Vitamin+C+in+Citrus+Juices-Hinnah


 * ===Vitamin C in Citrus Juices===**




 * Abstract:**
 * **VITAMIN C CONTENT IN CITRUS JUICES**. **Hinnah**  . The purpose of this lab was to determine the amount of vitamin C in orange, lemon, and grapefruit juice and compare the amount to a standard derived from a vitamin C tablet. The method used for this experiment was titration which allows for concise data for the start and end of a reaction if executed correctly. The goal was then to calculate the amount of vitamin C in 25ml of juice and compare the amounts to true values. The hypothesis of the experiment was that orange juice would have the greatest amount of vitamin C per millimeter of juice. The data suggests that the order of decreasing vitamin C content is grapefruit, orange juice, and then lemon juice; therefore the data does not support the hypothesis. In 25ml of juice, orange juice has 12.1 mg vitamin C, lemon had 8.29ml, and grapefruit juice has 25.2 mg. The true values were: 12.4 mg for orange juice, 7.69 mg for lemon juice, and 9.39 mg for grapefruit juice. Consequently, the percent errors were 2.4% for orange, 7.80% for lemon, and 168.4% for grapefruit. The large error for grapefruit could be explained through student error and the fact that vitamin C is very unstable. In conclusion, with error the order of increasing vitamin C content is grapefruit juice, orange juice, and then lemon juice, but when considering the true values the order should be orange juice, grapefruit juice, and then lemon juice. Key words: Titration, citrus juices, buret, vitamin C (ascorbic acid), redox reaction, starch solution, iodine solution ||
 * Results/Data: **


 * Table 1: Mass of Substances in solutions**


 * Starch Solution || 1.36 grams cornstarch ||
 * Iodine Solution || 0.61 grams potassium iodide

0.61 grams iodine ||
 * Original Ascorbic Acid solution || 0.64 grams vitamin C tablet (500 mg) ||
 * Verified ascorbic acid solution || 0.13 grams vitamin C tablet (100 mg) ||


 * Table 2: Trial for finding the Vitamin C (standard)**

+ 13.40 ml + 5.70ml || stop at 50.0 ml stop at 50.0 ml stop at 8.10 ml || 83.90 ml ||
 * **Trail Number** || **Initial reading in ml** || **End reading in ml** || **ml iodine needed for color change** ||
 * **1** || 5.10 ml


 * Table 3: Orange Juice Trials**

+ 15.45 ml || Stop at 49.85 ml 45.20 ml || 25.20 ml ||
 * **Trial Number** || **Initial Reading in ml** || **End Reading in ml** || **Amount of iodine solution used in ml** ||
 * **1** || 14.70 ml || 47.50 ml || 27.80 ml ||
 * **2** || 37.90 ml
 * **3** || 7.56 ml || 32.70 ml || 25.14 ml ||
 * **Average:** || **X** || X || 26.05 ml ||


 * Table 4: Lemon Juice Trials**

+32.30 ml || Stop at 49.10 ml Stop at 40.90 ml || 17.60 ml ||
 * **Trial Number** || **Initial Reading in ml** || **End Reading in ml** || **Amount of iodine solution used in ml** ||
 * **1** || 40.10 ml
 * **2** || 11.12 ml || 27.75 ml || 16.63 ml ||
 * **3** || 9.15 ml || 28.42 ml || 19.27 ml ||
 * **Average:** || **X** || **X** || 17.83 ml ||

+ 27.10 ml || 48.10 ml 45.25 ml || 52.55 ml || +21.57 ml || 49.65 ml 36.30 ml || 55.83 ml || à not including trials 1 and 2 ||
 * Table 5: Grapefruit Juice Trials**
 * **Trial Number** || **Initial Reading in ml** || **End Reading in ml** || **Amount of iodine solution used in ml** ||
 * **1** || 17.20 ml || 48.60 ml || 31.40 ml ||
 * **2** || 27.75 ml || 48.45 ml || 22.70 ml ||
 * **3** || 13.70 ml
 * **4** || 8.50 ml
 * **Average:** || **X** || **X** || 54.19 ml

The above results indicate that out of orange, grapefruit, and lemon juice the order of amount of vitamin C in 25 ml of juice in decreasing amount is grapefruit, orange, and then lemon. The amount of iodine solution needed to change the color of the juice to a dark blue/black for grapefruit was 54.19 ml, for orange juice it took 26.05 ml, and for the lemon juice, 17.83 ml. We then averaged the amount of iodine solution needed to composite our data. The grapefruit average is composed of only trials 3 and 4 because the first two trials we not done accurately. The amount of iodine solution needed to change the color of the ascorbic solution (with .13 grams of vitamin C = 100 mg tablet) was 95.06 ml. With the above data we are able to calculate the amount of vitamin C in grams and in mg in each 25 ml of juice which then can be compared to the label on the juice bottles.


 * Table 6: True Values for Juices (from nutritiondata.com):**


 * Juice || Amount per of vitamin C (mg) in 250 ml ||
 * Orange || 124 ||
 * Grapefruit || 93.9 ||
 * Lemon || 76.9 ||


 * Paragraph explaining calculations (next page):**

Using the data from tables 1-5, we were able to calculate the amount of vitamin C in each of the juices. The standard vitamin C content was obtained from the 500mg vitamin C tablet which is 4.65 x 10^(-4) g vitamin C/1.00 ml of iodine solution. From this we were able to calculate that in 25.0 ml of orange juice there is 12.1 mg vitamin C, in lemon juice, 8.29 mg vitamin C, and in grapefruit there is 25.2 mg vitamin C. With the true values in table 6 we were able to calculate the percent error for each juice: orange 2.4% error, lemon 7.80% error, and grapefruit 168.4% error.


 * Summary of scientific journal:**

Vitamins E and C in the prevention of cardiovascular disease in men: the Physicals Health Study II randomized controlled trial

Research has been done to suggest that vitamins C and E may reduce the risk of cardiovascular disease in men, but few long term trials have been evaluated. The possible effects of vitamin C, vitamin E and other antioxidants are that they may reduce cardiovascular disease by trapping organic free radicals that prevent tissue damage. Some studies of vitamin C suggest that consuming over 700 mg/d is significantly associated with 25% reduction in coronary heart disease risk. The Department of Medicine at Brigham and Women’s Hospital in Boston conducted a long term vitamin C and E supplementation trial to evaluate whether it decreased the risk of cardiovascular diseases. The Physician’s Healthy Study enrolled 14,641 US male physicians between the years of 1997 and 2007. 754 of these men had prevalent cardiovascular diseases. All men enrolled were chosen at random regardless of their medical history. Each enrolled had to consume 400 IU of vitamin E every other day and 500 mg of vitamin C daily. The results were that there were 1245 cases of cardiovascular events including stroke, cardiovascular morality, and myocardial infarction. In conclusion, long-term supplements of vitamin C and E did not reduce the risk of major cardiovascular events. Sesso H, Buring J, Christen W, Kurth T, Belanger C, MacFadyen J, Bubes V, Manson J, Glynn R, Gaziano J. Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial. Division of Preventive Medicine. 300(18):2123-33.

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