Vitamin C in Juices: Difference between revisions
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[[Category: | [[Category:Demos]] | ||
=Experimental outline= | =Experimental outline= | ||
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#Vitamin C Standard solution (1 mg/mL)(use 1.00 mL per experiment) | #Vitamin C Standard solution (1 mg/mL)(use 1.00 mL per experiment) | ||
#Starch solution (sue 1.00 mL per experiment and control for 2.00 mL total) | #Starch solution (sue 1.00 mL per experiment and control for 2.00 mL total) | ||
#Iodine solution (we actually make | #Iodine solution (we actually make I<sup>3-</sup>; need up to 1.00 mL per experiment, so need 2.00 L) | ||
=Procedure for fruit juice or drink= | =Procedure for fruit juice or drink= | ||
Latest revision as of 18:48, 27 March 2024
Experimental outline
Determine the Vitamin C content in various freshly squeezed fruit juices. Compare kiwis and oranges (high concentration of Vitamin C) to peaches or apples (low concentration of Vitamin C). Or, blend a vegetable in water to create a solution that can be tested. Use cheesecloth or fiber to remove the fiber from the solution. Bell peppers are particularly high in Vitamin C but the green ones are supposed to have higher content than the red or orange ones. The Natural Hub has we page that lists the Vitamin C content of many fruits at: http://www.naturalhub.com/natural_food_guide_fruit_vitamin_c.htm
Materials
- Fruit juices and fruit drinks containing vitamin C (use 1.00 mL per experiment)
- Vitamin C Standard solution (1 mg/mL)(use 1.00 mL per experiment)
- Starch solution (sue 1.00 mL per experiment and control for 2.00 mL total)
- Iodine solution (we actually make I3-; need up to 1.00 mL per experiment, so need 2.00 L)
Procedure for fruit juice or drink
- Carefully squirt 1.0 mL of fruit juice or drink into a 10 mL graduate cylinder
- Carefully squirt 1.0 mL of starch solution in to the same 10 mL graduated cylinder
- Empty the contents of the cylinder into a small Erlenmeyer flask.
- Use a pipet bulb to add the iodine solution.
- Count the number of drops it takes to form a purple color.
Swirl the flask to make sure the solution stays purple. If it doesn’t, add one more drop.
- Report your number of drops to the assistant.
- Repeat the procedure with the vitamin C standard
Procedure for vitamin C standard
- Carefully squirt 1.0 mL of vitamin C standard into a 10 mL graduated cylinder
- Carefully squirt 1.0 mL of starch solution into the same 10 mL graduated cylinder
- Empty the contents of the cylinder into a small Erlenmeyer flask.
- Use a pipet bulb to add the iodine solution.
- Count the number of drops it takes to form a purple color.
Swirl the flask to make sure the solution stays purple. If it doesn’t, add one more drop.
- Report your number of drops to the assistant.
- You can calculate the mg vitamin C from the following equation:
- Amount of Vitamin C (mg)=(number of drops to fruit juice) / (number of drops to Vitamin C standard)
The equation above has been simplified from this equation Estimated Vitamin C content = (1 mL) x (1mg/mL) x (number of drops to fruit juice) / (number of drops to Vitamin C standard)