ARS | Publication request: Extrusion cooking: Legume pulses

Submitted to: Encyclopedia of Agricultural, Food, and Biological Engineering
Publication Type: Book / Chapter
Publication Acceptance Date: April 19, 2010
Publication Date: September 28, 2010
Citation: Berrios, J.D. 2010. Extrusion cooking: Legume pulses. In: Helman, D.R., Moraru, C.I., editors. Encyclopedia of Agricultural, Food, and Biological Engineering. 2nd edition. New York, NY: Taylor & Francis Group. p. 453-464.

Interpretive Summary: Extrusion is a mechanical process used to create objects or products of desired shapes, sizes, and texture by forcing material through a die opening under pressure. If the food is heated during the extrusion by external heaters in additional to mechanical friction, this process is known as extrusion cooking. Extrusion cooking is a relatively new and advanced food processing technique, compared to traditional baking and other cooking methods, to produce variety of specialty foods, including puff snacks and breakfast cereals. The rise in consumer demand for convenience foods, health awareness and role of pulses in meeting these demands motivated researcher Dr Jose De J. Berrios of ARS' Western Regional Research Centre in Albany, Calif., Dr Juming Tang and Dr Barry Swanson at Washington State University to use extrusion in the development of unique, healthful, crunchy, great-tasting expanded snack-type foods from legume pulses such as lentils, garbanzos and dry peas and beans. This article presents a valuable and critical review of research work using extrusion technology for the potential development of value-added foods from legume pulses.

Technical Abstract: Extrusion is used commercially to produce high value breakfast and snack foods based on cereals such as wheat or corn. However, this processing method is not being commercially used for legume pulses seeds due to the perception that they do not expand well in extrusion. Extrusion cooking of pulses (lentils, dry peas, chickpeas, and black beans) through a Werner & Pfleiderer 37 mm Continua twin screw extruder run at screw speeds of 250-500 rpm, die temperatures of 120-160 oC, and feed moisture of 25-18% (wwb), produced highly expanded extrudates. The extrudates had reduced concentration of total oligosaccharides and significantly (p<0.05) higher in vitro protein digestibility than the controls (un-extruded) samples. Results of sensory evaluation tests demonstrated that the extrudates were considered acceptable as snacks and breakfast cereal type products. This article presents a valuable and critical review of research work using extrusion technology for the potential development of value-added foods from legume pulses.