Purpose:
* To investigate the vitamin C content of fruit juice * To investigate which type of fruit juice provides the most vitamin C
The quantity of vitamin C in food and drink can be determined using a simple colour test. Vitamin C decolourises the blue dye DCPIP (dichlorophenolindolphenol). Vitamin C is an antioxidant and reduces the DCPIP. DCPIP changes from blue to colourless (or slightly pink) as it becomes reduced.
We will be testing a range of different fruit juices to see which contains the highest concentration of vitamin C
Hypothesis: * I predict that the orange might be the juice that provides the most vitamin C; this is because it is widely promoted as a ‘high vitamin C juice’. * Grapefruit juice might contain the second highest amount of vitamin C; also because of it promotion in the media.
Vitamin C is a water-soluble compound that is essential for life. It is involved in many processes in the human body, including: the production of collagen in the connective tissue; the synthesis of dopamine, noradrenaline and adrenaline in the nervous system; and the synthesis of carnitine, which is important in the transfer of energy to the cell mitochondria. A deficiency in vitamin C causes scurvy, a disease that affected sailors in the 16th - 18thCenturies. It was discovered that fresh fruit, e.g. limes and oranges, or sauerkraut (preserved cabbage) provided the sailors with protection from scurvy.
Safety: * Running should be avoided in the laboratory to prevent accidents especially when handling liquids * Goggles should be warn at all times when carrying out the experiment * Care should be taken when handling glass wear * The supervisor should be informed about any spillages of liquid that may be hazardous to others in the laboratory.
Controlled variables: * Temperature; If a juice is higher in temperature than the other, it will cause the reaction to