GB1566854A - Process of treatment of grain products - Google Patents

Description

(54) A PROCESS OF TREATMENT OF GRAIN PRODUCTS (71) We, CESKE VYSOKE UCENI TECHNICKE of Praha, Czechosovakia, a corporation organised and existing under the laws of the Czechoslovak Socialist Republic do hereby declare the invention, for which we pray at a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a process of mechanical and hydrothermic treatment of grain products, which improves their utilisation in the alimentary and particularly in the foodstuff industry.

The quick increase of population in the whole world requires also provision of the required amount of food of vegetable and animal origin and the required fodder for domestic animals. This is possible both by increase of production and by improvement in the utilisation of the products.

The improvement of the effectiveness of utilisation of agricultural products for feed ing purposes and as raw products for the alimentary industry is performed by their treatment whereby substances contained in vegetable products are economically transformed to substances which are from the point of view of nutrition and production more advantageous, whereby their usable parts are made better accessible to digestion enzymes.

Important agricultural products for fodder and food are grain products. These products are now mostly prepared by grindmg, pressing and steaming. These processes did not change in principle for a considerable time, only devlces for their carrying out have been improved, the preparation being sometimes a combination of different processes. Hydrothermic processes have been for instance introduced, in which the grain products are heated by steam or dry thermic processes in which grain products are heated by hot air or by the action of very short electromagnetic waves, by infrared radiation or similar means.

A thermo-mechanical treatment of cereal flour with destruction of starch has been also tried with positive results. In this treatment the grain products are ground at elevated temperatures in rolling mills with a differential speed high of the rolls.

There is also a known process according to the British patent specification No.

1,108,911, in which wheat flour is produced with purely mechanical destruction of starch by milling cold conditions on a milling stand with rolls having differential speeds in the ratio of 8 : 1 up to 80 : 1.

In the purely mechanical method the destruction of the starch grains is only small.

An improved effect can be obtained by the simultaneous action of heat, moisture and possibly also pressure. The obtained result is also influenced by the length of duration of the treatment.

By increase of the temperature and prolongation of the time of action of moist heat in the course of milling, the degree of destruction of starch grains is substantially increased.

It is possible to select the useful prolongation of time within which the milled products remain in the rolling stand at both mentioned milling processes at suitable conditions of pressure, temperature and moisture. This time amounts to a fraction of a second.

It is an object of this invention to eliminate this drawback of the mechanical and hydrothermic preparation of grain products.

A construction is selected for milling stands with relatively different speed of the milling surfaces, enabling according to the required effect and kind of treated grain product to use an angle for introduction of the milled product by using rolls of different diameters or of rolls and of a supporting milling surface and thus increase the time within which the milled product remains in the milling gap and consequently also improve the possibility of utilization of treated grain products.

When the diameters of the rolls are large, the curvature of their curved surfaces is reduced and thus also the angle of introduction of the milled products is reduced, and the time within which the milled product remains between the milling surfaces will be longer.

It is also possible to prolong this time in a construction having a supporting milling surface by adjustment of the dimensions and curvature of this supporting milling surface.

All similar adjustments of construction alter the time during which the treated grain product remains in the milling gap within limits of fractions of a second. But a suitable selection of this time in connection with the other parameters may significantly influence the effect of the treatment.

In a mechanical and hydrothermic treatment the milled product is heated to a temperature above 100"C, which can be adjusted by the control of the respiration or cooling of the milling surface. In the course of this heating the moisture of the grain products is transformed to steam which takes part in the process of destruction of the starch grains.

The mechanical and hydrothermic preparation of grain products according to this invention simultaneously dries the milled product. If the initial moisture content is low and this would reduce the effect of the said action of the generated steam, the milled product can be prior and/or in the course of the treatment wetted by water or steam to the desired degree.

The mechanical and hydrothermic treatment according to this invention is from the economic point of view also advantageous, as in case of a high content of moisture in the milled product the latter is dried in the course of its treatment to have a moisture content suitable for storing.

The treatment according to this invention requires for driving of the milling surfaces at different relative speed somewhat more power, than in case of a standard treatment by milling. The higher costs for power are however more than balanced by the improved possibility of utilisation of the products treated by the process according to this invention.

The invention provides a process for mechanical and hydrothermic treatment of grain products, in which the grain products are introduced into a milling gap between two milling surfaces, at least one of which is formed by the curved surface of a rotating cylinder, the relative speed of the surfaces being higher than 3 m/s, preferably 11 to 15 mls, the milling gap being, within a zone extending 50 mm upstream and 50 mm downstream of the narrowest portion of the milling gap, measured along an equidistant line between the two milling surfaces in a plane perpendicular to the axis of rotation of the rotating cylinder, at the most 15 mm wide, while the temperature in the milling gap is maintained above 100"C.

An improvement of the effect of the described mechanical and hydrothermic preparation can be achieved in that already to a certain degree thermically or hydrothermically treated grain products are introduced into the milling gap immediately after this thermic or hydrothermic pretreatment.

As a prior stage of preparation a twostage thermic treatment of grain products by infrared radiation can be used, in which after passage through heat zones, the grain products are introduced instead into a commonly used press, into the arrangement for mechanical and hydrothermic treatment according to this invention without any cooling. The technological parameters of this prior treatment - the time of application of the radiation, the intensity and similar are adjusted to obtain the maximum overall effect from the point of view of value for feeding purposes.

Thus a further improvement of the degree of destruction of starch, an improvement of the possibility of digestion and of utilization for feeding purposes and also for treatment in the alimentary industry is achieved.

Examples of application 1. When using two rolls of the same diameter 400 mm the width of the milling gap is 10,5 mm at the maximum. The revolutions of the roll with the higher speed is 1000 rpm, of the roll with the lower speed 430 rpm, with a relative speed of milling surfaces approximately 12 m/s.

2. The roll with the lower speed has a diameter 400 mm and 175 rpm, the roll with the higher speed a diameter 200 mm and 1000 rpm. The maximum width of the milling gap is 13,5 mm, the relative speed of milling surfaces approximately 6.8 m/s.

3. Two rotating cylindrical surfaces, the larger with an internal operating surface with a diameter 500 mm and 570 rpm., the smaller with an external operating surface with a diameter 200 mm and 1000 rpm have a width of the milling gap 8 mm and a relative speed of the grinding surfaces approximately 4.4 m/s.

4. A roll with a diameter 200 mm and 500 rpm has a relative speed with respect to a supporting milling surface about 5.2 m/s.

The length of the curved supporting milling surface is 170 mm.

5. Barley, which has been prior irradiated for 30 seconds by infrared radiation and maintained for further 60 seconds at the obtained temperature of 132"C is immediately thereafter introduced into a milling gap formed by a slow moving roll of a diameter 400 mm and 175 rpm and by a fast moving roll of a diameter 300 mm at 1000 rpm.

Five times more destructed starch has been found in the product by an enzymatic method than in barley just milled.

WHAT WE CLAIM IS: 1. A process for mechanical and hydrothermic treatment of grain products, in which the grain products are introduced into a milling gap between two milling surfaces, at least one of which is formed by the curved surface of a rotating cylinder, the relative speed of the surfaces being higher than 3 m/s, the milling gap being, within a zone extending 50 mm upstream and 50 mm downstream of the narrowest portion of the milling gap, measured along an equidistant line between the two milling surfaces in a plane perpendicular to the axis of rotation of the rotating cylinder, at the most 15 mm wide, while the temperature in the milling gap is maintained above 100"C.

2. A process according to Claim 1 wherein the relative speed is substantially 11 to 15 m/s.

3. A process according to Claim 2 wherein the relative speed is substantially 12 mls.

4. A process according to Claim 1, wherein the grain products are introduced into the milling gap immediately after prior thermic or hydrothermic treatment.

5. A process according to Claim 1, substantially as herein described with reference to Examples 1 to 5.

6. A product made by a process according to any one of Claims 1 to 5.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. obtained temperature of 132"C is immediately thereafter introduced into a milling gap formed by a slow moving roll of a diameter 400 mm and 175 rpm and by a fast moving roll of a diameter 300 mm at 1000 rpm. Five times more destructed starch has been found in the product by an enzymatic method than in barley just milled. WHAT WE CLAIM IS:

1. A process for mechanical and hydrothermic treatment of grain products, in which the grain products are introduced into a milling gap between two milling surfaces, at least one of which is formed by the curved surface of a rotating cylinder, the relative speed of the surfaces being higher than 3 m/s, the milling gap being, within a zone extending 50 mm upstream and 50 mm downstream of the narrowest portion of the milling gap, measured along an equidistant line between the two milling surfaces in a plane perpendicular to the axis of rotation of the rotating cylinder, at the most 15 mm wide, while the temperature in the milling gap is maintained above 100"C.

2. A process according to Claim 1 wherein the relative speed is substantially 11 to 15 m/s.

3. A process according to Claim 2 wherein the relative speed is substantially 12 mls.

4. A process according to Claim 1, wherein the grain products are introduced into the milling gap immediately after prior thermic or hydrothermic treatment.

5. A process according to Claim 1, substantially as herein described with reference to Examples 1 to 5.

6. A product made by a process according to any one of Claims 1 to 5.