the object of the present invention is to further improve a process for the gentle modification of the functional properties of a protein preparation , preferably of protein isolates or protein concentrates from vegetable seeds , by heating the protein preparation , for the production of fresh or dry products as a base material or additive for protein - containing foodstuffs , in such a manner that a defined , selective , uniform determination of the functional properties is possible throughout the entire protein preparation volume . in particular , the drawbacks related to conventional heating with thermal convection should be avoided . furthermore , a device for heating a protein preparation gently should be provided which is inexpensive and not complicated a key element of the present invention is that a process for the gentle modification of the functional properties of a protein preparation , preferably of protein isolates or concentrates from vegetable seed , by heating the protein preparation , for the production of fresh or dry products as a base material or additive for protein - containing foodstuffs , is further improved in such a manner that the protein preparation is exposed to an electromagnetic high - frequency field by means of which the protein preparation is heated with a largely uniform temperature distribution throughout the entire volume of the protein preparation . the present invention is based heating very slow flowing protein preparations by means of penetrating heating in order to introduce the energy input as quickly and uniformly as possible throughout the entire volume of the to - be - heated protein preparation . an element of the present invention is that the use of high - frequency fields leads to uniform thermal input throughout the entire volume of the preparation , which , in addition , can be determined directly and immediately to a defined degree by regulating the electric fields . the penetrating heating generated by high - frequency fields for a protein preparation with viscous flow behavior is also suited for products with a high solid substance content , because the energy input leads to uniform heating with no local overheating , such as for instance on the walls of the vessel . for gelling the proteins , the proteins can be directly heated with no mechanical input , such as for example a stirring device . preferably , dielectric heating occurs using high - frequency fields with frequencies between 10 and 40 mhz . such hf fields permit heating protein preparations , in which proteins are distributed polydispersely as a pastose liquid or in an aqueous solution or are in a swollen or precipitated state , uniformly throughout the entire volume of the protein preparation . in particular , the solubility , viscosity , water - binding , oil - binding and / or gelling behavior as well as dispersive power of the protein can be determined in this manner . the use of hf - fields permits heating protein preparations with a dry substance content of up to 45 % with no local overheating . provision of a uniform heating temperature and immediate influence of the energy input in the to - be - heated protein preparation by regulating the hf energy permits heating the protein preparation over a very narrow time window to an exact as possible temperature level . thus , selective energy input can be realized within seconds , for example , by being able to heat the protein preparation to a prescribed temperature level with a fluctuation range of few ° c . usually heating temperatures range between 70 ° c . and 90 ° c . an invented device for carrying out the process described in the preceding is fundamentally provided with a feed means which conveys the to - be - heated protein preparation in the heating zone . the heating means essentially comprises a hollow channel surrounded by a hf - field - penetrable material . furthermore , an element of the present invention is that an electrode arrangement is provided which generates a homogeneous hf field inside the heating zone . finally , a feed unit is provided which conveys the to - be - heated protein preparation through the hollow channel of the heating zone . the present invention is made more apparent using a preferred embodiment with reference to the following figures without the intention of limiting the scope or spirit of the overall invention . fig1 illustrates a device for heating a protein preparation according to the aforedescribed process , fig2 illustrates a flow chart of a prior art process for extracting protein concentrates and protein isolates . fig1 shows a device for gentle , uniform heating of a protein preparation for defined modification of the functional properties of the protein contained in the preparation . a feed pump 1 feeds the , usually viscous , protein preparation , which for example emerges as curd from a precipitation , in the direction of a hollow channel 2 , which preferably is made of quartz glass . before the heating zone 3 , the hollow channel 2 is provided with a channel region k in which the protein preparation is homogenized with the aid of a static mixer sm and / or reagents r can be added for selective modification . the heating zone 3 is limited by hf electrodes 4 , which generate a homogeneous hf field inside the hollow channel 2 which functions as an enclosure of the protein preparation . care must be taken that the to - be - heated protein preparation is conveyed in the heating zone 3 without any air inclusions , because air inclusions are isolation regions for the hf fields . preferably , the electrodes are glued onto the hollow channel 2 made of quartz glass . the protein preparation fed uniformly through the heating zone 3 is uniformly heated by the hf fields and , on the right side of the fig2 is conveyed from the heating zone 3 for subsequent drying . the temperatures between 70 ° c . and 90 ° c . attainable in heating zone 3 results in denaturing the protein in the protein preparation which is connected with structure changes in the protein . with the aid of the process and device of the invention , water and energy requirements for functionalizing proteins are reduced . no dilution steps and therefore no additional energy - intensive drying steps are needed for functionalizing . thus , the process of the invention contributes to considerable reduction in energy consumption . in addition to this , the cost and complexity of the device for uniform heating of the protein preparation is very small . with the aid of the process of the invention cut - resistant , gels can be obtained using hf fields by employing high protein and dry substance concentrations in the sample , respectively in the protein preparation . thus , the manner of heating with the invention in particular , permits heating high - viscous proteins without allowing shear forces due to stirring or scraping to effect the to - be - heated protein . the duration of the thermal input is controllable by the velocity with which the to - be - heated protein preparation is conveyed through the heating zone . moreover , another pipeline , in which the heated protein preparation can predry , can be connected following the heating zone . furthermore , the protein preparation can be filled in the form of protein curd into foil tubes , for example endless sheathing , and conveyed in this way through the heating zone without prior mixing . with this process , a finished , packed and pasteurized protein gel can be produced as a cut - resistant foodstuff after cooling . it is advantageous that gelling and pasteurizing occur in a single step inside the packaging , which offers the advantages of sterility .
the invention relates to a method and device for changing the functional features , with no alteration thereof , of a protein preparation , preferably isolates or concentrates from plant seed - based proteins . the inventive method consists in heating a proteinic preparation for producing perishable or dry products as a starting material or component for protein - containing foodstuff . according to the invention , the proteinic preparation is exposed to a high frequency electromagnetic field , so that , due to evenly distributed temperature , the total volume of the proteinic preparation is heated .