COMPARING THE CALCIUM
CONTENT OF VARIOUS TYPES
OF MILK
By: Rebecca Allen
PROBLEM
Purpose: To determine how raw goat’s milk,
pasteurized goat’s milk, raw cow’s milk, UHT 2%
cow’s milk, 2% organic cow’s milk, 2% cow’s milk,
whole cow’s milk, and skim cow’s milk compare
in terms of calcium content by means of an EDTA
titration.
 Importance: Calcium is an essential mineral for a
healthy body, and it is important for consumers
to know which of the wide variety of types of milk
on the market provides the greatest calcium
content.

BACKGROUND INFORMATION
Multiple studies have shown a greater content of
calcium in raw milks as compared to pasteurized
milk varieties. Also, studies have shown a
greater content of calcium in goat milk varieties
as compared to cow’s milk varieties.
 Important Vocabulary:
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Pasteurization
UHT
EDTA Titration
Organic Milk
Raw Milk
BACKGROUND INFORMATION
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Calcium is an essential mineral for…
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Healthy bones and teeth
Regulation of metabolic processes
Lowering risk of colon cancer, heart disease,
osteoporosis, and obesity
Prevention of preeclampsia, rickets, and strokes
Regulation of blood pressure
Improved premenstrual moods
Proper blood clotting
HYPOTHESIS

If raw goat’s milk, pasteurized goat’s milk, raw
cow’s milk, UHT 2% cow’s milk, 2% organic cow’s
milk, 2% cow’s milk, whole cow’s milk, and skim
cow’s milk are tested for calcium content, then
raw goat’s milk will contain the highest quantity
of calcium.
CONTROLS AND EXPERIMENTAL VARIABLES
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Independent Variable: Type of Milk
Dependent Variable: Calcium Content
Controls:
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EDTA titration process used for all milk samples.
Milk products were tested within the expiration date.
Milk products were of the same brand when possible.
Each milk variety had its own set of labeled beakers and
pipettes to eliminate contamination.
Each trial was compared to the color of the control sample
respectively.
Extraneous Variables:
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Different brands of milk
Different shelf life lengths
Added vitamins (can alter % digestion of calcium)
Retrieved from sources at different times
Different dairy farm locations and animal diets
MATERIALS
800 mL NH₃ + NH₄Cl Buffer
 1600 mL H₂O
 Eriochrome Black T Solution
 15 mL of each milk variety
 EDTA Solution
 48 Labeled Beakers
 8 Pipettes and rubber bulb
 2 Burettes and 2 Burette Clamps
 Magnetic Stirring Objects

PROCEDURE
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Label each of the 48 beakers with its appropriate title.
Prepare necessary solutions (Eriochrome Black T, EDTA,
and Buffer to maintain pH > 7.0).
Rinse burettes with EDTA solution to remove prior residue.
Assemble burettes and magnetic stirrers.
Pipette 3 mL of milk into the corresponding labeled beaker
(X Milk – Trial 1).
Add 40 mL of H₂O.
Add 20 mL of Buffer.
Add 10 drops Eriochrome Black T solution.
Magnetically stir.
Test pH – Color change only occurs at pH > 7.0
Titrate the mixture with the EDTA solution in the burette
until a distinct color change from purple/magenta to blue.
Repeat this process for 5 trials of each of the 8 varieties of
milk.
CALCULATIONS
 EDTA⁻⁴
+ Ca2+  CaEDTA⁻2
 1:1 mole ratio of EDTA : Ca
 Molarity of EDTA = 0.01 mol/L
 Atomic Weight of Ca = 40.08 g
 Sample Calculation:
Average Amount of Calcium (mg)
9
8
7
Mg of Calcium
6
5
Average Amount of Calcium (mg)
4
3
2
1
0
Raw Goat’s Pasteurized Raw Cow’s UHT Cow’s 2% Fat
Whole Skim Cow’s Organic
Milk
Goat’s Milk
Milk
Milk
Cow’s Milk Cow’s Milk
Milk
Cow’s Milk
Type of Milk
Type of Milk
Trial Number
Initial EDTA Burette Reading
(mL)
Final EDTA Burette Reading
(mL)
Volume EDTA (mL)
Raw Goat
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
0.45
13.81
31.70
16.51
28.23
8.16
19.98
1.30
14.70
27.79
17.60
18.40
27.79
39.51
31.52
12.61
0.92
23.60
13.40
26.91
3.52
0.83
18.01
30.35
17.00
1.00
18.35
16.05
33.90
28.94
2.99
2.75
15.00
14.45
25.65
25.50
36.11
5.97
5.48
7.18
12.55
28.20
41.47
28.23
40.13
16.35
37.74
14.70
27.79
40.64
27.97
31.52
39.51
50.00
40.90
23.60
13.40
38.79
26.91
40.94
18.01
16.40
32.10
44.40
31.69
16.05
33.90
28.94
46.27
42.60
15.00
14.50
25.70
25.65
36.11
40.38
49.89
19.78
20.70
20.30
12.10
14.39
9.77
11.72
11.90
8.19
17.76
13.40
13.09
12.85
10.37
13.12
11.54
10.49
9.39
10.99
12.48
15.14
13.51
14.03
14.49
15.57
14.09
14.05
14.69
15.05
15.55
12.89
12.37
13.66
12.01
11.75
10.70
11.15
10.46
14.88
13.78
13.81
15.22
13.12
Pasteurized Goat
Raw Cow
UHT 2% Cow
2% Cow
Whole Cow
Skim Cow
Organic Cow
Type of Milk
Average Amount of
Calcium (mg)
Standard Deviation
Raw Goat’s Milk
8.385
1.64169
Pasteurized Goat’s
Milk
7.455
3.38997
Raw Cow’s Milk
4.401
1.41717
UHT 2% Cow’s Milk
5.303
1.57691
2% Cow’s Milk
5.844
0.6167
Whole Cow’s Milk
5.571
1.36597
Skim Cow’s Milk
4.493
0.6629
Organic Cow’s Milk
5.675
0.86465
STATISTICAL ANALYSIS
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One Way Analysis of Variance (ANOVA) –
Compares the means of each group
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Fisher F-Value was calculated for the data: 21.453
Fisher F-Value corresponds to P-Value of
significance.
P < 0.0000001 = Less than a million to one chance
that results were not significant.
In summation, each of the 8 groups were
significantly different from each other, in terms of
calcium content.
ANALYSIS
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Possible explanations for the results:
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Pasteurization process and UHT processing.
Partial removal / full removal of fat content in 2%
cow’s milk and skim cow’s milk
Calcium content diminishes with freshness
Feed quality/characteristics
Lactation cycle stage
Seasonal changes in calcium content
Daily fluctuation
ANALYSIS
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Possible errors:
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Milk products were not purchased directly from the
manufacturer in some cases, so superior freshness
could not be insured.
Milk products were purchased from different sources.
One cannot be sure of the amount of variability
allowed on either side of the “best by” date, despite
all milk products being well within this estimate.
One cannot be sure of the lactation cycle stage of the
goats from which the goat milk products were
produced.
One cannot be sure of the specific weather conditions
of each farm from which milk products were produced
at the time of milking.
CONCLUSION
The milk variety shown to have the highest
calcium content: raw goat’s milk (8.385 mg Ca)
 The milk variety shown to have the lowest
calcium content: raw cow’s milk (4.401 mg Ca)
 The hypothesis is accepted because the data
showed raw goat’s milk to have the highest
calcium content of all varieties of milk tested.
 In conclusion, the consumer may be better off
purchasing raw goat’s milk as compared to other
varieties of milk from a nutritional standpoint.

RECOMMENDATIONS
Purchase milk varieties from the same
manufacturer to rule out variables dealing with
weather conditions and location.
 Purchase directly from the manufacturer to
insure superior freshness.
 Test milk varieties for calcium content
immediately after production and processing to
insure superior freshness.
 Determine lactation cycle stage of goats used for
milk production prior to milking.

EXTENSIONS
Comparing calcium content of alternative milks,
such as soy, almond, and rice milk.
 Exploring the effects of farm location and climate
on calcium content of milk.
 Exploring the effects of diet on cow and goat milk
varieties.
 Comparing the calcium content of various type of
cheeses, yogurts, or other dairy products.
 Investigating the impact of age and lactation
cycle stage of animals on calcium content of milk.
 Determining which variety milk has the most
humanly digestible calcium content.

RESOURCES
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Processed Skim Milk, Whole Milk, and Spinach.” Journal of Food Science 56.3
(2006) : 864-866. Web. 29 Oct. 2009.
Pettifor, John M. “Nutritional Rickets: Deficiency of Vitamin D, Calcium, or
Both?” The American Journal of Clinical Nutrition 80.6 (2004) : n.p. Web. 29
Oct. 2009.
Ott, Christopher. “The Surprising Benefits of Calcium.” Natural Health Jan.- Feb.
(2002) : 55. Web. 28 Oct. 2009.
Krebs, Nancy F. “Optimizing Bone Health and Calcium Intakes of Infants,
Children, and Adolescents.” Pediatrics (2006) : n.p. Web. 29 Oct. 2009.
“Building Strong Bones: Calcium Information for Health Care Providers.” U.S.
Department Of Health and Human Services – National Institute of Child
Health and Human Development (2006) : 1-4. Web. 28 Oct. 2009.
Baron, JA, M. Beach, J.S. Mandel, et al. “Calcium Supplements for the Prevention
of Colorectal Adenomas.” New England Journal of Medicine 340.2 (1999) : 101107. Web. 27 Oct. 2009.
RESOURCES
Bucher, HC, G.H. Guyatt, R.J. Cook, et al. “Effect of Calcium Supplementation on
Pre-Induced Hypertension and Preeclampsia.” Journal of the American Medical
Association 275 (1996) : 1113-1117. Web. 29 Oct. 2009
“Calcium 101: How It Does a Body Good.” The Cleveland Clinic Foundation. 2008.
Web. 28 Oct. 2009.
University of Granada. "Goats' Milk Is More Beneficial To Health Than Cows'
Milk, Study Suggests." Science Daily 31 July 2007. 31 January 2010
<http://www.sciencedaily.com /releases/2007/07/070730100229.htm>.
"Standard Deviation Calculator." Easy Calculation.com. HIOX India, n.d. Web. 21
Feb. 2010. <http//:easycalculation.com/statistics/standard-deviation.php>.
Tóth, Á., M. Borbély, and Z. Gyori. "Examination of protein and calcium content of
consumer milks and breakfast drinks." CABI Abstract Database. Tejgazdaság,
n.d. Web. 21 Feb. 2010.
<http://www.cababstractsplus.org/abstracts/Abstract.aspx?AcNo=2005301745>.
"Raw Milk Vs. Pasteurized Milk." A Campaign for Real (Raw) Milk. Farm-toConsumer Legal Defense Fund, n.d. Web. 21 Feb. 2010.
<http://www.realmilk.com/rawvpasteur.html>.
RESOURCES
Gillis, Erin . "The Effect of Heat Treatment on the Nutritional Value of Milk." Faculty Articles.
California State University - Los Angeles, 1 Sept. 2005. Web. 19 Feb. 2010.
<www.calstatela.edu/faculty/hsingh2/articles/milk.research.pdf>.
"Goat Dairy Foods." Dairy Research & Information Center. UC Davis - DRINC Program, n.d.
Web. 26 Feb. 2010. <http://drinc.ucdavis.edu/goat1.htm>.
Kluiber, RW. "EDTA Titration for Ca+2 in milk.." Milk: Calcium and Nutrition. Rutgers
University, 18 Nov. 1998. Web. 20 Feb. 2010. <http://genchem.rutgers.edu/Milk.html>.
Nolte, Molly. "Info on Raw Goat Milk & Pasteurization." Fias Co Farm. N.p., 18 Jan. 2010.
Web. 26 Feb. 2010. <http://fiascofarm.com/dairy/rawmilk.htm>.
Shelton, Herbert. "Destructive Effects Of Pasteurization."ChestofBooks.com. N.p., n.d. Web. 20
Feb. 2010. <http://chestofbooks.com/health/natural-cure/The-Hygienic-SystemOrthotrophy/Destructive-Effects-Of-Pasteurization.html>.
"The Michigan Fresh Unprocessed Whole Milk Workgroup: Benefits and Values." Michigan
Food & Farming Systems - MIFFS. N.p., 23 Oct. 2009. Web. 26 Feb. 2010.
<http://www.miffs.org/MIfuwmilk/benefitsvalues.htm#6>.
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<http://www.milk.co.uk/page.aspx?intPageID=43>.Top of Form
ACKNOWLEDGEMENTS
Special thanks to Mrs. Joan Bechtel for all of her
assistance in the lab during this experiment. It
would not have been possible without her
expertise and guidance.
 Thank you to my parents for their continued
support of everything I endeavor to achieve.
 This project would not have been possible
without the help of PJAS and CASEF sponsors
Mr. Jason Sibbach and Mr. Jason Ambler.
 Thank you to all the professionals who make
PJAS and CASEF possible for students to learn
and compete in these competitions.
