Explanation of the operation process of the food extruder

Extrusion technology has achieved rapid development and wide application in the food field. After the food is extruded by the snack food machine, its material properties have changed significantly. The macromolecular substances contained in the food, such as protein, starch, cellulose, etc., are cut into pieces under the action of high temperature, high pressure and strong shear force. Small molecular substances, thereby improving the taste of food, increasing the content of soluble dietary fiber and the digestion and absorption rate of the human body, and improving its nutrition. In addition, there are microorganisms and easily oxidized substances in food raw materials, which can be controlled by extrusion and puffing, thereby prolonging the shelf life of food and improving consumer safety.

After the material containing a certain amount of moisture is fed into the machine cavity of the snack food machine, the material is forced to move forward under the helical push of the screw, and is formed under the action of moisture, heat energy, propulsion, friction, and shearing force. Heat and pressure in high pressure processing environments. In the process of being pushed, the material is refined due to shearing and extrusion; due to the high temperature and high pressure environment, the gas between the materials is squeezed out, the density continues to increase, the temperature continues to rise, and the extrusion force is also increasing. , so that the material in the cylinder is in a high pressure of 3-8MPa and a high temperature environment of 120-200 ° C, the physical properties of the material have changed, such as starch gelatinization, degradation, protein denaturation, cellulose partial degradation, refinement, some Harmful factors are removed, enzymes are inactivated, etc. When the material is forced out of the die mouth of the snack food puffing machine, the pressure suddenly drops to normal pressure, the water evaporates rapidly, the temperature drops, and the volume of the material expands several times instantly, thus forming a loose and porous puffed food.