Jump to main content

Investigate the Vitamin C Level in Bell Peppers During Various Stages of Ripeness

236 reviews


Areas of Science
Time Required
Short (2-5 days)
Material Availability
Titration equipment and supplies are needed. A kit is available from our partner Home Science Tools.
High ($100 - $150)
Adult supervision 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 Chemistry Safety Guide

Recommended Project Supplies

Get the right supplies — selected and tested to work with this project.

View Kit

*Note: For this science project you will need to develop your own experimental procedure. Use the information in the summary tab as a starting place. If you would like to discuss your ideas or need help troubleshooting, use the Ask An Expert forum. Our Experts won't do the work for you, but they will make suggestions and offer guidance if you come to them with specific questions.

If you want a Project Idea with full instructions, please pick one without an asterisk (*) at the end of the title.


Vitamin C is a water-soluble vitamin that has many functions in the body. Vitamin C is needed to bolster the immune system. It is an antioxidant that protects LDL cholesterol from oxidative damage, and it is needed to make collagen, a substance that strengthens many parts of the body, such as muscles and blood vessels. Our bodies do not make vitamin C, so we must get it from dietary sources. Citrus fruits, carrots, avocados, and spinach all have vitamin C. Bell peppers, like the ones shown in Figure 1, below, also contain vitamin C. Red, yellow, and orange bell peppers are all ripe versions of the green bell pepper. But how do the vitamin C levels vary among the different colors or ripeness of bell peppers? Does ripeness matter? To quantify the amount of vitamin C, you will need to do some titrating.
A green, yellow and red bell pepper

Figure 1. Colorful bell peppers. (Luc Viatour, 2008.)

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 a de-seeded and de-stemmed bell pepper that has been blended with water (and then filtered using cheesecloth). You may want to weigh the bell pepper before blending it and adjust your samples so that you use the same amount of each type of bell pepper. This will make it easier to compare your results. For more information about doing a titration, visit the Science Buddies webpage Titration Tutorial: Tips & Tricks for Titrating.

So which color bell pepper do you think will have the most vitamin C, or do you think they will all have similar amounts? Try this science project and do some titrations to find out for yourself!


This next entry is an article that discusses the level of vitamin C as a function of ripeness in a variety of bell peppers.

  • Antoniali, S. et al. (2007). Physico-Chemical Characterization of 'Zarco-HS' Yellow Bell Pepper for Different Ripeness Stages. Scientia Agricola, Vol. 64, No. 1. Retrieved October 8, 2008.
icon scientific method

Ask an Expert

Do you have specific questions about your science project? 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.


If you like this project, you might enjoy exploring these related careers:

Career Profile
Ever 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… Read more
Career Profile
Good 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
Career Profile
As the world's population grows larger, it is important to improve the quality and yield of food crops and animal food sources. Agricultural technicians work in the forefront of this very important research area by helping scientists conduct novel experiments. If you would like to combine technology with the desire to see things grow, then read further to learn more about this exciting career. Read more
Career Profile
There is a fraction of the world's population that doesn't have enough to eat or doesn't have access to food that is nutritionally rich. Food scientists or technologists work to find new sources of food that have the right nutrition levels and that are safe for human consumption. In fact, our nation's food supply depends on food scientists and technologists that test and develop foods that meet and exceed government food safety standards. If you are interested in combining biology, chemistry,… Read more

Contact Us

If 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:
  1. What is your Science Buddies kit order number?
  2. 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?

Contact Us

News Feed on This Topic

, ,

Cite This Page

General 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.

MLA Style

Science Buddies Staff. "Investigate the Vitamin C Level in Bell Peppers During Various Stages of Ripeness." Science Buddies, 23 June 2020, https://www.sciencebuddies.org/science-fair-projects/project-ideas/FoodSci_p039/cooking-food-science/vitamin-c-level-in-bell-peppers-during-various-stages-of-ripeness. Accessed 6 Dec. 2023.

APA Style

Science Buddies Staff. (2020, June 23). Investigate the Vitamin C Level in Bell Peppers During Various Stages of Ripeness. Retrieved from https://www.sciencebuddies.org/science-fair-projects/project-ideas/FoodSci_p039/cooking-food-science/vitamin-c-level-in-bell-peppers-during-various-stages-of-ripeness

Last edit date: 2020-06-23
Free science fair projects.