Dairy-Based Ingredients Offer Function andNutrition

Dairy-Based Ingredients Offer Function and Nutrition

by Heather Granato

Dairy is an essential component of many functional food items. In fact, milk could be considered a functional food in its own right, full of minerals, protein and growth compounds. However, increasing numbers of manufacturers are turning to isolated dairy components for their nutritional benefits.

According to a study of 1,000 consumers, conducted by Dairy Management Inc. (DMI) with funding from America's dairy farmers, 90 percent of consumers agree that products containing dairy ingredients are good for you. Mike LaPolla, DMI's marketing director of dry dairy ingredient marketing, wrote in the Oct. 12, 2001, "Cheese Market News" that "Dairy ingredients, including nonfat dry milk, whey proteins and milk minerals, can enhance a variety of new product formulations by adding nutritional value, providing functional benefits and improving flavor, mouthfeel and texture."

The health benefits of dairy have been attributed to individual factors, as well as the overall combination. For example, researchers at Boston's Children's Hospital found that patterns of increased dairy consumption could reduce the risk of Type II diabetes and cardiovascular disease (JAMA, 287, 16:2081-9, 2002). Another study, conducted at the University of Tennessee, found that calcium in dairy products could shift energy metabolism from storage to thermogenesis (as measured by increased body temperature), increase lipolysis (fat burning) and decrease lipogenesis (fat storage) (J Am Coll Nutr, 21, 2:146S-51S, 2002).

Dairy has also been shown to play a role in reducing hypertension; in fact, low-fat dairy products are an important aspect of the Dietary Approaches to Stop Hypertension (DASH) study. One review of studies on dairy products and risk of stroke and hypertension noted it was difficult to associate just one mineral with the health effects, because "an appropriate metabolic balance of [calcium, magnesium and potassium] is important and because of the strong correlations among [them] when dairy products are consumed" (J Nutr, 131, 7:1875-8, 2001).

A combination of minerals is even important in treating osteoporosis, for which the Food and Drug Administration approved a health claim linking intake of calcium with a reduced risk of osteoporosis. The ratios of calcium-to-phosphorus and calcium-to-magnesium ensure that calcium is stored in the bones and other metabolic processes are not adversely affected.

The positive effects of a combination of minerals are one reason many manufacturers are turning to milk minerals rather than straight calcium for fortification. Fiona O'Keeffe, marketing manager with Monroe, Wis.-based Glanbia Ingredients, said the company offers TruCal, a naturally derived dairy ingredient with a balanced mineral profile plus protein and lactose, which is now generally recognized as safe (GRAS) for food products.

Glanbia offers a range of dairy-based ingredients, including proteins. The primary dairy proteins are casein and whey; whey is available as both concentrates and isolates. Casein is a white, tasteless, odorless protein precipitated from milk by rennin. Whey (the watery part of milk remaining after the manufacture of cheese) is a source of lactose, minerals, vitamins and protein. Whey protein isolate (WPI) is manufactured by drying the pasteurized whey and isolating approximately 90 percent of the protein; whey protein concentrate is usually about 25 percent protein. According to DMI, the most commonly used method is ultrafiltration to take out the low-molecular weight compounds and concentrate the proteins in the retentate.

The primary functional application for these proteins has been in the sports nutrition industry, enhancing bars and beverages for maximum strength benefit. Studies have shown the ability of casein and whey proteins to increase muscle mass and muscle strength. In one study in Boston, casein protein was shown to improve nitrogen retention and overall anticatabolic effects for subjects (Ann Nutr Metab, 44, 1:21-9, 2000).

Whey protein has been shown to have similar effects in both animal and human studies. For example, in a trial appearing in the International Journal of Sports Nutrition & Exercise Metabolism (11, 3:349-64, 2001), whey protein supplementation led to significant improvements in knee extension peak torque and lean muscle mass.

Whey protein contains a range of nutritional compounds, including complex proteins such as immunoglobulins. There are five classes of immunoglobulins, including IgA (found in the gut), IgE (linked to hypoallergenic responses) and IgG (the most abundant and active type). IgA, IgE and IgG are the three main types that are found in whey protein.

Whey also contains several types of amino acids and growth factors, including lactoferrin. Studies have shown lactoferrin's ability to impact nutrient absorption and maximize growth. A recent study of lactoferrin supplementation in dairy calves found that lactoferrin added to milk or colostrum positively impacted calf growth and performance (J Dairy Sci, 85, 5:1237-42, 2002). It also has strong antimicrobial and antiviral activity. Lactoferrin supports immunity by down-regulating inflammation (Biochem Cell Biol, 80, 1:103-7, 2002) and may prevent viral infiltration into cells (Antiviral Res, 52, 3:225-39, 2001).

One natural, concentrated source of immune and growth factors such as lactoferrin is colostrum. The pre-milk fluid produced from the mother's mammary glands during the first 72 hours after birth provides a range of nutrients to ensure the health of the newborn. As a functional ingredient, it supports healthy immune function and enteric health.

"Colostrum has naturally occurring nutritional compounds 20 to 50 times what are found in milk, and offers ease in formulation," said Randy Kjelden, president of Brookings, S.D.-based Sterling Technologies, a supplier of colostrum.

Among the healthy components in colostrum are growth factors, lactoferrin, immunoglobulins, proline-rich polypeptides (PRP), vitamins and more. Insulin-like growth factors are among the most abundant growth factors in colostrum. Colostrum has been extensively studied, even meriting a supplement to the November 2000 issue of the British Journal of Nutrition (BJN) on "Beneficial Natural Bioactive Substances in Milk and Colostrum." Among the topics explored were the characteristics of Igs for immune function (75-80), abilities of colostrum components to reduce blood pressure (119-25) and the antimicrobial and antiviral activity of a range of components for immune and gut health (127-134).

Colostrum's ability to positively affect enteric health is tied to its immune-building properties. "Colostrum supports gut health by stimulating villi growth and benefiting nutritional uptake," Kjelden said. One recent study underscored colostrum's ability to benefit immune function through delivery of immunoglobulins to the gut to prevent gastroenteric infections (Curr Opin Infect Dis, 14, 3:295-300, 2001). Another paper in the BJN supplement focused on the ability of colostrum products to prevent infectious diseases through gut health (135-46).

Ongoing research is adding to the existing database on benefits of whole dairy ingredients, such as colostrum and milk minerals, to human health. Manufacturers who are delivering these nutritional compounds in easier packages (such as functional bars and drinks) will likely see growth in consumer interest and demand.

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