Effect of Air on Vitamin C in Simply Orange Juice and Lemonade
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Abstract:
THE EFFECT OF AIR ON VITAMIN C CONTENT IN ORANGE JUICE AND LEMONADE. Kristina. The purpose of this lab was to determine if air had an effect on the content of Vitamin C in Simply Orange Juice and Lemonade. This was done through a set of titrations, using an iodine solution along with starch and HCL indicators, on juice samples left out for certain periods of time. The iodine solution was used to react with each juice in the form of an oxidation-reduction reaction, while the starch was used to make the iodine appear blue and indicate the reaction. The results of the titrations showed that Vitamin C decreased in the orange juice but not in the lemonade. The Vitamin C in 20 mL of orange juice decreased from .0060 g, having little exposure to air and just out the fridge, to .0051 g, having 24 hours of exposure. This was a decrease of .0009 g of Vitamin C. As for the lemonade, the results of the experiment were very small and showed that the Vitamin C in 50 mL of lemonade had decreased from .00020 g to .00017 g (after 3 hours of exposure), but then returned to the amount of .00020 g after 24 hours of exposure. A reason the lemonade did not bring great results may be because there was very little Vitamin C in the lemonade to begin with. An error that affected both juices in this experiment was that the amounts of iodine solution used were not recorded to the correct decimal place, meaning our averages were not precise.
Key Words: Vitamin C, Oxidation-Reduction Reaction, Titration, Iodine Solution, Orange Juice, Lemonade, Air Exposure.


Data Tables and Calculations:

Table 1: Titration of 30 mL Vitamin C Solution
Amount of Vitamin C in tablet (according to label)
Mass of Vitamin C tablet before crushing
Mass of Vitamin C tablet used
Amount of Vitamin C in the tablet
Starting level of iodine solution in burette
End level of iodine solution in burette
Amount of iodine solution used
.50 g
.63 g
.09 g
.63g=.09g
.50 g x
.63x=.045

x= .07 g
5.5 mL
1.2 mL
50.2 mL
19.1 mL
44.7 + 17.9=62.6 mL

Table 2: Titration of 50 mL Simply Lemonade Straight out the Fridge (No Oxygen)
Trials
Temperature (Degrees Celsius)
Beginning level of Iodine Solution used (mL )
End level of Iodine Solution used (mL )
Amount used of Iodine Solution (End-Beginning)
#1
3
6.7
7.2
.5
#2
3
7.2
7.5
.3
#3
3
7.5
8.0
.5
#4
5
1.3
2.0
.7
#5
5
2.0
2.7
.7
#6
5
2.7
3.5
.8
Average: 0.6 mL = .00020 g Vitamin C

Table 3: Titration of 20 mL Simply Orange Juice Straight out the Fridge (No Oxygen)
Trials
Temperature (Degrees Celsius)
Beginning level of Iodine Solution used (mL )
End level of Iodine Solution used (mL )
Amount used of Iodine Solution (End-Beginning)
#1
4
5.0
23.3
18.3
#2
4
6.2
23.4
17.2
#3
4
23.4
41.9
18.5
#4
4
3.5
20.0
16.5
#5
4
20.0
38.8
18.8
#6
4
2.5
12.3

11.9
23.3

9.4 +11.0= 20.4
Average: 18.0 mL = .0060 g Vitamin C

Table 4: Titration of 50 mL Simply Lemonade sitting out for 3 hours
Trials
Temperature (Degrees Celsius)
Beginning level of Iodine Solution used (mL )
End level of Iodine Solution used (mL )
Amount used of Iodine Solution (End-Beginning)
#1
16
3.4
4.0
.6
#2
16
4.0
4.2
.2
#3
16
4.2
4.5
.3
#4
20
8.0
8.9
.9
#5
20
8.9
9.1
.2
#6
20
2.7
3.5
.8
Average: 0.5 mL = .00017 g Vitamin C

Table 5: Titration of 20 mL Simply Orange Juice sitting out for 3 hours
Trials
Temperature (Degrees Celsius)
Beginning level of Iodine Solution used (mL )
End level of Iodine Solution used (mL )
Amount used of Iodine Solution (End-Beginning)
#1
19
4.7
17.7
13.0
#2
19
17.7
30.8
13.1
#3
19
30.8
48.0
17.2
#4
20
10.4
28.8
18.4
#5
20
28.8
49.8
21.0
#6
20
19.7
40.1
20.4
Average: 17.2 mL = .0058 g Vitamin C

Table 6: Titration of 50 mL Simply Lemonade sitting out for a 24 hour period
Trials
Temperature (Degrees Celsius)
Beginning level of Iodine Solution used (mL )
End level of Iodine Solution used (mL )
Amount used of Iodine Solution (End-Beginning)
#1
20
.1
.8
.7
#2
20
.8
1.3
.5
#3
20
1.3
1.8
.5
Average: 0.6 mL = .00020 g Vitamin C

Table 7: Titration of 20 mL Simply Orange Juice sitting out for a 24 hour period
Trials
Temperature (Degrees Celsius)
Beginning level of Iodine Solution used (mL )
End level of Iodine Solution used (mL )
Amount used of Iodine Solution (End-Beginning)
#1
20
1.8
16.6
14.8
#2
20
16.6
32.7
16.1
#3
20
32.7
47.5
14.8
Average: 15.2 mL = .0051 g Vitamin C



Vitamin C and the Common Cold
Many people have begun to believe that Vitamin C can cure and prevent the common cold. Robert M. Douglas and Harri Hemila of the Department of Public Health challenged this idea by conducting placebo-controlled trials that focused on communities that took 200 mg oral doses of Vitamin C. They tested the duration of respiratory episodes of people with the cold and without. Their results concluded that 23 community studies showed there was no alteration of the cold, but for those who are marathon runners, skiers, and soldiers exposed to cold had an average of 50% reduction in having the cold, if Vitamin C is taken prior to exercising. They learned that with children there was a greater reduction of the cold at 14% then adults which had a reduction of about 8%, but still there was barely any effect of Vitamin C on the cold symptoms. Vitamin C did not cure the common cold greatly in normal populations, so Douglas and Hemila believe that the idea of Vitamin C being able to cure the cold should not be taken too seriously since there were not large affects.



Bibliography
Douglas M, Robert, Hemila, Harri. 2007. Vitamin C for Preventing and Treating the
Common Cold. 2(6):168.