Effect of Temperature on Content of Vitamin C
A daily intake of Vitamin C is essential for humans. Without it, the disease scurvy develops as sailors, explorers and people during the long winters in the Northern hemisphere found before the time of Captain Cook. The British Navy started giving sailors lime juice to prevent scurvy on long voyages in 1795. Vitamin C is found in high levels in foods such as oranges, limes, lemons, blackcurrants, parsley and capsicums. Vitamin C is water soluble and is therefore not stored or synthesized in the body, thus a daily supply is required. It breaks down, and is no longer effective due to factors such as extreme temperatures or storage for more than a few days. Aim
To investigate the effect of temperature of juice on the content of Vitamin C. Variables
Independent: Temperature of orange juice – 25°C, 50°C, 100°C Dependent: Content of Vitamin C recorded by the number of Iodine drops Controlled: Amount of orange juice – 2mL measure using a 25mL pipette Controlled: Amount of starch solution – 2mL measure using a 25mL pipette Controlled: Amount of hydrochloric acid 1M – 2 drops from a dropper bottle Controlled: Amount of distilled water – 4mL measure using a 25mL pipette Controlled: Molar concentration of hydrochloric acid (HCl) – 1M controlled using the same dropper bottle of HCl each time Hypothesis
As the temperature of the juice increases the content of Vitamin C will decrease. Materials
Nudie orange juice
Dropper bottle hydrochloric acid 1M
3 conical flasks
Test tube rack
Heat proof mat
1. Place 10mL of Nudie orange juice in a 250mL beaker.
2. Using a Bunsen burner, heat the juice to 25°C.
3. Measure temperature by placing a thermometer in the juice. 4. Once juice is 25°C, using a 25mL pipette, add 2mL of the juice into a clean conical flask. 5. Using a 25mL pipette, add 4 mL of distilled water and 2mL of starch solution. 6. Add 2 drops of hydrochloric acid 1M (HCL).
7. Using a dropper bottle of iodine, add iodine drops counting the number of drops added and mixing the solution after each drop. 8. Once the solution starts to turn purple, record the number of iodine drops added for purple to appear. 9. Clean conical flasks using water.
10. Repeat steps 1-9 with 50°C juice and 100°C juice. Complete 3 trials for each. Risk Assessment
Hydrochloric can irritate the skin if in contact
Keep the lid closed when not in use.
Wear gloves, a safety coat and glasses
Risk of Bunsen burner burning the skin
Turn the Bunsen burner off when not in use
Use a heat proof mat underneath it
Keep a safe distance when burning
Test tubes are breakable and my cut the skin
Keep test tubes in the test tube rack
Handle with care
Effect of temperature of juice on the content of Vitamin C
Temperature of orange juice
Number of Iodine drops
Vitamin C also known as ascorbic acid is an essential water-soluble nutrient for humans and some animal species. Vitamin C acts as an antioxidant serving to prevent cellular damage which is the common pathway for cancer, aging, and a variety of diseases. Vitamin C is also required to make collagen, a protein that aids the healing of wounds. The body also needs vitamin C as it improves the absorption of iron and supports the immune system. Vitamin C can be found predominantly in citrus fruits and green vegetables. The Recommended Daily Intake (RDA) is 60 mg per day. Vitamin C deficiency may cause Scurvy. Taking too much vitamin C can cause diarrhea, nausea and stomach cramps. Vitamin C is the most unstable vitamin which can be easily denatured. At high temperature, in the presence of sun light and oxygen...
Bibliography: Admin. (2013, February 14). At What Temperature Does Vitamin C Denature? Retrieved April 15, 2014, from Vitaminable: http://www.vitaminable.com/at-what-temperature-does-vitamin-c-denature.html
Ehrlich, S. D. (2011, July 7). Vitamin C (Ascorbic acid). Retrieved April 15, 2014, from University of Maryland Medical Center: http://umm.edu/health/medical/altmed/supplement/vitamin-c-ascorbic-acid
Office of Dietary Supplements. (2011, June 24). Vitamin C. Retrieved April 15, 2014, from Office of Dietary Supplements - National Institutes of Health: http://ods.od.nih.gov/factsheets/VitaminC-QuickFacts/
Please join StudyMode to read the full document