Core Practical: The vitamin C content of fruit juice Firstly, the role of vitamin C in the body is an important one. It is needed for multiple functions such the formation of collagen for healthy gums, teeth, blood vessels and plays a strong role in fighting infections. The recommended amount of vitamin C is 60 to 90 milligrams per day, and of the citrus produced in the U.S harvest, about 90 percent was processed into juice. Thus, it suggests that orange juice is popular and a readily available source of vitamin C, so it must be important for people to know just how much vitamin C their orange juice is providing them. Aim: to investigate the vitamin C content of orange juice, find out how much vitamin C it takes to decolourise DCPIP solution and the effects of titrating orange juice.
Independent variable: vitamin C solution/orange juice.
Dependent variable: volume of vitamin C solution/orange juice required to decolourise 1cm of DCPIP solution. Equipment: * 1% DCPIP solution * 1% vitamin C solution * Orange juice * Test tubes * 5ml Syringe * Volumetric pipette/burette (1cm ) * Pipette filler * Eye protection Method: vitamin C solution DCPIP solution * Using the syringe, place 1cm of blue DCPIP solution into a test tube before making sure there is no air bubble present in the syringe. * Place the burette into the 1% vitamin C solution and use the pipette filler to help draw up and secure the solution in place. * Add the vitamin C solution drop by drop to the test tube. * Shake the test tube in between drops. * Continue until the blue colour just disappears (turns dark purple) * Record the number of drops of vitamin C solution used, and the volume of vitamin C solution used to decolourise the DCPIP. * Repeat two more times. Method: Orange juice