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.
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 | | | |...
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