Them Bones Need Calcium

Theres no debate about the effect of insufficient calcium consumption. The National Osteoporosis Foundation (NOF), Washington, D.C., estimates that 10 million Americans over the age of 50 suffer from osteoporosisa disease that causes bones to become fragile and highly susceptible to fractureand roughly 1.5 million people suffer an osteoporosis-related fracture each year. Chances are, many of these people ignored their calcium needs during their early critical period for building optimal bone mass, or later in life, when calcium can slow the progression of the disease (see Food Product Design, October 2000, Building Better Bones, www.foodproductdesign.com/articles/464/464_1000nn.html).

Studies show milk products provide almost three-quarters of the American food supplys calcium, with dairy products typically containing one-third of the RDA of calcium per serving. But, as the figures point out, there is still an unmet need for increased calcium consumption. As the osteoporosis problem worsens, the food industry is racing to discover innovative new ways to bring consumers this vital nutrient.

The insolubles

Developers have several options for GRAS calcium salts. Inorganic salts tend to be rich in calcium but poor in solubility. Calcium carbonate (CaCO3) is one of the most-bio-available forms of calcium. With roughly 40% calcium, CaCO3 provides high levels of calcium with low addition rates. Poor solubility (less than 0.1 gram calcium per liter of water at 25ºC) at all but acidic pHs can sometimes cause problems: grittiness and sedimentation can occur in low-viscosity fluids, and cloudiness can occur in clarified systems. CaCO3 can also impart a soapy taste in high-pH and high-fat systems.

Tricalcium phosphate (TCP), another inorganic salt, has a calcium level and solubility characteristics similar to CaCO3. TCP, while not chalky, can potentially contribute the same gritty texture as CaCO3. The phosphates do, however, present an advantage over carbonates, according to Amr Shaheed, senior scientist, Innophos Inc., Cranbury, NJ, because they are a dual source of nutritional ingredientscalcium and phosphorusboth of which are proven to develop healthier bones.

Commonly used in dry systems such as nutritional bars, cookies, cereals and snacks where insolubility does not adversely affect mouthfeel, particle-size modification can make the insolubles suitable for previously off-limits applications. Ultra-fine TCP can be added to moderately thick products like processed cheese or drinkable yogurt. Viscosity suspends particles small enough to go unnoticed by the consumer.

Product modification also improves solubility. A specialized combination of anhydrous and monohydrate forms of monocalcium phosphate has a minimum calcium content of 14.5%, and typically of 15%, according to Shaheed. Although the blend was originally designed for beverages, he suggests fruit spreads, yogurts, acidic sauces and dressings may be additional applications.

Stir it in

Although organic calcium sources provide less calcium than the inorganics, the calcium from organic salts is more bioavaliable and less likely to impact flavor. 

Calcium lactate delivers 13% calcium, solubility of 9.3 grams of calcium per liter of water and a neutral taste. Calcium gluconate brings 9% calcium and similar solubility. Both forms are well-suited for any application that requires good solubility and neutral taste. Combining the two, calcium lactate gluconate (or calcium lactogluconate) provides even greater solubility and reduced dissolution rates. The neutral taste suits it for mild-tasting products, while enhanced solubility allows inclusion in syrups.

Super-solubility can sometimes cause problems. Free calcium ions can catalyze pectin gelation in fruit purées and concentrates. Calciums two positive charges will react with anthocyanins, deeply colored pigments in dark fruit juices, shifting finished-product color. Lactates can also interact with proteins, as in milk-based beverages, and precipitate out.

Calcium citrate has lower solubility than lactates and gluconates0.2 grams calcium per liter of waterbut greater calcium content (21%). Like most calcium salts, solubility increases with decreasing pH. Unique to calcium citrate is improved solubility at low temperatures, allowing use in cold processes. Conversely, reduced reactivity at high temperatures decreases the chance of adverse interactions with other components during thermal processing.

Problems due to insolubility can often be avoided through seemingly unlikely combinations. Highly soluble calcium salts will precipitate in milk-based products. Calcium carbonate will settle out, as it is insoluble. By combining calcium carbonate with calcium lactate and insoluble calcium phosphate (acting as a buffer), calcium carbonate will not settle or precipitate.

Health helpers

Nutritionists agree that our bodies absorb only 25% to 35% of the calcium in our diet. But improving these odds is possible. Vitamin D is crucial for proper calcium absorption and maintenance of normal blood levels of calcium (and phosphorous).

Inulin, oligofructose and fructooligosaccharides are mixtures of poly- and oligosaccharides that differ in the degree of polymerization. Their ß (2-1) linkage resists hydrolysis in the upper digestive tract, making them nondigestible oligosaccharides, which are then fermented by the colonic microflora, improving digestive health and digestive efficiency.

While early studies indicated inulin, oligofructose and fructooligosaccharides improved calcium uptake only at very high consumption levels, Joe ONeill, executive vice president of sales and marketing, Orafti Active Food Ingredients, Morris Plains, NJ, reports that a combination of these prebiotics increases the amount of calcium absorbed by the body. The latest research by Dr. Steven Abrams at the Childrens Nutrition Research Center, Baylor College of Medicine, Houston, concluded that the extra absorbed calcium is going exactly where it is neededstraight to the bones. Clinical studies have demonstrated that oligofructose-enriched inulin increases bone mineral density.

Double duty

Calcium salts can provide functional benefits in food systems beyond the scope of nutrition. Tricalcium phosphate is commonly used in dry mixes where its flow-conditioning properties maintain a smooth-flowing character by preventing caking.

Calcium acid pyrophosphate can be used as a leavening agent in a variety of baked goods, including those where healthy attributes are targeted, or for general leavening purposes where it provides excellent finished-product characteristics, including clean flavor profile, uniform cell structure and ideal volume, notes Barbara Heidolph, principal, ICL Performance Products LP, St. Louis. Calcium acid pyrophosphate (CAPP) provides a controlled leavening and may aid in strengthening dough systems via calcium-protein interactions. CAPP carries 19% calcium and none of the sodium present in traditional leavening agents, allowing manufacturers to explore label claims such as low sodium and a good source of calcium.

R. J. Foster is a wordsmith with over 15 years of experience in the food industry, specializing in technical communication services. He can be reached by e-mail at [email protected]. 

Dsigning Dairy for Bone Health

Calcium has long been linked to building strong bones and a reduced risk of osteoporosis. Now health claims pending before FDA may expand these positive associations with bone health to include vitamin D, as well.

Vitamin D is critically important to effectively and efficiently absorb the calcium in our diets, says Greg Miller, Ph.D., M.A.C.N., executive vice president, science and research, Dairy Management Inc. and the National Dairy Council, Rosemont, IL, People need sufficient calcium and vitamin D to develop optimal peak bone mass and preserve it throughout life.

While the body can produce all the vitamin D it needs if exposed to enough sunlight, many lack this nutrient because of where they live, the color of their skin and even the clothes they wear. The National Dairy Council calls vitamin D deficiency an unrecognized epidemic affecting all age groups.

Formulators fortify many dairy foodsincluding milk, selected yogurt varieties and some cheeses with vitamin D to bridge the gap between recommended and actual intakes and to enhance absorption of the calcium thats naturally abundant in dairy foods. The standard for vitamin D fortification of cows milk sold in the United States is 400 IU per quart. The Institute of Medicine, Washington, D.C., recommends 200 IU per day of vitamin D for children and adults under 50.

The recommended amount grows as people age and presumably get less sunlight: 400 IU per day for those 51 to 70, and 600 IU per day for those 71 and older. The 2005 Dietary Guidelines for Americans recommend that at-risk groups consume 1,000 IU per day.

Now, dairy-food manufacturers are likely to get additional ways to market the health benefits of low-fat and fat-free milk and other dairy products containing vitamin D and calcium. FDA is expected this year to issue a final rule on new health claims, fi rst proposed in July 2004, that connect calcium and vitamin D with a reduced risk of osteoporosis.

The final rule is expected to permit claims that apply to all products that are considered excellent sources of calcium or calcium and vitamin D. Excellent source means the products must include at least 20% of the recommended daily value and meet general requirements for health claims set forth in Title 21 of the Code of Federal Regulations, Part 101.14. Reduced-fat, low-fat and fat-free milk and select yogurt varieties may be eligible to use the combination claim, while other yogurt varieties and low-moisture, part-skim mozzarella could potentially use the calcium claim.

The new claims will provide another opportunity for dairy and food manufacturers to communicate a products health benefit in a more simplified, consumer-friendly way, says Miller. Were far from where we need to be for bone health, which is three servings of low-fat milk and dairy foods each day, according to the 2004 Surgeon Generals report, Bone Health and Osteoporosis.

To learn more about dairy label claims and dairy products, ingredients, processing, packaging and nutrition, visit www.innovatewithdairy.com. 

Dairy Management, Inc.