Process Packs Protein into Snacks

By Jim Core
November 20, 2003

Whey proteins that are left over after cheesemaking are a key ingredient in new nutritious snack foods produced under a process developed by the Agricultural Research Service.

ARS recently filed a patent on the process, which uses a standard industry device, called the twin screw extruder, to make crunchy snacks with the whey proteins. The new snacks could help meet the demands of health-conscious consumers. The ARS-developed technique already has drawn the interest of food companies.

By using whey, the process boosts protein in expanded snacks--such as breakfast cereals, corn puffs, cheese curls and energy bars--from the traditional average of about 2 to 5 percent to 35 percent.

Most crunchy snacks are made from high-starch products such as corn flour, according to Charles Onwulata, a food technologist at the ARS Eastern Regional Research Center (ERRC) in Wyndmoor, Pa. An extruder, consisting of a long, heated barrel with two mixing screws inside, cooks the starch as the screws mix and push it through the machine to form the snack food. The crunchiness of the snack is determined by moisture content and temperature as it leaves the extruder.

Onwulata and other researchers with the ERRC Dairy Processing and Products Research Unit wanted to improve the nutritional profile of puffed snack foods by extruding corn flour with concentrated forms of whey.

At first, however, they found that the whey, in a form called whey protein isolate (WPI), reduced the crunchiness, color and texture of extruded snack foods. According to Onwulata, they were able to change the temperature and moisture in the extruder, so that the WPI blended well with corn flour to make crunchier snacks.

Those interested in licensing this technology should contact ARS' Office of Technology Transfer at telephone number (301) 504-6905.

ARS is the U.S. Department of Agriculture's chief scientific research agency.