Extrusion processing is widely used in food processing sectors for developing ready-to eat snacks like pasta, breakfast cereals, baby food, pet foods, etc. Extrusion aids in restructuring the starch and proteins present in the raw materials to develop ready-to-eat products. The short time in extrusion processing aids in retainment of higher quantity of nutrients as compared to conventional technologies. It is used to develop food products such as breakfast cereals (oat, wheat, rice, millet, corn), ready to eat snacks, confectionary products (caramels, toffees, candies), pet food, baby food, puffed snacks, rice and dal analogues, meat analogues etc.
Extrusion results in denaturation of proteins, decreases the lipid oxidation, helps in gelatinization of starch and also reduces the anti-nutritional factors. The final products obtained after extrusion have lower moisture content that enhances their shelf life by preventing microbial growth with zero disposal problem.
Apart from the cereal based conventional extruded food products, the demand for development of millets and pulse-based products with improved nutritional and functional value are rising now. More focus is given on the application of extruded flour as fat replacers, hydrocolloids and novel ingredient for the development of protein and fiber rich, low-glycemic and gluten free food products. A sound knowledge is required on the food material properties, its corresponding cooking temperature, and screw speed to avoid material burning, chocking, and overheating inside the screw casing. Also, proper training is required on die attachment, screw fitting and material handling.