New and emerging R&D tools enhance dairy product quality.

Researchers and developers need much more than an available processing facility to transform innovative ideas into successful new dairy products. Those ideas must somehow be turned into palatable products that meet an existing - or created - demand.

Dairy developers have long understood the role quality testing plays in product appearance, flavor, aroma, texture, stability and other parameters. The market has no room for a pizza cheese that browns before it melts - or for a flavored milk that leaves behind a bitter aftertaste.

Adequate testing during the research and development (R&D) phase, therefore, is critical to the production of a high-quality product. Moreover, new and emerging tools and technologies can help dairy processors improve or simplify lab quality measurements to ensure full-scale production delivers the desired results.

Choice Cheese

Process cheese can be coaxed into shapes or spreads and also is a featured ingredient in many other food products. When it comes to melting or machineability, its functionality requirements might vary greatly from one application to another.

Functionality tests, therefore, are critical to the creation of a process cheese, says Mary Anne Drake, Ph.D., associate professor of food science at North Carolina State University. For example, machineability is crucial if the product is to be transformed into shreds, cubes, sticks or slices, she says. A bit of legwork on the R&D side could mean the difference between clearing a "bunch of gummed up paste every 30 minutes on the machine" and churning out a cleanly sliced product, she adds.

An instrument originally created to evaluate the cooking characteristics of a starch could one day help process cheese developers speed up the laboratory manufacturing process and assess critical functionality parameters such as viscosity. According to Lloyd Metzger, Ph.D., an assistant professor of food science in the University of Minnesota's Office of Food Science and Nutrition, the Rapid Visco Analyzer, or RVA, slashes product development time. Manufactured by Newport Scientific Pty Ltd. of Australia, the RVA is distributed in the United States by Foss North America, Eden Prairie, Minn. Essentially, it simulates the temperature and stirring profile used to make process cheese on a large scale.

Unlike traditional setups, says Metzger, which typically involve a small-scale cooker holding product in the "10- to 20-pound range," the RVA allows researchers to work on a very small scale. "You make about a 25-gram batch of processed cheese, so you can look at numerous formulations in a very short period of time at a low cost," he says.

Metzger and fellow researchers currently are in the testing phase. "We're actually assessing changes that we know influence processed cheese characteristics, and then seeing if we get data that make sense based on what we know already," he says.

Because numerous formulation options come into play for process cheese, "it's really difficult to assess whether or not you're having an effect on the product," says Metzger. "You have so many ingredients to look at. It may be adding a specific type of starch or a gum if it's a spread." He says he has used the RVA to screen ingredients for a number of companies and is pleased with the results so far.

During the laboratory manufacturing process, Metzger says he measures the process cheese's viscosity and evaluates whether or not the product is "doing what it's supposed to do." The cheese must have a certain viscosity to be pumped appropriately or run on the process line, he adds.

Metzger then measures the characteristics of the unmelted cheese - factors such as its firmness and adhesive characteristics. To do this, Metzger transfers the cheese to a cylinder, where he performs texture analysis after the product is cooled. He then places the cheese back into the RVA, where the product is remelted to determine if it has the appropriate flow properties.

Because the cheese ingredients in a process cheese have a significant natural variability, Metzger also uses the RVA to conduct research on natural cheeses. "Studies I'm doing now are to make natural cheeses that 1 know have different properties that will influence process cheese characteristics," he says. "Then I use the RVA to make process cheese out of them and, at the same time, make process cheese on a larger scale, in a larger cooker, and then compare those results."

Beyond RVA

Metzger says he is experimenting with fluorescent spectroscopic analysis techniques that could one day provide realtime data related to process cheese manufacture. "I think online analysis is really an area that will start to blossom," he says. "While you're manufacturing the process cheese, you're analyzing its characteristics and know immediately whether it was manufactured properly or what its functional properties are going to be."

John Lucey, Ph.D., an assistant professor in the Department of Food Science at the University of WisconsinMadison, says in-line instruments such as improved coagulation sensors could someday help product developers determine the best time to cut the curd in cheese making, especially in situations in which the cheesemilk is altered by processing.