Putting the Missing Ingredient into Snack Foods

Increasing the dietary fiber from less than three to more than 10 percent in favorite snack foods is now possible with help from Agricultural Research Servicescientists. The best part is that consumers can get the added health benefit of the fiber without tasting the difference.

Many snack foods are cooked using a method known as extrusion. This is the process of forcing corn, wheat or rye meal flour and other ingredients through a die under high pressure, and sometimes heat, essentially cooking the mixture.

Until now, it has been difficult to add cereal fibers during extrusion without causing undesirable texture, which then decreases consumer acceptance, according to food technologist Charles I. Onwulata of the ARS Eastern Regional Research Centerin Wyndmoor, Pa.

However, Onwulata and his team found that by including dairy proteins such as casein or whey as a binder to hold everything together, they could also add more dietary fiber during extrusion cooking. The texture of the resulting snack food was found to be comparable in texture to other snack foods currently on the market, according to Onwulata.

Products such as breakfast cereals, corn puffs, cheese curls and energy bars are sometimes prepared using the extrusion process. Many of these products have less than one gram of fiber per 50 grams of product. According to Onwulata, his product can contain as many as 15 grams of fiber in a 50-gram bar. The recommended fiber intake is 20 to 35 grams a day, but Americans average only about 15 grams of fiber a day in their diets. Studies suggest fiber decreases the risk of heart disease, some cancers, high blood pressure and diabetes.

In a separate project, Onwulata has filed for a patent on a process that uses milk protein to envelope fiber and keep it from soaking up water when used in many foods. Reducing the water-holding capacity of the fiber improves food quality, according to Onwulata. He works in the ERRC's Dairy Products Research Unit.

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