Testing the concentration of Vitamin C in different juices and fruits

Test the concentration of vitamin C in various juices and fruits. Purpose: - Test the concentration of vitamin C in various kinds of juice and fresh fruit. Assumption: - I think that all fresh fruits and fresh juices contain more vitamin C than processed juices and concentrates Background: - Vitamin C, also known as ascorbic acid, is the most important of human beings It is one of nutrients. It is mostly used for all metabolic reactions in the body. It is also used as a food additive.

Experiments included titrated vitamin C tablet solutions using freshly squeezed (orange, lemon) juice, commercially available (orange, lemon) juice, vitamin C, DCPIP solution and vitamin C in each juice and vitamin C tablet Calculate the concentration. . Experimental results are listed in the table below. Types of freshly squeezed juice Drying agent Juice (ml) required for DCPIP solution | Orange | 0 | Compared with artificial juice, tablets with high vitamin C contain a high content of vitamin C, vitamin C The tablets are light. This assumption has not been confirmed. My prediction should match the results of our group experiment. From the observation results, when freshly squeezed juice is added, the color of the DCPIP solution becomes colorless, but when commercial juice is added, a large amount of discoloration is required to decolorize.

In this survey, we titrate the vitamin C (ascorbic acid) content of 7 kinds of juice purchased from the supermarket. I test the presence of vitamin C using an organic indicator solution called DCPIP (dichlorophenol indophenol) which decreases from dark blue to a colorless form in the presence of vitamin C. Reduction is where the molecule loses oxygen molecules, acquires hydrogen atoms, or acquires electrons. Oxidation is the opposite, that is to obtain oxygen molecules, to lose hydrogen atoms, or to lose electrons. The amount of juice used to change DCPIP to a colorless color will be recorded and the content of vitamin C measures the dose of known vitamin C concentration solution used to make DCPIP colorless It is determined by that.

In this experiment, we will investigate how the temperature affects the loss of orange juice vitamin C stored for a certain period of time. Equal amounts of freshly squeezed orange juice with known (initial) vitamin C concentration were stored at different temperatures, ie 10 ° C., 20 ° C., 30 ° C., 40 ° C., 50 ° C. and 60 ° C. for 5 days. After the storage period, the vitamin C concentration at each temperature was measured by DCPIP titration and the difference from the initial concentration was calculated to calculate the amount of decrease of vitamin C. The result of this experiment shows that as the temperature rises the amount of loss of vitamin C increases and 10 ° C is the optimum temperature at which the concentration of vitamin C is minimized.