Термопластическая экструзия в процессах пищевой биотехнологии

Abstract

The development of food biotechnology involves the improvement and optimisation of all stages of the technological process – from the pretreatment of raw materials to the stages of biocatalysis, fermentation and derivation of finished product. Based on relevant scientific sources, a review of the prospects for the integration of thermoplastic extrusion into food biotechnological production, which has a number of technological and economic advantages, is carried out. It is shown that extrusion as a stage of pre-treatment of raw materials increases the degree of solubility, allowing further hydrolysis of starch, protein and non-starch polysaccharides, with a corresponding increase in the yield of bioconversion products. In distillation processes, the use of extruded starch-containing raw materials can become a factor in increased ethanol yield and a reduction in the formation of minor metabolites of fermentation; in brewing, it allows the expanded use of unmalted materials in the preparation of wort; while, in the deep cultivation of microorganisms (enzyme producers), it can be a factor in the increased concentration of the medium and consequent synthesis of enzymes. Positive results for the derivation of nutrient media on extruded raw materials for microbiological production of L (+) lactic acid, production of starter cultures and multicomponent fermented milk-containing products are reported. A combination of extrusion and biocatalysis in the extruder chamber allows maltodextrins to be obtained having a dextrose equivalent of up to 10 units. In addition to the processing of starchy substrates by extrusion in combination with biocatalytic treatment, a deep modification of biopolymers materials having a high protein and dietary fibre content, for example, hydrolysis with heat-stable antigenic properties of the protein fractions of glycinin and conglycinin in soybean meal, increases the functionality of the bran content of water-soluble araboxylans in specialised extruded products. The main factors affecting the degree of processing of raw materials and the quality of the target products are moisture content and extrusion temperature, as well as dosage of enzyme preparations. The possibilities of combining the processes of extrusion and biocatalysis in one reactor system or directly in the extruder chamber are described. These can significantly increase the concentration of processed biotechnological media, simplify the hardware and process composition of production lines, at the same time as increasing production capacity and energy efficiency.