The processing process of extruded food is completely different from the cooking and curing process of ordinary food processing, and the heating, curing and extrusion molding of extruded food are completed in an extruder in a very short time and almost simultaneously. The general process of processing is: food raw materials are mixed according to different formulas, after pretreatment, into the screw extrusion machine, under the rotation of the screw, kneaded into a very sticky and plastic dough, and then continue to be subjected to shearing and heating, which produces a certain pressure under the control of the die head, resulting in starch gelatinization, protein denaturation, enzyme inactivation, and microbial reduction. All these processes are generally completed within 5-10s, the longest is but 1min time, the temperature can reach 200℃, so people call this extrusion process called high temperature short time (HTST) process, in the production of puffed food, the pressure of the material before the die can reach more than 10MPa, so, At present, this process is also called high temperature, high pressure, short time process (HHS).

When the food is extruded from the die, due to the sudden drop in pressure, the water vapor rapidly expands and disperses, making the product form a porous structure, which is completely different from the aging process of baking cookies and secondary puffed food. The special heating and pressurizing method in this extrusion process can have a favorable effect on the food, such as the digestibility, comfort and mildew eradication rate of the food tend to be maximum. The harmful effects on food, such as Browning and damage to nutrition, tend to be minimal.

Because the food processed by extrusion machine has many advantages, it has been widely used in the food processing industry and has developed rapidly. In general, extrusion processing has the following characteristics:

1 Variety is good. A wide variety of food products can be obtained on the same extruder by changing material varieties, formulations and processing conditions.

2. Large production capacity. An extruder provides a continuous processing unit from conveying to extrusion, with a small footprint, but a much larger production capacity than any other steaming molding unit of the same volume.

3 Low cost. The labor force, equipment space and energy consumption required by the unit product are smaller than other cooking and forming devices, and the cost is low and the efficiency is high.

4 Products come in a variety of shapes. The extrusion machine can produce various shapes that are difficult to produce by other processing methods by changing the form of the die head and the cutting method.

5 High product quality. High temperature, high pressure, short-term processing makes starch gelatinization and protein denaturation, thus changing the digestibility of food, this processing makes the nutritional loss of food minimal, but at the same time can destroy most of the bad factors in food, and has the effect of sterilization.

6. High energy utilization rate. The extrusion processing device is to cook various foods in the case of relatively low moisture content in the material, which greatly reduces the energy contained in the cooking and re-drying of the food after cooking.

7 The production of new foods is easy. The extruder can modify proteins, starches and other food ingredients to produce new products.

8 Almost no loss of food raw materials. Extruder under the control of almost how many raw materials into the number of products, there is no loss of raw materials in the process, but also does not produce pollutants, which is a very important advantage of food extrusion processing.

These advantages of extrusion processing are exactly in line with the sustainable development strategy of mankind, so it is promising.

DAYI machinery company in extruding technology has been studied for nearly 30 years, the technology has been quite mature, the quality of the machine and a full range of services, making big billion machinery in the industry among the best. Over the years, DAYI machinery has been widely praised at home and abroad. In the future, we will continue to provide higher quality equipment and better service.

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