EXTRUDATES FROM VEGETABLE RAW MATERIALS WITH A HIGH LIPID AND FIBER CONTENT

The application of composites obtained by extruding the vegetable raw materials with a high content of starch, lipids, proteins and dietary fibers as a functional additive to flour confectionery and bakery products is very important. Meanwhile to obtain high quality extrudates from the raw materials with such a composition on the commercially available equipment is impossible because of the unstable nature of the extrusion process. One of the important vectors of thermoplastic extrusion development of multicomponent vegetable raw materials has been proved in this article based on the study of the reaction of capillary-porous extrudates on a medium with reduced air pressure. Its scientific concept is that the humidity of raw materials and lipid content significantly affect the intensity of "decompression explosion" of the extrudate leaving the spinneret of the machine. The acceptable value of extrudate porosity in the processing of raw materials with a high content of lipids and dietary fibers is achieved by creating the air pressure below atmospheric one in a special extruder chamber. The experiments conducted showed that the content of the main ingredient of the extruded mixture (milk thistle) and the moisture content of its mass fraction have a decisive influence on the extrudate porosity with a high content of lipids and dietary fibers. To receive a polycomponent extrudate based on milk thistle seeds as a filler one should use wheat grain with the moisture mass fraction of 14%, corresponding to basic conditions for this culture according to GOST P 52554-2006. Under this condition, the highest extrudate porosity can be obtained having not more than 25% of milk thistle with a mass fraction of moisture 24-28%.