The increase in the number of cases of allergic reactions and celiac disease is an important problem. The solution to this problem is the search and development of relevant and effective ways to eliminate gluten. Specific amino acid sequences glutamine and proline determine the resistance to protease hydrolysis of the structural domains of gluten fractions. The analysis of the literature data showed that an alternative to the gluten-free diet is the use of biotechnological methods for modifying ingredients containing gluten. Such methods include the use of leavens on the base of lactic acid bacteria or enzyme preparations containing peptidases specific to gluten biocatalysis. In addition, the pretreatment of raw materials by extrusion cooking contributes to an increase in the degree of gluten hydrolysis. The effect of the thermoplastic extrusion and various enzyme systems containing proteases, amylolytic, cellulolytic and hemicellulolytic enzymes on the changes in the molecular weights of wheat protein fractions was studied. It was found that extrusion as a factor of protein modification significantly affects the proteolysis of wheat proteins using enzyme systems of different substrate specificity. The most effective hydrolysis was shown by the use of a complex enzyme preparation Amyloprotoorizin. including The effect was also noted after bioconversion of non-extruded wheat. An algorithm for the technology of wheat snacks based on the processes of extrusion and biocatalysis of proteins with specific proteases for the elimination of gluten is devepoped. The practical implementation of the technology will make it possible to obtain ready-to-eat snacks, which will be investigated for the preservation or elimination of antigenic properties during clinical trials.

When developing new types of gluten-free products, the extrusion and biocatalysis technologies use is promising. Extrusion enables to obtain ready-to-eat products of the high consumer demand with a porous structure from gluten-free cereals (snacks, ready-made breakfasts, crispbreads and various types of food concentrates), without using the functional structure-forming properties of gluten. In turn, biocatalytic technologies can provide enzymatic proline and glutamine protein bond hydrolysis of structural protein domains resistant to the digestive enzyme action. The main extrusion processing problem of wheat hydrolysates with a reduced gluten amount mixed with other raw materials is the high moisture content in the extruder. The work aimed at studying the process of additional steam extraction from the extruder cabinet during the high-moisture mixtures extrusion and its influence on the quality of finished products, i.e. gluten-free snacks. The study object was rice flour and wheat hydrolysate mixtures with a mass fermentolysate fraction of 25 and 35 %, extruded using a steam extraction system. As a result of the conducted studies, a man revealed that with an increase in steam extraction, the pressure in the extruder cabinet and the shear moment significantly increased, the process temperature slightly increased. This effect is due to the moisture content decrease in the extruder cabinet after steam extraction and, accordingly, the shear deformations energy increase. There was an additional steam extraction accompanied by an increase in specific electricity consumption by 64–79 %. The texture samples analysis demonstrated that the steam extraction and the amount of hydrolysate introduced had a significant effect on the snacks texture: the hardness decreased from 10.5 to 3.5 N, while the number of micro-fractures characterizing the crispness increased from 11.4 to 13.6. The color characteristics evaluation of the obtained snacks showed their insignificant dependence on the steam extraction. The use of a steam extraction device enables to increase the hydrolysate content in the extruded mixture and improve finished products quality during high-moisture mixtures processing.

The extrusion process advantage of agricultural raw materials processing into food and feed over traditional technologies is the high specific productivity, energy efficiency and versatility of use. The presence of a large number of control factors and influence on the raw materials quality, such as operating parameters and structural elements, make extrusion a difficult reproducible process when scaling or moving from one installation to another. But this aspect is the reason for the maximum flexibility of extrusion systems and the possibility of their continuous improvement. One of the ways for the extrusion technology development is the improvement of equipment and design solutions in the field of energy saving. Investigations of the thermoplastic extrusion process of wheat grinding with the application of the recovery of steam heat generated by a special configuration of screw elements and its degassing with the feeding into the processed material were carried out in the work. The modernized extruder Werner & Phleiderer Continua 37, supplemented by a developed recuperative unit and a steam line, was used to achieve this goal. An assessment of changes in energy consumption during steam recovery was carried out. The physicochemical properties of the experimental and control samples of wheat grain extrudates obtained under various operating conditions were investigated and determined. It was found out that the steam recovery mode is a statistically significant reason for increasing the humidity of the extruded product from 3.8 to 5.0 bulk density - by 15% relative to the mode without recovery. A decrease in the explosion coefficient and the water-holding capacity of the extrudates during operation in the regenerative mode of extrusion was noticed. The presented method with additional thermal effects on the processed raw materials allows us to expand the technological capabilities of the process of thermoplastic extrusion in obtaining products of various functional and technological purposes.