Using raw potato peel in the production of extruded feed additive

The paper is concerned with some aspects of processing raw potato peelings. It presents the dynamics of potato production in the world and in Ukraine, and analyses the figures on yields of this crop. Methods of processing potatoes at Ukrainian enterprises have been considered. It has been found that the bulk of the waste (15–60%) is formed during peeling raw potatoes. Methods of utilisation of potato peelings have been analysed. Problems of using fresh potato peel in the diet of farm livestock have been analysed. The technological operations of potato waste processing have been considered, and it has been substantiated how practical the method of extrusion is. The advantages of manufacturing an extruded feed additive with the use of potato peel have been shown. The physical properties, chemical composition, and term of storage of fresh potato peel have been determined. It has been found that fresh potato peel is poorly storable and hardly flowable, so it must be processed within 48 hours. To produce an extruded feed additive including crushed wheat grain and fresh potato peel in the ratio 9:1, a step-by-step scheme has been developed. The physical properties, the content of individual nutrients and minerals, and the shelf life of the extruded additive have been determined. It has been established that manufacturing the feed additive by the method suggested allows increasing the product’s nutritional value, prolonging its shelf life, improving its sanitary quality, technological properties, and conditions of feeding potato peel to livestock. It has been found that when the amount of potato peel introduced is 10% and that of crushed wheat grain is 90%, the optimal moisture content is 16.5%. Besides, this ratio results in the minimum energy consumption and in a coefficient of expansion high enough. During extrusion, the physical properties change: the moisture content, angle of repose, and bulk density decrease, while the flowability increases, which makes the feed additive suitable for use in the feed products technology. Besides, extrusion of the feed additive is accompanied by reduction in crude protein, crude fibre, and crude fat. It has been established that the shelf life of the additive is 4 months