ADVANTAGES
- high quality of full fat soybeans
- low level of anti-nutritional soy factors such as trypsin inhibitors to 10 … 15%
- the digestibility of soy protein is increased
SEQUENCE OF OPERATION
Preliminary crushed soybeans or other grain crops are supplied into hopper and preconditioner of extruder.
The preconditioner is a component that pre-heats, moistures and at the same time mixes and injects hot steam into raw material. Dry steam pressure is 0.2-0.5 MPa and temperature – 110-130 °C. The raw material is softened and heated to 65-75 °C.
Preconditioning increases the production capacity of extruder, improves the quality of raw material and reduces the wear of the working parts over 20%.
Extrusion is a process of thermal treatment, sterilization, dehydration, texturing and granulating of the final product.
Raw material is heated by steam during a short-term (4-6 sec.) and pressed to 30 atmospheres. During the time of thermal process (which is less than 6 seconds) the protein and lysine content is not reduced.
Moisture is vaporized and starch cells are ruptured and availability of carbohydrates action of digestive enzymes is increased. In the process of extrusion the amount of protein increases.
The output of finished product increased by 3.4% compared to dry extrusion. After extrusion with preconditioning, for example full-fat soya does not require any drying.
Short but intensive heat, moisture and pressure is an effective way to destroy salmonella and other pathogenic bacteria, fungi and mould.
