Grade Level: 8th - 10th; Type: Health Science/ Food Science/Chemistry
We will find out whether 100-percent fruit juice has more Vitamin C than juice with artificial ingredients.
When one thinks of Vitamin C, pictures of oranges usually come to mind. That's because vitamin C is highly abundant in citrus fruits such as oranges, lemons, limes, and grapefruits. Does juice made from these fruits naturally have more Vitamin C than artificial fruit juices? In this experiment, we will be using three different kinds of orange juice: from concentrate, not from concentrate, and an orange-flavored drink with artificial sweeteners/flavors (Sunny D).
- Orange Juice
- From Concentrate (like Minute Maid brand) Not From Concentrate (like Tropicana or Florida's Natural brand)
- Orange-flavored Drink (like Sunny D)
- Beaker (if you are going to use a burner); Pot (if you are going to use a stove)
- Several test tubes w/ rack
- A white piece of paper
- Pen and paper for notes
Preparing the Iodine Indicator
- Mix cornstarch (one tbsp) and water together to make a paste.
- Add 250ml of water and boil for about five minutes.
- Using a dropper or a pipette, add 10 drops of the boiled solution to 75ml of water.
- Add iodine to the mixture until it turns a dark-purple color.
Comparing Vitamin C Levels
- With a dropper, add 5ml of the iodine indicator solution to a standard 15ml test tube. Using a clean dropper (to prevent contamination), add 10 drops of the orange juice from concentrate into the test tube.
- Clean the dropper and do the above for the “not-from-concentrate” juice sample as well as the orange-flavored drink.
- Compare which one turns a darker color. The darker color means there is less Vitamin C present in that particular sample.
Terms/Concepts: Vitamin C; Metabolic function; Heat; Cooking; Necessary functions of organisms