The basic principle of extruder and extrusion

The core equipment for the continuous extrusion cooking process is the extruder. The extruder has the functions of compression, mixing, mixing, melting, puffing and molding. The cavity of the extruder can be divided into 3-5 zones, each zone can be heated by steam or electric, or can be heated by extrusion friction to achieve the purpose of cooking materials, the material is in the cavity under the action of high temperature and high pressure, starch Gelatinization, protein denaturation. When the material passes through the various regions of the extruder chamber, soluble flavor materials and pigments can be injected into the material through the cavity under the action of high pressure. At the end of the extrusion chamber, the molten material is extruded through the die hole of the die plate under the action of high pressure. Due to the sudden drop of pressure, the water vapor rapidly expands and dissipates, causing the product to form a porous structure, and then the puffed material is Rotate the knife to cut into a certain size product.

Single-screw extruders and twin-screw extruders are the most commonly used in breakfast cereal production, while twin-screw extruders are more advantageous than single-screw extruders because of the material size of single-screw extruders. The requirements for moisture and components are strict, and it is easy to cause problems such as backflow of materials and easy wear of the screw.

Characteristics of extrusion technology

*Very variability *Production capacity *Low cost *Various product shapes *Health, low nutrient loss, high digestion and absorption rate

* High energy utilization rate * Easy production of new foods * Little loss of nutrition in food ingredients

It is currently recognized as a health and safety food in the world.

Application of extrusion technology

1. Snack food and snack food 2. Breakfast cereals 3. Macaroni food (extrusion temperature 50 ° C, screw speed 80 rpm, exhaust)

4. Instant powder infant food 5. Modified starch and denatured cereal powder 6. Bread slice 7. Instant tea

8. Soybean tissue protein (raw material moisture 43%, below 60 ° C / below 60 ° C / below 180 ° C / below 180 ° C) 9. Feed production

10. Candy and chocolate