Aim of investigation:
To investigate what type of fruit juice contains most Vitamin C and therefore contains the most antioxidants.

Equipment:
• Range of fruit juices
• Standard 1% vitamin C solution
• Pipette and burette to measure volumes
• Standard laboratory glassware and apparatus
• DCPIP 0.1%
Variables:
• Dependent: Volume of vitamin C in fruit juice
• Independent: The type of fruit juice
• Control: Volume of DCPIP, test tube size and pipette.
Method:
1. Firstly, syringe 1cm3 of DCPIP solution into a test tube
2. Then using a pipette or a burette add the vitamin C solution drop by drop to the DCPIP. Gently give the test tube a shake after each drop. Continue to add drops until the solution in the test tube has turned from blue to colourless.
3. Repeat this procedure with the other fruit juices provided.
Results table:

Juice tested Volume of juice required to decolourise 1cm3 of 0.15 % DCPIP solution Average volume of juice required (cm3) 1 2 3 Control 2.00 2.60 2.20 2.30
Orange
2.00 2.25 2.10 2.12
Grapefruit
1.50 1.70 1.65 1.61
Lemon
1.90 1.70 1.60 1.73
Pineapple
0.25 0.04 0.15 0.15

Graph:

Conclusion:
In conclusion, it can be seen that the largest volume of fruit juice required to decolourise the DCPIP solution was the orange juice suggesting that it contained a smaller amount of vitamin C in comparison to the Pineapple juice which decolourised the DCPIP with only an average of 0.15cm3. Vitamin C is an example of an antioxidant which can protect against radical harm. Unstable radicals can cause damage our cell components including our DNA during chemical reactions when an atom has an unpaired electron and are highly reactive. During the development of some types of cancer, heart disease and premature ageing, we may be exposed to free radicals as a source of cure. Antioxidants