Amount of Antioxidants in Three Green Tea Samples

Amount of antioxidants in three green tea samples
Aim: To compare the amount of antioxidants in three green tea samples and hence recommend a brand of green tea bag contains a higher antioxidants content to the public.

Introduction
Problem to investigate: Amount of antioxidants in three green tea samples
Hypothesis: It is the antioxidants like catechins, a form of flavonoids, present in the green tea to cause the DCPIP solution to change from blue to colourless.
Prediction: The DCPIP solution is predicted to change from blue to colourless when green tea sample is added. For green tea sample with a higher antioxidants content, it is predicted that less amount of green tea sample is needed to cause the colour change of DCPIP solution.
Principles: Green tea is the best food source of a group of antioxidants flavonoids called catechins. In test tubes, catechins are more powerful than vitamin C and E in halting oxidative damage to cells. **DCPIP, dichlorophenol indophenol solution, is used in a food test to test for presence of vitamin C and other antioxidants like catechins in the green tea sample.**
|Independent variables |Dependent variables |Controlled variables |**Control |
|brand of green tea sample |volume of green tea sample used to |volume of DCPIP solutions |titrate boiling water with DCPIP |
| |reach the endpoint of titration of |time to brew the tea bag sample |solution. |
| |DCPIP solution and green tea sample |mass of tea bag sample | |
| | |volume of water to brew the tea bag | |
| |