With the advent of industrial manufacturing, extrusion found application in food processing of instant foods and snacks. The main role of extrusion was originally developed for conveying and shaping fluid forms of processed raw materials. Present day, extrusion cooking technologies and capabilities have developed into sophisticated processing functions including: mixing, conveying, shearing, separation, heating, cooling, shaping, co-extrusion, venting volatiles and moisture, encapsulation, flavor generation and sterilization. Products such as certain pastas, many breakfast cereals, premade cookie dough, some french fries, certain baby foods.
Generally, high-temperature extrusion is used for the manufacture of ready-to-eat snacks, while cold extrusion is used for the manufacture of pasta and related products intended for later cooking and consumption. The processed products have low moisture and hence considerably higher shelf life, and provide variety and convenience to consumers.
Classification of extrusion foods:
According to the extrusion craft, you can classify the following types:
1. Food Type directly struido, such as the main matter of cereal, potato or beans, are made by the squeezed by the extrusion machine, in conditions of high temperature and pressure, use the difference pressure of the machine.
2.Type of baked goods: such as the main stuff of cereals, potatoes or beans as the main raw material, they are made by roasting and other extrusion heating methods
3. Type of Fried Foods: such as the main stuff of cereals, potatoes or beans, made by the fried oil.
4. Other types of swollen foods: use the baked or extruded foods as a billet, add with cocoa products, marmalade or nuts as excipients.