Determination of Calcium
Content in Milk Alternatives
Tim and Dan’s Excellent Real World Project
What are we doing?
• To determine the amount of calcium in four
milk alternatives (Soy, Almond, Lactaid,
Chocolate) and a 1% dairy control
• To compare the calcium levels in each with
how they compare to the control and the
manufacturer’s claim
(Radical!)
What chemicals do we need?
• Standard Calcium
Solution
– 2.5 g CaCO3 in 100 mL of
0.1M HCl. Diluted to 1 L
• EDTA Solution
– 15 g disodium EDTA
diluted to 1 L
• Calcium Indicator
– Hydroxy Naphthol Blue
• 0.5M KOH (to adjust
pH)
(Hydroxy Naphthol Blue)
How are we gonna do it, dude?
•
•
•
Combine 5 mL of distilled water, 10 mL EDTA and
5 mL increments of KOH (to adjust pH to
approximately 13) to a 125 mL Erlenmeyer flask
Add 200-300 mg of the calcium indicator and
the color should change from clear to light blue
Back titrate excess EDTA with the standard
calcium solution until color changes to violet.
This will be the blank titration used for
calculations
Sorry about all that writing. Here’s a
picture of puppies!*
*drinking milk
But here’s more procedure…
• Repeat the same procedure as previously
stated, but substitute 5 mL of milk alternative
for the distilled water
• Perform each titration three times for
accuracy
(Procedure acquired from Titration of calcium
and magnesium in milk with EDTA by Patrick
G. McCormick)
Surely there must be data!
Here it is…and don’t call me Shirley…
• Mass EDTA: 15.0084 g
• Mass CaCO3: 2.5070 g
Distilled Water
Trial
Ca
indicator
(g)
Sample
(mL)
EDTA (mL)
KOH (mL)
CaCO3
added
(mL)
1
.2503
5
10
5
16.70
2
.2535
5
10
5
16.75
3
.2653
5
10
5
16.70
Control (1% white milk)
Trial
Ca
indicator
(g)
Sample
(mL)
EDTA (mL)
KOH (mL)
CaCO3
added
(mL)
1
.2673
5
10
5
10.50
2
.2529
5
10
5
10.65
3
.2637
5
10
5
10.90
1% Chocolate Milk
Trial
Ca
indicator
(g)
Sample
(mL)
EDTA (mL)
KOH (mL)
CaCO3
added
(mL)
1
.2562
5
10
5
12.72
2
.2569
5
10
5
12.30
3
.2590
5
10
5
13.15
Silk (Original)
Trial
Ca
indicator
(g)
Sample
(mL)
EDTA (mL)
KOH (mL)
CaCO3
added
(mL)
1
.2530
5
10
5
11.23
2
.2565
5
10
5
10.40
3
.2628
5
10
5
11.11
1% Lactaid
Trial
Ca
indicator
(g)
Sample
(mL)
EDTA (mL)
KOH (mL)
CaCO3
added
(mL)
1
.2539
5
10
5
11.72
2
.2553
5
10
5
11.61
3
.2557
5
10
5
12.30
Almond Breeze (Original)
Trial
Ca
indicator
(g)
Sample
(mL)
EDTA (mL)
KOH (mL)
CaCO3
added
(mL)
1
.2605
5
10
5
8.50
2
.2551
5
10
5
8.55
3
.2565
5
10
5
8.20
Calculations
Soo…what’d we get?
• 1% - 10.48 %/240 mL
• Chocolate – 12.69 %/240 mL
• Silk – 11.21 %/240 mL
• Lactaid – 11.70 %/240 mL
• Almond – 8.48 %/240 mL
How does that compare?
•
•
•
•
•
Manufacturer’s Claim
1% - 30 %/240 mL
Chocolate - 30 %/240 mL
Silk - 45 %/240 mL
Lactaid - 30 %/240 mL
Almond - 30 %/240 mL
•
•
•
•
•
Our Results
1% - 10.48 %/240 mL
Chocolate – 12.69 %/240
mL
Silk – 11.21 %/240 mL
Lactaid – 11.70 %/240 mL
Almond – 8.48 %/240 mL
In Conclusion
Through our methods, we discovered that the
best alternative is the Lactaid
This provides the second most calcium per
serving, but the most as a true alternative
It is also the closest to the reported value for the
milk alternatives we tested
Silk turned out to be the biggest
disappointment, having the largest difference
in reported vs. experimental
Error
• An important source of error comes from our
calculations. We couldn’t find the density for
the Almond milk and Silk so we used the
chocolate’s density
• Another source could be the potential of
slightly titrating past the equivalence point