The subject of the invention is a method of isolation of beta-glucane of wheat, in particular of oat and barley, the invention concerns the method of obtaining beta (1-3, 1-4) glucane by means of cavitation, and in particular by means of ultrasonic cavitation.

Glucanes are homo-poiysaccharides build of glucose monomers. Glucose is a hexose, i.e. sugar containing six carbons, which gives numerous possibilities of creating connections. For this reason glucanes are a group of compounds presenting various physical, chemical and functional properties.

Beta-glucane of oat, with bonds 1-3, 1-4 is a substance, whose influence on health is very well documented, thus it was awarded with an EFSA - European Food Safety Authority consent for application in so called health claims on products manufactured and sold in the European Union. It is also a substance recognized and approved on the international market, by (inter alia) the American Food and Drug Administration, it proves that the commercial potential of beta-glucane is significant and justifies research and development of the methods of isolation of beta-glucane of primary raw materials.

The aim of the invention is to provide the end precipitation method of obtaining a bio-active poly-saccharide , i.e. the beta-glucane. At the same time it is desirable to create a process characterised by low media consumption and high efficiency of beta-glucane isolation of the primary raw materials, as that prevails in existing economic conditions in assessing its profitability in industrial applications.

The Polish patent no. 217750 provides information on non-starch polysaccharides, in particular β-glucane of wheat, in particular of common oat Avena sativa, and concerns specifically the method of obtaining high purity β - (1-3, 1-4) - glucane. This method is characteristic in that the grain before milling is subject to high temperatures, ranging from 60 ^e C to 130°C, preferably 90°C, and then the extraction is made by means of alkaline solution with pH between 8 and 11, preferably pH=9,5, in temperature from 10 to 50°C, preferably 25°C. The advantage of the method is that the obtained β-glucane preparations have high molecular weight, thus a great ability to bind water and create gels.

The patent claim no. 389995 gives information on production method of nutrition substances, beta-glucane, insoluble fibre and preparation of oat protein from bran, characteristic in that the following processes are included in the method: the raw material is transported do a tank, water and ethanol from a tank are added, and such suspension is mixed in temperature from 50°C to 100°C, - cooled down with cooling water from a cooling aggregate and the suspension is directed to a vibrating screen; the filtrate from the sieve, that contains ethanol is directed to ethanol recovery station, where ethanol is distilled, returned to a tank by means of a pump, and the decoction of ethanol recovery is concentrated and directed to a tank by means of a pump; the concentrated bran fraction, resting on a screen, is directed to a tank, where it is suspended in water and NaOH solution fed from a tank, next the suspension is mixed in the temperature from 50°C to 100°C, - after cooling with cooling water from a cooling aggregate, the suspension is directed to a vibrating screen by means of a pump, and separated solids are directed to a tank, where they are mixed with the decoction, and the filtrate is directed to the tank and acidified with HCI addition, next the protein fraction is precipitated, the liquid is directed to a centrifuge by means of a pump, in the centrifuge the protein fraction is separated and transported to a tray drier, the protein after drying is directed for confectioning; the filtrate recovered during centrifuging is directed to a tank and neutralised with NaOH, fed from a tank with a pump, next ethanol is added by means of a pump from a tank and that causes precipitation of beta- glucane in a tank. The suspension is directed on a vibrating screen by means of a pump, and separated beat-glucane in solid form is directed to a tank, where it is suspended in small amounts of ethanol fed from a tank by means of a pump, next it is directed by means of a pump to a spray drier, and finally for confectioning; the filtrate remaining on the screen is directed to the alcohol recovery station, where ethanol is distilled and returned to a tank by means of a pump, next the decoction from ethanoi recovery is concentrated by means of evaporation excess water, the liquid thus obtained is directed to a tank, mixed with other components and the suspension is directed by means of a pump to a tray drier, the dried preparation of insoluble fibre is then directed for confectioning. The subject of the invention is also the set of tanks and technological devices connected by means of pumps and pipelines, used for application of the above described method.

The abovementioned methods allow for recovery merely up to 70% of the beta-glucane contained in the raw material. Unexpectedly, using the phenomenon of cavitation proved successful in increasing the efficiency of extraction of the active substance, i.e. beta-glucane from oats, and in particular from oats up to 95% of the primary content, simultaneously reducing the consumption of the media used in the process, in particular to lower significantly the temperature of the process stages.

Cavitation is a physical phenomenon that consists in rapid change from liquid phase to gaseous phase due to decrease of pressure. When the liquid rapidly speeds up, in accordance with the principle of energy conservation , the static pressure of liquid decreases, !n the gaseous state the solvent penetrates the extracted substance with greater efficiency than in liquid state. That allows for increase in extraction efficiency and decrease of the process duration.

The invention consists in using the phenomenon of cavitation in at least one operation during the isolation of 1-3, 1-4 beta-glucane of any wheat raw material, preferably oats or barley. The wheat raw material, preferably grain, milled grain or its fractions, such as flour or bran, are subject to defatting in conditions enabling occurrence of cavitation, preferably sonic cavitation. Intense mixing results in effective penetration of the plant-tissue by a solvent in various states of aggregation, followed by defatting of the raw material and transport of the lipid mass to 50% solution of water: organic solvent, preferably ethyl alcohol, prepared proportionally to the mass ratio of the raw material, respectively from 1:1 to 1:5, preferably 1:3. The process of defatting by means of cavitation mixing is carried out in the temperature from 0° C to 60 ^e C, preferably 25 ^e C. The defatted raw material is subject to water extraction, using cavitation, preferably sonic cavitation, with mass ratio of the water solvent to original mass of the raw materia! in the process, respectively from 5:1 to 20:1, preferably 10:1. PH of the extraction process ranges from 6,0 to 8,0 preferably 7,0 and is reached by adding appropriate chemical compound, that increases the environment alkalinity, preferably metai hydroxide. The temperature during the extraction process ranges from 1° C to 60 °C, preferably 30 °C, and the water extract is separated from the insoluble suspension by means of typical methods: filtration, centrifuging, sedimentation or flocculation. Separation of the extract from the solid parts is carried out by means of typical methods, and the filtrate containing water extract of the defatted raw material is subject to processing in the cavitator, preferably by means of sonic cavitation during 10 - 60 min, preferably 30 min in order to denaturate the proteins, next the protein are isolated from the solution by means of typical methods: filtration, centrifuging, sedimentation or flocculation. Next, the de-proteinised filtrate, containing the water extract, is subject to cavitation, preferably sonic cavitation, with organic solvent, preferably ethyl alcohol, in proportion ranging from 1: 0,1 to 1: 0,3, preferably 1:0,2, in the temperature 0° C to 30 °C, preferably from 15 °C, resulting in precipitation of the beta-glucane, which is separated with typical methods and dried.

Example. 1. Defatting of the wheat (raw material) by means of sonic cavitation.

10 kg of grain of the decorticated grain of oat is placed in a feeding tank containing 50% solution of water: alcohol in the amount of 30kg. The defatting process takes place in the temperature of 25°C during 20 min., one sonic throughflow cavitator with at least one reaction chamber. Due to the forces operating during cavitation, the structure of plant tissue is damaged, resulting in effecting release of lipids to the solution. Analogous test was performed without using the cavitator in a heated tank, for comparison purposes. Separation of the same amount of fat required 3 hours of heating with intense mixing in the temperature 80-90 °C.

Example 2. Separation of beta-glucane from defatted raw material by means of sonic cavitation.

The raw materia! in the form of oat bran, defatted with typical methods, in the amount of 5 kg (in recalculation to dry mass) was mixed in the cooled feeding tank with 50kg of water with pH adjusted to 7,0 by adding NaOH. This mixture was submitted to cavitation in the flow sonic cavitator with at least one reaction chamber. The process was carried out in the fixed temperature of 30 °C during 30 min. After the extraction was complete, the water extract was separated from insoluble suspension by centrifuging. The efficiency of extraction was 87% considering the content of beta-glucane in the raw material {lower efficiency was related with using raw materia! defatted with methods other than cavitation for the test). Example 3. Denaturation of proteins in the filtrate containing water extract of defatted raw material.

The post-extraction part containing, inter alia, beta-glucane and barley proteins that originated from the process of isolation of beta-glucane of barley in the form of flour, that has been defatted with typical methods, and then subject to water extraction in 35 °C, with addition of Na ₂ C0 ₃ and separated into liquid and solid fraction by means of centrifuging. The filtrate (1001) was then directed to sonic flow cavitator with the feeding speed of 500 1/h. The cavitation time was 60 mtn, that was enough for five passes of the fed volume through the reaction chamber of the cavitator. Rapid changes of pressure and local overheatings caused denaturation of proteins, separated from the filtrate by means of centrifuging.

Example 4. Precipitation of beta-glucane of the solution using sonic cavitation.

The de-proteinised filtrate in the amount of 250 I containing water solution of beta-glucane, among others, obtained by means of extraction methods of barley, described in literature, is introduced to the feeding tank, to which later the ethyl alcohol is added in the mass ratio 1: 0,2. The mixture thus obtained is fed to the flow cavitator, where intense mixing takes place. Ethyl alcohol reaches the hydrated chains of beta-glucane and causes displacement of water, and as a result, precipitation of beta-glucane of the solution. The temperature of the process is 5°C.