The extrusion and puffing technology has been developed rapidly and widely in the food field. The food is extruded and processed by the leisure food making machine. The material characteristics of the food are obviously changed. The macromolecular substances contained in the food such as protein, starch, cellulose, and the like are cut into small molecular substances under the action of high temperature, high pressure, and strong shearing force so that the taste of the food is improved. The content of the soluble dietary fiber and the digestive absorption rate of the human body are improved, the nutrition of the soluble dietary fiber is improved. Besides, that microorganism in the food raw material and the easily oxidized substance can be controlled by the extrusion and expansion, so that the shelf life of the food is prolonged, and the food safety of the consumer is improved.
Puffed principles of leisure food making machine:
After the material containing sure water is fed into the machine cavity of the leisure food, the material is forced to move forward under the helix of the screw. The material is heated and pressed in the high-temperature and high-pressure processing environment formed under the action of water, heat energy and propulsive force, friction force, and shearing force. In the process of being pushed, the material due to the role of shear and squeeze and was refined. The gas between the materials due to the high temperature and high-pressure environment was extruded and discharged, the density continues to increase, the temperature continues to rise, and the suppression force is growing. Such materials in the barrel in the high pressure of 3-8m / h and 120-200DEG C high-temperature environment, the physical properties of the material changes. Such as starch gelatinization, degradation, protein denaturation, cellulose degradation, refinement. The removal of some harmful factors, enzyme inactivation, and so on. When the material is extruded from the die mouth of the snack food puffing machine, the pressure drops to atmospheric pressure, moisture flash suddenly, the temperature decreases. The volume of the material instantly several times the expansion, resulting in the formation of loose texture and porous structure of the puffed food.
The characteristics of the extrusion and puffing technology of the leisure food making machine are as follows:
1. The food expansion machine improves material processing characteristics.
The extrusion and puffing have a great influence on the physical and chemical properties of the material. After the material is extruded and expanded, the expansion force of the material increases, the water holding capacity is improved, the solubility is greatly improved, and the specific surface area is increased. The change of the material’s physical and chemical properties also greatly improves the material’s processing property.
2. Puffing food extrusion machine improves food flavor and taste.
With extruded products, the starch granules are fully gelatinized, the mature starch is converted from raw starch. The amylose content is increased, the sugar and dextrin content is reduced, and the protein is denatured. The insoluble dietary fiber is converted to soluble dietary fiber to a certain extent. While some of the aromatic components may have a certain degree of loss during the extrusion process, the Maillard reaction due to high temperature in the processing process will form a new flavor substance. The extrusion and puffing can also remove certain bad smells.
3. Leisure food equipment improves food stability and prolongs shelf life.
In the extrusion process, after the material is extruded, the moisture evaporates instantly, which reduces the water content in the food. Due to the high-temperature action, the pathogenic bacteria and microorganisms in the material are killed, the lipase and other enzymes lose their activity. Besides, the extruded food is not easy to produce “retrogradation phenomenon.” The existence of these factors provides a powerful guarantee for improving food stability.
4. The food extrusion equipment improves production efficiency and the utilization rate of by-products.
Extrusion processing technology has high production efficiency and high utilization rate of raw materials. Besides, extrusion technology can process most of the grain and oil by-products, such as wheat bran, soybean meal, corn husk, and other grain by-products into new foods, which improves the utilization rate of grain by-products and increases its added value.
5. The nutrition loss is small, easy to be digested, and absorbed by the body.
Extrusion is a high temperature and short time processing process, the heating time of raw materials is short, and the degree of destruction of nutrients is small. The side chain breakage of amylose in the material improves the digestibility of the body. It degrades the molecular structure of macromolecular substances such as protein and fat in varying degrees so that the product is easy to digest and absorb.
Extrusion technology is a new type of food processing technology. Leisure food making function improves the processing characteristics of materials, improves the utilization rate of raw materials, improves the taste, destroys anti-nutritional factors, kills microorganisms, and reduces the waste of resources. Therefore, the application of leisure food, making machines in the food field, has a very broad prospect.
In recent years, the developed countries are strengthening the research and popularization of whole-wheat food, and its production has become a new scale. The production and consumption of whole wheat food have increased year by year. However, the research and development of whole wheat food in China is still in the initial stage, and whole wheat food is rarely seen in the market. The application of extrusion and puffing technology is essential to the comprehensive utilization and development of grain oil in China.