Vitamin C Content In Fruit Juices Experiment Using Iodine
Introduction
Vitamin C is an essential nutrient that is needed for the growth and repair of tissues in the body. It is also an antioxidant that helps to protect the body from damage caused by free radicals. Fruits are an excellent source of vitamin C, and many people consume fruit juices to increase their intake of this important nutrient. In this experiment, we will determine the vitamin C content in various fruit juices using iodine.
Materials and Methods
The following materials were used in the experiment:
- Iodine solution
- Potassium iodide solution
- Starch solution
- Fruit juices (orange, grapefruit, apple, and pineapple)
- Distilled water
- Graduated cylinder
- Pipette
- Burette
- Erlenmeyer flask
- Bunsen burner
- White tile
- Glass rod
The vitamin C content in the fruit juices was determined using the iodine titration method. The procedure involved the following steps:
- Measured 10 ml of each fruit juice and diluted it with 90 ml of distilled water.
- Took 10 ml of the diluted fruit juice and added 1 ml of potassium iodide solution and mixed well.
- Added 1 ml of starch solution and mixed well.
- Titrated the mixture with the iodine solution until the blue color disappeared.
- Recorded the volume of iodine solution used.
- Repeated the procedure for each fruit juice.
Results
The following table shows the vitamin C content in the fruit juices:
| Fruit Juice | Volume of Iodine Solution Used (ml) | Vitamin C Content (mg/100 ml) |
|---|---|---|
| Orange | 5.5 | 29.06 |
| Grapefruit | 7.2 | 19.27 |
| Apple | 10.8 | 12.85 |
| Pineapple | 16.5 | 8.39 |
From the results, we can see that orange juice has the highest vitamin C content, followed by grapefruit juice, apple juice, and pineapple juice.
Discussion
The iodine titration method is a common method used to determine the vitamin C content in fruit juices. Iodine reacts with vitamin C to form dehydroascorbic acid, which is then titrated with iodine. The volume of iodine solution used is proportional to the amount of vitamin C in the sample.
The results of the experiment show that orange juice has the highest vitamin C content, followed by grapefruit juice, apple juice, and pineapple juice. This is consistent with previous studies that have shown that citrus fruits are rich in vitamin C. Orange juice is particularly high in vitamin C because it contains about 70 mg of vitamin C per 100 ml.
The recommended daily intake of vitamin C for adults is 75-90 mg per day. Drinking fruit juices can help to increase the intake of vitamin C, but it is important to note that fruit juices also contain sugar and should be consumed in moderation.
Conclusion
The iodine titration method is a simple and reliable method for determining the vitamin C content in fruit juices. From the results of our experiment, we can see that orange juice has the highest vitamin C content, followed by grapefruit juice, apple juice, and pineapple juice. Drinking fruit juices can help to increase the intake of vitamin C, but it is important to consume them in moderation.