In temperate climates, such as Japan or Europe, people ear fresh fruits in summer, but eat tinned, preserved, or cooked foods in the winter. The latter being more susceptible to heat, possibly breaking down the amount of vitamin C in them. This experiment tested for the vitamin C content in fresh fruit juices and commercially sold drinks. This experiment was conducted mostly on citrus fruits because vitamin C is said to be abundant in citrus fruits. The experiment was also performed on non-citrus fruits. The experiment was performed on these two types of fruit drinks because vitamin C contributes to maintaining a healthy body, especially during the winter, when citrus fruits are not in season. AS a result, the amount of vitamin C found in each type of juice would be essential in knowing what drinks to choose during the winter to provide the most or the optimum amount of vitamin C. .

             Using this information, the following hypothesis was formed. Since vitamin C is labile (meaning susceptible to change and unstable), the commercially sold juices, which have most likely been heat treated and stored in various conditions for various periods of time, should have lower vitamin C content than fresh fruit juices. The commercially sold juices would have most likely been exposed to the conditions leading to the deterioration in the content of vitamin C. .

             In this experiment the independent variables were the juices that were being tested for their vitamin C content. The volume of each required to make a standard volume of DCPIP (dichlorophenolindophenol) change from blue to clear was measured.1 This was the dependent variable. These juices were first filtered and then titrated using a burette. The fixed variable of the experiment was the amount of DCPIP in each beaker and the room temperature. Both of these remained constant throughout the experiment. The importance of the room temperature being constant and not too high is because otherwise the vitamin C content of any and all the juices may have been altered, since vitamin C is heat labile.