The Great Mineral Balancing Act

Minerals are essential to optimum health for all ages. From major minerals like calcium and phosphorus to trace minerals like zinc and copper, minerals play a role in vital physiological structure and functions throughout life. Health authorities frequently express concern about deficiencies or excesses of key minerals associated with diseases, such as iron and anemia, calcium and osteoporosis, and sodium and hypertension. But, in reality, many minerals work together as a team to accomplish a mission, and an imbalance among the players can also contribute to problems in both bioavailability and functionality.

Weighing the need for balance 

Well-known mineral teams include calcium, phosphorus and magnesium for bone and muscle health; sodium, potassium and chloride for fluid and acid-base balance; and iron and copper for hemoglobin and several enzymes involved in metabolism. Many trace elements also contribute to health.

Fluoride, known primarily for dentalcaries prevention, assists in bone and teeth formation. Zinc and selenium contribute to proper immune-system function. Iodine is essential to thyroxine formation and, thus, is important to metabolic regulation. Chromium works with insulin in glucose metabolism. Both molybdenum and manganese function with enzymes to facilitate body processes. In the future, research on boron, cobalt, nickel, silicon and many other trace minerals may reveal the need for an even wider array of minerals in our diets and provide insight into other mineral teams.

The causes of low and imbalanced intakes of minerals vary from poor food choices to suspected declines in content due to changes in growing conditions for produce and animals. At a meeting of the American Association for the Advancement of Science in St. Louis last Feb. 2006, Donald Davis, Ph.D., a biochemist at the University of Texas, Austin, discussed the “dilution effect” of high-yield crops on nutrient levels. He reported on recent studies that documented 5% to 35% less vitamins, minerals and protein in fruits, vegetables and wheat over the past 50 years and pointed to the need for finding ways to maintain yield while reversing the dilution effect.

In the Jan/Mar 2006 issue of Food Magazine, a publication of the Food Commission, the results of an unpublished study by Dr. David Thomas, a primary healthcare practitioner and independent researcher in the United Kingdom, demonstrated some dramatic declines in the mineral content of meat and dairy. His comparison of government nutritional tables from the United Kingdom published in 1940 and 2002 showed up to 80% less iron in meat, milk and cheese; 10% less copper and 60% less magnesium in meat products; and 25% less magnesium and 90% less copper in dairy products.

As taste and convenience became primary market drivers in the last half of the 20th century, other changes in food supply impacted the mineral content of foods. The introduction of more processed foods led to increased sodium but without an increase in its major cation teammate, potassium. The increased consumption of carbonated beverages and subsequent decrease in milk consumption resulted in higher phosphorus and lower calcium intake. Now recommendations by health authorities encourage eating patterns designed to correct these imbalances.

Fortification first steps 

To overcome deficiencies in the food supply and consumption levels, manufacturers target several minerals for fortification. According to S.L. “Sam” Wright IV, president and CEO, Wright Enrichment, Inc., San Francisco, calcium, iron, phosphorus, magnesium, zinc, iodine, copper and potassium are commonly added to food. These have specified DRV levels in Title 21 of the Code of Federal Regulations (CFR), Part 104, Section 20, “Nutritional Quality Guidelines for Foods.” Wright states that, “these all can be provided by GRAS sources.” Regulations on appropriate levels for other minerals exist, as well. “Sodium also is assigned a DRV level in 21 CFR 101 for the purpose of labeling. Additional minerals with RDIs as specified in 21 CFR 101 are manganese, selenium, chromium, molybdenum and chloride; however, there are no GRAS sources of molybdenum or selenium,” he adds.

The addition of minerals to a food matrix needs careful scrutiny. “Many minerals are chemically reactive,” says Wright. “Chemical reactions with oxygen, free radicals, vitamins and other food components are made possible in the presence of water and can negatively impact the color, flavor or appearance of the food, or catalyze other negative changes in the food. Reactivity is affected by processing and storage times and conditions.”

Unfortunately, the forms with greater bioavailability create more problems. “The more soluble a mineral, the greater its bioavailability (its ability to be absorbed and utilized by the body); also, the greater its potential impact on the entire system from a reactivity standpoint.” says Wright. “Iron (in the +2 ferrous state) and copper are prooxidants and can initiate lipid oxidation yielding rancidity and off-flavors. Vitamins A, D and C are also susceptible to iron- and copper-induced oxidation with instability and destruction; these reactions are accelerated with increased temperature.” He recommends strategies for minimizing interaction that include physical avoidance by adding the minerals at another stage in processing, separate from the vitamins; changing the mineral source; or encapsulating to protect the mineral from interactions and mask taste.

A high level of minerals can also result in adverse health effects. “Excessive intake of minerals can lead to toxicity. Of most concern are the trace minerals such as selenium and iodine, but also excess iron can lead to hemochromatosis. Excess sodium intake can be negative for individuals with, or susceptibility to, high blood pressure. Excessive intake of zinc can affect calcium absorption and can result in copper-deficiency anemia,” Wright explains.

Bundling benefits 

Mother Nature frequently supplies nutrients that work as a team in the same food. For example, milk supplies calcium and phosphorus in an ideal ratio. It also contains magnesium, thus providing key minerals needed for bone health in one package. Additionally, research indicates that milk’s high potassium and calcium content with minimal sodium may factor into promoting normal blood pressure.

However, when it comes to formulating functional food and beverages, manufacturers turn to ingredient suppliers to help provide the proper balance of minerals in amounts appropriate for physiological benefit, with minimal impact on taste and processing conditions.

According to Ram Chaudhari, senior executive vice president and chief scientific officer, Fortitech, Inc., Schenectady, NY, the hot items for fortification in staple foods are iron, iodine and calcium, but in functional foods, the list expands to include zinc, selenium, chromium and molybdenum. “You don’t need 100% RDA, you just need a moderate level. At the 100% level, products won’t taste good,” he notes. “There is more interaction among minerals, which impacts the color, taste and texture of the product.” In products like nutrition bars, he says, “you see the complete spectrum of minerals. They are not highly heated, and by using microencapsulated or chelated minerals, you don’t have interactions.”

Chaudhari says interactions can affect bioavailability. For example, in the presence of too much iron, copper and zinc absorption will decrease. And calcium and phosphorus in a 1.2:1 ratio will stay in a colloidal form, which is more absorbable. “Some minerals are not very compatible, so vitamins sometimes help, like vitamin C and iron,” he says. “And depending on the type of product, you need to consider an organic versus an inorganic form. If the mineral is too soluble, then it will react quickly. From the absorption view, this is better, but it interacts sooner, which causes other quality problems.”

According to Alice Wilkinson, director of product development, nutrition ingredient division, Watson Foods Co., Inc., West Haven, CT: “Macro minerals, such as calcium, phosphorus, magnesium and potassium, take up quite a bit of space in a formulation based on a significantly higher percent Daily Value. They can cause a product to become dry or pasty and will mute flavors. Nonreactive sources should be chosen if possible (e.g., dimagnesium phosphate over magnesium oxide). If a reactive source is chosen, we would use an encapsulated form if the processing conditions allow for it.”

Lipid-encapsulated nutrients improve the stability of heat- and oxygenlabile vitamins and decrease reactivity of minerals. “Different encapsulation mediums may provide increased stability in particular applications, as well,” notes Wilkinson. “In an instant-hot-cereal application, the lipid-coated nutrients will decrease reactivity of the vitamins with the minerals and other ingredients. For example, encapsulated magnesium oxide will cause significantly less oxidation of fats and proteins than an unencapsulated product. Different encapsulation mediums have differing functionality based on melt point, etc.,” she states.

As for other minerals, “micro minerals can have a macro impact, specifically in regards to flavor, pH and reactivity,” says Wilkinson. “We use encapsulated versions wherever possible.”

When it comes to balancing nutrients in a product formulation, Wilkinson says that calcium and phosphorus are the biggest issue. “Nutritionally, you want to see them at a 1:1 ratio,” she continues. “Dicalcium phosphate is 29.5% calcium and 22.8% phosphorus, and this is the closest available for that need. When you start adding in magnesium (as dimagnesium phosphate) or potassium or sodium in similar forms, we have to do some formulation balancing to keep them correct by using several sources, such as tricalcium phosphate, monocalcium phosphate, calcium carbonate, etc.”

Drink dilemmas 

From a consumer standpoint, drinking a beverage fortified with needed minerals provides assurance for nutritional benefit in a convenient, easy-toconsume product. But from a manufacturing standpoint, formulating, packaging and storage challenges abound.

Chaudhari says that the major factors to consider in choosing ingredients for mineral-fortified beverages are the forms—ready-to-drink (RTD) or powdered —and whether they’re clear or opaque. “If it is a powder, then you can use microencapsulated and chelated forms, because you only mix and drink, and there is minimal sediment. In ready-to-drink, if you use microencapsulated, then you get sediment. Then, when the mono- and diglycerides melt, the fat floats to the top. So you need an emulsifier or stabilizer to keep the minerals in solution in these products,” he states.

As for packaging and storage considerations, Chaudhari says: “In ready-to-drink beverages, an opaque bottle is better because, in a clear bottle, there can be color changes due to the catalytic effect of copper, iron and zinc. Also, fat, in the presence of light, will catalyze peroxidation, so if a clear bottle is used, then an antioxidant like tocopherol is added. In powdered beverages, high temperature (greater than 80°F to 85°F) and humidity (at 70% or higher) are problems. If the product is opened, then it absorbs moisture and becomes difficult to scoop and there are taste changes. It is best to store them at less than 75°F and less than 70% humidity.”

According to Wilkinson: “In beverages, we will typically incorporate the macro minerals, such as calcium, magnesium, phosphorus and potassium, as micronized versions when possible. This enables a better dispersion of the less-soluble minerals. Typically, the less-soluble sources are preferred as they can carry counter ions (i.e., dicalcium phosphate) that meet other label claims and, being less soluble, create fewer issues in regard to changes in taste, color and pH. Certain RTDs require the more-soluble sources, especially if the product is to be clear, but they take up more space (e.g., 10% DV for calcium, as calcium lactate requires 746 mg of the ingredient; 10% DV as calcium carbonate requires 250 mg) and can cost much more. These implications need to be taken into consideration during formulation.”

Creating solutions 

Custom-ingredient manufacturers work closely with their customers to create the right mix of minerals for their products. Their expertise in bioavailability and ingredient functionality allows them to find the best chemical form to meet labeling and processing requirements, as well as provide the right balance of minerals to meet nutritional and product-quality needs. Other advantages to custom premixes include convenience and decreased ingredient, storage and manufacturing costs. A close alliance between product developers and ingredient suppliers provides the best solutions.

Chaudhari sums it up best: “Fortifying with minerals is a constant challenge. You have to deal with chemistry, nutrition and the processing of foods and beverages. There are no simple solutions—every product is different and has different requirements.”

Angela M. Miraglio, M.S., R.D., is a Fellow of the American Dietetic Association from Des Plaines, IL. Her firm, AMM Food & Nutrition Consulting, provides communications and technical support to the food and beverage industry. She can be reached at

[email protected].