Extrusion technology has the potential to provide increased food security to Africa, while creating job opportunities and saving energy, according to a report by food scientists published by the Institute for Food Technology. The technology, which, in simple terms, is forcing materials through a fixed opening, is incredibly energy efficient. When applied to food (typically by using a flour-like form of some grain and a liquid), it can utilize materials that are normally wasted, while maximizing grains’ nutritional value. Products of extrusion cooking, which are generally ready-to-eat and shelf-stable, can add variety to diets in food insecure areas.
Extruded products are created by use of cold extruders or extrusion-cookers, which can be either single-screw or twin-screw machines, the latter of which bring more flexibility and variety to the production process, according to Dr. Mian Riaz, researcher at the Food Protein Research and Development Center at Texas A&M University.
Extrusion can process basic ingredients like sorghum, millet, rice, and maize into a wide array of textures, shapes, and flavors, and can greatly improve their nutritional content when they are processed along with inexpensive forms of protein, such as soybean meal, according to research by Veronica Obatolu, researcher at the Institute of Agricultural Research and Training in Ibadan, Nigeria.
In addition to its potential to improve Africans’ diets, extrusion is extremely environmentally friendly and economically viable. According to Riaz, extrusion means significant savings in raw materials, labor, and capital investment. Furthermore, by way of extrusion, materials that would otherwise be discarded—such as damaged kidney beans or pieces of egg shells and unborn chicks—can be converted into food or animal feed, according to a video produced by ExtruAfrica, an initiative launched in 2011 that organizes conferences and training sessions dedicated to extrusion technology, bringing together experts from around the world.
“Extrusion technology, as a cooking process, is particularly suitable for the beneficiation of by-products as it is energy efficient, environmentally friendly and compared to other cooking processes, it has no waste streams that need to be treated,” said LJ Grobler, professor of mechanical engineering at North-West University in Potchefstroom, South Africa and head of ExtruAfrica.