New uses for curds and whey

by Amina Ali

cold, refreshing glass of milk may seem like a simple beverage, but it's actually a highly complex liquid. A U of G researcher is unravelling the mysteries of milk so they may be applied to an ever-expanding variety of creamy foods and drinks.

Food science professor Doug Dalgleish is investigating how milk proteins such as caseins and whey proteins function as ingredients in other foods. His basic research is supported by the Ontario Dairy Council, a trade association of many major food companies that use milk or its components in the formulation of products. By understanding milk ingredients and what they do, these companies will be able to use milk ingredients more effectively.

Milk components have always served as effective emulsifiers and texturing agents in foods. But Dalgleish's research allows milk components to be used both in improving infant formulas and soups and in creating new products entering the market such as health/sports drinks. Its a win-win-win situation -- dairy producers will sell more milk, food processors can expand their product lines, and consumers will gain better textured and varied foods.

"The world dairy community should maximize the use of its materials," says Dalgleish. "Expanding the use of milk ingredients such as proteins is one way to use this nutritious product to its fullest."

He begins by extracting milk proteins and studying their interactions with other food components. His research aims to answer common questions posed by food processors. Is an emulsion -- a suspension of small oil droplets surrounded by milk proteins that provides a creamy flavor -- stable enough to be added to foods without causing an adverse reaction during storage? Will it remain stable during processing at low pH to reduce microbial contamination?

The food industry is eager to use milk ingredients as emulsifiers in processed foods. As interest mounts for new fruity health/sports drinks, the need for an emulsion to maintain the properties of the juice becomes clear. Milk proteins are among the best for the job because of their superior functional and nutritional properties. Dalgleish's job is to investigate the basic properties of milk proteins and how these properties can be altered.

"We are trying to understand these interactions at the molecular level," he says. "Studying the basic chemistry and physics of the system provides insight into milk, a complex liquid food."

This basic underpinning research offers an explanation for the value of emulsifiers, especially for complicated liquid food products. Achieving this understanding will allow current food products to be improved and new ones to be made.

The Ontario Dairy Council's support for this research is matched by the Natural Sciences and Engineering Research Council. Several multinational food companies have also been involved.