ANALYSIS OF TECHNICAL AND TECHNOLOGICAL EQUIPMENT PROCESSES OF EXPANDED FEED PREPARATION

Extruders and expanders belong to the family of HTST (high temperature short-term) equipment capable of performing the task of cooking food and feed under high pressure. Because the effects of high temperatures occur only for a short time, the undesirable effects of denaturation of proteins, amino acids, vitamins, starch and enzymes are limited. Physical and technological aspects such as heat transfer, mass transfer, pulse transfer, temperature time have a strong influence on the properties of food and feed during extrusion and expanded cooking and can significantly affect the quality of the final product. The aim of the research is to analyze the technical and technological equipment of extrusion and expanded feed preparation processes and substantiate the feasibility of using expanders. The use of expanders in the feed pellet processing line has many advantages, the most important of which are: improved feed nutrition (better feed conversion); more efficient use of low-quality raw materials or even waste; sterilization of bacteriologically contaminated materials; better control of liquid additives; reduction of energy consumption of pellet press; increasing the productivity of the pellet press; expanding the product range; the possibility of using fibrous materials; reduction of dust emissions and losses during granulation. The economic and food aspects of the use of expanders make their use understandable and justified in the feed industry. The use of an expander-granulator kit increases the cost of production by 10-15 % compared to granulation alone. However, the overall income and expenditure account is positive due to the qualitative results that offset the costs incurred. The use of expanders in the global feed industry is growing every year, which is also reflected in the wider range of recently produced animal feed. The benefits of this technique are beginning to be appreciated in underdeveloped countries. Its usefulness is fully confirmed by feed manufacturers who have already implemented the above production methods.