Studying grain moisture influence on the extrusion process and the finished products quality

The purpose of the study is to improve the quality of the preparation of extrudates by optimizing the moisture content of the grain supplied for processing. Tasks: experimental substantiation of rational parameters of moisture content of raw materials supplied for processing, the diameter of the die hole and their influence on the quality indicators of the extrudate. The study was carried out at the Engineering Center of the Krasnoyarsk State Agrarian University on a screw-type extruder. Novosibirskaya-31 wheat was used as a raw material, as one of the widely used by agricultural producers of the Krasnoyarsk Region. When conducting research, wheat with an initial moisture content of 9.8 % was moistened with water at a temperature of 18-20 °C to 12, 14, 16, 18, and 20 %. The grain was tempered using plastic containers in a room with a temperature of 18-20 °C. Within 12 hours, the vitreousness of the grain was determined. During extrusion, dies with a diameter of 5; 8, and 10 mm were used. The experiment on extruding wheat grain using a die with a diameter of 5 mm showed a negative result, the raw material burned in the working chamber of the extruder due to an increase in pressure and temperature above the maximum allowable. When extruding with a spinneret with a hole diameter of 10 mm, the increase in the volume of the extrudate compared to native wheat at the initial moisture content of the grain entering the processing Wn = 14.0 % was β = 2.05. The best result was obtained when installing a die with a diameter of 8 mm, at Wn = 14.8 %, the increase in the volume of the extrudate was β = 3.06, the moisture content of the resulting product was Wn = 6.5 %.