Soymilk is often calcium fortified to bring the calcium content up to a level similar to cow’s milk. Tricalcium phosphate (TCP) is a common fortificant in aseptically packaged soymilk but the use of calcium carbonate is growing. Issues with calcium fortification can include calcium-protein interactions leading to coagulation—especially during pasteurization or ultra-high-temperature (UHT) processing—and settling of insoluble calcium during storage. Precipitated calcium carbonate (PCC) has been shown to have minimal interaction with soy protein. PCC is also available in significantly smaller particle sizes than TCP which should improve settling stability.

Precipitated Calcium Carbonate (PCC) vs. Tricalcium Phosphate (TCP) for Calcium Fortified Soymilk
A previous study has demonstrated that PCCs interact weakly with the proteins in dairy and non-dairy beverages including fresh whole milk, non-fat dry milk, casein and calcium caseinate, whey, soymilk, and soy protein isolate. Click here to read more about this Specialty Minerals Inc. (SMI) study.

To continue with this work, the SMI Healthcare Laboratory compared the use of various levels of PCC and TCP along with phosphate pH buffer in soymilk and soy protein isolate (SPI) suspensions. After UHT processing, changes in physical and sensory properties were tested.

The results of this study were:

• While the PCC used has a smaller particle size than the TCP, the TCP has a higher specific surface area.
• Short-term static settling tests did not show differences between PCC and TCP in full soymilk formulations—but in soy protein isolate slurries without suspension stabilizer, the highest amount of settle was observed with TCP.
• Accelerated settling tests showed greater residue with TCP in all formulations. Less settling with PCC may result in formulations requiring less stabilizer and/or having longer shelf lives.
• PCC caused a 1 unit increase in pH but phosphate buffer was effective at bringing pH back to its native value. TCP did not change pH.
• PCC makes soymilk less yellow.
• Neither product caused a chalky taste in soymilk but there were slightly more flavor changes with PCC than with TCP.
• PCC and TCP bind about the same amount of soy protein in the SPI slurry and neither cause degradation of soluble proteins.
• PCC is an excellent choice for the development of economical, shelf-stable soymilk and soy-based beverages.

Click here to download a set of PowerPoint slides with the details of methods, materials, and test results.

Specialty Minerals Precipitated Calcium Carbonate (PCC) For Soymilk
The PCC that produced the results in this study was ViCALity Albafil^® PCC, a 0.7 micron prismatic particle with a narrow particle-size distribution.

Its small particle size helps it settle more slowly and thus stays in suspension longer. It is a low-lead PCC with less than 500 ppb (parts per billion lead), so it fits in many formulations that must comply with California Proposition 65 lead limits.

If the formulation requires even lower amounts of lead, then an ultra-low-lead equivalent is available. This is CalEssence^® 70 PCC, which has less than 125 ppb lead.

In formulations that call for the longest shelf life with minimized settling, an even smaller particle can help—one of SMI’s nano PCCs. Nano particles are, by definition, less than 100 nanometers in size. The two uncoated SMI’s nano PCCs are 70 nanometer, or 0.07 micron particles. Multifex-MM^® USP PCC is USP and FCC (Food Chemicals Codex) certified for calcium carbonate and Kosher. It is sold under this trademark in North America and the Asia-Pacific region. The same product, trademarked Calofort^® U PCC, is EP, BP and EU E170i certified, and Kosher. It is sold in Europe and the rest of the world. Both are manufactured in the SMI plant in Birmingham, U.K.

Click here to learn more about the use of these SMI PCCs in soymilk and other beverages and the effect of particle size on suspension and settling.

Learn more:

• SMI minerals in soymilk
• SMI minerals in food fortification uses
• SMI minerals in beverages – cow’s milk, soymilk, powdered drinks
• SMI minerals in liquid meals and infant formulas
• SMI minerals in tofu
   
• SMI calcium carbonates for food, nutritional supplements, pharmaceuticals and personal care products
• Choosing the right grade of SMI calcium carbonate for consumer products.
• CalEssence^® PCCs for healthcare uses
• ViCALity^® PCCs for healthcare uses
• Calofort^® U and Multifex-MM^® nano PCCs for healthcare uses
   
• U.S. Recommended Daily Intake (RDI) for Calcium
• Useful information for formulators: Downloadable information sheets on formulating with calcium carbonate, the effect of particle size and shape in a product, high bioavailability of calcium carbonate, California Proposition 65 lead limits and calcium carbonate lead levels.
• Osteoporosis: Anyone Can Be At Risk – Even You! - A downloadable information sheet.
   
• SMI minerals in consumer products. See products you use every day - foods, nutritional supplements, pharmaceuticals, cosmetics, toiletries, and other personal care items – which use SMI talcs and calcium carbonates.
   
• What is Precipitated Calcium Carbonate (PCC)? A minerals introductory webpage.
• What is Precipitated Calcium Carbonate (PCC) for Healthcare? - A downloadable information sheet.
• What is Nano Precipitated Calcium Carbonate (PCC)? A minerals introductory webpage.
   
• Download technical data sheets and MSDS for Specialty Minerals products
• Request a sample
   
• About Specialty Minerals Inc.
• Specialty Minerals plant profiles: Adams and Birmingham
• Quality, GMP and ISO at Specialty Minerals