Executives ... FYI.

Cereal products that contain high levels of high fiber can reduce calorie uptake and provide health benefits linked to chronic disease. However, a high-fiber content tends to diminish the quality of the final product and negatively impact consumer acceptability of cereal products, such as baked goods and pasta. Scientists wanted to use extrusion to produce high-fiber precooked flour to see if this method would increase its functional properties. They wanted to compare the rheological and functional properties of extrusion-processed pre-cooked whole wheat flour obtained by oven-drying and freeze-drying.

The investigators produced pre-cooked flours using a lab-scale twin-screw co-rotating extruder configured for low-shear and low-temperature processing. The swelling and pasting properties of the pre-cooked flours were characterized using rapid visco-analyzer methodology. The rheological properties were characterized using mixograph methodology. The quality of cookies and tortillas was also characterized by AACC-approved methods.

The scientists found that freeze-dried pre-cooked flour had similar swelling and pasting properties to oven-dried flour. Water absorption increased in the pre-cooked flours. The drying techniques had no significant effect on the quality of the cookies.

So, extrusion technology can produce pre-cooked wheat flour that has the same functionality for baked products, as well as oven-dried pre-cooked flour that has similar rheological and functional properties as freeze-dried flour.

Contact: Ron Madl, Department of Grain Science and Industry, Kansas State University, 101A BIVAP Building, 1980 Kimball Ave., 201 Shellenberger Hall, Manhattan, KS 66506. Phone: 785-532-7022. Fax: 785-532-7010. Email: rmadl@ksu.edu.