Conclusion

Bread reacted with the iodine solution, therefore bread contains complex sugar.

Testing for Protein (Biuret Test)

Aim:
I want to find out how to test for protein.

Equipment:

• Test tube
• Food Sample
• Sodium Hydroxide
• Copper Sulfate

Method:

1. Put the food sample into the test tube.
2. Add 5 drops of Sodium Hydroxide into the test tube.
3. Add 5 drops of Copper Sulfate into the test tube.
4. Gently shake from side to side

Results:

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

Conclusion:
The solution turned purple so therefor egg does contain protein.



Photos: