FULL FAT SOY EXTRUDER
What does the extruder do?
- decreases the urease activity in soy up to 0,05…0,2 pH
- opens up the fat cells
- the full fat soy is heated prior the oil pressing process
ADVANTAGES
of soy processing in the extruder:
improved nutrient digestibilities
deactivation of soy antinutrients
a high-temperature and a short-time process that is easily controlled and does not destroy proteins
FINAL PRODUCT:
full fat soy (also called as full fat soya or full fat meal)
RAW MATERIALS:
soybeans, dehulled soybeans (with moisture of 8…12%)
Raw soybeans cannot be used as such for animal feed as they contain antinutrients, such as trypsin, lipases, lectins and urease.
If you process the soy properly you can have full fat soy a perfect feed ingredient because of its protein, linoleic acid and lecithin contents.
All can be deactivated, modified or reduced through proper heat treatment to minimize or eliminate their adverse effect.
Since all these inhibitors are proteins, caution should be taken to assure that no destruction of the oilseed protein occurs.
This can be accomplished only through optimum processing and good quality control measures.
Extrusion cooking has some additional advantages, which other methods do not offer, for example a high temperature and shorter time cooking process will minimize degradation of food nutrients while improving the digestibility of protein by denaturation.
Dry extruders are single screw extruders with a segmented screw put together around the shaft. In between the screw a restriction (steam lock, choke plate) of different diameters can be placed to increase the cook and shear.
When material moves in the barrel, and comes across these restrictions, it is unable to pass through, and consequently, pressure builds up and a back flow is created.
With the help of the screw conveyor the soybeans are fed into the extruder barrel.
Due to a high pressure, high shear and temperature it is compressed, mixed and heated up to 120...140 °С. A short cooking time of 25...40 seconds, saves the protein in full fay soy preventing protein denaturalization. The urease activity decrease up to 0,05…0,2 pH
The discharged product from the extruder is the full fat soy. Usually it may be used as:
- feed component for poultry which is rich in proteins and fats
- the feedstock for mechanical oil extraction and obtaining the soy oil cake