Hey, Do You C My Potatoes? Determining Vitamin C Amounts in Cooked Potatoes *
|Time Required||Short (2-5 days)|
|Material Availability||Titration equipment and supplies are needed. A kit is available from our partner Home Science Tools.|
|Cost||High ($100 - $150)|
|Safety||Adult supervision is required. Iodine solution is poisonous. Avoid skin and eye contact. Wear chemical safety goggles and rubber gloves when handling the concentrated solution. For more tips, consult the Science Buddies Chemistry Safety Guide.|
As you know, vegetables not only taste good, but they are good for you. Many vegetables are a great source of vitamin C. Vitamin C is a water-soluble antioxidant that plays an important role in protecting the body from infection and disease. Humans do not make vitamin C on their own, so we must get it from dietary sources. Potatoes, like the ones shown in Figure 1, below, are one good source of vitamin C. Does cooking them affect how much vitamin C they have? In other words, if you boil a potato, is some of the vitamin C lost to the water that the potato is boiled in? In this cooking and food science project, you can investigate this and determine whether boiling a potato for a longer amount of time makes it lose more vitamin C or not. To quantify the amount of vitamin C, you will need to do some titrating.
Figure 1. Potatoes, like these large Russet potatoes, naturally have vitamin C.
Titration is a chemistry technique used to determine the unknown concentration of a chemical in a solution. For information on how to titrate, consult the references in the Bibliography and the science fair project idea Which Orange Juice Has the Most Vitamin C?. You could use the titration kit from our partner Home Science Tools and follow the Procedure for that science project idea, but instead of using orange juice, use liquid that potatoes have been boiled in for different amounts of time. To get a good vitamin C yield, you will want to boil the potatoes in as little water as possible (by filling a pot with a layer of potatoes and just barely submerging them all in water). To take your vitamin C measurements, you could take water samples after the potatoes have boiled for 10 minutes, 30 minutes, and 60 minutes, or you could try different time points. Let the liquid cool to room temperature before titrating it. You may also want to further dilute the Lugol's iodine solution to have more accurate readings (since potatoes have less vitamin C than orange juice). For more information about doing a titration, visit the Science Buddies webpage Titration Tutorial: Tips & Tricks for Titrating.
So how do you think cooking potatoes will affect how much vitamin C is left in them? Try this science project and do some titrations to find out for yourself!
Cite This PageGeneral citation information is provided here. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed.
Last edit date: 2018-09-21
The following websites describe how to titrate vitamin C from vegetables.
- University of Canterbury. (n.d.). Determination of Vitamin C by Redox Titration with Iodine. Science Outreach. Retrieved October 7, 2008, from http://www.outreach.canterbury.ac.nz/chemistry/vitamin_C_iodine.shtml
- Helmenstine, A. (n.d.). Vitamin C Determination by Iodine Titration. Retrieved October 7, 2008, from http://chemistry.about.com/od/demonstrationsexperiments/ss/vitctitration.htm
- Wikipedia Contributors. (2008). Vitamin C. Wikipedia: The Free Encyclopedia. Retrieved October 7, 2008, from http://en.wikipedia.org/w/index.php?title=Vitamin_C&oldid=243741812
News Feed on This Topic
Recommended Project Supplies
Ask an ExpertThe Ask an Expert Forum is intended to be a place where students can go to find answers to science questions that they have been unable to find using other resources. If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.
Ask an Expert
Contact UsIf you have purchased a kit for this project from Science Buddies, we are pleased to answer your questions.
In your email, please follow these instructions:
- What is your Science Buddies kit order number?
- Please describe how you need help as thoroughly as possible:
Good Question I'm trying to do Experimental Procedure step #5, "Scrape the insulation from the wire. . ." How do I know when I've scraped enough?
Good Question I'm at Experimental Procedure step #7, "Move the magnet back and forth . . ." and the LED is not lighting up.
Bad Question I don't understand the instructions. Help!
Good Question I am purchasing my materials. Can I substitute a 1N34 diode for the 1N25 diode called for in the material list?
Bad Question Can I use a different part?
If you like this project, you might enjoy exploring these related careers:
Dietitian or NutritionistEver wondered who plans the school lunch, food for patients at a hospital, or the meals for athletes at the Olympics? The answer is dietitians and nutritionists! A dietitian or nutritionist's job is to supervise the planning and preparation of meals to ensure that people—like students, patients, and athletes—are getting the right foods to make them as healthy and as strong as possible. Some dietitians and nutritionists also work to educate people about good food choices so they can cook and eat their own healthy meals. Read more
Food Science TechnicianGood taste, texture, quality, and safety are all very important in the food industry. Food science technicians test and catalog the physical and chemical properties of food to help ensure these aspects. Read more
BiochemistGrowing, aging, digesting—all of these are examples of chemical processes performed by living organisms. Biochemists study how these types of chemical actions happen in cells and tissues, and monitor what effects new substances, like food additives and medicines, have on living organisms. Read more
News Feed on This Topic
Looking for more science fun?
Try one of our science activities for quick, anytime science explorations. The perfect thing to liven up a rainy day, school vacation, or moment of boredom.Find an Activity
Explore Our Science Videos
Colorful Melting Ice Ball Patterns - STEM Activity
Slippery Slopes - STEM activity
How to Make Elephant Toothpaste