Using yeast biomass hydrolyzate in the grain extrudate technology

The purpose of research is to study the effect of adding yeast biomass hydrolyzate to extruded wheat flour, used as a model base, on the operating parameters of extrusion - temperature and pressure in the extruder chamber, shear moment, which characterizes the energy consumption for the process of processing mixtures, and physicochemical parameters of extruded products. Promising ingredients, sources of protein, essential amino acids and other essential nutrients are yeast biomass and its processed products. A study was conducted on the effect of adding yeast biomass hydrolyzate on the process of extrusion of wallpaper wheat flour and the physicochemical properties of the resulting extrudates. It has been established that extrusion with a fixed productivity of 28 kg/h of mixtures of flour and dried yeast biomass hydrolyzate in an amount of up to 10 % does not significantly affect the extrusion performance parameters; the specific mechanical energy when processing mixtures with yeast biomass hydrolyzate slightly exceeded the specific mechanical energy of flour extrusion. The effect of adding yeast biomass hydrolyzate on the bulk density of extrudates, expansion coefficient, and structural and mechanical properties was insignificant. Analysis of the texture of the samples showed that the addition of yeast biomass hydrolyzate significantly increased the hardness and reduced the number of microfractures in the extrudates obtained by reducing the moisture content and increasing the extruder productivity, which determine the tightening of the extrusion mode. The effect of adding yeast biomass hydrolyzate on the amino acid composition of extrudates was established. It was shown that the content of bound amino acids increased by 14.2 %, free by 412 %. The maximum increase in the content of free amino acids was noted for alanine (18 times), lysine (15.5 times), glutamic acid (13.7 times). For the same acids in a bound state, the increase was 68 %, 49 % and 20.4 %, respectively.