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 16.70 2 .2535 16.75 3 .2653

Control (1% white milk) Trial Ca indicator (g) Sample (mL) EDTA (mL) KOH (mL) CaCO3 added (mL) 1 .2673 5 10 10.50 2 .2529 10.65 3 .2637 10.90

1% Chocolate Milk Trial Ca indicator (g) Sample (mL) EDTA (mL) KOH (mL) CaCO3 added (mL) 1 .2562 5 10 12.72 2 .2569 12.30 3 .2590 13.15

Silk (Original) Trial Ca indicator (g) Sample (mL) EDTA (mL) KOH (mL) CaCO3 added (mL) 1 .2530 5 10 11.23 2 .2565 10.40 3 .2628 11.11

1% Lactaid Trial Ca indicator (g) Sample (mL) EDTA (mL) KOH (mL) CaCO3 added (mL) 1 .2539 5 10 11.72 2 .2553 11.61 3 .2557 12.30

Almond Breeze (Original) Trial Ca indicator (g) Sample (mL) EDTA (mL) KOH (mL) CaCO3 added (mL) 1 .2605 5 10 8.50 2 .2551 8.55 3 .2565 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 Our Results 1% - 30 %/240 mL Chocolate - 30 %/240 mL Silk - 45 %/240 mL Lactaid - 30 %/240 mL Almond - 30 %/240 mL 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