by: siobhan dougherty. p roblem which kind of orange juice, frozen, bottled, or freshly squeezed,...
TRANSCRIPT
PROBLEM
Which kind of orange juice,
frozen, bottled, or freshly
squeezed, contains the most
amount of vitamin C?
BACKGROUND INFORMATION
Orange juice is a good source of vitamin C and potassium
Vitamin C is necessary for normal growth and development
The process of concentrating OJ results in a slight loss of vitamin C
Frozen orange juice is about 3x more concentrated than regular
orange juice
The original amount of oxygen and carbon dioxide in a can of
orange juice changes over time.
Some bottled juice may be fresher than others, and therefore may
contain different amounts of vitamin C.
Redox titration is a common method of determining the amount of
vitamin C in a substance, represented by the formula: I2 + starch
(C6H10O5) = starch-iodine complex.
HYPOTHESIS
If the amount of vitamin C in
different samples of orange juice
(bottled, frozen, and freshly
squeezed) was measured by using
a starch-iodine indicator, then the
frozen orange juice would contain
the most amount of vitamin C.
MATERIALS freshly squeezed orange juice bottled orange juice frozen orange juice three 50.0 mL beakers one 300. mL beaker one 1.00 L beaker medicine dropper stirring rod one 500. mg vitamin C tablet mortar and pestle goggles
apron gloves 2.00 grams of corn starch distilled water bunsen burner wired gauze tripod 1.00 mL of tincture of
iodine lighter paper pencil
PROCEDURE Make the starch-iodine solution by filling a 300. mL beaker with 200.
mL of cold distilled water Add 2.00 grams of corn starch to the 200. mL of distilled water Bring mixture to a full boil using a bunsen burner (making the starch
solution) Fill a liter beaker with water Add 8.00 mL of the starch solution and 1 mL of tincture of iodine to
the 1 liter beaker of water, which completes the making of the vitamin C indicator (will become a dark blue color)
Stir gently Pour 15.0 mL of this indicator into a 50.0 mL beaker Use a medicine dropper to obtain a sample of the freshly squeezed
orange juice Add this sample drop by drop to the beaker of the vitamin C indicator Gently swirl Continue to add the freshly squeezed orange juice, drop by drop, to
the vitamin C indicator until the indicator turns from blue to colorless *make sure to swirl gently after each drop*
CONTINUED… Record the amount of drops it took to for the freshly squeezed
orange juice to turn the vitamin C indicator colorless Repeat steps 6-12 for four more trials with the freshly
squeezed orange juice Repeat steps 6-13 with the frozen orange juice and then the
bottled orange juice Record Results (number of drops) Repeat steps 6-12 for the distilled water (note: only one trial is
done with this control) Obtain a mortar and pestle Completely crush a 500. mg vitamin C tablet using the mortar
and pestle Mix this crushed tablet with 100. mL of distilled water Fill a 50.0 mL beaker with 15.0 mL of the vitamin C indicator Add the tablet and water mixture to the indicator drop by drop
until the indicator turns from blue to colorless Record Results (number of drops)
VARIABLES independent variable: type of orange juice (freshly
squeezed, frozen, and bottled)
dependent variable: amount of vitamin C in each sample
of orange juice, expressed by the amount of drops it takes
to titrate the vitamin C indicator (shown by a color change)
controls
positive: vitamin C tablet
negative: distilled water
constants: procedural technique, amount of orange juice
tested for each trial, same vitamin C indicator, place where
the project was conducted
DATA/RESULTS(IN NUMBER OF DROPS)
Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 AVG Stddev CI
bottled orange juice 50.0 48.0 54.0 55.0 53.0 52.0 2.92 2.56
frozen orange juice 12.0 10.0 12.0 11.0 12.0 11.4 0.894 0.784
freshly squeezed orange juice 14.0 15.0 13.0 15.0 13.0 14.0 1.00 0.877
Trial 1 Trial 2 Trial 3 Trial 4 Trial 5
500mg tablet with 100ml water 4 4 4 0 0
distilled water 100 drops and nothing happened
Controls
TTEST RESULTS
fresh sq bottled14 5015 4813 5415 5513 533.2E-09
bottled frozen50 1248 1054 1255 1153 121.8E-09
frozen fresh sq12 1410 1512 1311 1512 13
0.0025
All results are under .05, meaning there is a significant difference between all three
of the samples of orange juice
CONCLUSION
The purpose of this experiment was to test whether there were
varying amounts of vitamin C in different kinds of orange juice.
The experiment concluded that frozen orange juice contained
the most vitamin C (1.67 mg/mL), with freshly squeezed
orange juice close behind, but with bottled orange juice
trailing by a significant amount. These results supported the
hypothesis of the experiment.
Frozen and freshly squeezed orange juices are more beneficial
to humans than bottled orange juice is because those juices
actually satisfy the daily requirement of vitamin C per day,
which is 60 mg.
IF THIS EXPERIMENT WAS TO BE DONE AGAIN…
Changes to be Made
Using more kinds of orange juice other than just frozen,
bottled, and freshly squeezed and more brands of each.
Conducting more trials to ensure accuracy and having all
testing done on the same day in the same environment.
Use a more accurate method, other than a dropper, to
obtain the correct amount of orange juice for each trial.
Sources of Error
The different orange juice samples were stored and
handled before being used for this experiment and the
age and conditions of the products before coming into
possession for the experiment are not known.
WORKS CITED Boyd, J., & Peterson, G. (2010). Quality of Canned Orange Juice. Industrial and Engineering Chemistry,
37(4), 370-373.
Dolson, L. (2010). What You Need to Know about Complex Carbohydrates. Retrieved October 6, 2010, from About.com website: http://lowcarbdiets.about.com/ od/ nutrition/ a/ starch.htm
Helmenstine, A. M. (2010). Vitamin C Determination by Iodine Titration. Retrieved October 7, 2010, from About.com website: http://chemistry.about.com/ od/ demonstrationsexperiments/ ss/ vitctitration.htm
Medline Plus. (2009). Vitamin C. Retrieved October 6, 2010, from U.S. Department of Health and Human Services website: http://www.nlm.nih.gov/ medlineplus/ ency/ article/ 002404.htm
Obikoya, D. G. (2010). Iodine Information. Retrieved October 21, 2010, from Seacra Enterprises, Inc website: http://www.vitamins-nutrition.org/ vitamins/ iodine.html
Practically Edible. (2010). Frozen Orange Juice Concentrate. Retrieved October 21, 2010, from http://www.practicallyedible.com/ edible.nsf/ pages/ frozenorangejuiceconcentrate
Rushin, W. (2008). Chemical Analysis by Redox Titration. Retrieved October 19, 2010, from Cary Academy website: http://chem.lapeer.org/ Chem2Docs/ RedoxTitration.html
Shilton, N., & Nally, P. (2001, October 6). The Last Word. New Scientist, (2311). Retrieved from http://www.newscientist.com/ article/ mg17223116.600-the-last-word.html
University of Canterbury. (2007). Determination of Vitamin C by Redox Titration with Iodine. Retrieved October 20, 2010, from http://www.outreach.canterbury.ac.nz/ chemistry/ vitamin_C_iodine.shtml
Clark, N. (1999, June 26). Vitamin C, Supplements and Simple Foods. Rowing News, 6(10), 6. Retrieved from http://books.google.com/ books?id=SU0EAAAAMBAJ&pg=PT5&dq=vitamin+c+in+orange+juice&hl=en&ei=-WeuTMGlPML98Aa4s6zTBA&sa=X&oi=book_result&ct=result&resnum=3&ved=0CEEQ6AEwAg#v=onepage&q=vitamin%20c%20in%20orange%20juice&f=false
Ronzio, R. A. (2003). Orange Juice. In Nutrition and Good Health (2nd ed., p. 478). Retrieved from http://books.google.com/ books?id=1bzCYeHoJ8sC&pg=PA478&dq=orange+juice+vitamin+c&hl=en&ei=UlSuTJhAoL78Aa2mMmaCw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CEUQ6AEwAg#v=onepage&q=orange%20juice%20vitamin%20c&f=false