Does fresh squeezed orange juice have more Vitamin C than store bought Vitamin C sources?
I think that fresh squeezed orange juice will change the indicator color faster than store bought Vitamin C sources. I think this
because I have found, through research, that fresh oranges contain 130% of our daily recommended allowance compared to most
Vitamin C sources which only contain 100%, and that Vitamin C can be destroyed through processing.
Moms are always worried about their family getting enough vitamins and minerals in their diets. While shopping one day I bought
oranges and wondered which source of Vitamin C would be best for my family.
While thinking about this problem I came up with my hypothesis: I think that fresh squeezed orange juice will change the indicator
color faster than store bought Vitamin C sources. I think this because I have found, through research, that fresh oranges contain 130%
of our daily recommended allowance compared to most Vitamin C sources which only contain 100%, and that Vitamin C can be
destroyed through processing.
I wanted to see if there was any Vitamin C differences between fresh, frozen, refrigerated, and non refrigerated orange juice. I also
wanted to know how a Vitamin C supplement or drop would compare to orange juice as a Vitamin C source. When I devised my
plan, I tried to make sure all my variables were controlled. I used all the bottled juices as prepared. The frozen juice was made
according to package directions. To prepare the fresh orange I took two slices of the fresh orange and squeezed them into a cup.
Each of the supplements were dissolved in 60 ml of water and then used as a source. The other important controlled variable was the
indicator. I needed to make sure I had an accurate indicator to use for all the source trials. My final results showed that the Vitamin C
pill changed the color of the indicator the fastest with 2 drops of the Vitamin C source. The fresh orange came in second with 5 drops
of fresh orange juice needed to change the indicator. This was followed by the frozen orange juice and the Vitamin C drop. Both of
the bottled orange juices took the longest to change the color of the indicator.
In conclusion I have proven that my hypothesis was wrong, and that the Vitamin C pill had a faster affect on the indicator. This
means that the Vitamin C pill had a stronger presence of Vitamin C than the other sources.
Starch-Iodine - Vitamin C Indicator
Tincture of Iodine
2 Graduated Cylinder (25 ml)
Glass Container for storage
Small Sauce Pan
Sources of Vitamin C
Freshly Squeezed Orange Juice
Minute Maid Bottled Orange Juice from Refrigerator
Minute Maid Frozen Orange Juice
Minute Maid Bottled Orange Juice Off the Shelf
Vitamin C Pill - 1000 mg
Halls Defense Vitamin C Supplement Drop
60 ml Syringe
24 3 oz Plastic Cups
2 Small Bowls
White Paper Squares
1. Make Vitamin C indicator
• Add 2 g of corn starch in 200 ml of cold, distilled water and stir with spoon. Bring the mixture to a full boil in pan. Let cool
• To 1 liter of water, add 8 ml of the starch solution and 1 ml of tincture of iodine.
• Note: The color of the starch indicator should be a royal blue. Just before doing the lab, check the indicator and dilute the
concentration so that a workable number of drops of fresh orange juice (5-25) turn the indicator colorless.
2. Make vitamin solution for the vitamin pill and drop
• Dissolve each source into 60 ml of distilled water
3. Make fresh orange juice from orange
• Squeeze 2 orange slices with clean hands into cup or bowl
4. Use syringe to measure out 16 ml of the Vitamin C indicator. Place into 3 oz cups for each Vitamin C source being tested. Note:
Be sure to label cups with marker.
5. Using a clean medicine dropper, add a drop of one of the orange juice samples to the indicator in the cup. Gently swirl the liquids
6. Continue to add orange juice, drop by drop, until the indicator changes from blue to colorless. Note: Be sure to swirl after each
drop is added.
7. Observe and count the number of drops of orange juice you needed to add to the indicator to cause it to lose all of its color. Juices
low in Vitamin C will begin to dilute the indicator. The indicator will start to take on the color of the juice. If this occurs, indicate
that no satisfactory end point was reached. Record the number of drops added in the chart on your data sheet.
8. Place cup over white paper square to make sure you have a colorless solution.
9. Repeat the above steps for each orange juice sample being tested. Note: Be sure to use a different medicine droppers for each
source tested and to use clean cups for each trial.
10. Test each juice three times and calculate the average number of drops required to change the indicator.
Number of Drops Needed to Change the Indicator
Different types of orange juices Responding Variable
Vitamin C Indicator
Same brand of orange juice
Same amount of indicator tested for each trial
Used a different dropper for each Vitamin C source
Same amount of water to dissolve Vitamin C drop and pill
Swirled cup the same each time
The original purpose of this experiment was to see if fresh squeezed orange juice has more Vitamin C than store bought Vitamin C
The results of the experiment showed that the indicator gave evidence that there was Vitamin C present in each source. The table
below shows how many drops of the indicator were needed to change the indicator to a colorless solution.
Number of Drops Needed to Change the Indicator
Vitamin C Trial 1 Trial 2 Trial 3 Average
Frozen 7 6 7 7
Refrigerated 9 9 10 9
Fresh 4 5 5 5
Not Refrigerated 8 9 8 8
Vitamin C Drop 7 8 7 7
Vitamin C Pill 2 2 2 2
My hypothesis was that fresh squeezed orange juice would have more Vitamin C than store bought Vitamin C sources. The results
indicate that this hypothesis should be rejected. The Vitamin C source that changed the indicator with the least amount of drops was
the Vitamin C pill.
This experiment did prove that the easiest way to get your percent of daily value is to take a Vitamin C pill. It only needed 2 drops of
the indicator to show a color change, which give evidence to Vitamin C. According the package label, it is also the only way to get
Vitamin C. The second best way to obtain Vitamin C is by eating a fresh orange. This was proved by only adding 5 drops of the
indicator to make a color change. The nutrition facts from, www.fruitsandveggiesmorematters.org, states that one fresh orange has
130% of daily requirements of Vitamin C per serving. The third most efficient way to get your daily recommended daily allowance of
Vitamin C is to drink frozen orange juice or suck on a Vitamin C drop. Both of these sources needed 7 drops of the indicator to change
the color from blue to clear. Both bottles of orange juice, refrigerated and not refrigerated, came in last with needing 8 and 9 drops of
the indicator to change the color. They have the same amount of daily recommended Vitamin C, at 100%. I did think the refrigerated
bottle would have tested better, because the label stated that it was pure squeezed orange juice. Vitamin C is very important to have in
your diet. Children from ages 1-10 should get 40-45 mg of Vitamin C daily, and adults and adolescents should get 50-60 mg a day.
One important function of Vitamin C is collagen, a protein necessary for the formation of connective tissue in the skin, ligaments and
bones. Vitamin C also helps connective tissue from during the healing of wounds and in the growth and repair to tissues. Other
functions of Vitamin C include aiding in red blood cell formation, preventing hemorrhaging, and fighting bacterial infections. The
human body cannot make and has a limited ability to store this chemical and it is therefore essential that is be ingested frequently.
Because of the results of this experiment, I wonder if changing the Vitamin C pill from 1000 mg to 65 mg, like the drop, would have
made a difference in the results. This is one variable that I did not think of when conducting my experiment. I would be more
conscious of this problem the next time I ran the experiment.