In this investigation, I aim to measure and compare whether there is a higher content of vitamin C in a fruit or a juice by measuring the volume of the sample required to decolourise a solution of dichlorophenolindophenol (DCPIP).
For this experiment, I aim to investigate and compare the content of vitamin C in the fruit against the fruit juice. The theory of this method is a titration with dichlorophenolindophenol (DCPIP). DCPIP is a redox dye and Ascorbic acid reacts with the DCPIP solution, changing the colour from a deep blue to either a pale pink or colourless solution. They react in a 1:1 state, so I can use the amount of ascorbic acid required to work out how much vitamin C is found in the other types of juice. This is known as a “redox reaction.” A “redox reaction” is also known as a “reduction-oxidation reaction”, it is when the oxidation number of the reactants is changed. (To change oxidation number, electrons must either be added to or removed from reactants.)
Vitamin C, which is also known as ascorbic acid, is a water-soluble vitamin. Ascorbate/ vitamin C is also a highly effective antioxidant, since it protects the body against oxidative anxiety and can prevent or slow oxidative damage to our bodies. But unlike most mammals and other animals, humans do not have the ability to make their own vitamin C. Therefore, we must obtain vitamin C through our diet.
When our cells use oxygen, they naturally produce “free radicals,” which are chemicals that form naturally inside the body through the process of oxidation. These free radicals travel right the way through our bodies causing damage to our cells, organs and the body’s delicate chemical balance. “Free radicals” are highly unstable; therefore they damage cells by grabbing and donating electrons and this can cause the development on atherosclerosis. Extensive damage by these is thought to be a factor of developing CHD’s.
References: Image of oxidation from: http://mnh20.wordpress.com/2010/05/23/the-aura-of-%E2%80%98antiseptic%E2%80%99-in-red-ox-titration/