Dry whey an alternative to gum arabic.

Beverage formulators frustrated with the instability of gum arabic are able to turn to a dry dairy ingredient that provides greater stability. Research into the emulsification properties of whey protein isolate (WPI) shows that it provides the same functional characteristics as gum arabic, even when used in much lower concentrations in a formulation.

Scientists at the University of Massachusetts (Department of Food Science, Amherst, MA 01003) tested an application of WPIs in conditions commonly found in a fruit-style beverage system. They used rheological equipment to define environments in which whey proteins would perform well. Combining a heat-treated WPI with a sugar, such as a polysaccharide, enables it to maintain its liquid state. This makes it a viable alternative as an emulsifier in a beverage formulation. In addition, whey proteins can substitute for gum arabic because that gum contains a protein in its makeup.

WPI can extend the shelf life of beverage formulations up to one year. The types of beverages that might benefit from the use of WPI include infant formulas, fruit-based drinks, and sports and nutritional beverages. Additional studies might investigate the use of WPI as an emulsifier in salad dressings and other foods.

Gum arabic is more expensive than WPI, and a formulator usually needs 20 times more gum arabic than whey protein to achieve the same effect. In 1997, the United States imported 10.8 thousand metric tons of gum arabic, commonly used as an emulsifier in citrus-flavored beverages, such as fruit-style drinks, juice mixes and blends.

In a related area, we recently told you how engineers at the University of Wisconsin (College of Agricultural and Life Sciences, 1605 Linden Dr., Madison, WI 53706) have applied for patent protection on a process that extracts specific proteins from whey. The scientists are using ion exchange to separate the proteins of whey more thoroughly than previously possible. By separating individual proteins, processors can take advantage of their special biological and physical functions.

The research focuses on finding ways to separate various proteins and minerals in whey. Lactoferrin is an iron-binding protein that has been isolated from whey. Babies need iron for normal growth and development. Many infants don't get enough of the substance. Lactoferrin grabs onto the iron in food, making more of the mineral available to the body.

Alpha-lactalbumin, a calcium-binding protein, enhances calcium absorption. It is one of the few proteins that remain clear when heated to pasteurization temperatures. Adding it to boxed juice could raise nutritional value by supplying protein and calcium. A third whey protein is lycomacropeptide. Some babies are born with a genetic disorder called PKU. These babies cannot digest a particular amino acid. As a result, people with PKU follow a strict low-protein diet to avoid the offending amino acid. Glycomacropeptide is unique in that it does not have this amino acid, making it a potentially rich source of protein for people with PKU.

Further information. At the University of Massachusetts: D. Julian McClements; phone: [phone]; fax: [phone]. At the University of Wisconisn: Mark Etzel; phone: [phone]; fax: [phone]; email: [e-mail].