With the appearance of the extruding technologies the opportunity to reprocess such cereals as soya, rape, wheat, corn, barley etc. with the maximum profitably is came in sight.
In the base of extruding of grainand grain mixture are the two processes – the mechanochemical one and the „explosion”.
The last one, an explosion, is the result of an abrupt pressure change inside of a seeds at the moment the seeds are at the exit of an extruder. Both processes are uninterrupted and run under the high degree of compression and particular speed of raw material passing through the extruder.
The principle of dry extruding method lies in the impact with the high temperature together with an abrupt pressure change at the moment of emission of a product from extruder.
The optimal level of thermal impact is 150°С at the end of the cycle and has to be within from 3 to 4 seconds (the whole process duration is 25 seconds). It causes equable denaturation of native protein, without infraction of primary compounding of amino acids and at the same time preserves nutritive value of protein. The ferments activity, first of all, the inhibitors of triypsin in soya, decreases to the acceptable standard, providing maximum feeding efficiency.
An energy layer in grain is presented with carbohydrates (cereal, peas) and fat (soya). Starch gelates under the passing through the extruder and expands on exit. This effect is provided by disturbance of granules structure and cleavage of the molecular chain. The whole process associates with hot moisturization of this polysaccharide. The difference is that under the extruding the process occurs under the conditions of lower moisture and much faster. That moisture, which is necessary for greasing of the extruder, is quite sufficient for gelation. Moisture evaporates on exit of the product and starch gel hardens fast. Certain percent of starch transform into dextrins under extruding, that associates with the act occurred under parching of grain.
Extruding increases availability of oil in soya due to disruption of oil cells. It happens under a pressure jump (40-1 atm) at the moment of jumping out of the product. That is why the extrudate presents oily homogeneous mass. Under parching this effect is not achieved even in case of the finest crushing of soya beans. The extrudate does not rancidify for a long time because of lecithin, tocopherol and inactivation of lipo oxidase.
Extruding facilitates to a complex compound formation of fat with starch in grain in the ratio 1:10, and also has an effect on fibre, changing its density with structure destruction with mechanical factors and moisture.
Under the recommended duties of the extruding most part of microflora (bacteria, fungi) is lost in grain. It is very important if grain is afflicted by Penicillium and has large bacterial load. Microorganisms of corn and wheat grain are lost completely in the process of extruding, and in barley there is about 6% of microorganisms because of high temperature (130-160°С) and pressure (20-80atm).
Our equipment will be interesting both for a farmer and a huge production, as we have modification groups of different productivity.