Puffing is a food processing method. It is to put the processed food into a closed container, heat and pressurize it, and suddenly reduce the pressure. The water in the food will vaporize and expand, so that many small holes will appear in the food, which will become crisp and become puffed. food. The basic principle is to let the raw material suddenly depressurize under the condition of heating and pressurizing to make it expand.
The main purpose of the puffing process for dog food is to:
1. Improve the palatability of pet food;
2. Change or improve the nutritional value of pet food;
3. Improve pets’ digestion and absorption rate of food;
4. Change the shape and structure of pet food to make it easier for pets to eat;
5. Change the different nutritional index contents of pet food, such as reducing the water content to increase the shelf life of the food and facilitate storage;
6. Change the bulk density of food, extrusion granulation, and briquetting to increase the bulk density of food;
7. Kill various molds, salmonella and other harmful substances to improve the safety and hygiene of pet food;
Based on the above purpose, below we analyze and compare two different puffing methods in the dog food puffing process. It can be divided into two types, one is dry type, and the second is wet type.
Dry type extrusion requires adding moisture to the raw materials during production and processing. The raw materials are not pre-conditioned before entering the barrel. All the heat generated during the extrusion process is caused by the raw materials passing through the screw and barrel under the action of mechanical extrusion. produce.
The difference between wet type and dry type is that before entering puffing, it enters the pre-condition in advance, and uses steam to heat and moisten the pet food raw materials, so that the starch in the raw materials is pre-gelatinized, the protein is denatured, and the raw materials are softened. It is beneficial to improve the puffed granulation effect of dog food, improve the puffed quality and the added protein content of the product.